Serum FABP4 concentrations decrease after Roux-en-Y gastric bypass but not after intensive medical management.

BACKGROUND: Serum concentrations of fatty acid binding protein 4, an adipose tissue fatty acid chaperone, have been correlated with insulin resistance and cardiovascular risk factors. The objective of this study were to assess relationships among Roux-en-Y gastric bypass, intensive lifestyle modification and medical management protocol, fatty acid binding protein 4, and metabolic parameters in obese patients with severe type 2 diabetes mellitus; and to evaluate the relative contribution of abdominal subcutaneous adipose and visceral adipose to the secretion of fatty acid binding protein 4. METHODS: Participants were randomly assigned to intensive lifestyle modification and medical management protocol (n = 29) or to intensive lifestyle modification and medical management protocol augmented with Roux-en-Y gastric bypass (n = 34). Relationships among fatty acid binding protein 4 and demographic characteristics, metabolic parameters, and 12-month changes in these values were examined. Visceral and subcutaneous adipose tissue explants from obese nondiabetic patients (n = 5) were obtained and treated with forskolin to evaluate relative secretion of fatty acid binding protein 4 in the different adipose tissue depots. RESULTS: The intensive lifestyle modification and medical management protocol and Roux-en-Y gastric bypass cohorts had similar fasting serum fatty acid binding protein 4 concentrations at baseline. At 1 year, mean serum fatty acid binding protein 4 decreased by 42% in Roux-en-Y gastric bypass participants (P = .002) but did not change significantly in the intensive lifestyle modification and medical management protocol cohort. Percentage of weight change was not a significant predictor of 12-month fatty acid binding protein 4 within treatment arm or in multivariate models adjusted for treatment arm. In adipose tissue explants, fatty acid binding protein 4 was secreted similarly between visceral and subcutaneous adipose tissue. CONCLUSION: After Roux-en-Y gastric bypass, fatty acid binding protein 4 is reduced 12 months after surgery but not after intensive lifestyle modification and medical management protocol in patients with type 2 diabetes mellitus. Fatty acid binding protein 4 was secreted similarly between subcutaneous and visceral adipose tissue explants.