Although metabolic surgery was originally performed to treat hypercholesterolemia, the effects of contemporary bariatric surgery on serum lipids have not been systematically characterized.

MEDLINE, EMBASE, and Cochrane databases were searched for studies with ≥ 20 obese adults undergoing bariatric surgery (Roux-en-Y gastric bypass [RYGBP], adjustable gastric banding, biliopancreatic diversion [BPD], or sleeve gastrectomy). The primary outcome was change in lipids from baseline to 1 year after surgery. The search yielded 178 studies with 25,189 subjects (preoperative body mass index 45.5 ± 4.8 kg/m²) and 47,779 patient-years of follow-up.

In patients undergoing any bariatric surgery, compared with baseline, there were significant reductions in total cholesterol (TC; −28.5mg/dL), low-density lipoprotein cholesterol (LDL-C; −22.0 mg/dL), triglycerides (−61.6 mg/dL), and a significant increase in high-density lipoprotein cholesterol (6.9 mg/dL) at 1 year (P < .00001 for all). The magnitude of this change was significantly greater than that seen in nonsurgical control patients (eg LDL-C; −22.0 mg/dL vs −4.3 mg/dL). When assessed separately, the magnitude of changes varied greatly by surgical type (P_interaction < .00001; eg, LDL-C: BPD −42.5 mg/dL, RYGBP −24.7 mg/dL, adjustable gastric banding −8.8 mg/dL, sleeve gastrectomy −7.9 mg/dL). In the cases of adjustable gastric banding (TC and LDL-C) and sleeve gastrectomy (LDL-C), the response at 1 year following surgery was not significantly different from nonsurgical control patients.

Contemporary bariatric surgical techniques produce significant improvements in serum lipids, but changes vary widely, likely due to anatomic alterations unique to each procedure. These differences may be relevant in deciding the most appropriate technique for a given patient.