Relation of Reduction in Urinary Albumin Excretion to Ten-Year Cardiovascular Mortality in Patients With Type 2 Diabetes and Systemic Hypertension

Abstract

Microalbuminuria is one of the strongest predictors of both adverse renal and cardiovascular disease (CVD) outcomes in patients with type 2 diabetes mellitus. Although measurement of urinary albumin excretion (UAE) is widely recommended, limited data are available to suggest that reducing UAE translates into a reduction in long-term cardiovascular mortality, particularly among patients without overt nephropathy, who constitute most patients with type 2 diabetes worldwide. We assessed whether changes in the UAE at 1 year were associated with cardiovascular mortality in 393 patients with hypertension and type 2 diabetes during a 10-year period. On univariate analysis, CVD history, age, diabetes duration, and change in UAE at 1 year were associated with cardiovascular mortality risk (hazard ratio 2.60 for those with CVD history, 95% confidence interval [CI] 1.47 to 4.62; hazard ratio 1.59 per 10 years of diabetes duration, 95% CI 1.12 to 2.25; and hazard ratio 1.49 per log UAE increase, 95% CI 1.13 to 1.96). In a stepwise Cox regression model that included baseline UAE and CVD history, the 10-year predicted mortality of those with a decrease in UAE of 2 logs at 1 year was 4.7% (95% CI 1.4% to 7.8%). For those with an increase in UAE of 2 logs at 1 year, it was 24.5% (95% CI 10.1% to 36.5%). In conclusion, these data support current guideline recommendations to screen for UAE in all patients with type 2 diabetes, even in the absence of nephropathy, and suggest that serial UAE measurements even after the initiation of antihypertensive therapy has prognostic value independent of traditional cardiovascular risk factors.