[Is the recent decrease in cholesterolemia in the Czech Republic convincing evidence?]. / Je nedávný pokles cholesterolémie v Ceské republice prukazný?

BACKGROUND: The objective of the study was to evaluate the 8-year trend of serum cholesterol levels in six districts of the Czech Republic, to assess whether the reduction of mean values of total cholesterol recorded during the period between 1985 and 1992 was convincing and to discuss possible causes and consequences of this development. METHODS AND RESULTS: Three cross-sectional surveys of risk factors were implemented in independent random 1% samples of the population aged 25-64 years. In 1985 1256 men (respondence rate 81.5%) and 1317 women (85%) were examined, In 1988 1357 men (85.2%) and 1412 women (88.4%), in 1992 1142 men (73.2%) and 1211 women (76.7%). A detailed check of the deviations in estimations during different time intervals from reference values provided evidence that the analytical method did not have an impact on the revealed changes. In men the mean total cholesterol level was 6.21 (95% confidence limit 6.14-6.28 mmol/l in 1985; 6.29 (6.23-6.35) mmol/l in 1988; 5.99 (5.91-6.06) mmol/l in 1992. In women the mean value of the total cholesterol level was 6.19 (6.12-6.25) mmol/l in 1985; 6.23 (6.17-6.30) mmol/l in 1988; 5.95 (5.88-6.02) mmol/l in 1992. According to variance analysis (ANOVA) the serum cholesterol in 1992 was lower by 0.22 mmol/l (p < 0.0001) than in 1985 and by 0.28 mmol/l (p < 0.0001) lower than in 1988. The drop of cholesterol between 1988-1992 may have been caused by dietary changes recorded in the population. According to nationwide data after 1990 there was a marked drop of the consumption of meat and meat products, milk and dairy products and animal fats, while the consumption of vegetable fats increased. Despite these dietary improvements, in six districts in 1992 fats accounted for 37% of the energy intake, the P/S ratio was only 0.41 in men and 0.46 in women. In these districts in 1992 and 1993 a decline of the standardized mortality rate from IHD in men was recorded. CONCLUSIONS: During an eight-year period the mean serum cholesterol level of men and women decreased significantly in six districts of the Czech Republic. This change was probably associated with a restricted intake of foods which have an impact on the serum cholesterol level.

[Serum lipid and lipoprotein levels in children in relation to their dietary habits and parental blood cholesterol]. / Hladiny sérových lipidu a lipoproteinu u detí ve vztahu k jejich nutricním návykum a k cholesterolémii rodicu.

In a group of 2000 Prague children aged 11-12 years the distribution of serum cholesterol levels was assessed. For further investigations 100 children with cholesterol levels above the 95th percentile (HYPER) were selected and 100 children with values between the 5th and 10th percentile (HYPO). Children and parents were subjected to detailed clinical and laboratory examination, in children the three-day dietary intake was assessed. Boys of the HYPER group had significantly higher LDL, HDL and VLDL cholesterol levels as well as levels of apolipoprotein B and less favourable values of the atherogenic index (AI). Girls of the HYPER group had significantly higher mean values of LDL-cholesterol and apolipoprotein B and also less favourable values of the AI. In the group HYPER children no abnormalities were detected in the carbohydrate metabolism nor a higher incidence of obesity although they differed significantly from children in the HYPO group as regards parameters of the lipid spectrum. The energy value of the consumed diet of children in the HYPER and HYPO group does not differ significantly. Although in boys of the HYPER group there was a higher ratio of total fat and animal fat (p less than 0.05), neither the percentage ratio of fatty acids nor the P:S ratio differed significantly in children of the HYPER and HYPO group. Parents of children of the HYPER group had significantly higher mean cholesterol, apolipoprotein B, LDL cholesterol values and less favourable values of the atherogenic index than parents of children of the HYPO group. The incidence of hypercholesterolaemia in the families of these children was also significantly higher.

Cholesterolaemia in school-age children and hypercholesterolaemia aggregation in the family.

The distribution of cholesterol values was established in a group of 2,000 Prague children aged 11-12 years. Of these, 100 children with cholesterol values exceeding the 95th percentile (HYPER), and 100 children with values between the 5th and the 10th percentiles (HYPO) were selected for follow-up. In addition to a thorough clinical and laboratory examination in children and parents, three-day food consumption was registered in children. Even though differing significantly from those assigned to the HYPO group in lipid spectrum parameters, HYPER group children did not show any abnormalities in carbohydrate metabolism or increased incidence of obesity. There is no significant difference in the energy values of food consumed by HYPER and HYPO children. Although a significantly higher proportion (in per cent) of total lipids and animal fat consumption was found in HYPER boys (p less than 0.05), the proportions (in per cent) of fatty acids, and the unsaturated/saturated fatty acid ratio in HYPER and HYPO children did no differ significantly. Parents of HYPER children showed significantly higher mean values of cholesterol, apolipoprotein B, LDL cholesterol and more unfavourable atherogenic index values. Hypercholesterolaemia aggregation in both parents was likewise significantly higher in children assigned to the HYPER group.

The effect of stress on circadian rhythms.

The authors chose four types of intensive stress in man and show their effect on the circadian rhythms of selected parameters. Sleep deprivation reduces mean sideraemia and oscilation amplitudes. The morning rhythm maximum shifts to early morning hours. Acute fasting does not change the biorhythm of serum iron despite that mean sideraemia increases. On the other hand, realimentation is associated with a marked drop of iron level and a shift of the morning maximum to early afternoon hours. Stress induced by isolation in humid warm environment initiates a decrease of systolic blood pressure. While biorhythm amplitude remains unchanged peak systolic pressure moves from the usual 18 to 20 hours up to 23 to 24 hours. Stress caused by diagnostic cardiac catheterization results in biorhythm inversion of the urinary excretion of catecholamines and 17-OH-corticoids. On the day of catheterization, performed in all cases in the morning hours, the usual morning peak values of adrenaline shifted to afternoon hours and those of noradrenaline and 17-OH-corticoids even to late night hours. For practical purposes, biorhythm changes can be used as indicators of the effect and intensity of stress.

[Vitamin C and psychomotor reactivity]. / Vitamin C i psikhomotornaia reaktivnost'.

The effect of vitamin C on the activity of the brain was studied. In groups of workers well provided for with vitamin C allowances a reduced number of industrial traumas was noted, which can be attributed to a greater concentration of attention and better reactivity. This could be achieved by administering daily doses of 100-150 mg of vitamin C. Workers engaged in night shifts were found to show improved psychotechnical test results with an ascorbinemia level of over 0.5 mg%. In a group of volunteers aged 16 to 18 years the results of psychomotor tests improved after a 14-day daily taking of 1000 mg of the vitamin C.