High-density lipoprotein composition in obesity: interrelationships with plasma insulin levels and body weight.

Hyperinsulinism may play a role in the development of atherosclerosis. In this study we analyzed the interrelationships between plasma glucose, insulin, body weight and high-density lipoproteins (HDL) in a group of obese women and faced the question of what is the effect of obesity on insulin, glucose and HDL relationships. HDL cholesterol was significantly lower, while HDL triglycerides resulted significantly higher in the obese women than in the controls. The two groups did not show any difference in the serum concentration of HDL apoprotein A-I and apoprotein A-II. There was an inverse correlation between fasting plasma glucose and summated means of glucose and insulin levels after an oral glucose tolerance test and HDL cholesterol in the two groups; on the contrary a positive relationship between the same parameters and HDL triglyceride occurred. HDL cholesterol was inversely related also to the weight index, while HDL triglyceride concentration was directly correlated with this parameter in the two groups. Partial correlation analysis demonstrates that, when exposed to similar plasma insulin and glucose levels, HDL cholesterol and triglyceride concentrations were no longer correlated with the weight index, and therefore that the significant correlations between these variables are likely to be due to the significant correlations of each of them with plasma glucose and insulin levels. Further studies clarifying the role of glucose and insulin in determining HDL composition would appear important.