Increased leptin concentrations correlate with increased concentrations ofinflammatory markers in morbidly obese individuals

Objective: To study whether an increase of plasma leptin concentrations, as observed in the case of increased body weight, is associated with an infla mmatory state. Subjects: Sixty-three healthy subjects with body mass index (BMI) ranging f rom 20 to 61 kg/m(2). Measurements: Plasma concentrations of leptin, the inflammatory parameter s oluble TNF-alpha receptors (TNFR55 and TNFR75), the acute phase proteins li popolysaccharide binding protein (LBP), serum amyloid A (SAA), alpha -acid glycoprotein (AGP), C-reactive protein (CRP), plasminogen activator inhibit or-1 (PAI-1) and the anti-inflammatory soluble Interleukin-1 decoy receptor (sIL-1RII) were measured. Results: As expected, BMI correlated significantly with leptin (r=0.823, P< 0.001), but also with all acute phase proteins, both soluble TNF receptors and PAI concentrations. After correction for BMI and sex, no significant co rrelation between leptin and the acute phase proteins was seen. Interesting ly, however, leptin strongly correlated with both TNF receptors (r=0.523, P <0.001 for TNFR55 and r=0.438, P<0.001 for TNFR7S). Conclusions: This study shows the development of a pro-inflammatory state w ith increasing body weight. The BMI independent relationship between leptin and both soluble TNF-receptors is consistent with a regulatory role for le ptin in the inflammatory state in morbidly obese subjects.