Genotype-influenced changes in serum HDL cholesterol after short-term overfeeding in man: association with plasma insulin and triglyceride levels.

Six pairs of male monozygotic (MZ) twins were submitted to a 22-day overfeeding period during which they ingested a daily surplus of 1,000 kcal above their individual daily energy needs in the form of a mixed diet. Serum lipids, lipoproteins, and apoprotein A and B concentrations were measured before and after the overfeeding period. Percentage of body fat, fasting plasma glucose, and insulin levels as well as plasma glucose and insulin concentrations after a glucose challenge were also measured before and after overfeeding. Results showed that before overfeeding, MZ twins exhibited a significant intrapair resemblance for total serum cholesterol (CHOL), triglycerides (TG), low density lipoprotein cholesterol (LDL-C), and for the high density lipoprotein-cholesterol/total cholesterol ratio (HDL-C/CHOL) (8.2 less than or equal to F ratios less than or equal to 32.7, P less than .01). The overfeeding experiment induced significant increases only in serum CHOL (P less than .01) and in serum LDL-C (P less than .05). However, although mean group values of serum TG, HDL-C, and HDL-C/CHOL ratio were not significantly modified by overfeeding, there were large interindividual variations in the response of these variables to the experiment. Results suggest that changes in serum TG, HDL-C, and in the HDL-C/CHOL ratio were significantly associated with the genotype of the subjects as a significant intrapair resemblance in the response to overfeeding was observed for these variables (0.69 less than or equal to r less than or equal to .85, P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)