RESUMO
The purpose of this study was to verify if microalbuminuria (AER) could be an early feature of renal hemodynamic changes in essential hypertension. Fifty-three patients with newly diagnosed essential hypertension (EH) underwent 24-hour blood pressure monitoring (24h-BP). Furthermore, AER and glomerular filtration rate (GFR) were evaluated by obtaining 24-hour urine collection: day- and night-time urine was kept separate. Data from the 53 EH patients were analyzed both collectively and after subdivision into two subgroups based on AER values (less or more than 16 micrograms/min). In the 53 EH patients, 24h-AER correlated significantly to both 24h systolic and diastolic blood pressure (BP) (r = 0.58 and 0.67, respectively). The subgroup with AER greater than 16 micrograms/min showed higher values of 24h-BP and GFR than the other subgroup. Moreover, in the first subgroup, 24h-systolic BP (r = 0.61) and 24h-diastolic BP (r = 0.68) correlated with AER. Our data seem to indicate that among the hypertensive patients, there is a subgroup of subjects whose hypertensive disease is characterized by high blood pressure as well as elevated microalbuminuria and glomerular filtration rate values. Increased microalbuminuria in newly diagnosed hypertensive disease seems to be due to glomerular hypertension and early altered microvascular permselectivity, and would thus indicate an early clinical expression of altered renal hemodynamics.