Lipid effects of obesity operations

To achieve weight reduction, and specifically to lower blood lipids, we performed the first 40- to 4-cm end-to-end jejunoileal bypass in August 1970. Since 1975 we have also used gastric bypass, modified from Alden, for weight reduction. Lipids from 205 jejunoileal bypass and 106 gastric bypass patients have been sequentially analyzed from 1 to 3 years postoperation. After jejunoileal bypass cholesterol was lowered 33% by 6 weeks after surgery (P < 0.001). By 12 months, the cholesterol was lowered 42% from a preoperative value of 189 ± 35 (mean ± 1 SD in mg%) to 110 ± 27, n = 205 → 159, P < 0.001; this reduction was maintained through 36 months postbypass. At 12 months after bypass the other lipids showed similar lowering: total serum lipids, 37% (from 677 ± 181 to 425 ± 106, n = 189 → 158, P < 0.001); phospholipids, 34% (220 ± 47 to 146 ± 35, n = 162 → 137, P < 0.001); SF 0-12 lipoproteins, 30% (275 ± 70 to 194 ± 47, n = 162 → 118, P < 0.001); and SF 12-400 lipoproteins, 42% (from 188 ± 14 to 110 ± 63, n = 162 → 118, P < 0.001). The gastric bypass also resulted in lipid lowering during the first year after the bypass operation. The cholesterol values were lowered 14% (from 191 ± 30 to 165 ± 31 mg%, n = 106 → 51, P < 0.001); total serum lipids, 20% (675 ± 138 to 541 ± 115, n = 82 → 36, P < 0.001); triglycerides, 35% (176 ± 98 to 114 ± 63, n = 106 → 51, P < 0.001); phospholipids, 17% (225 ± 39 to 186 ± 43, n = 79 → 36, P < 0.001); SF 0-12 lipoproteins, 21% (310 ± 85 to 245 ± 80, n = 71 → 28, P < 0.001); and SF 12-400 lipoproteins, 48% (170 ± 89 to 88 ± 99, n = 70 → 28, P < 0.001). Thus, both jejunoileal and gastric bypass lower the blood lipids, however, the jejunoileal effect is generally greater; specifically, the cholesterol reduction after jejunoileal bypass is three times that engendered by gastric bypass.