Independent links between plasma xanthine oxidoreductase activity and levels of adipokines.

AIMS/INTRODUCTION: Xanthine oxidoreductase (XOR), a rate-limiting and catalyzing enzyme of uric acid formation in the purine metabolism, is involved in an increase in reactive oxygen species. Plasma XOR activity has been shown to be associated with obesity, smoking, liver dysfunction, hyperuricemia, dyslipidemia and insulin resistance.

MATERIALS AND METHODS: The association between plasma XOR activity measured by using liquid chromatography and mass spectrometry and levels of adipokines, including adiponectin, fatty acid-binding protein 4 (FABP4) and fibroblast growth factor 21 (FGF21), were investigated in 282 subjects (male/female: 126/156) with no medication of the Tanno-Sobetsu Study.

RESULTS: Female subjects had lower plasma XOR activity than did male subjects. Smoking habit was associated with the increased activity. Plasma XOR activity was positively correlated with concentrations of FABP4 (r = 0.192, P < 0.001) and FGF21 (r = 0.208, P < 0.001), HOMA-R as an index of insulin resistance and uric acid and was negatively correlated with adiponectin level (r = -0.243, P = 0.001). Multivariate regression analyses demonstrated that levels of adiponectin, FABP4 and FGF21 were independent determinants of plasma XOR activity after adjusting age, gender, uric acid and HOMA-R. With additional adjustment of smoking habit, the level of FABP4, but not that of adiponectin or FGF21, remained as an independent predictor of plasma XOR activity.

CONCLUSIONS: Plasma XOR activity is independently associated with levels of adipokines in a general population of subjects without medication. This article is protected by copyright. All rights reserved.