Sex specific serum uric acid levels are associated with ischemic changes on ECG and with 20-year all-cause mortality among older adults.

Background: Uric acid is an emerging biomarker for cardiovascular morbidity and mortality, but its association with all-cause mortality and ECG findings remains unestablished, specifically among older adults. We aimed to evaluate the association between serum uric acid (SUA) with incidental findings of ECG abnormalities and with long-term all-cause mortality.

Methods: We conducted a prospective cohort study of 851 community dwelling men and women, who were examined between 1999 and 2008, and followed over 20 years until December 2019 for all-cause mortality. Subjects free of Gout or diuretics treatment at baseline were included. SUA was categorized according to sex-specific tertiles and evaluated against baseline ECG findings and all-cause mortality.

Results: Mean baseline age was 72±7 years and 416 (49%) were females. Ischemic changes on ECG were observed in 85 (10.0%) participants, of them 36 (13.5%) belonged to the upper SUA tertile and 49 (8.4%) to the lower ones (p = 0.02). Multivariable logistic regression showed 80% higher odds for ischemic changes on ECG among participants in the high SUA tertile (adjusted-OR = 1.8, 95%CI 1.1-2.9, p = 0.03) compared with the lower SUA two-tertiles. During a median follow-up of 14 years, 380 (44.7%) participants died. SUA ≥5.3 mg/dl for women and ≥ 6.2 mg/dl for men, was associated with a 30% greater risk for all-cause mortality in a multivariable Cox regression model (HR = 1.3, 95%CI: 1.0-1.6, p = 0.03).

Conclusions: High SUA level was associated with ischemic changes on ECG and with an increased risk for all-cause mortality over 20 years of follow-up among community dwelling older adults free of Gout. Even lower sex-specific thresholds of SUA were associated with all-cause mortality than previously proposed. SUA should be considered as a biomarker for cardiovascular risk and all-cause mortality.