Visceral Adipose Tissue Loss and Insulin Resistance 6 Months after Laparoscopic Gastric Banding Surgery: A Preliminary Study

Increased visceral adipose tissue (VAT) is thought to be a risk factor for cardiovascular and metabolic diseases. There are only limited data on whether VAT loss after laparoscopic gastric banding surgery (LGBS) is related to risk factor reduction. This study determined whether improvements in risk markers, in particular insulin resistance, were related to VAT reduction at 6 months after LGBS (T2). Thirty-four LGBS patients and 17 normal weight controls underwent initial and T2 testing. Fasting venous blood samples were taken to evaluate glucose, insulin, hemoglobin A(1c), lipids, C-reactive protein (CRP), and hormone profiles. Insulin resistance was estimated using the homeostasis model assessment (HOMA) index. VAT was measured using CT techniques. Data were analyzed using repeated measures ANOVA and regression analysis. Results at T2 showed that patients had significant improvements in body composition, HOMA, and hemoglobin A(1c). There were also reductions in plasma renin activity and leptin, and increases in ghrelin and GLP-1. Reductions in VAT were significantly correlated with reductions in insulin, HOMA, and glucose. While high density lipoprotein cholesterol, triglycerides, CRP, and the apolipoprotein A1/B ratio were also improved, VAT reduction was significantly correlated only with an increased apolipoprotein A1/B ratio. These data indicate that 6 months after LGBS there were significant improvements in many cardiovascular and metabolic risk markers. However, VAT reduction was most strongly associated with reductions in insulin resistance. Body weight loss was not associated with markers of improved insulin sensitivity.