U‐Shaped Association Between Serum Uric Acid Levels With Cardiovascular and All‐Cause Mortality in the Elderly: The Role of Malnourishment

BACKGROUND: The link between elevated serum uric acid (SUA) levels and cardiovascular disease (CVD)–related mortality in the elderly population remains inconclusive. Nutritional status influences both SUA and CVD outcomes. Therefore, we investigated whether SUA‐predicted mortality and the effect‐modifying roles of malnourishment in older people. METHODS AND RESULTS: A longitudinal Taiwanese cohort including 127 771 adults 65 years and older participating in the Taipei City Elderly Health Examination Program from 2001 to 2010 were stratified by 1‐mg/dL increment of SUA. Low SUA (<4 mg/dL) strata was categorized by malnourishment status defined as Geriatric Nutritional Risk Index <98, serum albumin <38 g/L, or body mass index <22 kg/m(2). Study outcomes were all‐cause and CVD‐related mortality. Cox models were used to estimate hazard ratios (HRs) of mortality, after adjusting for 20 demographic and comorbid covariates. Over a median follow‐up of 5.8 years, there were 16 439 all‐cause and 3877 CVD‐related deaths. Compared with the reference SUA strata of 4 to <5 mg/dL, all‐cause mortality was significantly higher at SUA <4 mg/dL (HR, 1.16; 95% confidence interval, 1.07–1.25) and ≥8 mg/dL (HR, 1.13; confidence interval, 1.06–1.21), with progressively elevated risks at both extremes. Similarly, increasingly higher CVD‐related mortality was found at the SUA level <4 mg/dL (HR, 1.19; confidence interval, 1.00–1.40) and ≥7 mg/dL (HR, 1.17; confidence interval, 1.04–1.32). Remarkably, among the low SUA (<4 mg/dL) strata, only malnourished participants had greater all‐cause and CVD‐related mortality. This modifying effect of malnourishment remained consistent across subgroups. CONCLUSIONS: SUA ≥8 or <4 mg/dL independently predicts higher all‐cause and CVD‐related mortality in the elderly, particularly in those with malnourishment.