Plasma concentrations of adipocyte fatty acid binding protein in patients with Cushing's syndrome

Serum adipocyte fatty acid-binding protein (FABP-4)concentrations are linked to human obesity and other features ofmetabolic syndrome. Patients with Cushing´s syndrome (CS)develop numerous features of metabolic syndrome due to chroniccortisol excess. Here we tested the hypothesis that chronicallyincreased cortisol levels in CS patients may alter circulating levelsof FABP-4. Fourteen patients with CS, 19 patients with simpleobesity (OB) and 36 healthy control subjects (C) were included inthe study. Serum FABP-4 concentrations were significantly higherin both CS and OB patients relative to C group, but they did notdiffer between CS and OB groups. In a combined population ofall groups, serum FABP-4 levels correlated positively with BMI,body fat content, serum glucose, triglycerides, HbA1c and HOMAindex and were inversely related to HDL-cholesterol, restingenergy expenditure and freeT3 levels. We conclude that FABP-4levels are significantly increased in both patients with simpleobesity and obese patients with Cushing´s syndrome. Wesuggest that increased FABP-4 concentrations in CS patients arerather due to their excessive fat accumulation and relatedmetabolic abnormalities than due to a direct effect of cortisol onFABP-4 production.