Postprandial changes in plasma total cholesterol (TC) are minimal and there is essentially no difference between fasting vs random TC concentrations, as reflected in the small diurnal coefficient of variation (CV) for TC of 2.5%. Similarly, a cholesterol-rich meal within the last 24 hours lacked an impact on plasma TC. Thus, random specimens are acceptable in blood cholesterol screening. The intraindividual biological CV (CVb) for plasma TC as measured over a long period was estimated from the data of several published studies to be 6.0%, which, when combined with a probable analytical CV (CVa) of 5% during screening, gave a total intraindividual CV (CVt) of about 8% for the single cholesterol assay. There is consensus that 'high TC values' acquired during screening should be confirmed under the conventional laboratory setting capable of CVa of 3% or less.
The serum lipid and lipoprotein levels of 59 obese Chinese children with a mean age of 13.0 years and mean relative weight of 164.2% were analysed. Between 40% to 54% of these children had elevated lipid and lipoprotein levels and about 78% had reduced high density lipoprotein (HDL) level when compared to healthy American and Japanese children. The obese children also had higher mean levels of total cholesterol (TC) and lower HDL compared to male adults in the local population. Those with elevated TC had higher mean relative weight (170% vs 159%, p < 0.05). In view of the close association between hyperlipidaemia and atherosclerosis, obese children should be carefully screened and managed to prevent long term morbidity and mortality of coronary artery disease.
Study site: Obesity clinic, School Health Services, Ministry of Health, Singapore