with familial hypercholesterolemia

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Treat-To-Target Familial Hypercholesterolemia

A prospective study on gender differences in treatment, cardiovascular outcomes, and risk factors in individuals

with familial hypercholesterolemia

Kaia Johansen

Master thesis Department of Nutrition

Faculty of Medicine

UNIVERSITY OF OSLO

May 2021

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Treat-to-Target Familial Hypercholesterolemia

A prospective study on gender differences in treatment, cardiovascular outcomes, and risk factors in individuals with familial hypercholesterolemia

Kaia Johansen

http://www.duo.uio.no

Trykk: Reprosentralen, Universitetet i Oslo

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Treat-To-Target Familial Hypercholesterolemia

A prospective study on gender differences in treatment, cardiovascular outcomes, and risk factors in individuals

with familial hypercholesterolemia

Kaia Johansen

Supervisors:

Kjetil Retterstøl Kjell-Erik Arnesen

Hilde Risstad

Master thesis Department of Nutrition

Faculty of Medicine University of Oslo

May 2021

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Abstract

Background and aim: Individuals with familiar hypercholesterolemia (FH) have an increased risk of atherosclerotic cardiovascular disease (CVD) related to elevated low-density lipoprotein cholesterol (LDL-C) from birth. Treat-to-Target Familial Hypercholesterolemia (TTTFH) aimed to lower LDL-C and cardiovascular risk in patients at a specialised out-patient lipid clinic in a real-life setting by optimising lipid-lowering medication, a heart-healthy diet, and a healthy lifestyle. This thesis aimed to describe the treatment and its effect over 8–14 years, particularly with regards to gender differences, but also differences between individuals with and without CVD.

Methods: TTTFH was conducted in three visits at the Lipid Clinic at Oslo University Hospital.

Participants received medical consults, dietary and lifestyle counselling. The first visit was in 2006, the second in 2007, and the third visit, end of follow-up, was conducted in five parts from 2014-2020. Most participants attended medical consults also regularly between visits.

Results: Of the 259 participants with genetically verified FH, 54% were men, and 46% were women. CVD was established in 34% at the end of follow-up. The mean±SD age at the first cardiovascular event was 46±12 years in men and 51±11 years in women (p=0.022, non- significant after correcting for multiple testing). Women used significantly fewer lipid-lowering medications (p=0.003), and fewer women used high-intensity statin therapy (p<0.001) compared to men. Both genders significantly reduced LDL-C during the study period of mean±SD -0.9±1.6 mmol/L to 2.9±1.3 mmol/L in men and -0.9±1.6 mmol/L to 3.2±1.4 mmol/L in women. Men had lower LDL-C than women at the end of follow-up (p=0.029). During the study period, the percentage achieving LDL-C <2.5 mmol/L increased from 5% to 33%. The diet was heart-healthy and stable during the study period for both genders. More than half of the participants were overweight or obese and increased in weight during follow-up. Individuals with CVD had lower LDL-C, used more lipid-lowering medication, and had a healthier diet than individuals without CVD. However, the prevalence of metabolic syndrome was more extensive in individuals with CVD.

Conclusion: This was one of few long-lasting prospective studies on individuals with genetically verified FH, suggesting that despite receiving treatment at a specialised lipid clinic, there is potential to further lower LDL-C. More intensive treatment is necessary to achieve treatment targets and lower cardiovascular risk, especially in women with FH.

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Acknowledgements

A great thank you to my supervisor Kjetil Retterstøl and co-supervisors Hilde Risstad and Kjell- Erik Arnesen, who also initiated this project. Thank you for your time, thoughts, ideas, and inputs, for all the knowledge you have shared, for inspiring me, and for helping me see the bigger picture during the last year.

A further thanks to all participants for taking part in this study, and to the Lipid Clinic, for facilitation during data collection and for allowing me to observe your work. A special thanks to dietitian Lili Dizdarevic who allowed me to perform consultations under her supervision, giving me feedback on my communication and skill with patients, encouraging me, and being available for discussion and debrief if I encountered topics unknown to me during my consultations with participants.

Thank you to all my amazing classmates for not only lunches, academic discussions, and long hours in the library but all the fun these five past years.

Last but not least, I am grateful for all the support I have received from everyone close to me this past year. You all know who you are.

Oslo, May 2021 Kaia Johansen

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List of tables

Table 1. Baseline characteristics of participants with genetically verified familiar

hypercholesterolemia ... 20 Table 2. Overview of cardiovascular events, conditions and procedures from birth until the end of follow-up, stratified by gender ... 22 Table 3. Age at first cardiovascular events, stratified by gender ... 23 Table 4. Use of lipid-lowering medication at the end of follow-up, stratified by gender ... 25 Table 5. Use of lipid-lowering medication at the end of follow-up, stratified by

cardiovascular disease status ... 26 Table 6 A, B, C. Blood lipid levels before the study start, at the start of study and the end of follow-up stratified by gender and cardiovascular disease status ... 28 Table 7. Diet obtained from the SmartDiet at the start of study and the end of follow-up, stratified by gender. ... 31 Table 8. Lifestyle factors at the start of study and the end of follow-up, stratified by gender 32 Table 9. Lifestyle factors at the start of study and the end of follow-up, stratified by CVD status ... 33

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List of figures

Figure 1. Illustration of the narrowing of blood vessels as low-density lipoprotein cholesterol oxidizes and forms lipid deposits and plaque in the vessel wall. ... 4 Figure 2. Illustration of how the three dominant genetic mutations in FH functions to reduce LDLR uptake of LDL-C in the cell. ... 5 Figure 3. Low-density lipoprotein cholesterol burden in individuals with or without familial hypercholesterolemia as a function of the age of initiation of statin therapy. ... 7 Figure 4. Schematic illustration of how the lipid-lowering medications statins, bile acid resins, Ezetimibe and PCSK9-inhibitors all functions to upregulate LDL receptors to lower LDL-C in plasma. ... 9 Figure 5. Flowchart of inclusion and follow-up of participants in Treat-to-Target Familial Hypercholesterolemia. ... 13 Figure 6. Prevalence of cardiovascular disease at the end of follow-up. ... 21 Figure 7. Number of lipid-lowering medications used at the end of follow-up, stratified by gender. ... 24 Figure 8. Intensity of statin therapy used at the end of follow-up, stratified by gender. ... 24 Figure 9. The SmartDiet score categories at the start of study and the end of follow-up, stratified by gender. ... 29 Figure 10. Achievement of low-density lipoprotein cholesterol treatment targets at the start of study and the end of follow-up, stratified by gender. ... 34

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Abbreviations

ANOVA, Analyses of variance

ASCVD, Atherosclerotic cardiovascular disease ApoA1, Apolipoprotein A1

ApoB, Apolipoprotein B BMI, Body mass index BP, Blood pressure

CABG, Coronary artery bypass graft CHD, Coronary heart disease

CRP, C-reactive protein CVD, Cardiovascular disease DLCN, Dutch Lipid Clinic Network

EAS, The European Atherosclerosis Society ESC, The European Society of Cardiology FH, Familial hypercholesterolemia

HbA1c, Hemoglobin type A1c HDL, High-density lipoprotein

HMG-CoA, 3-hydroxy-3-methylglutaryl coenzyme A LDL, Low-density lipoprotein

LDL-C, Low-density lipoprotein cholesterol LDLR, Low-density lipoprotein receptor

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LDLRAP, Low-density lipoprotein receptor-associated protein LLM, Lipid-lowering medication

Lp(a), Lipoprotein (a) MI, Myocardial infarction

NCEP ATP III, National Cholesterol Education Program Adult Treatment Panel III PCI, Percutaneous coronary intervention

PCSK9, Proprotein convertase subtilisin/kexin 9 SCORE, Systematic Coronary Risk Evaluation TAG, Triacylglycerol

TC, Total cholesterol TG, Triglycerides

TIA, Transient ischemic attack

TTTFH, Treat-to-Target Familial Hypercholesterolemia VLDL, Very-low-density lipoprotein

WC, Waist circumference

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1 Introduction

Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of morbidity and mortality throughout the world today, despite a decline in cardiovascular disease (CVD) mortality in the developed world. Regardless, CVD is accountable for 30% of years of lives lost (1-3). General health and health care have improved a lot in Norway since the 1950s when life expectancy was 71 years for men and 75 years for women. Life expectancy has increased by ten years for both genders until today, and Norway is among the top 20 countries in the world (4). Among the general population in Norway, mortality due to CVD decreases even though every fifth inhabitant has established CVD or is considered at high risk and thus receive treatment for prevention. CVD is observed more often in individuals with lower socioeconomic status (5), and it was long the leading cause of death in Norway, recently bypassed by cancer (1, 6). The incidence of myocardial infarctions (MI) decreases, and among the ones who experience a MI, the severity is lower, and more individuals survive than before (7). A less severe but higher prevalence of CVD is proposed due to an ageing population combined with improved treatment and better prevention of recurring CVD (8).

1.1 Cardiovascular risk factors

A wide range of cardiovascular risk factors is known, including hypercholesterolemia, diabetes type 2, hypertension, increased lipoprotein(a) (Lp(a)) and C-reactive protein (CRP), male sex, older age, a family history of CVD, particular ethnicities, tobacco use, physical inactivity, social deprivation, and psychosocial stress as well as overweight and obesity. An unfavourable and poor-quality diet characterised as high in sugars and red meat while low in fish, white meat, fruit, vegetables, nuts, and olive oil also increases the cardiovascular risk (9-12). With several cardiovascular risk factors present, the absolute risk of CVD increases considerably (10, 13).

Elimination of health risk behaviours in the general population is previously calculated to potentially prevent 80% of all CVD (9). Preventive and healthy habits initiated early in life are associated with a lower risk of disease later in life (14). Simultaneously as a reduction of blood lipid levels, hypertension and smoking are seen at the population level, other risk factors such as obesity and diabetes type 2 are increasing. The metabolic syndrome appears to promote the development of ASCVD directly (13) as this condition is defined by the coexistence of the individual cardiovascular risk factors hypertension, diabetes, and overweight combined with an adverse lipid profile.

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In most people, CVD is a product of numerous risk factors. Several tools have been developed to estimate cardiovascular risk on an individual level, such as the Framingham risk score used in the US and the Systematic Coronary Risk Evaluation (SCORE) risk chart used in Europe (9, 12). In Norway, NORRISK 2, a version of SCORE customised to Norwegian conditions, is recommended to calculate risk (15). Clinicians use such systems as a support for management strategies (15, 16). Individuals considered to be at high to very high total cardiovascular risk include individuals with familial hypercholesterolemia (FH), diabetes type 1 or type 2, chronic kidney disease, and individuals with established CVD. In these individuals, the risk score charts are unnecessary (12).

1.1.1 Gender differences

Sex differences usually refer to biological differences between men and women, whereas gender differences refer to social constructs, behavioural and cultural differences, and norms in men and women (17). This thesis uses the term gender, although sometimes the term sex would also fit. Gender differences affect cardiovascular risk more than biological differences (17). As in other fields of medical research, women have been underrepresented in cardiovascular research compared to men (18). Until recently, it was commonly reported for women to be more under-diagnosed, undertreated and to have worse outcomes in CVD than men (17, 19, 20).

However, a recent large prospective cohort study showed that the cardiovascular risk of women was lower, using the INTERHEART risk score and the Framingham risk score and that the incidence of first and recurring CVD was lower in women. Treatment for CVD was more common in women than men in primary prevention, but not for secondary prevention (21, 22).

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1.2 Cholesterol and lipoprotein metabolism

Cholesterol is a necessary component in the production of steroid hormones, cell membranes, and bile acids. The human body synthesises the cholesterol needed for function, making ingestion superfluous. Hepatocytes recycle or produce new cholesterol where 3-hydroxy-3- methylglutaryl coenzyme A (HMG-CoA) is rate-limiting for production. Cholesterol is found in blood, every cell of the body, and in foods derived from animals.

Chylomicrons, very-low-density lipoproteins (VLDL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL) are some of the lipoprotein particles involved in the cholesterol and lipid metabolism, containing apolipoprotein, phospholipid, triacylglycerol (TAG), and cholesterol. Chylomicrons, VLDL, intermediate-density lipoprotein, and LDL contain a single apolipoprotein B (ApoB) molecule, and the number of ApoB is a reasonable estimate of the total number of atherogenic lipoprotein particles in plasma. The same LDL cholesterol (LDL-C ) level may give a somewhat different risk depending on if the cholesterol is shared between bigger or smaller LDL particles, where the smaller the particles, the greater the penetration into the surrounding tissue. Elevated ApoB indicates an increased number of small dense LDL-particles, which is considered unfortunate (23). HDL contains versions of apolipoprotein A1 (ApoA1). Each HDL particle carries one to five molecules of ApoA1 (3, 9).

Fats ingested from food are primarily TAGs digested in the small intestine, absorbed as free fatty acids and monoglycerides by the enterocytes, forming micelles before entering the epithelial cells, where TAGs and proteins form chylomicrons. Chylomicrons deliver TAGs to peripheral tissue before the chylomicron-rest ends in the liver. In the liver, cholesterol of exogenous and endogenous origin, free fatty acids and fat-soluble vitamins are transported to peripheral cells as VLDL in plasma. After VLDL have delivered fatty acids to peripheral tissue, it is changed to LDL, and LDL transports cholesterol to the tissue before returning to the liver.

LDL transports about 70% of all cholesterol in plasma. The LDL is endocytosed in hepatic cells by the LDL receptor (LDLR). The adaptor protein low-density lipoprotein receptor-associated protein (LDLRAP) regulates endocytosis of LDL via ApoB. Most of the LDLR recycles after endocytosis of LDL. When proprotein convertase subtilisin/kexin type 9 (PCSK9) is complexed to the LDLR, it contributes to the degradation of LDLR, ending the intracellular recycling resulting in a reduced number of LDLR. HDL is produced in the liver and is involved in the reverse transport of cholesterol, facilitating LDL clearance transporting cholesterol from peripheral tissues to the liver (3, 13).

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1.3 Atherosclerosis

Atherosclerosis is a process of plaque formation in the arterial vessel wall, as illustrated in figure 1. Elevated LDL-C over time leads LDL to penetrate the arterial wall resulting in an accumulation of cholesterol and lipids as lipid deposits. The LDL is oxidised in the arterial wall, thus initiating an inflammatory response resulting in vascular injury. This process enables cholesterol to form plaques with foam cells and inflammatory cells. Plaque progression will gradually lead to narrowing the blood vessels and decreasing blood flow, giving tissue ischemia, which in the heart vessels results in angina pectoris. Eventually, a plaque rupture with the formation of blood clots in the heart vessels leads to a MI. If LDLRs fail to remove excessive LDL-C from circulation, plasma LDL-C level is elevated. There is consensus that LDL-C is a causal factor in the pathophysiology of ASCVD, and elevated LDL-C levels are associated with an increased risk of cardiovascular events (3).

In addition to the cardiovascular risk estimates from LDL-C, calculation of atherogenic lipoproteins in plasma, or ratios of atherogenic lipoproteins and non-atherogenic lipoproteins are methods for accessing risk such as the ApoB/ApoA1-ratio (9). Low HDL levels contribute to the acceleration of the atherosclerosis process, and high HDL cholesterol levels are associated with a low risk of ASCVD (3, 13, 24). Lp(a) is a mainly genetically determined lipoprotein that consists of an LDL-particle with one molecule of ApoB as well as an ApoA1 attached via a disulphide bond to Lp(a). Lp(a) is a cardiovascular risk marker independent of other risk factors, both for individuals with FH and in the general population, as it is causally related to premature development of atherosclerosis (25, 26).

Figure 1. Illustration of the narrowing of blood vessels as low-density lipoprotein cholesterol oxidizes and forms lipid deposits and plaque in the vessel wall.

Illustration from Servial Medical Art by Servier, licensed under a Creative Commons Attribution 3.0 Unported License (27).

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1.4 Familial Hypercholesterolemia 1.4.1 Genetics and pathophysiology

Figure 2. Illustration of how the three dominant genetic mutations in FH functions to reduce LDLR uptake of LDL-C in the cell.

Newly synthesized LDLR is produced and transported to the cell membrane, where it binds apoB, the protein on LDL, and removes LDL-C from plasma by endocytosis. (a) A loss-of-function mutation in the LDLR gene results in less effective LDLR. (b) A loss-of-function mutation in the APOB gene results in a lower ability of the LDLR to bind to ApoB. (c) A gain-of-function mutation in the PCSK9 gene results in accelerated LDLR degradation. All these mutations reduce the LDL-C uptake from plasma, resulting in elevated levels of LDL-C.

ApoB, apolipoprotein B; LDL, low-density lipoprotein; LDL-C, LDL cholesterol; LDLR, LDL receptor;

PCSK9, Pro-protein convertase subtilisin/kexin type 9. Adapted and printed with permission from © Cuchel et al. 2014. Published by Oxford University Press on behalf of the European Society of Cardiology (28).

FH is an autosomal dominant genetic disorder characterised by elevated LDL-C levels resulting in considerably premature atherosclerosis and increased risk of ASCVD if untreated (13). FH was first described as a hereditary disease in 1937, and treatment has improved remarkably since, but individuals with FH still have severely increased cardiovascular risk compared to unaffected individuals (29). There are three dominant genetic mutations in FH. The most common is a loss-of-function mutation in the LDLR gene, resulting in less effective LDLR and attenuated LDLR function shown in figure 2 (a), adapted and printed with permission (28).

More than 1200 different mutations are presently known for the LDLR gene, present in >90- 95% of individuals with FH. A loss-of-function mutation in the APOB gene reduces the binding of ApoB-containing lipoprotein to the LDLR, making the binding defective (figure 2 (b)),

a

b

c

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present in 2-5% of individuals with FH. A gain-of-function mutation in the PCSK9 gene accelerate PCSK9 degradation and strongly reduce the recycling of LDLR, where >20 different mutations are known, present in about 1% of individuals with FH as shown in figure 2 (c). An autosomal recessive form of FH also exists but is much rarer, a loss-of-function mutation in the LDLRAP1 gene (<1% of individuals with FH) (3, 13, 28).

LDL-C levels become elevated because of the reduced hepatic capacity to clear LDL from the circulation due to the mutations that affect the LDLR endocytic and recycling pathway causing reduced LDL-C uptake (13, 24, 30). Regardless of which mutation causes the condition, the extent of atherosclerosis and risk of cardiovascular events is proportional to LDL-C elevation and duration of exposure to elevated LDL-C levels (3).

1.4.2 Prevalence and diagnosis

Homozygous FH is caused by a double gene mutation and results in very high LDL-C levels from birth, development of ASCVD usually before the age of 20 years, and death before the age of 30 years if left untreated. The exact prevalence of homozygous FH is unclear. Eleven individuals in Norway are diagnosed (31). Worldwide the estimates range from 1:160 000 to 1:1 000 000 (28). All references to FH in this thesis refers to heterozygous FH.

FH affects 1:200-300 individuals worldwide. As the condition is dominant, any child of a parent with FH has a 50% probability of inheriting the mutation (3, 13). Untreated, FH results in 15- 20 years of life lost, but treatment better the prognosis considerably (32). About 9000 out of the estimated 17 000-25 000 individuals in Norway with FH have been genetically diagnosed.

Everyone suspected of having the mutation is offered genetic testing, and cascade screening effectively discovers more individuals with the mutation (31). The diagnosis can also be based on the Dutch Lipid Clinic Network Criteria (DLCN) for FH or other diagnostic tools.

Worldwide, it is estimated that <1% of affected individuals are diagnosed (13).

The only symptoms of FH are visual manifestations of cholesterol deposits such as tendon xanthomata, xanthelasmas, and corneal arcus that may appear after years of persistent hyperlipidemia. FH is overlooked in individuals and families with the condition, possibly because cardiovascular risk factors and CVD are common in individuals and families without the mutation. Finding and diagnosing all individuals with FH demands alert physicians and awareness of the condition (13).

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1.4.3 Cholesterol burden and treatment targets

Even with only moderately elevated LDL-C levels, individuals with FH have increased cardiovascular risk. The cholesterol burden over time is cumulative, and the risk is reduced by lowering LDL-C levels, which is the main reason why early detection and treatment initiation in FH is necessary (13, 32, 33). Early treatment initiation will additionally improve endothelial function, slow the atherosclerotic process and improve coronary outcomes (24). If untreated, a person with FH reaches the same cholesterol burden sufficient to develop coronary heart disease (CHD) at 35 years as an unaffected person reaches at 55 years, as illustrated in figure 3, printed with permission (13).

Figure 3. Low-density lipoprotein cholesterol burden in individuals with or without familial hypercholesterolemia as a function of the age of initiation of statin therapy.

LDL, low-density lipoprotein; LDL-C, low-density lipoprotein cholesterol; HDL-C, high-density lipoprotein cholesterol; CHD, coronary heart disease; FH, familial hypercholesterolemia. With permission to use from © The Author 2013. Published by Oxford University Press on behalf of the European Society of Cardiology (13).

The European Society of Cardiology (ESC)/European Atherosclerosis Society(EAS) guidelines for LDL-C treatment targets are utilised in Norway (9, 12). Treatment targets for individuals with FH were until recently LDL-C <2.5 mmol/L, or <1.8 mmol/L in case of increased risk in the form of established CVD, diabetes, or if treatment was initiated after age 40 years. In the most recent guidelines from 2019, targets are lowered to respectively LDL-C <1.8 mmol/L for individuals with FH, and <1.4 mmol/L for individuals with FH with additionally increased risk (9, 12). Lowering LDL-C below the current target level is beneficial for patients with ASCVD as the lower the LDL-C, the more the cardiovascular risk is reduced (34).

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1.4.4 Lipid-lowering medication

Several medical treatments to reduce plasma LDL-C are available. Figure 4 gives an overview of the most common lipid-lowering medications (LLM), adapted and printed with permission (3). Statins were introduced in Norway in the 1990s, and they reduce plasma LDL-C by inhibiting the enzyme HMG-CoA reductase, hence inhibiting the endogenous synthesis of new cholesterol and increasing LDLR mediated uptake of LDL-C. The ratio between statin and LDL-C reduction is type- and dose-dependent. LDL-C may be reduced up to 55 % with maximum effective statin treatment. Commonly reported side effects related to statins includes muscle pain and stiffness (3).

Ezetimibe lowers cholesterol by up to 20% by inhibiting dietary and biliary cholesterol absorption in the proximal jejunum in the small intestine. Ezetimibe targets and binds the Niemann-Pick C1-like inhibitor transporter protein in the intestinal enterocytes. The effect of Ezetimibe is additive to statins, and the combination reduces the incidence of CVD more than statin monotherapy (35-37).

PCSK9-inhibitors were first registered in Norway in 2015, a new potent agent turning out to be a game-changer in the treatment of FH (38). PCSK9-inhibitors can reduce LDL-C by up to 60%

on top of other LLM, for the first time enabling patients with FH to reach treatment targets, significantly lowering the cardiovascular risk. They work by extending the duration time an LDLR is functioning (34).

Bile acid resins inhibit bile reuptake from the intestines to the liver, requiring more bile production, reducing cholesterol levels and cardiovascular risk. Many patients report gastrointestinal side effects from resins (39). Plant sterols and stanols inhibit dietary absorption of cholesterol and reduce cholesterol by up to 10% (40). Red yeast rice made out of rice fermented with yeast forms monacolin K, which is identical to the statin lovastatin and works like low-potent statins to reduce LDL-C by up to 20%. Red yeast rice is considered a drug and not just a dietary supplement in Norway (41). Niacin can also be beneficial in reducing cardiovascular risk (26, 42, 43).

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Figure 4.

Schematic illustration of how the lipid- lowering medications statins, bile acid resins, Ezetimibe and PCSK9- inhibitors all functions to upregulate LDL receptors to lower LDL- C in plasma.

LDL, low-density lipoprotein; LDL-C, LDL cholesterol; PCSK9, Pro-protein convertase subtilisin/kexin type 9.

Adapted and printed with permission from © Ference et al. 2017. Published on behalf of the European Society of Cardiology (3).

All LLM except for bile acid resins are considered teratogenic and therefore contraindicated to use during contraception, pregnancy and lactation (12). The use of LLM is recommended to stop three months before fertilisation (44). Due to the interruption of treatment related to pregnancies, the LDL-C burden of women is increased compared to men, emphasising why treatment of women with FH should be initiated at an early age.

Medical treatment of FH should ideally be lifelong and presupposes adherence and daily use to achieve the intended effect. A potent statin dose together with Ezetimibe, and if tolerable, bile acid resins are most common (13). After PCSK9-inhibitors became available in 2015, they are used to treat persons with FH with additional cardiovascular risk (12) but is not widely used due to relatively high costs and restrictive reimbursement rules.

1.4.5 Dietary and lifestyle recommendations

Blood lipid levels are affected by diet and lifestyle. A heart-healthy diet is varied and characterised by a low intake of saturated fats, processed and red meat, salt and sugar, together with a higher intake of fruit, berries and vegetables, whole-grain foods, and fish, corresponding to the Norwegian dietary guidelines (45, 46). Low intake of saturated fats can reduce cholesterol levels in the general population and individuals with FH (40, 45, 47). Studies on the general population have found that exchanging saturated fats for unsaturated fats can reduce cholesterol

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in the blood by 30% (48), and by exchanging 5%E of saturated fats with unsaturated fats, cardiovascular risk is reduced by 10% (49, 50). However, for individuals with FH, a heart- healthy diet and a healthy lifestyle alone cannot reduce LDL-C so much that medication is redundant, but it is still an essential part of treatment (40).

Saturated fats are primarily found in foods of animal origin and a few vegetable fat sources, coconut oil and palm oil, among others. To reduce the intake of saturated fats, one may choose low-fat dairy and cheese, lean and unprocessed meats, and avoid vegetable oils high in saturated fats. Unsaturated fats are found in fish, nuts, seeds, and plant oils based on olive, soybean, rapeseed, or sunflower seeds. In addition to exchanging saturated fats with unsaturated fats, individuals with FH are recommended to avoid foods rich in cholesterol, such as egg yolks, liver, roe, and food products of animal blood. It is advised to consume <200 mg a day of cholesterol and chose filtered coffee instead of non-filtered coffee due to the fats in the coffee beans (51). For individuals with FH, intake of saturated fats should not exceed 7%E a day (52).

Trans fatty acids should be eliminated from the diet (53, 54). Some individuals experience a more prominent effect of dietary modifications on blood lipid values than others (54).

Further, dietary recommendations to individuals with FH includes consuming at least 25-35 grams of dietary fibre a day in the form of whole wheat, grains, legumes, and at least five servings of fruit, berries and vegetables a day. Dietary fibre inhibits the uptake of cholesterol in the intestines and improves intestinal function and blood glucose regulation. A high intake of viscous fibres found in fruit, berries, vegetables, beans and legumes, oats and barley, is recommended as a diet low in saturated fats, including foods high in viscous fibres and plant sterols, soy, and almonds reduced LDL-C as much as the use of a low-fat diet in combination with statin treatment in a group of non-FH patients with elevated LDL-C levels (48).

For individuals with FH, a lifestyle promoting health is advantageous as the increased cardiovascular risk due to genetics not is modifiable. A healthy lifestyle is in addition to a healthy diet, characterised by healthy body weight, regular physical activity and no smoking (40), as smoking is documented to significantly increase cardiovascular risk in individuals with FH (55). The general recommendation for physical activity in Norway is at least 150 minutes of moderate activity during a week (46). By reducing weight and waist circumference (WC) if overweight or obese, stop smoking, increase physical activity to preferably one hour daily, and choose a healthier diet, the metabolic risk factors blood pressure (BP) and glucose levels as well as cardiovascular risk will be reduced (56).

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1.5 The Lipid Clinic

All patients with FH in Norway are entitled to treatment at a specialised lipid clinic. The work of this master thesis was conducted at the Lipid Clinic at Oslo University Hospital, established in 1984 and the first of its kind in Norway. The doctors and dietitians at the Lipid Clinic focus on preventing cardiovascular disease with medical treatment and lifestyle advice. All patients are guided in lifestyle management to modify their manageable risk factors. This includes dietary advice, advice to stop smoking, engaging in physical activity, losing weight, keeping a stable weight, or preventing weight gain depending on the individual situation. The Lipid Clinic tries to give patients a good understanding of their state of health, emphasising why preventive treatments are essential.

1.6 Knowledge gaps

It is established how medication, diet, and lifestyle all influence blood lipid levels and cardiovascular risk. However, studies are often performed in ideal controlled study conditions.

Knowledge of how a mixed population of individuals with FH are treated in a real-life setting over a mean ten-year period during the last fifteen years is not well-documented. A real-life study over a longer period can be more transferable than randomised clinical trials over short periods. The gender aspect of treatment of FH in patients with a proven mutation is of great interest since women seem to be at equally high risk as men in the Norwegian FH population, in contrast to the general population, where a few studies recently have taken an interest (55, 57).

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2 Aim of the study

The Treat-to-Target Familial Hypercholesterolemia (TTTFH) investigated patients with FH in a real life-setting treated at a specialised lipid clinic to optimise treatment to achieve treatment target and reduce cardiovascular risk over ten years of follow-up. This master's project aimed to complete the third follow-up visit and describe the patients with a confirmed FH mutation.

2.1 Specific aims of this thesis

The overall aim of this thesis is to describe the cardiovascular risk factors over time and to investigate gender differences and differences between participants with and without CVD, particularly participants who developed CVD during follow-up with regards to

a. prevalence of CVD and age at onset of CVD i. the occurrence, cause, and age at death b. use of lipid-lowering medication

c. blood lipid levels and change in values throughout the study

d. adherence to dietary advice and change in the diet throughout the study

e. adherence to lifestyle advice regarding weight, physical activity, and smoking, and change throughout the study

f. achievement of treatment targets

2.2 Hypothesis

Intensive lipid-lowering treatment and advice on diet and lifestyle given by specialists can improve cardiovascular risk factors and lead to achieved treatment targets after a ten-year follow-up equally in men and women.

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3 Method and materials

3.1 Implementation of the study

TTTFF is a prospective study initiated in 2006 at the Lipid Clinic by Dr K. E. Arnesen. Initially, it was a project assessing the quality of treatment given to patients, where the goal was to improve patient care. The project was later converted to a registered study approved by The Regional Committee of Medical Ethics (appendix 6).

3.1.1 Recruitment of participants and inclusion criteria

From January until July of 2006, the consulting doctor invited all patients with FH or presumed to have FH to participate in the project. This was defined as the first visit of the study, referred to as the start of study. Of the 426 patients invited, 357 agreed to participate. The flowchart in figure 5 gives an overview of the inclusion of participants.

Figure 5. Flowchart of inclusion and follow-up of participants in Treat-to-Target Familial Hypercholesterolemia.

The third visit was conducted in five parts, starting in 2014 and ending in 2020, performed by different master’s students. TTTFH, Treat-to-Target Familial Hypercholesterolemia.

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Participants should have genetically verified, or definite, probable, or possible FH diagnosed by the DLCN criteria (appendix 5), be between 18-75 years and use LLM to be included in the study. Use of LLM was only an inclusion criterion at the first and second visits, individuals not using LLM due to pregnancy, lactating, or other reasons were not included. Willingness and capability to respond to questionnaires was a prerequisite. Participants could not participate in other projects at the Lipid Clinic at the time. Individuals who received LDL-apheresis or had other severe concomitant diseases were excluded.

Genotyping of all individuals with FH in Norway is performed at the Unit of Cardiac and Cardiovascular Genetics at Oslo University Hospital. Patients who had not been genetically tested for FH at the time of inclusion were later genotyped. Only participants with genetically verified FH were included in the analyses of this master thesis.

All participants were looked up in the journal system of Oslo University Hospital to access information on deaths. All deaths before the 31^st of December 2020 were registered.

3.2 Study visits and collection of data

A total of three visits have been completed. The first visit was the start of study in 2006, and the second visit was conducted in 2007, following the same protocol. Data were collected at the regular medical consultation and from medical records. Anthropometric measures of height, weight, WC, and BP were collected at the medical examination. The height measured at the first visit was used for all body mass index (BMI) calculations. The doctor filled the doctor’s form (appendix 8), and the participants filled the SmartDiet (appendix 10). At the first visit, participants also answered the Patient’s preference form (appendix 9).

The third and last visit, the end of follow-up, was conducted in five parts from 2014 until 2020.

For part 1-4, the visits, forms, and measurements were collected broadly according to the same procedure as for the first visits. Participants attended the visits when they came to their scheduled consult depending on the wait list system, as the majority were patients attending regular consultations (every 1-3 year). The parts consisted of a doctor's consult followed by a separate consultation by a master's student in clinical nutrition from the University of Oslo, discussing the SmartDiet, the Patient’s preference form and collecting anthropometric measures. A few consultations were by phone. A detailed description of methods at parts 1-4 is presented in previous master theses on TTTFH (58-61).

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3.2.1 Part 5 of the third visit

Participants who had not completed the last visit were invited to complete the study in the present master thesis. Some had been invited previously but declined because of pregnancies, lack of time, or that they had moved since the first visit and considered the travel route too long to attend a physical visit. All, except two participants, were no longer registered patients at the Lipid Clinic. They either received treatment for FH at another lipid clinic closer to where they lived or by their general practitioner or internist.

During the fall of 2020, invitation letters were sent to the 58 potential participants to their last registered address in the journal system at the Lipid Clinic. For the 12 participants whom we did not have access to phone numbers, we asked them to contact us if they wanted to participate, which one person did. The remaining 46 persons were contacted by phone up to three times on different days at different times of the day and received one text message after the first call.

The five participants who did not respond to any of our contact attempts were considered “could not be reached”. A total of 21 participants did not wish to participate, of which four initially accepted the invitation but withdrew later. The situation with Covid-19 was a common reason not to want to participate, as participation required a blood sample drawn at either a hospital or a doctor’s office, and many did not want to go there. A total of 22 participants were included in part 5 of the third visit.

Part 5 took form as a phone interview performed by the master student. When participants had accepted the invitation, they received information, consent forms, a blood sample requisition, and the SmartDiet version 2019 (appendix 11). When the consent form was returned, an interview where the master student filled the doctor’s form, the SmartDiet, and the Patient’s preference form on behalf of the participants were conducted. All participants wanted dietary counselling and lifestyle advice during the interview. Weight was self-reported, and measures of WC and BP were not collected as WC could be too inaccurate, and the participant would need access to a BP monitor. Two participants accepted an offered medical consultation by phone as part of the study. One of the participants attended the whole visit, a medical consultation, and the interview with the master student by physical attendance at the Lipid Clinic. Missing information was to the furthest extent collected from the patient’s medical records, and participation was documented in the form of a journal note.

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3.2.2 Cardiovascular disease

CVD was broadly defined as any cardiovascular event, condition or procedure, including CHD, cerebrovascular disease, peripheral artery disease, aortic disease, or a heart condition, as well as any sign of atherosclerosis, including asymptomatic conditions, but not including hypertension (62). In this thesis, the term cardiovascular event is used broadly, including cardiovascular procedures and conditions, all summarised as “cardiovascular events” in the results and discussion sections of the participants in TTTFH.’

The following groups were made for analytical purposes to compare individuals with and without CVD, depending on the onset of disease.

o No CVD: Participants who had not experienced any cardiovascular events during their lifetime until the end of follow-up.

o First CVD before study start: Participants who had experienced one or several cardiovascular events before inclusion to, and the start of the study, regardless of whether they experienced a new cardiovascular event during follow-up.

o First CVD after study start: Participants who experienced their first cardiovascular event after the study start.

3.2.3 Blood samples

Fasting blood parameters were taken regularly a few weeks before the visits or shortly after using a prefilled laboratory requisition. Most blood samples were analysed at Oslo University Hospital Biochemical Laboratory Department, but some were analysed at local hospitals or private doctors. CRP values were measured as regular or high sensitive-CRP and reported with exact levels or as <0.6, <1, or <5. The patients' first known and untreated total cholesterol (TC) and Lp(a) values were retrieved from the patients’ medical journals. Lp(a) value was most often measured only once for each patient and stated as mg/dL. Cases with Lp(a) as nmol/L were divided by 0.227 to convert to mg/dL (26). During most of the study period, treatment targets were LDL-C <2.5 mmol/L for participants without increased risk and LDL-C <1.8 mmol/L for individuals with increased risk, such as established CVD, diabetes or treatment start after the age of 40 (9), and these are the treatment targets referred to throughout this thesis.

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3.2.4 Metabolic syndrome

For the purpose of this study, metabolic syndrome was diagnosed retrospectively based on criteria from NCEP ATP III, where the presence of any three of the five criteria is defined as the presence of the metabolic syndrome. The five criteria were as follows: WC ≥102 cm in men and ≥ 88 cm in women, HDL-C <1.0 mmol/L in men and <1.3 mmol/L in women, triglycerides (TG) ≥1.7 mmol/L, systolic BP ≥130 mmHg or diastolic BP ≥85 mmHg, fasting plasma glucose

≥5.6 mmol/L or treatment for any of these deviations. Due to missing values for several participants, BMI >30 kg/m² was used as a substitute for increased WC, and Hemoglobin type A1c (HbA1c) values ≥6,3% were considered as increased fasting plasma glucose.

3.3 Materials

3.3.1 Doctor’s form

The doctor's form (appendix 8) developed for this study requests information on LLM, other medication, and side effects. Statin therapy was categorised according to intensity as defined by the 2013 ACC/AHA Guideline on the Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Risk in Adults (63). Information on lifestyle, partly complementary to the SmartDiet and the incidence of cardiovascular events, was also requested in the form.

3.3.2 The SmartDiet Questionnaire

The SmartDiet Questionnaire, referred to as the SmartDiet, evaluates how heart-healthy the diet is with particular regards to fat sources. The SmartDiet is self-instructive, takes ten minutes to complete and is validated for use in adults (64). It was developed and is in daily use at the Lipid Clinic. The first version from 2003 was revised in 2007, 2009, and 2019. It consists of 15 questions regarding the diet. All questions are scored from one to three points and are either qualitative or quantitative. A score below three points on any given question indicates that there is room for improvement for the topic of the specific question. The score depends on what food choice within a question is most often consumed or how often the food in question is consumed.

The questions regarding milk, cream, sour cream, cheese, meat as cold cuts, and dinner are all scored according to fat content. Questions on fat used in cooking and on bread are scored depending on fat quality. Questions on fish, mayonnaise, fruit, berries, and vegetables, the fibre

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content in bread, sugary containing bread spreads, drinks, and snacks are scored according to frequency. The total score is calculated by hand at the consultation by the dietician or doctor.

A total score <29 points are considered a low score, between 30-37 points is considered a medium score, and above 38 points is considered a high score. The maximum score is 45 points, and the higher the score, the healthier food choices and diet of the patient—the lower the score, the more room for improvement. Additional to the diet, the SmartDiet covers the lifestyle factors weight, height, consumption of alcohol, smoking habits, use of dietary supplements, and physical activity habits. The patient fills the SmartDiet before their consult, allowing the dieticians or doctors to overview the patient’s diet and potential for dietary or lifestyle improvements.

The 2003-version was used to the furthest extent in this study to compare results rightfully, and it is the version referred to unless other specified. If participants filled out another version, their answers were transformed to fit the 2003-version by the master student if possible. At the first two visits, the SmartDiet was for most participants discussed with either the doctor or with a dietitian in a separate consultation. At the third visit, the SmartDiet was discussed with the master’s student for all participants. Scores were modified if necessary. If two options were chosen for one question, the mean score was calculated. At the end of the follow-up, the master student recounted the total score for the available SmartDiets from the two first visits. In cases of missing answers, the total score was not calculated. Four separate categories for intake of dairy products, meat, fish, and fruit, berries and vegetables, were made by summing the score of the corresponding questions.

3.3.3 Patient’s preference form

A non-validated Patient’s preference form (appendix 9) made for TTT-FH asked how satisfied the participants were with their follow-up and their preferences regarding LLM and side effects.

The results were not analysed in this master thesis.

3.4 Ethics

Participation in the study was voluntary, and participants could withdraw at any point. Any uncertainties were clarified if necessary. Informed consent forms were signed and are stored in a locked room at the Lipid Clinic. All data presented are de-identified.

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3.5 Missing data

Missing data were, to the furthest extent, retrieved from medical records. Missing values were not substantial or assumed to affect results for other than the measurements of WC, that had the most missing variables. Regardless, the data on WC that was available were included. The number of participants analysed that deviated from the total number is either noted in the table or the table's footnote. Missing values from the first visit that were available from the second visit one year later were used as a substitute as the visits were in close approximation, and the long-time changes were of interest in this thesis. WC values from the second visit were used for 23 patients as the weight registered at the first and second visit was the same or differed no more than one kg. Other missing lifestyle factors were collected for 31 participants in different combinations of weight, WC, and SmartDiet scores. If the year for initiation of LLM was missing, this was registered to be the same year as the participants first visited the Lipid Clinic.

If participants' first visit at the Lipid Clinic was before the age of 18 years, the age of 18 years was set as the start of LLM.

3.6 Statistical analyses

All statistical analyses were performed in IBM SPSS Statistics for Windows, Version 27.0.

Double-checking measures were taken to reduce the risk of plotting errors. Missing values were given a blank cell in SPSS, and pairwise exclusion was used. Extreme values and outliers were double-checked.

Continuous variables were checked for normal distribution using Q-Q plots, and normally distributed variables were presented as means with standard deviation. Comparison of continuous parametric variables was performed with Students Paired or Independent Samples T-test. One-way analysis of variance (ANOVA) was used to compare three groups with continuous parametric variables. Skewed continuous variables were presented with median and interquartile range, and comparison between groups was performed with the Mann-Whitney U test. Categorical variables were presented with the number of cases and percentages.

Comparison between categorical variables was performed with the Chi-Square test of Independence or Fisher’s exact test depending on expected cell count. McNemar's test was used for paired samples test for categorical variables. P-values were corrected for multiple testing using false discovery rate, Benjamini-Hochberg procedure (65).

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4 Results

4.1 Baseline characteristics

Of the 301 participants who completed the third visit, 86% had genetically verified FH, and 14% were diagnosed according to the DLCN criteria. Baseline characteristics of the whole study population are summarised in appendix 1, and characteristics of the 259 participants with genetically verified FH included in these analyses are presented in table 1. The majority were Caucasian (data not shown). Men (54%) and women (46%) were comparable with regards to group size, age and follow-up time at the Lipid Clinic both before the study start and in the TTTFH study. The mean age was 43±13 years, ranging from 18 to 72 years, upon initiation of the study. Participants had received treatment at the Lipid Clinic before the study start for a mean of 10±7 years. Follow-up time during the study period ranged from 8-14 years with a mean of 10±2 years, giving 2590 person-years of observation.

At the start of study, 20.5% had experienced at least one cardiovascular event, increasing to 34% at the end of follow-up. The groups with and without CVD had comparable follow-up time in TTTFH (data not shown). Participants with no CVD were significantly younger, 48±12 years (range 27-81), than participants with CVD, 64±9 years (range 45-86) and 59±10 years (range 40-76) at the end of follow-up (p<0.001), as shown in table 1.

Table 1. Baseline characteristics of participants with genetically verified familiar hypercholesterolemia

Total Men Women p*

n (%) 259 (100) 139 (54) 120 (46) 0.238

Age and follow-up time, year(s), mean ± SD

Birth year 1963 ± 13 1964 ± 13 1963 ± 13 0.281

Age first visit at the Lipid Clinic 33 ± 16 32 ± 16 34 ± 15 0.288 Follow-up time at the Lipid Clinic before

the study start

10 ± 7 10 ± 6 10 ± 7 0.714

Age at the study start 43 ± 13 42 ± 13 44 ± 13 0.281

Follow-up time in TTTFH 10 ± 2 10 ± 2 10 ± 2 0.782

Different groups of CVD, n (%) 0.004

No CVD 171 (66) 88 (63) 83 (69)

First CVD before study start 53 (20.5) 38 (27) 15 (13)

First CVD after study start 35 (13.5) 13 (9) 22 (18)

Age at the end of follow-up, years, mean ± SD <0.001**

No CVD 48 ± 12 46 ± 11 50 ± 12

First CVD before study start 64 ± 9 64 ± 9 65 ± 10

First CVD after study start 59 ± 10 58 ± 11 60 ± 9

*p-values for comparison between men and women with Chi-squared test for categorical variables and Students t- test for parametric continuous variables. ** p-value for comparison of age of the toal of participants with one-way ANOVA. Corrected for multiple testing using false discovery rate. Significant values in bold. For the variables

“Age first visit at the Lipid Clinic” and “Follow-up time in TTTFH”: n=230 (n=119 men, n=111 women). CVD, cardiovascular disease; TTTFH, Treat-to-Target Familial Hypercholesterolemia.

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Figure 6. Prevalence of cardiovascular disease at the end of follow-up.

Number of participants n=259 (n=139 men, n=120 women). Distribution between genders reported as percentages within each CVD group. CVD, cardiovascular disease

4.2 Cardiovascular disease

Prevalence of CVD and an overview of the cardiovascular events, conditions and procedures in participants from birth until the end of follow-up is displayed in table 2. The percentage of men and women with CVD was comparable (37% vs 31%, p=0.321). It was most common to have experienced two or more cardiovascular events (table 2).

Figure 6 illustrates the prevalence of CVD among all participants, and with the percentage distribution of men and women within each group of no CVD, or first CVD before or after the study started. More men than women had onset of CVD before study start (72% vs 28%), opposite to after study start where fewer men than women had onset of CVD (37% vs 63%).

As shown in table 2, 61 participants (24%), had one or several severe events at the end of follow-up, defined as MI, CABG, PCI and aortic valve replacement in combination with any other cardiovascular event(s). Of the 31 participants who suffered a MI during their lifetime, three participants (two men and one woman) suffered a second MI at a later time point. More men than women (29% vs 18%) had a severe event defined as MI, CABG, PCI and aortic valve replacement (p=0.033), although not significant after adjustment for multiple testing. Fifteen individuals (6%) had asymptomatic cardiovascular conditions registered, defined as asymptomatic aortic valve sclerosis, asymptomatic calcification of aorta and carotid artery stenosis (table 2). Two of the individuals with CVD had atrial fibrillation as their only diagnosis, while the rest had some form of ASCVD (data not shown).

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Table 2. Overview of cardiovascular events, conditions and procedures from birth until the end of follow-up, stratified by gender

Total Men Women p

n (%) 259 (100) 139 (100) 120 (100)

Number of participants, n (%) CVD,

in any combination of event(s) (1-14 in table + 15 in footnote)

88 (34) 51 (37) 37 (31) 0.321

One cardiovascular event during lifetime 21 (8) 9 (7) 12 (10) 0.300 Two or more cardiovascular events during lifetime 67 (26) 42 (30) 25 (21) 0.086 Number of cardiovascular events registered among the 88 participants with CVD, n of each event Each event is registered once per individual in the table. Cases of second events1,2,3,11,14 are listed in the footnote.

Cardiovascular heart disease

1Acute myocardial infarction (MI) 31 22 9 0.040

2Coronary artery bypass grafting (CABG) 31 22 9 0.040

3Percutaneous coronary intervention (PCI) 39 25 14 0.156

4Angina pectoris 45 26 19 0.543

5Asymptomatic aortic valve sclerosis 17 8 9 0.572

6Asymptomatic calcification of aorta 7 2 5

7Aortic valve stenosis 3 2 1

8Aortic valve replacement 2 1 1

Cerebrovascular disease

9Carotid artery stenosis 37 27 10 0.011

10Stroke 7 5 2

11Transient ischemic attack 5 5 0

12Surgical treatment of cerebrovascular vessels 3 2 1 Peripheral artery disease

13Intermittent claudication 9 4 5

14Surgical treatment of peripheral artery disease 5 3 2

Number of participants, categorised by the severity of the cardiovascular event(s), n (%)

Individuals with… Total Men Women

Any form of CVD 88 (34) 51 (37) 37 (31) 0.321

*One or more severe events defined as ^1,2,3,8 in combination with any other cardiovascular event(s) ^(4-

7,9-14+15)

61 (24) 40 (29) 21 (18) 0.033

*One or more cardiovascular event(s) defined as

4,7,10,11,12, 13, 14 without presence of severe events

12 (5) 4 (3) 8 (7) 0.148

*Only asymptomatic cardiovascular condition(s) discovered upon extended examination ^(5,6,9), without presence of other cardiovascular event(s)

15 (6) 7 (5) 8 (7) 0.575

p-values for comparison between men and women using Chi-squared test or Fisher’s exact test depending on expected cell count. Adjusted for multiple testing using false discovery rate, none of the findings were significant.

Second events not listed in the table given as n=total(men/women): Second acute MI n=3(2/1), second CABG n=5(3/2), Two or more PCIs n=16(10/6); second TIA n=1 (male), second surgical treatment of PAD n=1 (male).

15 Cardiovascular events not listed in the table: mitral insufficiency (n=1), implantable cardioverter-defibrillator (n=4), aortic aneurysm (n=10), aortic aneurysm surgery (n=2), heart failure (n=4), ventricular arrhythmia (n=3), atrial fibrillation (n=12).

*All participants with CVD, categorised by severity.

CVD, cardiovascular disease; CABG, coronary artery bypass grafting; MI, myocardial infarction; PAD, peripheral artery disease; PCI, percutaneous coronary intervention; TIA, transient ischemic attack.

The term “cardiovascular event” also includes cardiovascular conditions and procedures.

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Table 3. Age at first cardiovascular events, stratified by gender

n Total n Men n Women p

First cardiovascular event ever 88 48 ± 12 51 46 ± 12 37 51 ± 11 0.022 First cardiovascular event ever in individuals with…

*One or more severe events defined as ^1,2,3,8 in combination with any

other cardiovascular event(s) (4-7,9-14+15)

61 44 ± 10 40 43 ± 10 21 46 ± 10 0.304

1MI 31 42 ± 11 22 41 ± 11 9 44 ± 11 0.423

2CABG 31 49 ± 11 22 46 ± 10 9 56 ± 12 0.019

3PCI 39 49 ± 10 25 48 ± 10 14 49 ± 10 0.904

*One or more cardiovascular event(s) defined as 4,7,10,11,12, 13, 14 without presence of severe events

12 57 ± 9 4 51 ± 8 8 61 ± 8 0.065

4Angina pectoris 45 49 ± 11 26 47 ± 11 19 51 ± 11 0.221

*Only asymptomatic cardiovascular condition(s) discovered upon

extended examination ^(5,6,9)

15 58 ± 9 7 60 ± 10 8 58 ± 9 0.698

All data given as years, mean ± SD. p-values for comparison between men and women using Independent Samples Students t-test. Adjusted for multiple testing using false discovery rate, none of the findings were significant. ¹MI, myocardial infarction; ²CABG, coronary artery bypass grafting; ³PCI, percutaneous coronary intervention;

4Angina pectoris, ⁵Asymptomatic aortic valve sclerosis, ⁶Asymptomatic calcification of aorta, ⁷Aortic valve stenosis, ⁸Aortic valve replacement, ⁹Carotid artery stenosis, ¹⁰Stroke, ¹¹TIA, Transient ischemic attack, ¹²Surgical treatment of cerebrovascular vessels, ¹³Intermittent claudication, ¹⁴Surgical treatment of peripheral artery disease

15Any other cardiovascular condition. *All participants with CVD, categorised by severity.

The age at first cardiovascular events is displayed in table 3. The first cardiovascular event ever, defined as any cardiovascular event registered first on the patient, had mean age 46±12 years in men and 51±11 years in women (p=0.022, not significant after adjustment for multiple testing), ranging from 25 to 72-73 years. Individuals with severe events were younger at their first cardiovascular event ever, at 44±10 years, compared to 57±9 years in individuals with one or more cardiovascular events without presence of severe events, and 58±9 years in individuals with only asymptomatic cardiovascular conditions (p<0.001, compared with one-way ANOVA) (table 3).

4.2.1 Deaths

Out of all participants attending the first visit in 2006, 21 participants, fifteen men and six women, died before the 31st of December 2020. Fourteen participants died between 2007–2018 before they were invited to the third visit. Seven participants died between 2016–2020 after they had completed the third visit. The reason for death was known for 14 of the 21 participants.

Of these, seven participants died of other illness than CVD, mainly cancer, one died in a traffic accident, and the reason was unknown for seven participants. Six participants, one woman and five men died by CVD (definitely or probably) at age 38 to 76 years, with median age 67 years (data not shown).

with familial hypercholesterolemia

Treat-To-Target Familial Hypercholesterolemia

A prospective study on gender differences in treatment, cardiovascular outcomes, and risk factors in individuals

with familial hypercholesterolemia

Kaia Johansen

Master thesis Department of Nutrition

Faculty of Medicine

UNIVERSITY OF OSLO

Treat-To-Target Familial Hypercholesterolemia

A prospective study on gender differences in treatment, cardiovascular outcomes, and risk factors in individuals

with familial hypercholesterolemia

Kaia Johansen

Supervisors:

Kjetil Retterstøl Kjell-Erik Arnesen

Hilde Risstad

Master thesis Department of Nutrition

Faculty of Medicine University of Oslo

Abstract

Acknowledgements

Table of contents

List of tables

List of figures

Abbreviations

1 Introduction

1.1 Cardiovascular risk factors

1.1.1 Gender differences

1.2 Cholesterol and lipoprotein metabolism

1.3 Atherosclerosis

1.4 Familial Hypercholesterolemia 1.4.1 Genetics and pathophysiology

1.4.2 Prevalence and diagnosis

1.4.3 Cholesterol burden and treatment targets

1.4.4 Lipid-lowering medication

1.4.5 Dietary and lifestyle recommendations

1.5 The Lipid Clinic

1.6 Knowledge gaps

2 Aim of the study

2.1 Specific aims of this thesis

2.2 Hypothesis

3 Method and materials

3.1 Implementation of the study

3.1.1 Recruitment of participants and inclusion criteria

3.2 Study visits and collection of data

3.2.1 Part 5 of the third visit

3.2.2 Cardiovascular disease

3.2.3 Blood samples

3.2.4 Metabolic syndrome

3.3 Materials

3.3.1 Doctor’s form

3.3.2 The SmartDiet Questionnaire

3.3.3 Patient’s preference form

3.4 Ethics

3.5 Missing data

3.6 Statistical analyses

4 Results

4.1 Baseline characteristics

4.2 Cardiovascular disease

4.2.1 Deaths