Association and Prognostic Impact of Heart Rate and Micro- Albuminuria in Patients with Type 2 Diabetes and Cardiovascular Disease: Results from the PROactive Trial

AIM: Microalbuminuria (MAU) and heart rate are established predictors of an adverse cardiovascular outcome. Recently, heart rate was described as an independent predictor of MAU in hypertensive patients, raising the question of a causal link. METHODS: In post-hoc analysis of the PROactive trial we examined the association of the baseline heart rate and MAU in diabetic patients with cardiovascular disease (n = 5,110, mean age 62 ± 8, 66% male) using logistic regression. Cox regression analysis was used to examine the independent impact of heart rate and MAU on the composite endpoint of all-cause mortality, myocardial infarction and stroke. RESULTS: Baseline heart rate was not associated with a significantly increased risk for MAU at baseline (OR 1.01 per 10 bpm, 95% CI 0.97-1.06, p = 0.48) or MAU at the final visit (OR per 10 bpm 1.04, 95% CI 0.98-1.11, p = 0.20). Similar results were observed in subgroups of patients with hypertensive blood pressure at baseline (OR 0.98 per 10 bpm, 95% CI 0.93-1.03, p = 0.42) or patients with a history of hypertension (OR 1.02 per 10 bpm, 95% CI 0.98-1.07, p = 0.31), respectively. Stratification by use of an ACE inhibitor/AT1-receptor blocker did also not change the results. In multivariate analysis, both heart rate and MAU were significantly predictive of a cardiovascular outcome. CONCLUSION: There was no evidence of an association between heart rate and MAU in diabetic patients with cardiovascular disease, independently of whether hypertension was present or not, but both markers were independently predictive of a cardiovascular outcome. These results do not support a causal link between heart rate and MAU.