UNEXPECTED DECREASE IN PLASMA HIGH-DENSITY LIPOPROTEIN CHOLESTEROL WITH WEIGHT-LOSS

High density lipoprotein (HDL) cholesterol is inversely related to coronary heart disease prevalence. Despite the fact that obese patients have lower plasma HDL-cholesterol concentrations, there are few prospective studies on the effect of weight loss on HDL-cholesterol. Consequently, plasma lipoproten levels were measured in 15 obese females before and after a 10 week weight loss program. Mean weight loss was 8.6±3.9 kg (P<0.001). Total plasma cholesterol and low density lipoprotein-cholesterol did not change significantly. Plasma triglyceride levels decreased (P<0.05) as did HDL-cholesterol (P<0.02). A subgroup of 11 of the subjects had repeat lipid measurements 8 months after the start of treatment. Mean weight loss at this time was 12.8±9.8 kg (P<0.01). No subject had returned to her pretreatment weight but mean weight loss was not significantly different from the 10 week value. At 8 months all lipid values, including HDL-cholesterol, had returned to their pretreatment value. By multiple regression analysis HDL-cholesterol decreased with increasing relative weight but also decreased with increasing rate of weight loss. These results suggest that negative caloric balance produces a decrease in HDL-cholesterol that in prospective studies may obscure the inverse relationship between HDL-cholesterol and indices of obesity.