Low high density lipoprotein-2 concentrations in obese male subjects

In this study we have compared the lipoprotein patterns, in particular HDL subfractions, of 34 obese men to those of 34 normoponderal normolipemic men, matched for age and use of tobacco. Obesity was associated with increased VLDL concentrations in only half the subjects. HDL concentrations in all obese subjects were lower than in matched controls. The decrease was most marked in the HDL2 subfraction in which cholesterol and protein contents were decreased by 50%; it was independent of triglyceride levels and not related to the severity of overweight. Moreover, while HDL2 was negatively correlated with BMI (P less than 0.01) when both populations were considered together, the correlation disappeared when calculated separately within each population, suggesting a threshold effect. The low levels of HDL2 might result from discretely altered lipolysis, not sufficient to cause an elevation in fasting triglyceridemia. In this case, HDL2 should prove to be a sensitive index of lipolytic efficiency.