Serum lipids, lipoproteins and apolipoproteins in children with and without familial history of premature coronary heart disease.

A positive family history of premature cardiovascular disease is recognized as an independent predictor of risk for cardiovascular death in first degree relatives. It is of great interest whether the progeny of families with manifest coronary heart disease can be discriminated from children with a negative family history. Therefore, we examined serum lipids, lipo- and apolipoproteins in 338 offspring whose fathers and/or mothers had been affected with a myocardial infarction before the age of 55, in comparison with 448 age- and sex-matched, healthy controls. Statistical analyses revealed marked differences between the two groups: In both age groups only high-density lipoprotein cholesterol (HDL-C), as a single parameter, and the ratios of total cholesterol (TC)/HDL-C, as well as low-density lipoprotein cholesterol (LDL-C)/HDL-C, showed a significant difference between the risk and nonrisk groups. Whereas the ratio of apolipoprotein A1 (ApoAI) to apolipoprotein B is the strongest discrimination in children less than or equal to 20 years, the ratio of HDL-C/ApoAI takes this position in the older ones. Apolipoproteins seem to be of considerable importance as risk indicators between offspring who might be at higher risk for later cardiovascular diseases, even in childhood and younger adolescence.

Cardiovascular risk factors in obese children in relation to weight and body fat distribution.

To assess the relationship between obesity and body fat distribution with cardiovascular risk factors in children, various measures of obesity and waist-to-hip circumference ratio (WHR) were related to serum lipids, lipoproteins, apolipoproteins, glucose, insulin, uric acid, systolic (SBP) and diastolic blood pressure (DBP). In boys univariate analysis revealed an association of triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein B (ApoB), the ratio ApoAI/ApoB, cholesterol/HDL-C, glucose and insulin to WHR. SBP and DBP and serum uric acid correlated with all measures of obesity [body mass index (BMI), percent overweight, percent body fat, skinfolds], but not with WHR. In girls lipid parameters (triglycerides, LDL-C, HDL-C, HDL2, ApoAI, ApoB) and atherogenic ratios correlated with measures of obesity and WHR. Glucose, insulin, SBP and DBP showed the highest correlation with WHR (r = 0.598, p less than 0.001 and r = 0.713, p less than 0.001). Multivariate analysis in girls revealed a first step dependency of ApoAI, the ratio cholesterol/ApoAI, insulin, SBP and DBP on WHR, triglycerides, HDL-C, LDL-C and the ratio ApoAI/ApoB, a first step dependency on percent body fat mass. In boys triglycerides, ApoB and the ratio ApoAI/ApoB were related to WHR for insulin, SBP and DBP, but a positive association with the WHR was found, explaining 33, 21.8, and 22.6% of the variance. This study demonstrates that cardiovascular risk factors in obese children are related to obesity and body fat distribution. Obese children with predominantly abdominal fat mass show a risk profile that is less favorable than gluteal-femoral fat distribution. Evaluation of body fat distribution in obese children, therefore, may help to identify persons most susceptible to cardiovascular risk in adulthood.

Precipitation with polyethylene glycol and density-gradient ultracentrifugation compared for determining high-density lipoprotein subclasses HDL2 and HDL3.

The purpose of this study was to compare quantification of cholesterol in high-density lipoprotein subfractions HDL2 and HDL3 by precipitation with polyethylene glycol (PEG) with that by density-gradient ultracentrifugation. Fresh serum samples from 32 fasting, obese children were analyzed with precipitation reagent "Quantolip" (Immuno AG), and then fractionated with a Beckman TL 100 ultracentrifuge with a swinging-bucket rotor. After centrifugation we carefully removed the supernate with a syringe and measured the cholesterol from each fraction enzymatically with CHOD-PAP reagent (Boehringer Mannheim). The low-density lipoprotein (LDL-), HDL2-, and HDL3-cholesterol values measured by ultracentrifugation did not differ significantly from those obtained by precipitation; the correlation coefficients (r) between the two methods were 0.96 for LDL, 0.75 for HDL2, and 0.96 for HDL3. The relatively simple PEG precipitation method used in this study measures total HDL and its major subclasses HDL2 and HDL3 with accuracy and precision comparable with those of the well-established ultracentrifugation method.