The effect of blood pressure control on the progression of chronic glomerulonephritis associated with hypertension

It is well known that hypertension (HT) frequently develops in patients with chronic glomerulonephritis (CGN) and that HT contributes to progession of CGN. So, proper antihypertensive therapy is required in hypertensive patients with CGN. However, there is so far no consensus of optimal blood pressure (BP) level to maintain the renal function in these patients. In order to evaluate the BP control level in the patients with renal insufficiency, we investigated the transition of BP and renal function in 22 CGN patients with HT (average age 36.5-9.9 years at the first medical examination, 15 male, 7 female, total 179.5 patient-years), who receive antihypertensive therapy for more than 5 years as outpatients at the second department of internal medicine of Tohoku University Hospital between 1975 and 1990. Renal biopsy had been performed in all these patients for CGN diagnosis. During this period 7 patients came to receive hemodialysis therapy from 5 to 10 (average 7.6-2.1) years after the first medical examination. In one of these 7 patients, the rate of decline in renal function accelerated after child-birth, and one after two years interruption of treatment. The other 13 patients are currently receiving drug treatments at our hospital. As a result, in CGN patients there was an optimal mean BP (MBP) control range, that is, when MBP was controlled in this range, the rate of decline in renal function became slow, but when MBP deviated from this range it became fast (p<0.01). Moreover, this range changed according to the serum creatinine (SCr) concentration level. From our study, the optimal MBP was 1) 100-115 mmHg when SCr was between 1.2 and 1.5 mg/dl 2) 105-115 mmHg when SCr was between 1.5 and 1.7 mg/dl 3) not less than 110 mmHg when SCr was between 1.7 and 2.0 mg/dl. In addition, when MBP was lower than this range, the rate of decline in renal function was faster than when MBP was higher than this range. These results demonstrate that it is able to delay the rate of the progession of CGN, if we control the MBP of CGN patients in optimal MBP range.