Beneficial effects of weight loss on plasma apolipoproteins in postmenopausal women.

A total of 39 postmenopausal women 40-70 years of age and undergoing hormone replacement therapy participated in a 6-month weight reduction program, which consisted of a low calorie diet (5040 KJ/day) and phentermine hydrochloride therapy. Subjects had an average body mass index of 35.95+/-5.32 kg/m(2) and 42.20+/-11.0 kg of total fat. Body mass index, plasma lipids, total and trunk fat, and plasma apoproteins were measured at baseline and after 3 and 6 months of the weight reduction program. Subjects experienced an overall 10% weight loss during the treatment period (P<0.001). Plasma LDL cholesterol and triglycerides were reduced by 18% and 15% (P<0.01) respectively, whereas HDL cholesterol was increased by 9% (P<0.01) over the 6-month period. Plasma apoproteins were significantly affected by weight loss. Plasma apolipoprotein (apo) B concentrations were reduced 6.5% (P<0.01), and apo C-III and apo E were reduced by 9% over 6 months (P<0.01). The observed decreases in plasma apo B were significantly correlated with the observed changes in plasma cholesterol (r=0.356, P<0.01) over 3 months. In addition, changes in plasma triglycerides were correlated with changes in both apo C-III (r=0.436) and apo E (r=0.354) over 6 months. These results suggest that weight loss may have multifactorial effects on lipoprotein metabolism, resulting in better plasma lipid and apoprotein profiles.