Upregulation of Plasma Insulin‐Like Growth Factor Binding Protein 2 Levels After Biliopancreatic Diversion in Humans

The biliopancreatic diversion surgery with duodenal switch (BPD‐DS) is a surgical procedure that not only induces significant weight loss, but also promotes remission of diabetes. However, the mechanism responsible for this insulin‐potentiating effect (both on sensitivity and production) is not yet clearly understood. The insulin‐like growth factor (IGF) binding protein 2 (IGFBP‐2) is a 36 kDa circulating protein that has been recently suggested to modulate insulin sensitization and fat accumulation. In humans, a low‐circulating concentration of IGFBP‐2 has been associated with obesity and insulin resistance. We thus tested the hypothesis that BPD‐DS would trigger an increase in IGFBP‐2 levels. Plasma IGFBP‐2 was quantified by enzyme‐linked immunosorbent assay in 77 severely obese men and women before and up to 1 year after BPD‐DS surgery. Baseline IGFBP‐2 levels were 159 ± 17 ng/ml. Plasma IGFBP‐2 levels increased significantly as soon as 24 h after BPD‐DS surgery and were further augmented at both 6 months and 1 year after the surgery, reaching 748 ± 65 ng/ml. Changes in IGFBP‐2 concentrations were significantly and negatively associated with blood glucose, insulin, triglycerides, and total cholesterol levels. The present findings suggest that the rise in IGFBP‐2 levels is associated with the improvements in glucose and lipid metabolism in the short‐ and long‐term after BPD‐DS. The mechanisms for the augmentation in IGFBP‐2 after BPD‐DS and its contribution to insulin sensitization remain to be elucidated.