Apolipoprotein E/intrauterine undernutrition interaction and hypercholesterolemia in children

The inconsistency of data regarding intrauterine programming of cardiovascular risk factors may be largely caused by genetic predisposition and later lifestyle. We analyzed whether low birth weight and apolipoprotein E (Apo E) polymorphism participate in the onset of hypercholesterolemia in children. Our approach was based on hypothesis that genetically enhanced susceptibility of different individuals might influence the effects of intrauterine programming. Two groups were selected from 2000 children at the beginning of an ongoing study: high-cholesterol group (HCG, n=67) and low-cholesterol group as a control (LCG, n=72). Both groups were divided into tertilles according to birth weight and we compared birth weight and apo E gene polymorphism between and within groups. The birth weight in HCG was 0.3 kg lower than the controls (p<0.001). The frequency of apoE4 was 31 % in HCG and only 10 % in LCG. The frequency of apoE4+ genotypes was not significantly different between tertilles based on birth weight in HCG. We suppose that intrauterine undernutrition, demonstrated by a lower birth weight, participates in the development of hypercholesterolemia already in childhood. The effects of low birth weight and the candidate gene - apoE, are synergic.

[CRP--a marker of a pro-inflammatory state and cardiovascular risk]

The importance of elevated basal levels C-reactive protein (CRP) measured by a highly sensitive test has been known for over 10 years. Increased hsCRP concentration correlates with most of the classical risk factors in cardiovascular disease, however. This seriously complicates the interpretation of the elevated concentration. Concentrations of hsCRP are partly genetically determined and can easily be affected positively by lifestyle changes. These two factors lead us to conclude that the setting of hsCRP should not be used routinely at present in assessing the individual risk of complications for atherosclerosis.

[Czech Atherosclerosis Society Guidelines for the diagnosis and treatment of dyslipidemias in adults]

The present guidelines are based on the recommendations published in 2005 entitled "Prevention of Cardiovascular Diseases in Adulthood" summarizing the conclusions of nine Czech medical societies and agree with them in the assessment of individual risks of mortality from cardiovascular disease (CVD) according to SCORE tables. They reflect new research data in pathophysiology of dyslipidemias (DLP) and particularly the results of recent clinical trials of lipid-lowering therapy and their meta-analyses. They establish priorities for the screening and management of DLP, present suitable diagnostic methods, additional investigations of potential use in risk assessment, including some emerging risk factors and detection of sub-clinical atherosclerosis in persons in a moderate-risk category. Major changes include a lower LDL-cholesterol treatment target (< 2.0 mmol/L for all CVD individuals) and a possible use of apolipoprotein B as a secondary target in selected persons (< 0.9 g/L in high risk without CVD, < 0.8 g/L for CVD patients) and nonHDL-cholesterol (< 3.3 mmol/L in high risk without CVD, < 2.8 mmol/L for CVD patients). Therapy of individual DLP phenotypes (monotherapy and combination therapy) as well as basic principles for control examination at lipid-lowering medication are described. Recommended therapeutic lifestyle changes are shown. Enclosed are five annexes: DLP diagnosis; causes of secondary DLP; additional investigations of potential use in risk stratification; familial hypercholesterolemia; list of recommended foods; two variants of SCORE tables for risk assessment for the Czech Republic; the scheme of recommended procedures and treatment algorithm in DLP asymptomatic individuals.

[Czech atherosclerosis society guidelines for the diagnosis and treatment of dyslipidemia in adults]

The present guidelines are based on the recommendations published in 2005 entitled "Prevention of Cardiovascular Diseases in Adulthood" summarizing the conclusions of nine Czech medical societies and agree with them in the assessment of individual risk of mortality from cardiovascular disease (CVD) according to SCORE tables. They reflect new research data in pathophysiology of dyslipidemias (DLP) and particularly the results of recent clinical trials of lipid-lowering therapy and their meta-analyses. They establish priorities for the screening and management of DLP, present suitable diagnostic methods, additional investigations of potential use in risk assessment, including some emerging risk factors and detection of sub-clinical atherosclerosis in persons in a moderate-risk category. Major changes include a lower LDL-cholesterol treatment target (< 2.0 mmol/L for all CVD individuals) and a possible use of apolipoprotein B as a secondary target in selected persons (< 0.9 g/L in high risk without CVD, < 0.8 g/L for CVD patients) and nonHDL-cholesterol (< 3.3 mmol/L in high risk without CVD, < 2.8 mmol/L for CVD patients). Therapy of individual DLP phenotypes (monotherapy and combination therapy) as well as basic principles for control examination at lipid-lowering medication are described. Recommended therapeutic lifestyle changes are shown. Enclosed are five annexes: DLP diagnosis; causes of secondary DLP; additional investiga- tions of potential use in risk stratification; familial hypercholesterolemia; list of recommended foods; two variants of SCORE tables for risk assessment for the Czech Republic; the scheme of recommended procedures and treatment algorithm in DLP asymptomatic individuals.

The effect of fluvastatin on cICAM-1 as a biomarker of endothelial dysfunction in patients with dyslipidemia

AIM

Upregulation of intercellular adhesion molecule-1 (ICAM-1) expression has been suggested to play an important role in the pathogenesis of atherosclerosis. Lipid-lowering therapy with 3-hydroxy-methylglutaryl-coenzyme A reductase inhibitors reduces the incidence of atherosclerosis-related cardiovascular events. The aim of this study was to establish the effect of a 3-month treatment of fluvastatin on circulating (c)ICAM-1 and standard lipid parameters.

METHODS

A total of 14 patients (6 men and 8 women), 59.7+/-11 years old, with mean systolic and diastolic blood pressure 135+/-16.3 and 81+/-9.3 mmHg, respectively, fasting plasma cholesterol 6.2+/-1 mmol/L and plasma triglycerides 2.6+/-1 mmol/L, took part in the study. The observed parameters were measured before and after 3 months of therapy.

RESULTS

When comparing total cholesterolemia, low-density lipoprotein (LDL) cholesterol, and apolipoprotein B, there were significant decreases after a 3-month treatment. By contrast, no significant difference was observed when we compared the values of triglycerides, high-density lipoprotein (HDL) cholesterol, apolipoprotein A1 and, especially, of cICAM-1. Our results demonstrate the well-known capacity of fluvastatin to lower LDL- and total cholesterol; however, it failed to reduce cICAM after a 3-month treatment.

CONCLUSIONS

It can be concluded that a 3-month therapy with fluvastatin does not decrease cICAM-1 levels, despite normalization of cholesterol levels. The implication is that cholesterol may not induce endothelial activation by the initial upregulation of this adhesive molecule.

Gaining Insight from Flexible Models

Objectives: We present results from a secondary prevention trial of coronary heart disease (CHD) in the Czech male population from northern Bohemia with the history of myocardial infarction (MI) and high prevalence of metabolic syndrome. We compare several approaches to analyzing survival data from our study in terms of respective model assumptions.

Methods: While both the Cox and Weibull survival regression models assume proportionality of the hazard functions over time, in many instances this assumption appears incompatible with the data at hand. Gray’s implementation of flexible models using penalized splines allows for a more realistic assessment of the covariate effects which may vary over time.

Results: Gray’s model results revealed a steady decline in the age-adjusted intervention effect over time, which remained significant until about 2.7 years of follow-up. This was in contrast with the results obtained from the Cox and Weibull models which suggested an overall risk reduction due to intervention during the total follow-up of 6.7 years. Survival estimates based on the Cox and Gray models are shown for the two treatment groups and selected sample quantiles of the age distribution for illustration.

Conclusions: Gray’s time-varying coefficients model facilitated a more realistic assessment of the intervention effect. Using suitable historical controls with MI history the effect of intervention was found to gradully diminish over time.

Effect of diets on lipoprotein concentrations in heterozygous apolipoprotein E-deficient mice

Loss of apolipoprotein E synthesis causes increased serum cholesterol concentrations and the sensitivity to high-fat diet in mice. We analyzed the changes in lipoprotein and hepatic structures in apolipoprotein E-deficient mice kept on control diet and cholesterol diets. Basal cholesterolemia of heterozygous (+/-) mice (2.2+/-0.28 mmol/l) was the same compared to wild-type (+/+) mice (2.3+/-0.15 mmol/l), but was lower compared to homozygous (-/-) mice (10.3+/-1.40 mmol/l). In +/- mice, cholesterolemia rose to 3.2 mmol/l on cholesterol diet and to 9 mmol/l on cholate diet, to 3 mmol/l and 3.6 mmol/l in +/+ mice, and to 23.4 mmol/l and 70.5 mmol/l in -/- mice, respectively. While the ratio of cholesterol/triglyceride concentrations in VLDL, IDL and LDL fractions was not increased in +/- mice and +/+ mice, it was increased in -/- mice on control diet. On the cholesterol diet, this ratio rose and was dramatically increased by cholate diet in all groups of mice. Even though cholate supplementation increased cholesterol concentration, it led to substantial toxic changes in hepatic morphology of all animals. In conclusion, one functional apo E allele in +/- mice is effective in keeping serum cholesterol concentrations in normal range on a control diet, but not on the cholesterol and cholate diets.

Gaining insight from flexible models--assessment of the secondary prevention trial of CHD in the Czech male population with MI history

OBJECTIVES

We present results from a secondary prevention trial of coronary heart disease (CHD) in the Czech male population from northern Bohemia with the history of myocardial infarction (MI) and high prevalence of metabolic syndrome. We compare several approaches to analyzing survival data from our study in terms of respective model assumptions.

METHODS

While both the Cox and Weibull survival regression models assume proportionality of the hazard functions over time, in many instances this assumption appears incompatible with the data at hand. Gray's implementation of flexible models using penalized splines allows for a more realistic assessment of the covariate effects which may vary over time.

RESULTS

Gray's model results revealed a steady decline in the age-adjusted intervention effect over time, which remained significant until about 2.7 years of follow-up. This was in contrast with the results obtained from the Cox and Weibull models which suggested an overall risk reduction due to intervention during the total follow-up of 6.7 years. Survival estimates based on the Cox and Gray models are shown for the two treatment groups and selected sample quantiles of the age distribution for illustration.

CONCLUSIONS

Gray's time-varying coefficients model facilitated a more realistic assessment of the intervention effect. Using suitable historical controls with MI history the effect of intervention was found to gradully diminish over time.