Optimal threshold of urinary albumin-to-creatinine ratio (UACR) for predicting long-term cardiovascular and noncardiovascular mortality

Traditional cutoff values of urinary albumin-to-creatinine ratio (UACR) for predicting mortality have recently been challenged. In this study, we investigated the optimal threshold of UACR for predicting long-term cardiovascular and non-cardiovascular mortality in the general population. Data for 25,302 adults were extracted from the National Health and Nutrition Examination Survey (2005–2014). Receiver operating characteristic (ROC) curve analysis was performed to assess the predictive value of UACR for cardiovascular and non-cardiovascular mortality. A Cox regression model was established to examine the association between UACR and cardiovascular and non-cardiovascular mortality. X-tile was used to estimate the optimal cutoff of UACR. The UACR had acceptable predictive value for both cardiovascular (AUC (95% CI) for 1-year, 3-year and 5-year mortality, respectively: 0.769 (0.711–0.828), 0.764 (0.722–0.805) and 0.763 (0.730–0.795)) and non-cardiovascular (AUC (95% CI) for 1-year, 3-year and 5-year mortality, respectively: 0.772 (0.681–0.764), 0.708 (0.686–0.731) and 0.708 (0.690–0.725)) mortality. The optimal cutoff values were 16 and 30 mg/g for predicting long-term cardiovascular and non-cardiovascular mortality, respectively. Both cutoffs of UACR had acceptable specificity (0.785–0.891) in predicting long-term mortality, while the new proposed cutoff (16 mg/g) had higher sensitivity. The adjusted hazard ratios of cardiovascular and non-cardiovascular mortality for the high-risk group were 2.50 (95% CI 1.96–3.18, P < 0.001) and 1.92 (95% CI 1.70–2.17, P < 0.001), respectively. Compared to the traditional cutoff value (30 mg/g), a UACR cutoff of 16 mg/g may be more sensitive for identifying patients at high risk for cardiovascular mortality in the general population.