Serum uric acid and long-term mortality from stroke,coronary heart disease and all causes

Abstract

Background

Increased serum uric acid (SUA) levels are linked to obesity, dyslipidemia, diabetes and hypertension. Whether SUA carries a risk for coronary heart disease (CHD) and stroke remains uncertain.

Design

A prospective cohort study.

Methods

Of an original cohort of middle-aged workers who were examined in 1963 and followed-up for 23 years, 9125 men, free of CHD at entry, are included in this study. Subjects were divided into quintiles according to baseline SUA levels. Hazard ratios (HR) for all-cause, CHD, and stroke mortality were estimated in SUA quintiles, with the third serving as a referent.

Results

During follow-up, 2893 deaths were recorded, including 830 ascribed to CHD and 292 to stroke. The HR for all death [1.22, 95% confidence interval (CI) 1.09–1.37] and CHD (1.29, 95% CI 1.05–1.58) were increased in the upper SUA quintile. Fatal stroke showed a U-shaped relationship as both the upper (HR 1.48, 95% CI 1.02–2.17) and bottom (HR 1.43, 95% CI 0.99–2.08) quintiles were associated with a higher risk. Adjustment for confounders reduced the HR of the upper quintile for all outcomes, but did not attenuate the association of the bottom quintile with stroke (HR 1.52, 95% CI 1.04–2.23). When analysed separately by stroke type, the latter association seemed to be stronger for hemorrhagic (HR 3.27, 95% CI 1.14–9.33) than for ischemic stroke (HR 1.34, 95% CI 0.87–2.05).

Conclusion

In addition to findings supporting increased mortality among hyperuricemic subjects, we identified an association between low SUA levels and fatal stroke, which deserves further investigation.