Facilitated long chain fatty acid uptake by adipocytes remains upregulated relative to BMI for more than a year after major bariatric surgical weight loss.

Abstract

ObjectiveThis study examined whether changes in adipocyte LCFA uptake kinetics explain the weight regain increasingly observed post bariatric surgery.DesignThree groups (10 patients each) were studied: patients who were not obese (NO: BMI 24.2±2.3 kg/m2); patients with obesity (O: BMI 49.8±11.9); and patients classified as super obese (SO: BMI 62.6±2.8). NO patients underwent omental & subcutaneous fat biopsies during clinically indicated abdominal surgeries; O were biopsied during bariatric surgery, and SO during both a sleeve gastrectomy and at another bariatric operation 16±2 months later, after losing 113±13 lbs. Adipocyte sizes & [3H]-LCFA uptake kinetics were determined in all biopsies.ResultsVmax for facilitated LCFA uptake by omental adipocytes increased exponentially from 5.1±0.95 to 21.3±3.20 to 68.7±9.45 pmol/sec/50,000 cells in NO, O, and SO patients, respectively, correlating with BMI (r = 0.99, p < 0.001). Subcutaneous results were virtually identical. By the 2nd operation, the mean BMI (SO patients) fell significantly (p<0.01) to 44.4±2.4 kg/m2, similar to the O group. However, Vmax (40.6±11.5) in this weight-reduced group remained ~2X that predicted from the BMI:Vmax regression among NO, O, & SO patients.ConclusionsFacilitated adipocyte LCFA uptake remains significantly up-regulated ≥1 year after bariatric surgery, possibly contributing to weight re-gain.