Differences between home blood pressure and strictly measured office blood pressure and their determinants in Japanese men

Conventional office blood pressure (OBP) and home blood pressure (HBP) measurements are often inconsistent. The purpose of this research was (1) to test whether strictly measured OBP values with sufficient rest time before measurement (st-OBP) is comparable to HBP at the population level and (2) to ascertain whether there are particular determinants for the difference between HBP and st-OBP at the individual level. Data from a population-based group of 1056 men aged 40-79 years were analyzed. After a five-min rest, st-OBP was measured twice. HBP was measured after a 2-min rest every morning for seven consecutive days. To determine factors related to Delta SBP (HBP minus st-OBP measurements), multiple linear regression analyses and analyses of covariance were performed. While st-OBP and HBP were comparable (136.5 vs. 137.2 mmHg) at the population level, Delta SBP varied with a standard deviation of 13.5 mmHg. Smoking was associated with a larger Delta SBP regardless of antihypertensive usage, and BMI was associated with a larger Delta SBP in participants using antihypertensive drugs. The adjusted mean Delta SBP in the highest BMI tertile category was 4.6 mmHg in participants taking antihypertensive drugs. st-OBP and HBP measurements were comparable at the population level, although the distribution of Delta SBP was considerably broad. Smokers and obese men taking antihypertensive drugs had higher HBP than st-OBP, indicating that their blood pressure levels are at risk of being underestimated. Therefore, this group would benefit from the addition of HBP measurements.