Residual small artery impairment in hypertensive patients with normal albumin–creatinine ratio

Objectives Previous studies have suggested that urine albumin excretion (UAE) mirrors generalized vascular damage; however, it is unclear to which degree UAE mirrors small artery impairment. Design We enrolled 67 patients with uncomplicated essential hypertension (EH) during stable antihypertensive therapy. F-Rmin, ACR on three non-consecutive morning urine samples, pulse wave velocity (PWV), and 24-h ambulatory blood pressure (ABPM) were measured. Results ACR was low (0.39 and 0.30-0.60), but abnormal small artery structure defined as F-Rmin > mean + 2 standard deviations of normotensive value (1.99 + 1 mmHg min/(ml/100 ml)) was present in 45% (n = 30). The mean F-Rmin was 2.89 ± 0.09 mmHg min/(ml/100 ml). ACR correlated significantly to PWV (r(2 )=( )0.11; p < 0.05) and pulse pressure (r(2 )=( )0.15; p < 0.001), but not F-Rmin and (r(2 )=( )0.05, p = 0.07). Conclusions Abnormal microvascular structure was present even in EH patients with low UAE. ACR correlated to arterial stiffness and not to small artery structure; therefore, UEA did not reflect microvascular damage in this population. ACR and F-Rmin thus reflect two distinct types of subclinical organ damage in hypertension.