Abstract 10743: Lipoprotein Insulin Resistance Score, but Not Traditional Measures, Discriminates Patients With Pre-operative Metabolic Syndrome at up to One Year Following Bariatric Surgery

Lipoprotein insulin resistance (LPIR) is a composite biomarker representative of atherogenic dyslipidemia characteristic of early insulin resistance. Clinically, it is elevated in obesity and may provide information not captured in HbA1c and HOMA-IR. Although bariatric surgery is the most effective intervention for severe obesity, reduces diabetes incidence, and resolves the metabolic syndrome, the effect of bariatric surgery on LPIR is untested. We sought to assess the effects of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) on LPIR in severely obese, non-diabetic women.Anthropometric measures and blood sampling were performed preoperatively and at six, and 12 months postoperatively. LPIR was measured by NMR spectroscopy.Among 53 women (RYGB, n=22; SG, n=31), mean age was 32?7 years and BMI 44.1?6.4 kg/m2. LPIR was reduced by 35?4% and 46?4% at six and 12 months after surgery, respectively, with no difference by surgical procedure. 27 of 53 subjects met IDF criteria for the metabolic syndrome prior to surgery and exhibited higher HOMA-IR, HbA1c, nonHDL-C and LPIR preoperatively. Twenty-five of 27 subjects experienced resolution of the metabolic syndrome diagnosis postoperatively. Concordantly, the preoperative differences in HOMA-IR, HbA1c and nonHDL-C between those with and without metabolic syndrome resolved at six and 12 months. In contrast, subjects with the metabolic syndrome prior to surgery show persistent elevated LPIR scores at six and 12 months post-operatively, suggestive of potentially unappreciated residual dyslipidemic risk.We are the first to show improvement in insulin resistance, as measured by LPIR, following bariatric surgery. We also show that this measure discriminates those with a preoperative metabolic syndrome diagnosis at up to one year post-operatively. Larger prospective studies are needed to determine the additive value of LPIR in characterizing cardiometabolic risk in severely obese patients.