Inverse association between coffee drinking and serum uric acid concentrations in middle-aged Japanese males

Consumption of caffeine-rich beverages, which have diuretic properties, may decrease serum uric acid concentrations. We examined cross-sectionally the relationship of coffee and green tea consumption to serum uric acid concen trations in 2240 male self-defence officials who received a pre-retirement health examination at four hospitals of the Self-Defence Forces between 199 3 and 1994. The mean levels of coffee and green tea consumption were 2.3 an d 3.1 cups/d respectively. There was a clear inverse relationship between c offee consumption and serum uric acid concentration. When adjusted for hosp ital only, those-consuming less than one cup of coffee daily had a mean ser um uric acid concentration of 60 mg/l, while that of those drinking five or more cups of coffee daily was 56 mg/l (P < 0.0001). No such relationship w as observed for green tea, another major dietary source of caffeine in Japa n. The relationship between coffee consumption and serum uric acid concentr ation was independent of age, rank in the Self-Defence Forces, BMI, systoli c blood pressure, serum creatinine, serum total cholesterol and serum HDL-c holesterol concentrations, smoking status, alcohol use, beer consumption an d intake of dairy products. These findings suggest that coffee drinking may be associated with lower concentrations of serum uric acid, and further st udies are needed to confirm the association.