Background: Microalbuminuria is an established risk factor for cardiovascular morbidity and mortality. Recently, the prognostic value of low-grade albuminuria for cardiovascular disease has been suggested. However, most studies were performed in heterogeneous population.

Methods: The association between urinary albumin excretion and arterial stiffness was evaluated in subjects with never treated hypertension and without diabetes and cardiovascular complications. Urinary albumin creatinine ratio (UACR) was measured with morning spot urine sample after overnight fasting. Arterial stiffness was measured with brachial-ankle pulse wave velocity (baPWV). Definition of low grade albuminuria was UACR <22 for men or <31 mg/g creatinine for women according to 2007 ESH/ESC guideline. The 236 subjects (mean age 51 ± 11 years, range 26–77, 61% men) were analyzed.

Results: The linear regression analysis showed a significant correlation between UACR and baPWV (beta = 9.52; P < 0.0001), that was independent by multiple linear regression model including, as independent variables, age, gender, body mass index, mean arterial pressure, total cholesterol and smoking (beta = 5.66; p = 0.0115). Compared with those in the lowest UACR quartile, subjects in the highest quartile (UACR > 11.7 mg/g) showed higher baPWV (1492 ± 213 vs. 1655 ± 313 cm/sec) with general linear model adjusted for age, gender, body mass index, mean arterial pressure, total cholesterol and smoking (B=98.5; p = 0.0084).

Conclusion: Hypertensive subjects with urinary albumin excretion in the upper normal range were not free from target organ damage. The present study suggests that the current threshold of microalbuminuria should be lowered.