A longitudinal study of the antilipolytic effect of insulin in women following bariatric surgery

Abstract

Insulin resistance of glucose utilization is fully restored following BMI normalization after bariatric surgery. We investigated if this also pertains to insulin-induced effects on fatty acid handling. Forty-three women with obesity (OB) were investigated before and 2 years after Roux-en-Y gastric by-pass when BMI was <30 kg/m2 (PO) and compared with 26 never obese women (NO). The Adipo-IR index was used as measure of insulin antilipolytic sensitivity. Changes (delta) in circulating glycerol and fatty acid levels during hyperinsulinemic euglycemic clamp represented the insulin maximum antilipolytic effect. Overall fatty acid utilization was reflected by delta fatty acids minus 3 × delta glycerol. Adipo-IR was higher in OB than in NO and PO (p < 0.0001), the latter two groups having similar values. Insulin lowered glycerol levels by about 70% in all groups, but delta glycerol was 30% larger in PO than in NO (p = 0.04). Delta adds and adds utilization were similar in all groups. We conclude that women with obesity, whose BMI is normalized after bariatric surgery, have improved maximum in vivo antilipolytic effect of insulin above expected in absolute but not relative terms as regards glycerol changes, while the handling of circulating fatty acids is changed to the normal state.