[Microalbuminuria, a marker of artery rigidity and cardiac dysfunction]

Microalbuminuria is considered as a marker of endothelial dysfunction and is associated with an increase in cardiovascular risk. The aim of this study was to evaluate this parameter as a potential marker of artery rigidity and left ventricle (LV) function.

We included 375 subjects referred to a health assessment center. They were 228 men and 147 women aged in means of 52.7 and 53.1 years, respectively. Among this population, 57 had type 2 diabetes, 28 of them with hypertension, 65 were hypertensive but free of diabetes, and 39 were free of diabetes but exhibited a metabolic syndrome (NCEP-ATP III). Urinary albumin excretion rate (UAER) was determined. Artery rigidity was evaluated by pulse pressure of the brachial artery (plethysmographic method), pulse pressure of the radial artery and aorta and pulse wave velocity (PWV) measured by aplanation tonometry (SphygmoCor). LV afterload was appreciated by LV telesystolic pressure and coronary perfusion by the diastolic area/systolic area ratio for aortic pressure curve (Buckberg index).

UAER correlated with PWV in the overall population (p<0.0001) and in the diabetic sub-group (p<0.001). In the overall population UAER correlated with LV telesystolic pressure (p=0.006) but not with Buckberg index. In the overall population and the diabetic subgroup, the artery rigidity indexes correlated strongly with LV telesystolic pressure, and radial and aortic pulse pressure correlated negatively with Buckberg index.

These data suggest that 1) microalbuminuria may be considered as a marker of artery rigidity, in line with experimental data which indicate the deleterious role of endothelial dysfunction on artery compliance; 2) artery rigidity is a potent determinant of LV afterload and coronary perfusion, in particular in diabetic patients.