A cross-sectional survey of home blood pressure in a rural community in northern Japan

A cross-sectional survey was performed on home blood pressure recordings (home BP) in a rural community in northern Japan. In total, 1190 participants (495 men and 695 women which consist 61.5% of the greater than or equal to 15 year-old regional population, n = 1933) were asked to measure home BP every morning for a month, using a semiautomatic BP measuring device. The actual measurements were done 16.8 +/- 10.2 times (mean +/- SD) for men and 19.0 +/- 9.4 times for women. Home systolic (SBP) and diastolic BP (DBP) was elevated gradually with age in both sexes, although DBP tended to fall after reaching 70 years old in men. SBP and DBP thus measured were significantly lower than those of casual BP of ordinary Japanese people reported by the Ministry of Health and Welfare, Japan, by 11.4 +/- 4.3 mmHg SBP (mean +/- SD) and 5.9 +/- 1.6 mmHg DBP in men, and 12.7 +/- 5.1 mmHg SBP and 8.1 +/- 2.5 mmHg DBP in women. When WHO criteria were applied to the home BP, 2.8% of men and 0.6% of women were considered to be definitely hypertensive, and 7.9% of men and 6.4% of women as of borderline cases, indicating the underestimation of hypertensive population by means of home BP. Based on these data, we demonstrated the values equal to 1SD or 2SDs above the mean in each age group to tentatively determine biological normalcy. It is necessary to define the relationship between home BP and target organ disease or hypertensive complications. A long-term prospective study is also necessary to define the relationship between home BP and long-term morbidity or mortality.