AMBULATORY BLOOD-PRESSURE IN THE TRANSITION FROM NORMOALBUMINURIA TO MICROALBUMINURIA - A LONGITUDINAL-STUDY IN IDDM PATIENTS

To describe the development in blood pressure (BP) in relation to urinary albumin excretion (UAE) more exactly, 44 initially normoalbuminuric type I diabetic patients and 21 healthy individuals were included in a 3.1-year follow-up study by using ambulatory BP (AMBP) monitoring. Six patients developed microalbuminuria according to accepted criteria (progressors; UAE at follow-up was >20 mu g/min). Initial UAE was higher in this group (9.0 x/divided by 1.4 mu g/min) compared with both the nonprogressors (5.2 x/divided by 1.6 mu g/min) and the control subjects (3.9 x/divided by 1.6 mu g/min), P < 0.01. The values were almost identical for initial 24-h AMBP between the progressors and the two other groups. The transition to microalbuminuria (31.7 x/divided by 1.8 mu g/min) was associated with an increase in 24-h systolic AMBP of 11.5 +/- 8.3 mmHg, which was significantly higher than the increase in the nonprogressors (3.1 +/- 7.7 mmHg) and the control subjects (2.2 +/- 6.1 mmHg, P = 0.02). Significant correlations were detected between development in UAE and development in systolic and diastolic 24-h AMBP (r = 0.39, r = 0.41, P < 0.01). In addition, an increase in UAE, even including increases within the normoalbuminuric range, was always associated with an increase in 24-h AMBP (P < 0.01). Ordinary clinical measurements did not reveal any of these differences or correlations. In conclusion, a close association between increases in UAE and 24-h AMBP emerges in this study. Initial BP was not increased in the progressors. The transition from normoalbuminuria to even modest microalbuminuria is associated with significant BP increases but only when AMBP monitoring is analyzed,