Metformin-induced changes in serum lipids, lipoproteins, and apoproteins in non-insulin-dependent diabetes mellitus.

Forty patients with NIDDM and hyperlipoproteinemia were selected for a 12-week double-blind placebo-controlled trial to study the effects of metformin on lipoprotein concentration and composition. A significant decrease occurred in VLDL-apo B and all lipid components of VLDL, indicating a decreased number of circulating VLDL, while LDL-apo B was unchanged. Moreover in VLDL the relative TG content increased, the cholesterol content decreased, while in LDL the TG content decreased and the cholesterol content increased, indicating a change in the particle distribution over the spectrum VLDL-IDL-LDL. The initially enhanced TG-content in HDL was reduced. While a reduction in VLDL is observed together with improving glucose control irrespective of the applied method, the observed compositional changes in VLDL and LDL have not been described before and seem to be metformin-specific.