Effects of fibric acid derivatives and metformin on postprandial lipemia.

It was suggested that postprandial lipoproteins (PPLp) may play an important role in atherogenesis. We studied PPLp metabolism and its response to drugs in seven hypertriglyceridemic subjects, 23 men with isolated low HDL-C levels, and nine non-diabetic glucose intolerant subjects. Results were compared with those found in a group of 19 healthy normolipidemic individuals. We used the vitamin A-fat loading test which specifically labels PPLp with retinyl palmitate (RP). In the hypertriglyceridemics the areas under RP curves of the chylomicrons were 6.3-fold and those of non-chylomicrons 2.9-fold higher than in normals (P < 0.01). Gemfibrozil 1200 mg/day caused a dramatic decrease in chylomicrons 73% and nonchylomicrons 31%. In subjects with isolated low HDL-C, RP chylomicron curves were significantly higher than in normals (17.733+/-6.821 vs 13939+/-6217 microg/l per h, P < 0.005). Bezafibrate 400 mg/day reduced RP chylomicrons and nonchylomicron levels by 35% (P < 0.0001) in 15 responders with an increase in fasting HDL-C 35+/-3 to 40+/-22 mg/dl (P < 0.0001). No response was found in eight subjects. In the nine glucose intolerant subjects, metformin reduced postprandial insulin area under the curve from 389 to 245 mU/ml (P <0.01) chylomicron and nonchylomicron RP areas were 3.6- and 3-fold higher than in normals and were reduced by 56 and 32%, respectively. In conclusion gemfibrozil, bezafibrate and metformin were shown to be beneficial in the clearance of PPLp in hypertriglyceridemic patients, subjects with isolated low HDL-C levels and nondiabetic glucose intolerant subjects, respectively.