THE ROLE OF DISEASE DURATION AND HYPERTENSION IN ALBUMIN EXCRETION OF TYPE-I DIABETES-MELLITUS

The objective of this study was to examine the relationship between blood pressure, albumin excretion, and renal function in patients with type I diabetes mellitus. The study design was as follows: nonselected consecutive patients with type I diabetes mellitus were divided into three groups by level of albumin excretion rate (AER): < 20-mu-g/min, 20 to 200-mu-g/min, and > 200-mu-g/min. The setting for the study was an outpatient diabetic clinic in a tertiary referral center. There were 166 patients studied: 53% men, 47% women, 86% white, 17% treated for hypertension. Seventy-six percent had an AER < 20-mu-g/min, 18% had an AER of 20 to 200-mu-g/min, and 6% had an AER of > 200-mu-g/min. Glycosylated hemoglobin did not differ between groups. AER was increased with age and disease duration (P < 0.005 by analysis of variance) after 10 yr of disease. Serum creatinine (P < 0.005) and systolic (P < 0.005) and diastolic (P < 0.01) blood pressures were also increased with AER. Serum creatinine and blood pressure were found to be increased in parallel after 10 yr of disease, but both remained within the normal range overall. A comparison of individual blood pressures in patients not taking antihypertensive drugs (N = 138) with age-related blood pressures of nondiabetic subjects revealed increased systolic and diastolic blood pressures at all ages. Group comparison demonstrated a significant link between increased AER and serum creatinine (declining renal function) and increased blood pressure after a latent period of 10 yr. Blood pressure appears to be increased from the earliest age in diabetes compared with healthy populations. Precession of either blood pressure or renal dysfunction could not be established in these cross-sectional comparisons. We suggest that "incipient hypertension" and evidence of incipient nephropathy are concurrent manifestations of a common vascular disease.