THE MORNING BLOOD PRESSURE SURGE IN PATIENTS WITH HYPERTENSION

Abstract

Objective: The aim of study was to definite validity and reliability of the new morning blood pressure surge (MBPS) assessment method in patients with arterial hypertension (AH).Design and method: We assessed 150 ambulatory blood pressure monitoring (ABPM) data of AH patients. ABPM monitor (Spacelabs 90207) was applied after the washout period. The new method determined the MBPS value as the difference between the mean BP during the period from 6 to 8 hours (for this period we determined the maximum rate of BP rise) and the minimum night BP (MBPS6_8/BPnigh_min). Test-re-test reliability (reproducibility) of the new method was determined as the correlation between the measurements of the first and second ABPM sessions carried out during the week (only for MBPS6_8/BPnigh_min indices). Construct validity of the new method was defined as the correlation between the MBPS6_8/BPnigh_min coefficient and left ventricular mass index (LVMI) (only for 98 patients). LVMI was measured using echocardiography (L. Teichholtz et all.). Results: The mean daytime BP was (M ± SD): systolic (SBP) – 141,1 ± 13,9; diastolic (DBP) – 90,1 ± 10,3 mm Hg. We found that the new method of MBPS assessment had a high degree of reliability: coefficient correlation (r) between parameters of the two ABPM sessions were (for MBPS6_8/BPnigh_min): for DBP r = 0,70, for SBP r = 0,83 (table 1). The validity of the new method was high: the MBPS value obtained using new method (MBPS6_8/BPnigh_min) correlated with LVMI (an objective factor of validation) (table 2). Conclusions: We found that the new method of the morning blood pressure surge assessment had a high level of validity and reproducibility (test-re-test reliability). The high reliability of the new method is probably due to the exclusion of subjective factors (patient's diary) in the evaluation of the MBPS value. The reference mean morning BP was determined for a fixed time period, and not by the patient's diary.