Behavior of insulin sensitivity and its relation to leptin and tumor necrosis factor-alpha in obese women undergoing liposuction: 6-month follow-up

Abstract

Metabolic syndrome is a group of pathological processes which involve insulin resistance, a biochemical and molecular disorder. Obesity appears to be the most frequent clinical component in metabolic syndrome. Subcutaneous fat, independent from visceral fat, is still controversial as a marker of the pathophysiology of insulin resistance. An open parallel-group clinical trial was performed of 12 women (age 30-40 years), with BMI from 30-33 kg/m2 and fasting glucose < or =110 mg/dl. 6 women were included in the "liposuction plus diet" group, and 6 were included in the "diet-only" group. Metabolic profile, including insulin tolerance test (ITT), leptin and tumor necrosis factor alpha (TNFalpha), was performed at baseline, 1 and 6 months in both groups. Subcutaneous and visceral fat was quantified with spiral tomography at baseline and after 6 months. Friedman and Wilcoxon test were used for intra-group differences, Mann-Whitney U for differences between groups, and Spearman test for correlation, with significance set at P<0.05. No difference existed between groups regarding clinical characteristics and metabolic profile. In the liposuction group, the increase in insulin sensitivity was (3.8+/-0.86, 3.1+/-0.85, 4.5+/-1.02 %/min, P=0.08. Insulin sensitivity did not correlate with subcutaneous fat, leptin, or TNFalpha. Leptin diminished at 1 month (52.7+/-6.04 vs 31.6+/-11.9), P=0.028, and correlated with the subcutaneous fat (r=0.957). In the diet-only group, TNFalpha diminished at 6 months, P=0.046. Subcutaneous abdominal fat correlates with leptin; nevertheless, it is a weak marker for TNFalpha and insulin sensitivity.