The Effects of Urinary Albumin and Hypertension on All-Cause and Cardiovascular Disease Mortality in Korea

BACKGROUND Urinary albumin levels and hypertension (HTN) are independently associated with an increased risk of all-cause mortality. The effect of albuminuria on mortality in the absence or presence of HTN is uncertain. This study aimed to evaluate the effect of albuminuria and HTN on all-cause and cardiovascular disease (CVD) mortality. METHODS Mortality outcomes for 32,653 Koreans enrolled in a health screening including measurements of the urinary albumin/creatinine ratio (UACR) at baseline and median follow-up of 5.13 years. Receiver operating characteristic curve analyses were performed in UACR and the cut-point was 5.42 mg/g. The participants for UACR at the cut-point of 5.42 μg/mg were categorized into UACR < 5.42 or UACR ≥ 5.42. HTN status was categorized as No HTN or HTN (defined as the absence or presence HTN). RESULTS The median (interquartile) baseline UACRs were higher in those who died than in survivors. Subjects with a UACR ≥ 5.42 mg/g without or with HTN showed a similar increased risk for all-cause mortality and CVD mortality, even after adjusting for known CVD risk factors compared to those with no HTN/UACR < 5.42 (reference), (all-cause mortality; hazard ratio [HR] 1.48; 95% confidence interval [CI] 1.02-2.15: HR 1.47; 95% CI 0.94-2.32, respectively), (CVD mortality; HR 5.75; 95% CI 1.54-21.47: HR 5.87; 95% CI 1.36-25.29). CONCLUSIONS The presence of urinary albumin and HTN is a significant determinant of CVD and death. Urinary albumin might be more attributable to CVD and all-cause mortality than HTN.