Circulating ANGPTL8/Betatrophin Concentrations Are Increased After Surgically Induced Weight Loss, but Not After Diet-Induced Weight Loss.

BACKGROUND ANGPTL8/betatrophin is a secreted protein reported to be involved in β-cell replication that has recently been shown to be more related to lipid metabolism. Weight loss represents a clinical situation of improvement of glucose homeostasis and overall metabolic control. The aim of the present study was to analyze the impact of weight loss induced by either a conventional dietary treatment or bariatric surgery on ANGPTL8/betatrophin concentrations. METHODS Serum concentrations of ANGPTL8/betatrophin were measured by ELISA in 158 subjects before and 1 year after weight loss induced either by conventional dietary treatment (n = 38) or bariatric surgery (sleeve gastrectomy, n = 20, or Roux-en-Y gastric bypass, n = 100). RESULTS Massive surgery-induced weight loss after SG or RYGB was accompanied by a statistically significant increase in circulating levels of ANGPTL8/betatrophin (28.1 ± 13.9 to 40.3 ± 22.8 ng/mL, P = 0.001 after SG; 24.6 ± 10.9 to 41.7 ± 19.4 ng/mL, P < 0.001 after RYGB), while remaining unchanged 25.6 ± 13.3 to 25.4 ± 10.7 ng/mL (P = 0.891) after diet-induced weight loss. The change in ANGPTL8/betatrophin levels was positively correlated with the change in HDL-C concentrations. CONCLUSIONS Our study showed that serum ANGPTL8/betatrophin concentrations were increased in obese subjects after surgically induced weight loss, but not after weight loss achieved by conventional dietary treatment. The change in ANGPTL8/betatrophin concentrations emerged as a significant predictor of the change in HDL-C levels after weight loss.