Analysis of leptin levels and the effect of urate-lowering therapy in patients with gout and metabolic syndrome

Background. Leptin, as one of the pro-inflammatory adipokines, is involved in the pathogenesis of both gout and me­tabolic syndrome, however, the effect of urate-lowering therapy in the combination of these diseases is not sufficiently studied. The purpose was to analyse the level of leptin and the effect of febuxostat in patients with gout and metabolic syndrome. Materials and methods. The study included 33 patients divided into a study group (20 men and two women with gout and metabolic syndrome) and a control group (8 men and three women without rheumatological disease). The body mass index (BMI), serum uric acid, leptin, IL-1, and IL-6 levels were analysed. Questionnaire and biomedical statistics methods were used. Febuxostat was used for the treatment of gout in the study group, at a dose of 60–80 mg once a day; the duration of observation was 6 months. Results. The leptin le­vel in the study group was 19.11 ng/ml (IQR 8.22–36.73) and was significantly higher than in the control group (11.13 ng/ml; IQR 5.91–16.86; p ≤ 0.05). Leptin level had a strong correlation with BMI and IL-6 levels (r = 0.77, p = 0.00002), and there was a medium-strength correlation between the levels of interleukins (IL-1 and IL-6) (r = 0.46, p = 0.03). After febuxostat administration in the study group, a significant decrease in uric acid levels was observed (478.0 μmol/l (IQR 428.0–533.0) vs. 295.5 μmol/l (IQR 220.5–353.0); p = 0.0004). There was a significant decrease in serum leptin, IL-1, and IL-6 levels (p < 0.05). In a small subgroup of patients with gout and metabolic syndrome (n = 10), a decrease in body weight was noted without additional dietary recommendations. Conclusion. Our results confirmed the importance of leptin in the pathogenesis of gout and metabolic syndrome and the effectiveness of febuxostat as a urate-lowering therapy in these patients.