Reproducibility of ambulatory blood pressure monitoring in hypertensive patients with type 2 diabetes mellitus

Abstract

Objective: To evaluate the reproducibility of ambulatory blood pressure monitoring (ABPM) (SpaceLabs-90207) and placebo effect on ABPM.

Methods: Blood pressure was measured in the office and over two ABPM periods with an interval from one to ten months (mean 4.9 months), in 26 patients with type 2 diabetes mellitus and hypertension. Eleven patients (G1) had two ABPMs without taking antihypertensive drugs for 15 days, whereas G2 (N=15) had the second ABPM after administration of a placebo for 15 days.

Results: In the evaluation of the coefficient of variation (CV) of diurnal (awake) systolic BP (DSBP), of diurnal (awake) diastolic BP (DDBP), of 24-hour systolic BP (24hSBP) and of 24-hour diastolic BP (24hDBP), the values found were 4.6%, 3.9%, 5.0%, 4.0% for G1 and 4.3%, 5.1%, 3.7%, 5.1% for G2 respectively. We also determined the CV of nocturnal (sleep) systolic and diastolic BP (NSBP and NDBP) for G1 (7.7%; 8.2%) and G2 (5.6%; 6.3%). Heart rate CV during alertness and sleep were: G1=5.9% and 9.0%; G2=6.9% and 5.8% respectively. When the total number of 'patients was analyzed, all variables showed a strong correlation between the first and second ABPM measurements (DSBP, r = 0.76; P < 0.001; DDBP, r = 0.65; p < 0.001; 24hSBP, r = 0.77; p < 0.001; 24hDBP, r = 0.70; p < 0.001; NSBP, r = 0.62; p < 0.001; NDBP, r = 0.52; p < 0.01). Office systolic and diastolic BP and 24hSBP and 24hDBP also showed correlation (r = 0.65; p < 0.001; r = 0.57; p < 0.01).

Conclusion: Mean of pressure levels measured by ABPM presented good reproducibility and were not affected by placebo.