Early and late effects of weight loss on lipoprotein metabolism in severe obesity.

In a group of grossly obese patients serum lipoproteins and the intravenous fat tolerance test were analysed before a weight reduction program (n = 98), after 6 weeks (n = 58) and 1 year (n = 15). At one year follow-up the mean weight had fallen from 120 to 105 to 100 kg, respectively. In spite of severe overweight, only a moderate hypertriglyceridaemia (males mean fasting concentration of plasma triglycerides (TG) 2.50 +/- 1.36, females 2.03 +/- 1.94 mmol/l) was found before treatment. After 6 weeks significant reductions were found in VLDL-TG, -cholesterol, LDL-cholesterol and HDL-cholesterol (P less than 0.05 at least). After one year VLDL-TG was still below pretreatment level, LDL-cholesterol had increased above pretreatment level, whereas HDL-cholesterol was significantly higher compared to pretreatment (P less than 0.05). Some previous studies suggest that weight loss may lead to HDL-cholesterol reductions, which would be undesirable. The present study indicates that after sustained weight loss and at a stable lower body weight, HDL-cholesterol levels may increase above pretreatment levels after an initial drop during the catabolic weight reduction phase.