HDL subfractions and adipose tissue metabolism in the reduced-obese state

The effect of weight reduction on fasting serum lipids and lipoproteins and adipose tissue lipoprotein lipase responsiveness to insulin was assessed immediately after and 3 mo subsequent to a mean 11.7% weight reduction in 14 women. Whereas reduction in fasting serum triglycerides persisted after 3 mo, reductions in serum cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein (HDL) cholesterol were not found at 3 mo. In fact, at 3 mo, levels of HDL cholesterol were higher than before weight reduction. Maintenance of the reduced-obese state also increased the HDL2-to-HDL3 cholesterol ratio (P less than 0.01), an effect strongly associated with the change in the responsiveness of adipose tissue lipoprotein lipase to insulin (r = 0.821, P less than 0.001). Moreover, after maintenance of the reduced-obese state, the HDL2-to-HDL3 cholesterol ratio also increased after the ingestion of corn oil and a 6-h insulin-glucose infusion, a response not present before weight reduction. Thus the effect of weight reduction on serum lipids and lipoproteins was not only time dependent, but for HDL, was strongly associated with changes in adipose tissue metabolism.