Blood pressure control in essential hypertension and impairment of renal function with age

Hypertension has been recognized to be an important cause for the development of end-stage renal disease (ESRD). We assessed the quality of blood pressure control in 103 patients with essential hypertension and correlated renal function and age. Patients were stratified into three subgroups by their blood pressure level under current medication. Group 1 were hypertensive patients with normalized blood pressure (< 140/90 mmHg, n = 25), group 2 patients with mild hypertension (140-159/90-99 mmHg, n = 43) and group 3 patients with moderate to severe hypertension (> 160/100 mmHg, n = 35). A negative correlation between age and creatinine clearance (C-Cr) could be confirmed for patients of group 1 (correlation coefficient r(1) = -0.56; p(1) < 0.01) and group 2 (r(2) = -0.55; p(2) < 0.001). Furthermore the regression coefficient (m) of decline in C-Cr versus age was higher in group 2 patients (m(2) = -1.83) than in group 1 (m(1) = -1.30). In group 3 we found no correlation of renal function with age, indicating that age may not be the leading variable. Patients in group 1 were all within normal limits of age adjusted C-Cr, but 12% in group 2 and 23% in group 3 had impaired C-Cr. Furthermore proteinuria was found to be 20% (group 1), 26% (group 2) and 31% (group 3). This analysis provides further evidence of the importance of blood pressure control in essential hypertension to preserve renal function.