DIFFERENTIAL DETERMINANTS OF AMBULATORY VS. HOME MORNING BLOOD PRESSURE MEASURED BY A SINGLE MULTISENSOR BLOOD PRESSURE MONITORING DEVICE: THE HI-JAMP STUDY BASELINE DATA

Abstract

Objective: Out-of-office blood pressure (BP) monitoring using ambulatory BP (ABP) monitoring (ABPM) and home BP (HBP) monitoring (HBPM) is recommended for hypertension management. However, BP level measured by ABPM and HBPM may not be consistent even when evaluated the same time-window, morning. This study investigated the determinants of the difference between ABP and HBP in the morning time measured by a multisensor BP monitoring device equipped with a high-sensitivity actigraph and a thermometer. Design and method: Medicated hypertension patients enrolled in the Home-Activity ICT-based Japan Ambulatory Blood Pressure Monitoring Prospective (HI-JAMP) Study consecutively underwent office BP monitoring, 24-h ABPM (with 30-min intervals), and 5-day HBPM (twice each morning and evening) using the same multisensor BP monitoring device (TM-2441; A&D Company, Tokyo). Morning ABP (average of 4 readings within 2-h after waking) and morning HBP (average of HBP readings measured in the morning over a HBPM period) were compared. In addition, this device recorded the wearer's fine-scale physical movement during a 24-h ABPM period and stored temperature data at the time of each BP measurement. Hourly averages of physical activity and temperatures at the time of HBPM (i.e., room temperature) were used for the analysis. Results: Among 2322 patients (males 53.2%, 69.2±11.5 years, average office systolic BP [SBP] 132.8±18.8 mmHg), morning home SBP was 2.4 mmHg higher than morning ambulatory SBP with standard deviation of 15.9 mmHg (ABP < HBP). In a multivariable analysis including conventional risk factors, older age and larger number of antihypertensive agents were significantly associated with [HBP > ABP], while history of cardiovascular disease (CVD) was significantly associated with [ABP > HBP]. In the analysis additionally including physical activity in the morning and room temperature at the morning HBP measurement, higher activity level was significantly contributed to [ABP > HBP] and lower room temperature was significantly contributed to [HBP > ABP]. Conclusions: In treated hypertensive patients, HBPM is recommended especially if the patient is older, taking multiple antihypertensive agents, or living in an environment with lower room temperatures in the winter, while ABPM is recommended if the patient has a history of CVD.