Association between IGF1/IGFBP3 with Lipid Metabolism and Chronic Low-Grade Inflammation and Alteration after Laparoscopic Sleeve Gastrectomy in Chinese Obese Subjects

Some studies have demonstrated the disturbance of IGF1/IGFBP3 axis in endocrine-metabolic diseases. We aimed to investigate the association between IGF1/IGFBP3 with glucose-lipid metabolism and chronic low-grade inflammation and the changes after laparoscopic sleeve gastrectomy (LSG) in Chinese obese patients. Thirty-six obese subjects were enrolled. Anthropometric data, routine laboratory biochemical parameters and IGF1/IGFBP3 levels were evaluated at baseline and 3 months after LSG. Serum total IGF1 and IGFBP3 levels were measured by enzyme-link immunosorbent assay and molar ratio of IGF1/IGFBP3 is represented as free IGF1 levels. In all subjects, total IGF1 was positively correlated with HDL-c (P<0.05), negatively with weight, BMI, waistline, hipline, waist/hip ratio, C-reactive protein (CRP) and tumor necrosis factor-α (TNF-α) (P<0.or P<0.01). Free IGF1 was negatively correlated with hipline, triglyceride (TG), CRP and TNF-α (P<0.or P<0.01). IGFBP3 was positively correlated with TG and free fatty acids (FFA) (P<0.or P<0.01). Both total IGF1 and IGFBP3 levels were significantly decreased after LSG (from 166.54±64.44ng/ml to 143.02±69.09ng/ml, P=0.048 and from 2556.54±756.99ng/ml to 2051.89±618.61ng/ml, P<0.001, respectively, and more reduction in IGFBP3 levels of 19.74%), while an increased tendency of free IGF1 levels was observed. In addition, changes of total IGF1/free IGF1 were negatively related to changes of CRP and TNF-α (P<0.or P<0.01), and change of IGFBP3 was positively related to change of FFA (P<0.05).

In conclusion, the IGF1/IGFBP3 axis is closely associated with lipid metabolism and chronic low-grade inflammation in Chinese obese patients. Decreased IGFBP3 and increased free IGF1 may partly account for the improved lipid metabolic and chronic low-grade inflammatory profiles after LSG.