Variations of ambulatory blood pressure with position in patients with type 1 diabetes - Influence of disease duration and microangiopathy in a pilotstudy

OBJECTIVE - To study the influence of position changes on 24-h ambulatory b lood pressure (ABP) in normotensive or mildly hypertensive normoalbuminuric patients with type I diabetes. RESEARCH DESIGN AND METHODS - A cross-sectional evaluation of patients was staged according to the duration of diabetes (DD) and the presence of micro angiopathy. We recruited 37 patients (30 men and 7 women), aged 38 12 years , who were non-notensive or mildly hypertensive (diastolic blood pressure [ DBP] < 105 mmHg) and free of antihypertensive treatment and microalbuminuri a, They were included according to DD (group 1, <5 years group 2, greater t han or equal to 10 years). An additional group of seven diabetic patients w ith microalbuminuria and mild untreated hypertension was also investigated. We recorded 24-h ambulatory blood pressure every 15 min with a position se nsor, which allowed for the discrimination between standing or supine/sitti ng position in the patient. RESULTS - Mean daytime (10:00 A.M. to 8:00 P.M.) ABP in supine/sitting posi tion did not significantly differ between groups 1 and 2. However, standing ambulatory systolic blood pressure (ASBP) and ambulatory DBP (ADBP) were s ignificantly higher than supine/sitting ASBP and group 1 (Delta SBP 4 +/- 5 , Delta DPB 4 +/- 6 mmHg, P < 0.01) but not in group 2 (Delta SBP 2 +/- 8, Delta DBP 2 +/- 4 mmHg, P = NS), Patients free of microangiopathy presented with significantly higher ABP in standing position than in sitting/lying p osition, whereas patients with retinopathy and/or nephropathy exhibited no significant increase of ABP during standing. CONCLUSION - The monitoring of position during ambulatory measurement of bl ood pressure in type I diabeuc patients shows different pattern-- in relati on to disease duration and the presence of microangiopathy.