Short term blood pressure variability and target organ damage-an observational study of ambulatory blood pressure monitoring in a clinic setting in South India

Abstract High blood pressure (BP) is an important risk factor for Cardiovascular diseases. The association of short term BP Variability (BPV) with target organ damage(TOD) is not clearly established. We conducted this observational study to evaluate the degree of concordance between Office Blood Pressure monitoring(OBPM) and Ambulatory Blood Pressure Monitoring (ABPM) and to study the effect of short term BPV on TOD. Patients attending clinics of the authors between January 2018 and August 2019 were enrolled. Their BP status was determined by OBPM and ABPM and the degree of concordance analysed. ABPM parameters between those with TOD and without TOD were compared using appropriate statistical measures. Data from 968 subjects (males 61.5%,mean age 59.39 ± 14.86 years) were analysed. Masked hypertension and white coat hypertension were seen in 138 (14.3%) and 50 participants (5.2%) respectively. There was moderate Concordance between ABPM and OBPM readings (Cohen’s kappa =0.692). There were 530(54.8%) non dippers and 189 (19.5%) reverse dippers. High morning surge (MS) was seen in 193(19.9%) and TOD in 225 (23.2%). Percent time elevation (PTE) of systolic BP (P=0.004,OR 1.009,95%CI 1.003,1.016) and diastolic BP in active period (p=0.034,OR 1.009,CI 1.001,1.017) and PTE of diastolic BP in passive period(p=0.006,OR 1.011,95%CI 1.003,1.018) ,as assessed by ABPM were significantly associated with TOD.Dipping status ,diurnal index and MS were not associated with TOD. ABPM is a useful tool for diagnosis and accurate categorisation of hypertension. Analysis of ABPM parameters helps to identify the patients with significant BP load who are at risk of developing TOD.