Epidemiology of hypertension in Japan: beyond the new 2019 Japanese guidelines

Abstract

From the national surveys of Japan over a 55-year period (1961-2016), a steady decrease was observed in systolic blood pressure (BP) levels among all age groups of men and women, but not in diastolic BP levels-particularly among men. Hypertension prevalence remains high: over 60% of men aged ≥50 years and women aged ≥60 years had hypertension in 2016. However, the control rates of hypertension have continuously improved over a 36-year period, and were ~40% in 2016. Nonetheless, the over 50% prevalence of uncontrolled hypertension is a major risk factor for future cardiovascular diseases. Of the estimated 43 million hypertensives in Japan, most (31 million, 72%) were under poor control. According to new Japanese hypertension guidelines (JSH 2019), there will be only a small increase (2.2 million, 2.1 percentage points) in adults who are recommended for antihypertensive medication compared with 2014 guidelines. However, an additional 5.3 million (22.1 percentage points) adults taking antihypertensive medication would have a BP above the target defined by JSH 2019. The number of hypertensives with poor control was targeted to decrease by 7 million-from 31 million in 2017 to 24 million in 2028-when the followings are achieved: (1) the prevalence of hypertension decreases by 5 percentage points; (2) the treatment rate of hypertension among hypertensives increases by 10 percentage points; and (3) the control rate of hypertension, defined as BP <140/90 mmHg, among individuals taking antihypertensive medication increases by 10 percentage points. Both high-risk and population strategies to manage and prevent hypertension deserve greater priority.

Keywords: Blood pressure; Epidemiology; Hypertension; Japan; Prevalence.