Decrease in leptin production by the adipose tissue in obesity associated with severe metabolic syndrome.

Objective: To evaluate the associations between leptinemia and the components of metabolic syndrome (MetS).

Methods: Fifty-one obese adults (9 men; 36.7 +/- 10.0 years; body mass index (BMI) 46.2 +/- 10.0 kg/m(2)) were submitted to clinical examination, determinations of body fat mass (BF, bioimpedance) and resting energy expenditure (REE, indirect calorimetry), and to hormonal and biochemical analysis. Patients were categorized into three groups, according to the number of criteria for MetS: Group I: none or 1; Group II: 2; and Group III: 3 or 4 criteria.

Results: Absolute leptinemia (LepA; 37.5 +/- 16.9 ng/mL) was directly correlated with BMI (r = 0.48; p = 0.0004), waist circumference (r = 0.31; p = 0.028) and BF (r = 0.52; p = 0.0001). Leptinemia adjusted for BF (LepBF) was inversely correlated with weight (r = -0.41; p=0.027), REE (r = -0.34; p = 0.01) and number of MetS criteria (r = -0.32; p = 0.02). There was no difference in LepA among the groups. LepBF in Group III (0.58 +/- 0.27 ng/mL/kg) was significantly lower compared to Group I (0.81 +/- 0.22 ng/mL/kg; p = 0.03) and Group II (0.79 +/- 0.30 ng/mL/kg; p = 0.02).

Conclusions: Leptin production by the adipose tissue is decreased in obese subjects fulfilling three or more criteria of MetS, suggesting a state of relative leptin deficiency in obesity associated with advanced stages of MetS.