MICROALBUMINURIA IS AN EARLY MARKER OF TARGET ORGAN DAMAGE IN ESSENTIAL-HYPERTENSION

Microalbuminuria has been associated with a cluster of metabolic and n onmetabolic risk factors, suggesting that it might indicate the presen ce of generalized microvascular damage in patients with essential hype rtension. To explore whether microalbuminuria is associated with early target organ damage, two groups of essential hypertensive patients, w ith (n = 17) (HtAlb+) and without (n = 16) (HtAlb-) microalbuminuria, and a control group (C) of healthy normotensive subjects (n = 20) were studied. The study groups, selected among participants of a large epi demiologic trial, were carefully matched for several potentially confo unding variables such as gender, age, duration of hypertension, and bo dy mass index. Albumin excretion rate was evaluated by radioimmunoassa y in three nonconsecutive timed overnight collections after 3 weeks of pharmacologic wash-out. Left ventricular mass was assessed by hl-B-mo de echocardiography, carotid wall thickness by a high resolution ultra sound scan, and renal vascular impedance by Doppler scan. Office as we ll as 24-h ambulatory pressure monitoring (Takeda TM-2420) were also e valuated. There was no difference between the two hypertensive groups for office and 24-h blood pressure levels except for a lower daytime/n ighttime systolic blood pressure ratio in the group with microalbuminu ria. Microalbuminuric patients showed signs of early organ damage as c ompared to normoalbuminuric patients and normal subjects, namely great er left ventricular mass indices (LVMI 167 +/- 7 g/m(2) in HtAlb+; 139 +/- 9 g/m(2) in HtAlb-; 118 +/- 5 g/m(2) in C, P <.001) and increased wall thickness of common carotid arteries (intima plus media thicknes s 12.5 +/- 0.2 mm in HtAlb+; 11.7 +/- 0.3 mm in HtAlb-; 11.2 +/- 0.2 m m in C, P <.001) as well as higher intrarenal vascular resistance (mea n resistive index 0.62 +/- 0.01 in HtAlb+; 0.59 +/- 0.01 in HtAlb-; 0. 59 +/- 0.01 in C, P <.05). In conclusion, microalbuminuria is an early marker of diffuse target organ damage in essential hypertension and t herefore can be useful to identify patients for whom more aggressive p reventive strategies or additional treatment measures are advisable. ( C) 1998 American Journal of Hypertension, Ltd.