Leptin serum levels in rheumatoid arthritis patients: relation to disease duration and activity.

Leptin is a peptide hormone with the tertiary structure of a cytokine, which not only regulates body weight by inhibiting food intake, but also modulates inflammatory and immune responses. The aim of the study was to investigate if there are connections between leptin concentrations and parameters of nutritional status and disease activity in a group of rheumatoid arthritis (RA) patients. The study group consisted of 37 patients. The mean leptin serum concentration was significantly higher in women than in men. The leptin concentrations correlated positively with BMI only in women with RA. The leptin concentrations were significantly higher in patients with erosive RA. Assessing the group of patients with long-standing RA (duration > 10 years), we found that leptin levels were significantly higher in patients with higher disease activity than in those with DAS28 < or = 5,1; there was also a positive correlation between serum leptin concentration and the value of DAS28, ESR and the number of tender joints. The results suggest that some important dependence exists between the risk of aggressive course of RA and increased leptin levels.