Microalbuminuria independently correlates to cardiovascular comorbidity burden in patients with hypertension

Microalbuminuria (MAU) is a marker for endothelial dysfunction and a predictor of cardiovascular events. Cardiovascular risk and mortality are mainly influenced by associated morbidities and risk factors.

The present analysis aimed to investigate the relationship between the number of cardiovascular comorbidities and both the prevalence of MAU and the extent of albuminuria (measured as urinary albumin excretion, UAE) in 21,867 high-risk hypertensive patients included in the I-SEARCH study. A total of 6,945 patients (32 %) suffered from at least one comorbidity, out of which 5,437 patients (25 %) had one cardiovascular comorbidity, 1,163 (5 %) patients had two, and 345 (2 %) had ≥3. The prevalence of MAU increased from 54 % in patients without cardiovascular comorbidity to 74 % in the presence of ≥3 comorbidities (p < 0.01). In a multivariate analysis, the presence of ≥3 cardiovascular comorbidities nearly doubled the risk for MAU (HR 1.79, CI 1.07-2.68, p = 0.025). Compared to other comorbidities, patients with left ventricular hypertrophy had the highest prevalence of MAU (68 %, p < 0.01). The extent of UAE was related to the number of concomitant disease and increased significantly in patients with ≥3 comorbidities compared to patients with no comorbidity (UAE of 80 mg/L: 12-22 %, p < 0.01; UAE of 150 mg/L: 8-19 %, p < 0.01).

In hypertensive patients at high cardiovascular risk, both the prevalence of MAU and the extent of albuminuria increase with the number of comorbidities.