Lack of effect of a moderate hypocaloric diet on visfatin levels in morbid obese patients: relationship with insulin resistance.

OBJECTIVES The insulin-mimetic adipocytokine visfatin has been related to obesity. The aim of this study was to examine whether weight loss could change visfatin concentrations in morbidly obese patients and its relationship with insulin resistance. MATERIAL AND METHODS This was an interventional study analyzing a population of 41 morbidly obese patients. A biochemical analysis was realized before and after 2 months on a hypocaloric diet. RESULTS After weight loss (average 4.41%), BMI, weight, fat mass, fat free mass, waist circumference, systolic blood pressure, serum glucose, total cholesterol, insulin and HOMA decreased. The serum concentrations of visfatin did not decrease (43.5 + 30.8 vs. 47.1 + 38.1 ng/ml). In the multivariate analysis visfatin concentrations as a dependent variable, only C reactive protein remained as an independent predictor in the model before diet, with an increase of 1.82 ng/ml (CI 95%: 0.02 - 3.61) basal visfatin concentrations with each increase of 1 mg/dl of CRP. Only HOMA remained as an independent predictor in the model after diet, with an increase of 11.4 ng/ml (CI 95%: 1.76 - 21.11) posttreatment visfatin concentrations with each increase of 1 unit HOMA. CONCLUSION Weight reduction after a 2 months on a hypocaloric diet is not associated with a significant change in circulating visfatin in morbidly obese patients.