Relationship between blood pressure and urinary albumin excretion in development of microalbuminuria

Two hundred nine consecutive normotensive insulin-dependent diabetic (IDDM) patients were followed prospectively from November 1982 to January 1988. Patient urinary albumin excretion rate (UAE) had to be normal (less than 30 mg/24 h) on at least two occasions before inclusion in the study. Patients were aged 18-50 yr with a duration of diabetes of 10-30 yr. UAE was measured every 4 mo, and supine blood pressure was measured annually. Two hundred five patients completed the study. Five years later, 15 patients had developed persistent microalbuminuria with median UAE greater than 30 mg/24 h for at least 2 yr (group 2), and 190 patients stayed normoalbuminuric (group 1). Although within normal range, initial UAE was significantly elevated in group 2 compared with group 1 (mean 19 mg/24 h [range 15-23 mg/24 h] vs. 11 mg/24 h [10-12], 95% confidence interval [CI], P less than 0.001). Initially, there was no difference in blood pressure between group 2 (mean systolic 122 mmHg [117-127], diastolic 80 mmHg [76-84]) and group 1 (mean 126 mmHg [124-128], 79 mmHg [78-80], 95% CI), and a significant increase in diastolic blood pressure could first be detected during the 3rd yr of persistent microalbuminuria (mean systolic 132 mmHg [124-140], diastolic 85 mmHg [81-89] vs. 128 mmHg [126-130], 79 mmHg [78-80], P less than 0.05). Initial hemoglobin A1c was significantly elevated in group 2 compared with group 1 (9.6% [8.8-10.4] vs. 8.5% [8.3-8.7], P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)