Determinants of lipid levels among children with heterozygous familial hypercholesterolemia in Norway

Nutritional Treatment in a Cohort of Pediatric Patients with Familial Hypercholesterolaemia: Effect on Lipid Profile

Background and aims: Familial Hypercholesterolaemia (FH) is characterised by a genetic alteration in the transport and metabolism of cholesterol that leads to elevated levels of total cholesterol (CT) and low-density lipoprotein cholesterol (LDL-C) and early onset of atherosclerosis. According to the current guidelines, diet and promotion of healthy habits are first-line treatments. Little is known about the effectiveness of cholesterol-lowering diet and healthy lifestyle habits on plasma cholesterol and lipid profile in children and adolescents with FH. The aim of the study is to investigate the effect of the nutritional counseling on plasma lipid profile in FH children at the first step of treatment. Methods: 115 FH children (2−17 years) were included in the study; dietary habits were evaluated through a Food Frequency Questionnaire (FFQ) and blood samples for lipid profile were collected at the enrollment (T0) and six months later (T1). Results: the lipid profile at T0 and T1, expressed as mean ± standard deviation in mg/dL, was, respectively: total cholesterol 285.9 ± 51.1 and 276.6 ± 46.8 (paired test difference p value < 0.01), LDL-cholesterol 214.9 ± 47.7 and 206.4 ± 46.6 (p value < 0.01), HDL-cholesterol 52.9 ± 13 and 54.4 ± 11.5 (p value 0.07), triglycerides 87 ± 46.7 and 82.2 ± 38.4 (p value 0.4), non-HDL cholesterol 233 ± 51.4 and 222.2 ± 47.4 (p < 0.01). In the dietary habits (weekly portions) we observed an improvement (p ≤ 001) for fruit and vegetables, fish, pulses, whole foods, and a reduction (p < 0.01) for meat, sausages, cheese, junk foods consumption. Conclusions: In FH children we have highlighted an improvement of the plasma lipid profile and in healthy dietary habits after nutritional counseling.

Mediterranean Dietary Treatment in Hyperlipidemic Children: Should It Be an Option?

BACKGROUND

Diet is considered the cornerstone of lipid management in hyperlipidemic children but evidence to demonstrate the effects of nutrient benefits on the lipid profile is limited.

AIM

The aim of this study is to evaluate the impact of the Mediterranean diet on low-density lipoprotein (LDL-C) and non-high density lipoprotein (HDL-C) decrease in primary hyperlipidemia affected children and in the achievement of therapeutical target levels.

METHODS

A retrospective cohort study was used, recruiting n = 223 children (10.05 ± 3.26 mean age years) with familial hypercholesterolemia (FH) (n = 61, 27%) and polygenic hypercholesterolemia (PH) (n =162, 73%). Secondary hyperlipidemias were excluded. Based on LDL-C and non-HDL-C decrease, participants were divided into two groups, named the Responder Group and Non-Responder Group. Participants and their families underwent dietary education by an expert nutritionist and were asked to fill in a weekly diary to be delivered at visits. Dietary indications were in line with daily caloric requirement, daily food quality and quantity intakes typical of the Mediterranean diet. These include carbohydrates, extra virgin olive oil, yoghurt and milk derivatives, fish and vegetable proteins, fresh seasonal vegetables and fresh fruits. Nuts or almonds were also recommended. The advice to limit intakes of meat, in particular red meat, and caution against junk food and sugar added food and beverages was provided. At medical visits, carried out at baseline (T0) and 6 months later (T1), children underwent anthropometric measurements and blood collection. Standard kits and methods were applied for lipid analysis. Statistical methods were performed by SAS version 9.4 (SAS Institute, Cary, NC, USA). Signed informed consent was given by parents according to the Declaration of Helsinki and the study was approved by the Local Committee.

RESULTS

The Responder Group (n = 156/223, 70%) included 45 FH and 111 PH children, while the Non-Responder Group (n = 67/223, 30%) included 16 FH and 51 PH children. The Responder Group showed total cholesterol (TC), LDL-C and non-HDL-C median percentage decreases of 9.45, 13.51 and 10.90, respectively. These statistically significant changes (p ≤ 0.0001) were similar in the FH and PH subgroups but just PH subjects reached the LDL-C and non-HDL-C target, which fell below 130 mg/dL and 145 mg/dL, respectively. Saturated fatty acids (SFAs) were the main dietary parameter that distinguished between the Responder Group and the Non-Responder Group (p = 0.014). Positive correlations were found at T1 between dietary total lipids, SFAs and cholesterol with serum LDL-C, non-HDL-C and TC variations. These latter serum parameters had an inverse correlation with dietary carbohydrate at T1. Among macronutrients, SFAs were finally demonstrated to be the predictor of serum lipids variation at T1.

CONCLUSIONS

The dietary intervention with a Mediterranean diet in children with primary hyperlipidemia significantly improves the lipid profile both in FH and PH subgroups and allows target levels of LDL-C and non-HDL-C in PH subjects to be reached. Responsiveness benefits should be primarily attributed to the reduction in SFAs, but changes in dietary lipids, cholesterol and carbohydrate intake may also play a role. In contrast, the Non-Responder Group showed a worsening of lipid profile regarding the unchanged diet.

Adults with familial hypercholesterolaemia have healthier dietary and lifestyle habits compared with their non-affected relatives: the SAFEHEART study

Objective

Healthy lifestyle habits are the cornerstone in the management of familial hypercholesterolaemia (FH). Nevertheless, dietary studies on FH-affected populations are scarce. The present study analyses dietary habits, adherence to a Mediterranean diet pattern and physical activity in an adult population with FH and compares them with their non-affected relatives.

Design

Cross-sectional study.

Setting

Data came from SAFEHEART, a nationwide study in Spain.

Participants

Individuals (n 3714) aged ≥18 years with a genetic diagnosis of FH (n2736) and their non-affected relatives (n 978). Food consumption was evaluated using a validated FFQ.

Results

Total energy intake was lower in FH patients v. non-affected relatives (P<0·005). Percentage of energy from fats was also lower in the FH population (35 % in men, 36 % in women) v. those non-affected (38 % in both sexes, P<0·005), due to the lower consumption of saturated fats (12·1 % in FH patients, 13·2 % in non-affected, P<0·005). Consumption of sugars was lower in FH patients v. non-affected relatives (P<0·05). Consumption of vegetables, fish and skimmed milk was higher in the FH population (P<0·005). Patients with FH showed greater adherence to a Mediterranean diet pattern v. non-affected relatives (P<0·005). Active smoking was lower and moderate physical activity was higher in people with FH, especially women (P<0·005).

Conclusions

Adult patients with FH report healthier lifestyles than their non-affected family members. They eat a healthier diet, perform more physical activity and smoke less. However, this patient group’s consumption of saturated fats and sugars still exceeds guidelines.

Dietary counseling is associated with an improved lipid profile in children with familial hypercholesterolemia

BACKGROUND AND AIMS

Familial hypercholesterolemia (FH) is a genetic disorder characterized by elevated levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C). Guidelines recommend cholesterol-lowering medication from 8 to 10 years of age and dietary recommendations. Little is known about the diet of FH children and the effect of dietary counseling. The aim of the study was to describe the diet of FH children with respect to fat quality, and to investigate if dietary counseling improved lipid profile.

METHODS

Fifty-four FH children (5-18 years) were included in the study and dietary intake was recorded with a pre-coded food diary for four days. Information about plasma lipid levels was obtained.

RESULTS

Median intake of total fat, monounsaturated fat, polyunsaturated fat (PUFA) and saturated fat (SFA) was 30.8, 10.4, 5.9 and 12.0 E %, respectively. Among non-statin treated FH children, SFA intake was significantly correlated with TC, LDL-C and apolipoprotein (apo) B (rsp = 0.55; p = 0.004, rsp = 0.46; p = 0.02, and rsp = 0.45; p = 0.02, respectively), and PUFA/SFA ratio significantly inversely correlated with TC (rsp = -0.42; p = 0.03). Compared to the first visit, non-statin and non-plant sterol treated FH children (n = 10) had significantly reduced levels of TC (p < 0.01), LDL-C (p = 0.01), high-density lipoprotein cholesterol (p = 0.02), apo B (p = 0.05) and apo A-1 (p = 0.02) levels at a later visit.

CONCLUSIONS

FH children had a higher intake of SFA than recommended and the SFA intake was positively correlated with plasma TC, LDL-C and apo B levels in FH children not using statins. Importantly, the plasma lipid profile was improved in FH children after dietary counseling where focus was on reducing intake of SFA and dietary cholesterol.

Children and young adults with familial hypercholesterolaemia (FH) have healthier food choices particularly with respect to dietary fat sources compared with non-FH children

Familial hypercholesterolaemia (FH) leads to elevated plasma levels of LDL-cholesterol and increased risk of premature atherosclerosis. Dietary treatment is recommended to all patients with FH in combination with lipid-lowering drug therapy. Little is known about how children with FH and their parents respond to dietary advice. The aim of the present study was to characterise the dietary habits in children with FH. A total of 112 children and young adults with FH and a non-FH group of children (n 36) were included. The children with FH had previously received dietary counselling. The FH subjects were grouped as: 12–14 years (FH (12–14)) and 18–28 years (FH (18–28)). Dietary data were collected by SmartDiet, a short self-instructing questionnaire on diet and lifestyle where the total score forms the basis for an overall assessment of the diet. Clinical and biochemical data were retrieved from medical records. The SmartDiet scores were significantly improved in the FH (12–14) subjects compared with the non-FH subjects (SmartDiet score of 31 v. 28, respectively). More FH (12–14) subjects compared with non-FH children consumed low-fat milk (64 v. 18 %, respectively), low-fat cheese (29 v. 3%, respectively), used margarine with highly unsaturated fat (74 v. 14 %, respectively). In all, 68 % of the FH (12–14) subjects and 55 % of the non-FH children had fish for dinner twice or more per week. The FH (18–28) subjects showed the same pattern in dietary choices as the FH (12–14) children. In contrast to the choices of low-fat dietary items, 50 % of the FH (12–14) subjects consumed sweet spreads or sweet drinks twice or more per week compared with only 21 % in the non-FH group. In conclusion, ordinary out-patient dietary counselling of children with FH seems to have a long-lasting effect, as the diet of children and young adults with FH consisted of more products that are favourable with regard to the fatty acid composition of the diet.

Oxidized LDL level is related to gene expression of tumour necrosis factor super family members in children and young adults with familial hypercholesterolaemia

OBJECTIVE

Familial hypercholesterolaemia (FH) is associated with increased risk of premature atherosclerosis. Inflammation is a key event in atherogenesis, and we have previously reported an inflammatory imbalance between tumour necrosis factor (TNF)α and interleukin-10 in children with FH. Based on the potential role of TNF-related molecules in inflammation, we investigated the regulation of other members of the TNF superfamily (TNFSF)/TNF receptor superfamily (TNFRSF) in children and young adults with FH and matched healthy controls.

METHODS

Expression of TNFSF/TNFRSF genes in peripheral blood mononuclear cells (PBMCs) was quantified in children and young adults with FH prior to (n = 42) and after statin treatment (n = 10) and in controls (n = 25) by quantitative real-time polymerase chain reaction.

RESULTS

First we found that, compared with controls, the mRNA levels of OX40L, BAFFR and TRAILR1 were significantly higher, whereas TRAIL and TRAILR3 were significantly lower in children and young adults with FH. Secondly, levels of oxidized low-density lipoprotein (oxLDL) were significantly raised in the FH group, and correlated with the expression of OX40L, BAFFR and TRAILR1. Thirdly, oxLDL increased mRNA levels of BAFFR, TRAILR1 and TRAILR4 in PBMCs ex vivo from individuals with FH. Fourthly, OX40, acting through OX40L, enhanced the oxLDL-induced expression of matrix metalloproteinase-9 in THP-1 monocytes in vitro. Finally, after statin treatment in children with FH (n = 10), mRNA levels of OX40L and TRAILR1 decreased, whereas levels BAFF, TRAIL and TRAILR3 increased.

CONCLUSION

Our findings suggest the involvement of some TNFSF/TNFRSF members and oxLDL in the early stages of atherogenesis; this may potentially contribute to the accelerated rate of atherosclerosis observed in individuals with FH.

Lipid and insulin levels in obese children: changes with age and puberty

OBJECTIVE

The goal was to describe the lipid profile and insulin changes seen in obese children and adolescents at different stages of puberty.

RESEARCH METHODS AND PROCEDURES

A cross-sectional study was conducted by chart review of 181 obese (BMI > 95th) children and adolescents 5 to 17 years of age, who were referred to the Center for Atherosclerosis Prevention for cardiovascular risk reduction from January 2003 through December 2003.

RESULTS

Eighty (44.2%) subjects were <12 years of age, and 101 (55.8%) were >or=12 years. Severity of obesity as expressed by BMI standard deviation score did not differ between these age groups. A significant difference with lower serum levels of total cholesterol, non-high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol was seen with older age and with advancing sexual maturity rating. Triglycerides, very-low-density lipoprotein cholesterol, and lipoprotein(a) levels remained elevated across age and pubertal stages. Insulin levels and insulin resistance as expressed by homeostasis model assessment were significantly higher with older age. Similar trends were observed both in obese boys and obese girls during puberty.

DISCUSSION

The most striking findings of this study are that in the 5- to 17-year-old obese population, the combination of elevated triglycerides and very-low-density lipoprotein cholesterol and low high-density lipoprotein cholesterol levels place them at greater cardiovascular risk than their non-obese peers, even when the changing patterns of lipids and lipoproteins seen during pubertal maturation are accounted for.

Screening and treatment for lipid disorders in children and adolescents: systematic evidence review for the US Preventive Services Task Force

OBJECTIVE

This was a systematic evidence review for the US Preventive Services Task Force, intended to synthesize the published evidence regarding the effectiveness of selecting, testing, and managing children and adolescents with dyslipidemia in the course of routine primary care.

METHODS

Literature searches were performed to identify published articles that addressed 10 key questions. The review focused on screening relevant to primary care of children without previously identified dyslipidemias, but included treatment trials of children with dyslipidemia because some drugs have only been tested in that population.

RESULTS

Normal values for lipids for children and adolescents are defined according to population levels (percentiles). Age, gender, and racial differences and temporal trends may alter these statistical cut points. Approximately 40% to 55% of children with elevated total cholesterol and low-density lipoprotein levels will continue to have elevated lipid levels on follow-up. Current screening recommendations based on family history will fail to detect substantial numbers (30%-60%) of children with elevated lipid levels. Drug treatment for dyslipidemia in children has been studied and shown to be effective only for suspected or proven familial monogenic dyslipidemias. Intensive dietary counseling and follow-up can result in improvements in lipid levels, but these results have not been sustained after the cessation of the intervention. The few trials of exercise are of fair-to-poor quality and show little or no improvements in lipid levels for children without monogenic dyslipidemias. Although reported adverse effects were not serious, studies were generally small and not of sufficient duration to determine long-term effects of either short or extended use.

CONCLUSIONS

Several key issues about screening and treatment of dyslipidemia in children and adolescents could not be addressed because of lack of studies, including effectiveness of screening on adult coronary heart disease or lipid outcomes, optimal ages and intervals for screening children, or effects of treatment of childhood lipid levels on adult coronary heart disease outcomes.

Apolipoprotein B as a Marker of Familial Hyperlipoproteinemia

AIMS

Families with 10-12-year-old schoolchildren were informed about and asked to participate in a study to identify children with hyperlipoproteinemia. We hypothesised that children and families with familial blood lipid abnormalities, specifically those with familial hypercholesterolemia (FH) and familial combined hyperlipidemia (FCHL), could be identified by the child's apolipoprotein B level exceeding the 95th percentile.

METHODS

Written information and consent was distributed to the families. Families whose child had an apoB concentration exceeding the 95th percentile were further examined. Children and parents were divided into normal, high and very high low density lipoprotein cholesterol (LDLC) groups. In adults a high LDLC level was defined as > 4.1-4.9, a very high as > 4.9 mmol/l, in children as > 3.4-4.1 and > 4.1 mmol/l, respectively. The triglyceride level was regarded as high when > 3.6 mmol/l.

RESULTS

Of 2,855 families, 2,186 agreed to participate. The 95th percentile apoB level was for boys 0.98 and girls 1.07 g/l. Of the 131 children with an apoB level above the 95th percentile, 109 families accepted further examinations. Of 109 hyperapoB children 23 were obese. Normal LDLC was found in 28 hyperapo B children of whom six parents had high/very high LDLC and one high triglyceride concentrations. A high LDLC level was found in 52 children of whom 23 parents had higy/very high LDLC and another five high LDLC and/or high triglyceride concentrations. A very high LDLC level was found in 29 children, in two of them due to hypothyroidism, 17 had a parent with high/very high LDLC and another two parents a high triglyceride concentration. Familial hypercholesterolemia, defined as a LDLC concentration above twice the normal one in the child and a very high level in a parent, was suspected in six families, five having a relative with premature CHD. The families with FCHL should be included in the 20 families with hyperapoB and a child with high-very high LDLC and a parent with very high LDLC or TG levels.

CONCLUSION

Of the 109 children examined due to the child's increased apoB concentration, about 20% were obese and 75% had an increased LDLC concentration. A familial occurrence of hyperlipoproteinemia was evident in about 50% of the families with an hyperapoB child. Six families probably suffer from familial hypercholesterolemia. The definite number of FCHL families could not be defined since extended pedigrees were not available. A high suspicion of FCHL was evident in 20 families. ApoB is an important marker of hyperlipoproteinemia of familial occurrence identifying families in need of primary CHD prevention.

The apolipoprotein epsilon4 allele confers additional risk in children with familial hypercholesterolemia

Children with familial hypercholesterolemia (FH) exhibit substantial variance of LDL cholesterol. In previous studies, family members of children with FH were included, which may have influenced results. To avoid such bias, we studied phenotype in 450 unrelated children with FH and in 154 affected sib-pairs. In known families with classical FH, diagnosis was based on plasma LDL cholesterol above the age- and gender-specific 95th percentile. Girls had 0.47 +/- 0.15 mmol/L higher LDL cholesterol, compared with boys (p = 0.002). Also in girls, HDL cholesterol increased by 0.07 +/- 0.03 mmol/L per 5 y (pfor trend = 0.005); this age effect was not observed in boys. The distribution of apolipoprotein (apo) E genotypes was not significantly different between probands, their paired affected siblings, or a Dutch control population. Carriers with or without one epsilon4 allele had similar LDL and HDL cholesterol levels. Within the affected sib-pairs, the epsilon4 allele explained 72.4% of the variance of HDL cholesterol levels (-0.15 mmol/L, 95% confidence interval -0.24 to -0.05, p = 0.003). The effect of apoE4 on HDL cholesterol differed with an analysis based on probands or on affected sib-pairs. The affected sib-pair model used adjustment for shared environment, type of LDL receptor gene mutation, and a proportion of additional genetic factors and may, therefore, be more accurate in estimating effects of risk factors on complex traits. We conclude that the epsilon4 allele was associated with lower HDL cholesterol levels in an affected sib-pair analysis, which strongly suggests that apoE4 influences HDL cholesterol levels in FH children. Moreover, the strong association suggests that apoE4 carries an additional disadvantage for FH children.

Apolipoprotein E genotype is not associated with cardiovascular disease in heterozygous subjects with familial hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia (FH) is a genetic disorder characterized by high low-density lipoprotein cholesterol levels and premature cardiovascular disease (CVD). There are important differences in the presence of CVD among heterozygous subjects with FH. Some of this variability can be explained by genetic factors, and the apolipoprotein (apo) E genotype has been proposed as a useful marker.

METHODS

We analyzed the apo E genotype in 706 non-related subjects who were heterozygous for FH from Spain. CVD was present in 198 subjects (28%), 132 men (41%) and 66 women (17%).

RESULTS

Apo E allele frequencies for the epsilon 3, epsilon 4, and epsilon 2 alleles were 0.89, 0.09, and 0.02 respectively. Age, body mass index, smoking status, high blood pressure, diabetes mellitus, presence of tendon xanthomas, total cholesterol level, triglyceride levels, high-density lipoprotein cholesterol level, low-density lipoprotein cholesterol level, and Lp(a) did not differ among genotypes. The incidence of CVD and the age of onset of CVD did not differ among genotypes either. In the multivariant analysis, apo E genotype did not contribute significantly to CVD.

CONCLUSIONS

Heterozygous men with FH have a very high risk of coronary disease in a Mediterranean country, and the apo E genotype in this large group of adults with FH is not associated either with CVD or lipid values, in contrast with the established effect in the general population.

Choices for treatment of hyperlipidaemia

A number of studies have established that lowering of serum cholesterol levels leads to striking reductions in cardiovascular events. Although children almost never experience myocardial infarction, stroke or coronary death, paediatric autopsy studies suggest that atherosclerosis starts in childhood. Moreover, the extent of atherosclerotic change in children can be correlated with the same risk factors, including serum cholesterol level, as identified in adults. As a result of these lines of evidence, the paediatric health care community has produced guidelines for treatment of children with hypercholesterolaemia, but has also debated the pros and cons of treatment. This controversy is unlikely to be resolved completely, because definitive studies would require several decades of follow-up and would raise serious ethical concerns. The purpose of this review is to summarize current views on the optimal approach to management of hyperlipidaemia in children, given current knowledge. We suggest that the child's sex, serum cholesterol level and family history of premature cardiovascular disease may be used to stratify risk. Children at exceptional high risk may be considered for pharmacological treatment.

Apolipoprotein E genotypes predict attendance rates at lipid clinic

Except for the rare epsilon22 genotype it remains largely unsettled whether apolipoprotein E genotype influences an individual's referral to lipid clinics. To test this hypothesis, we compared genotype distributions among 156 hypercholesterolemic and 83 hypertriglyceridemic patients attending a lipid clinic with that among 9241 individuals sampled from the Danish general population. The relative genotype frequencies of epsilon22, epsilon32, epsilon42, epsilon33, epsilon43, and epsilon44 were 0.005, 0.126, 0.026, 0.564, 0.251, and 0.027 in the general population, which differed from genotype frequencies in both hypercholesterolemic (chi2: P = 0.01) and hypertriglyceridemic patients (chi2: P < 0.001). By comparison with epsilon33, epsilon44 predicted a 2-fold increase whereas epsilon32 predicted a 2-fold decrease in the attendance rate at the lipid clinic for hypercholesterolemic patients (95% confidence intervals: 1.1-4.3 and 0.2-0.9). Among hypertriglyceridemic patients, epsilon22, epsilon42, epsilon43, and epsilon44 versus epsilon33 predicted 13-, 3-, 1 1/2-, and 3-fold attendance rates at the lipid clinic, respectively (95% confidence intervals: 4.5-39.9, 1.2-8.4, 1.0-2.8, and 1.1-7.6). These findings are in accordance with the fact that epsilon44 raises cholesterol levels, epsilon32 reduces cholesterol levels, and epsilon22, epsilon42, epsilon43, and epsilon44 raise triglyceride levels in comparison with epsilon33. These data suggest that hypercholesterolemic individuals carrying epsilon44 and hypertriglyceridemic individuals carrying epsilon22, epsilon42, epsilon43, or epsilon44 are relatively more often referred to lipid clinics than carriers of epsilon33.

Under-reporting of dietary intake by smoking and non-smoking subjects counselled for hypercholesterolaemia

OBJECTIVES

We asked whether under-reporting of energy and cigarette smoking were associated with choice of foods and dietary composition amongst subjects with hypercholesterolaemia who had received dietary instruction to lower serum cholesterol.

DESIGN, SETTING AND SUBJECTS

Dietary intake was assessed with a 4-day weighed food record in 205 women and 141 men, aged 20-73 years, being treated at a lipid clinic (tertiary referral centre). Under-reporting was assessed by calculating the ratio of energy intake (EI) to estimated basal metabolic rate (BMR).

RESULTS

The median EI/BMR was 1.1 for both men and women. EI/BMR did not differ according to smoking status, but correlated negatively with body mass index (Spearman's rho = -0.32, P = 0.0001). EI/BMR was inversely associated with energy-adjusted intakes of potatoes, vegetables, fish and low-fat meats, and positively associated with intakes of nuts, potato crisps, chocolate, sour and ice cream, oils, fatty meat spreads, cakes and biscuits, and with alcohol. Thus, low EI/BMR was associated with increased energy-adjusted intakes of protein, thiamine, riboflavin, niacin, iron and cholesterol and with decreased intakes of sugar, poly- and monounsaturated fats and vitamin E (all P < 0.05). Cigarette smokers had a higher energy percentage (E%) from fat than non-smokers (29 +/- 6 vs. 26 +/- 6), a lower E% from carbohydrates (50 +/- 7 vs. 54 +/- 7) and a lower intake of vitamin C (11 +/- 7 vs. 16 +/- 9 mg MJ-1; all P = 0.0001), reflecting an increased intake of fatty meats and a decreased intake of skimmed cheese, fruit, rice and pasta, and cakes and biscuits (all P < 0.05).

CONCLUSION

Weighed dietary records reflected a 'healthier' intake of fat, protein, sugar, alcohol and some micronutrients amongst under-reporters, suggesting that self-reported dietary intakes are biased in patients with hypercholesterolaemia. Lack of responsiveness to the diet should not be assumed when dietary data are based on self-report. Smokers report a higher intake of fat and lower intake of vitamin C than non-smokers, even after dietary counsel, and may require more intensive interventions to optimize the diet.

An update on familial hypercholesterolaemia

A report of a World Health Organization consultation on familial hypercholesterolaemia (FH) was recently presented in Geneva. The report provides an update on several aspects of FH such as the molecular basis, DNA diagnosis, clinical criteria for the diagnosis, treatment of FH adults and children, the role of diet, psychosocial aspects of FH, contacting and helping relatives with FH and gives suggestions for government cooperation. The report is reviewed here.

Carotid intima-media thickness and plaque in patients with familial hypercholesterolaemia mutations and control subjects

BACKGROUND

In individuals with familial hypercholesterolaemia (FH), ultrasonographic measurement of carotid intima-media thickness (IMT) and plaque may provide a non-invasive assessment of cardiovascular risk.

METHODS

We examined carotid artery IMT and its determinants in 79 non-smoking, normotensive, treated men and women with FH aged 26-46 years, and in 79 non-smoking, normotensive sex-, age- and body mass index-matched control subjects. FH was verified by molecular genetic analyses. The underlying mutation in the low-destiny lipoprotein receptor gene included a splice-site mutation, mutations predicted or shown to lead to class 2B mutations or other mutations that probably represent class I mutations (null alleles).

RESULTS

The carotid bifurcation and common carotid artery IMT was increased in men with FH compared with control subjects (0.81 +/- 0.15 mm vs. 0.74 +/- 0.19 mm and 0.61 +/- 0.13 mm vs. 0.55 +/- 0.14 mm respectively; P < 0.05). The carotid bifurcation IMT was increased in women with FH compared with control subjects (0.74 +/- 0.17 vs. 0. 66 +/- 0.15; P = 0.005). More subjects with FH had carotid plaque (54% vs. 14%; P = 0.0001). In multivariate analysis, male gender, level of low-density lipoprotein-cholesterol, cholesterol-years score and xanthoma were associated with IMT and plaque in subjects with FH. FH subjects with class 2B mutations had lower cholesterol levels than subjects with mutations belonging to the other classes. They also had a tendency towards a decreased common carotid artery IMT.

CONCLUSION

These findings confirm the importance of gender, xanthoma and lifetime cholesterol levels in relation to carotid atherosclerosis in FH. Whether the type of mutation causing FH modulates carotid artery IMT and plaque requires further study.

Genotype/phenotype correlations in familial hypercholesterolaemia

It is now possible to identify the specific gene defect in the majority of patients with familial hypercholesterolaemia. A potential benefit of this knowledge, in addition to helping with family screens, is to be able to predict the future clinical course. In order to do this, detailed genotype/phenotype correlation studies are required.

Familial hypercholesterolemia: potential diagnostic value of mutation screening in a pediatric population of South Africa

Three founder-related low-density lipoprotein receptor (LDLR) gene mutations, D154N, D206E and V408M, cause familial hypercholesterolemia (FH) in approximately 90% of South African Afrikaners. Two hundred and twenty-one South African children, from 85 affected families, were screened for the specific mutation identified previously in the index case. Sixty boys and 56 girls were heterozygous for mutation D154N (FH3), D206E (FH1) or V408M (FH2). Total and LDL cholesterol (LDLC) levels were similar among the children heterozygous for the three founder mutations, and mean values were significantly higher compared to those without a known mutation (p < 0.0001). Plasma cholesterol levels overlapped considerably between the different groups, suggesting that modifiable lifestyle factors remain important in children with FH. This study demonstrates the potential diagnostic value of mutation screening in a pediatric population with an enrichment of particular gene mutations.

Influence of genotype at the low density lipoprotein (LDL) receptor gene locus on the clinical phenotype and response to lipid-lowering drug therapy in heterozygous familial hypercholesterolaemia. The Familial Hypercholesterolaemia Regression Study Group

The relationship between molecular defect and clinical phenotype has been examined in 42 patients with heterozygous familial hypercholesterolaemia (FH) and premature coronary heart disease. The defined defects included mutations in the low density lipoprotein (LDL)-receptor gene (23/42) or the apolipoprotein B Arg3500Gln mutation (5/42). Mean LDL-cholesterol was higher, both before and during treatment with simvastatin and bile acid sequestrants, in patients predicted as having a 'severe' mutation than in those with a 'mild' mutation (8.72 +/- 2.02 mmol/l vs 6.63 +/- 1.8, P = 0.05 before and 4.51 +/- 0.90 mmol/l vs 3.19 +/- 0.58, P = 0.05 during treatment). Maximum inducible LDL-receptor activity in cultured lymphoblasts was inversely correlated with LDL-cholesterol before (r2 = 0.499, P = 0.002) and during (r2 = 0.478, P = 0.004) treatment in patients with a defined mutation in the LDL-receptor gene, but not in the 14 patients with no detectable molecular defect. LDL-cholesterol concentrations before and during treatment were significantly correlated in patients with a defined LDL-receptor gene mutation (r2 = 0.548, P = 0.0001), but not in those with no detectable genetic defect. All these correlations were weak, however and there were no differences in the response to treatment in terms of either relative reduction or absolute decrease in LDL-cholesterol concentration between patients with different LDL-receptor defects. We conclude that only part of the variable phenotype of heterozygous FH patients is explained by different LDL-receptor defects and that other factors determine the severity of their hypercholesterolaemia and the onset of coronary disease.

Colestipol tablets in adolescents with familial hypercholesterolaemia

The objective of this study was to examine palatability and side effects of the new tablet formulation of colestipol. A clinical series of 23 boys and 4 girls aged 10-16 years with heterozygous familial hypercholesterolaemia were given 2-12 g colestipol daily for 6 months in an open study. There were no serious side effects. The median reduction in low density lipoprotein cholesterol level was 20%. All preferred the tablets to resin granules they had tried previously. We conclude that low-dose colestipol tablets appear to be safe and effective, and are preferred by adolescents.