Serum lipids after gastric bypass surgery for morbid obesity.

Thirty-eight of 151 consecutive patients (25 percent) undergoing bypass surgery for morbid obesity had increased serum levels of total cholesterol (TC), triglycerides (TG) or both preoperatively. Ten patients had isolated TC elevation, six had isolated TG elevation and 22 had both TC and TG elevation. High density lipoprotein-cholesterol (HDL-C) levels were subnormal in 28 of the 38 patients (74 percent). Fasting lipid profiles were determined in the 38 hyperlipidemic patients at 6-month intervals postoperatively. Mean follow-up period was 29 months. By 6 months postop, patients had a greater than or equal to 20 percent mean reduction in TC and greater than or equal to 50 percent mean reduction in TG which were significant in comparison with preop levels and correlated with weight loss (P less than or equal to 0.05). Mean HDL-C levels had increased significantly vs. preop levels by 12 months postop (P less than 0.05). Lipid profiles became normal in 32 of the 38 patients (84 percent). Improvements in lipid profile were sustained in all patients with satisfactory weight loss but regressed after 12 months in patients who did not lose greater than or equal to 50 percent of their excess weight. These results suggest that abnormal serum lipid profiles can be permanently improved with sustained weight loss after gastric restriction surgery for morbid obesity.