Urine albumin/creatinine ratio below 30mg/g is a predictor of incident hypertension and cardiovascular mortality

BackgroundMicroalbuminuria is associated with cardiovascular disease (CVD) mortality, but whether lower levels of urine albumin excretion similarly predict CVD is uncertain. We investigated associations between urine albumin:creatinine ratio (UACR) <30 mg/g, and incident hypertension, incident diabetes mellitus, and all?cause and CVD mortality, during a maximum of 11 years of follow?up.Methods and ResultsIndividuals (37 091) in a health screening program between 2002 and 2012 with baseline measurements of UACR were studied. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% CIs for incident hypertension, incident diabetes mellitus, and mortality outcomes (lowest UACR quartile as reference) at follow?up. For linear risk trends, the quartile rank was used as a continuous variable in regression models. Nine?hundred sixty?three cases of incident hypertension, 511 cases of incident diabetes mellitus, and 349 deaths occurred during follow?up. In the fully adjusted models, there was a significant HR for the association between UACR and incident hypertension (highest UACR quartile HR 1.95 [95% CI 1.51, 2.53], P?value for trend across UACR quartiles P<0.001). In contrast, the association between UACR and incident diabetes mellitus was not significant (highest UACR quartile, HR 1.15 [95% CI 0.79, 1.66], P?value for trend P=0.20). For CVD mortality, with increasing UACR quartiles, there was a significant increase in HR across quartiles, P=0.029, (for all?cause mortality, P=0.078).ConclusionsLow levels of albuminuria, UACR below 30 mg/g, are associated with increased risk of incident hypertension and CVD mortality at follow?up, but are not associated with increased risk of incident diabetes mellitus