Serum uric acid and the risk of mortality during 23 years follow-up in the Scottish Heart Health Extended Cohort Study.

BACKGROUND

Elevated uric acid is a prevalent condition with controversial health consequences. Observational studies disagree with regard to the relationship of uric acid with mortality, and with factors modifying this relationship.

OBJECTIVE

We examined the association of serum uric acid with mortality in 15,083 participants in the Scottish Heart Health Extended Cohort (SHHEC) Study.

METHODS

Serum uric acid was measured at study enrollment. Death was ascertained using both the Scottish death register and record linkage.

RESULTS

During a median follow-up of 23 years, there were 3980 deaths. In Cox proportional hazards models with sexes combined, those in the highest fifth of uric acid had significantly greater mortality (HR 1.18, 95% CI: 1.06, 1.31) compared with the second fifth, after adjustment for traditional cardiovascular risk factors. This relationship was modified by sex (P-interaction=0.002) with adjusted HRs of 1.69 (95% CI: 1.40, 2.04) and 0.99 (95% CI: 0.86, 1.14) in women and men, respectively. Compared with the second fifth, the highest fifth of uric acid was most associated with kidney-related death (HR: 2.08, 95% CI: 1.31, 3.32).

CONCLUSION

Elevated uric acid is associated with earlier mortality, especially in women. Future studies should evaluate mechanisms for these interactions and explore the strong association with renal-related mortality.