Reduction of albumin urinary excretion is associated with reduced cardiovascular events in hypertensive and/or diabetic patients. A meta-regression analysis of 32 randomized trials.

Background: The association between renal dysfunction and risk of cardiovascular (CV) events and mortality has been reported in several studies. However, it is unclear whether reduction in urinary albumin excretion (UAE) is associated with reduced risk of clinical events. Therefore, we sought to investigate, in a meta-regression analysis of randomized studies enrolling hypertensive and/or diabetic patients, whether changes in UAE are associated with changes in CV outcomes and all-cause mortality.

Methods: MEDLINE, ISI Web of Science, Cochrane Database and Scopus were searched for randomized trials enrolling more than 200 diabetic and/or hypertensive patients, reporting UAE at baseline and at end of follow-up and CV events [CV death, myocardial infarction (MI), and stroke], as well all-cause mortality.

Results: Thirty-two trials enrolling 80,812 participants were included in analyses. Meta-regression analysis showed that each 10% reduction of UAE was significantly associated with 13% reduction of MI (Regression Coefficient [RC]:0.0055; 95% Confidence Interval [CI]:0.0014 to 0.0095; p=0.010), with 29% reduction of stroke (RC:0.0124; CI:0.0030 to 0.0218; p=0.013) and with 14% reduction of the composite outcome (CV death, MI, stroke)(RC:0.0059; CI:0.0027 to 0.0090; p=0.001), whereas not significantly associated with all-cause (RC:0.0028; CI:-0.0047 to 0.0103; p=0.486) and CV mortality (RC:0.0028; CI:-0.0047 to 0.0103; p=0.447). Results were mostly confirmed by sensitivity analysis. No heterogeneity or publication bias was detected.

Conclusions: Reduction in UAE is associated with reduced risk of MI and stroke in diabetic and/or hypertensive patients. These findings suggest that UAE changes may represent a valuable intermediate end-point for CV risk evaluation in clinical practice.