Improving the Detection of Hypertension and its Control - Blood pressure (BP) measured in the office is used to diagnose hypertension and guide BP management for adults taking antihypertensive medication. Guidelines recommend measuring BP outside of the office using ambulatory BP monitoring (ABPM) or home BP monitoring (HBPM) to confirm office BP, averaged across multiple visits. The evidence supporting this recommendation is weak since most prior studies compared BP on ABPM or HBPM against office BP measured at a single visit. Guidelines also recommend that ABPM be performed over a 24-hour period and HBPM be based on 2 measurements in the morning (AM) and 2 measurements in the evening (PM) for 7 days. Many guidelines endorse ABPM as the reference standard for out-of-office BP monitoring, but there are few data comparing ABPM to HBPM conducted for 7 days. We recently completed a study of 400 adults that compared BP measured during 3 office visits, on ABPM, and HBPM, each conducted following guideline-recommended approaches. The study found (1) BP on HBPM was associated with left ventricular mass index (LVMI), a marker of target end-organ damage, independent of office BP and BP on ABPM, (2) office BP and BP on ABPM were not associated with LVMI, independent of BP on HBPM, (3) HBPM was more reliable (i.e. reproducible) than ABPM and office BP, and (4) office BP was more reliable than ABPM. These results suggest a new paradigm that HBPM is superior to ABPM and office BP, and ABPM is not needed when office BP and HBPM are both performed. However, no one in this study was taking antihypertensive medication, few older adults were enrolled, and a minority had high office BP. These findings need to be tested in a larger study with broader generalizability. We propose to enroll 1,696 adults in New York, NY, Birmingham, AL, and Los Angeles, CA with screening systolic/diastolic BP <160/100 mm Hg; 50% of whom will be taking antihypertensive medication. The sample will be diverse based on age (33% in each age group: 18-39, 40-59, and ≥60 years), sex (50% women), race/ethnicity (≥25% non-Hispanic white, ≥25% non-Hispanic Black, ≥25% Hispanic, and ≥10% Asian), and office BP level (50% with office BP ≥130/80 mm Hg). Office BP will be measured at 3 visits. ABPM will be performed over two 24-hour periods and HBPM will be performed with 2 AM and 2 PM measurements per day over two 7-day periods. Two markers of target end-organ damage – LVMI on echocardiogram and albumin-to-creatinine ratio – will be assessed. We will determine whether BP on HBPM is more strongly associated with target end-organ damage than office BP and awake BP on ABPM (Primary Aim 1). We will determine if HBPM is more reliable than office BP and awake BP on ABPM (Primary Aim 2). We will also determine whether the findings are consistent using asleep BP and 24-hour BP instead of awake BP, and investigate potential differences among age, sex, and race/ethnicity subgroups (Secondary Aims). The study will determine the best approach to measure BP for diagnosing and managing hypertension, which has the potential to improve the health of millions of US adults.
