Changes in serum apolipoprotein B concentration after oral glucose or intramuscular insulin.

An oral glucose load or a single i.m. insulin injection given to normal human subjects was followed within 1 h by a fall in total serum apolipoprotein B concentration. Although both procedures caused a concomitant drop in serum albumin concentration, the apolipoprotein-B/albumin ratio fell significantly, indicating that the drop in serum apolipoprotein B concentration cannot be explained by hemodilution.

Serum lipid and lipoprotein profiles in childhood.

Serum lipids and lipoproteins as well as other factors have been shown to be predictive of future symptomatic coronary heart disease in adult populations. Many epidemiologic data are available on serum lipids in adults in different populations; similar data in children indicate a large geographic variability between different populations and even among individuals of the same population, suggesting that both genetic and environmental factors are determinants of serum lipid concentrations. Serum cholesterol at birth and during childhood is carried predominantly by low-density lipoprotein (LDL) and high-density lipoprotein (HDL) whereas very low-density lipoprotein (VLDL) remains very low during the same period. Longitudinal studies show that serum cholesterol level decreases slightly with age in boys but not in girls; the decreasing trend is most evident between 10 and 14 years of age. LDL cholesterol follows the same trend. A continuous slight increase in serum total and VLDL triglyceride has been shown with age. HDL cholesterol seems to maintain a constant level with only slight variation with age. Moreover, LDL cholesterol has great consistency with future levels. Measurements made in children confirm that high levels of cholesterol may be present at early ages, suggesting the need for follow-up studies in young populations in order to evaluate whether hypercholesterolemia in childhood is predictive of future coronary events.