Uncontrolled hypertension is associated with a rapid progression of nephropathy in type 2 diabetic patients with proteinuria and preserved renal function.

The relationship between blood pressure and progression of nephropathy was studied (the mean follow-up period of 32.6 +/- 17.9 (S.D.) months in 20 Type 2 (non-insulin-dependent) diabetic patients with clinical nephropathy (proteinuria greater than 0.5 g/day) and preserved renal function (serum creatinine level less than 150 mumol/liter). Fifteen hypertensive patients under antihypertensive treatment were divided into 2 groups: those with the mean diastolic blood pressure greater than or equal to 90 mmHg and/or the mean systolic blood pressure greater than or equal to 150 mmHg during the follow-up period were designated as Group A (n = 6) and the remainders as Group B (n = 9). Five normotensive patients without any anti-hypertensive treatment throughout the follow-up period served as a control group (Group C). The decline rate in GFR was significantly greater (p less than 0.05) in Group A (1.15 +/- 0.39 (S.E.) ml/min/month) than those in Groups B (0.33 +/- 0.08 ml/min/month) and C (0.40 +/- 0.09 ml/min/month), respectively. The decline rate in GFR showed significant positive correlations both with systolic (rS = 0.553, p less than 0.05) and diastolic (rS = 0.493, p less than 0.05) blood pressures in the 15 hypertensive patients. The age, initial glomerular filtration rate, duration of diabetes and mean HbA1c level during the observation period were comparable in Groups A, B and C, respectively. The results indicate that an uncontrolled hypertension is associated with a rapid progression of kidney impairment in Type 2 diabetic patients with overt nephropathy, as has been suggested in Type 1 (insulin-dependent) diabetic patients.