Increased levels of serum uric acid among ex-smokers.

Background: It remains unclear whether serum uric acid level increases after the cessation of smoking.

Methods: In 2000, we conducted a cross-sectional study on the effects of smoking cessation on serum uric acid levels by analyzing the results of annual health check-ups in the Japanese male working population (n = 16,642).

Results: The serum uric acid level (6.18 mg/dL) was the highest in ex-smokers, followed by that in never-smokers (6.10 mg/dL) and that in current smokers (5.98 mg/dL). Ex-smokers weighed 0.6 kg more than the never-smokers and 1.5 kg more than the current smokers. The frequency of alcohol intake was closely correlated to the smoking habits. The serum uric acid levels declined in all groups, after adjustments for age, body mass index, and alcohol intake, though the levels in ex-smokers were 0.2 mg/dL higher than those in current smokers.

Conclusion: The results suggested that alcohol intake contributed considerably to the serum uric acid levels and that smoking itself may have suppressed these levels via metabolic effects or the action of superoxides.