Objective: To assess the influence of basic clinical data on ambulatory blood pressure (AMBP) in insulin-dependent diabetes mellitus (IDDM) patients and to evaluate the reproducibility of the method.
Research design and methods: AMBP was measured in 66 IDDM patients with urinary albumin excretion (UAE) < 20 micrograms/min and in 53 healthy subjects. Determinants of AMBP were identified in a stepwise multiple regression model. In addition, 14 diabetic patients were monitored on two days of the same type, and 14 patients were monitored on one work day and one day off.
Results: In healthy subjects, sex was the most important determinant of 24-h blood pressure (BP), whereas UAE and age were the main covariates in diabetes patients. The male-female difference in 24-h diastolic BP (dBP) was 5.6 mmHg lower in diabetic patients than in healthy control subjects (P < 0.05). In patients with long diabetes duration, nighttime dBP (69 +/- 7 mmHg) was higher than in patients with medium diabetes duration (63 +/- 8 mmHg, P < 0.05; after matching for age and sex). Daytime dBP was 5 mmHg higher on a work day than on a day off (P < 0.02). Standard deviation of the difference for repeated measurement of 24-h systolic/diastolic BP in the same subject was 5.7/2.5 mmHg.
Conclusions: The male-female difference in 24-h dBP was attenuated in diabetes. The influence of UAE on AMBP was noticed even in normoalbuminuric diabetic patients. Standardized AMBP was highly reproducible.