PREVALENCE OF HYPERTENSION AND RATE OF BLOOD-PRESSURE CONTROL AS ASSESSED BY HOME BLOOD-PRESSURE MEASUREMENTS IN A RURAL JAPANESE COMMUNITY, OHASAMA

A cross-sectional community survey using home blood pressure measureme nts in northern Japan to estimate the prevalence of definite hypertens ion, white coat hypertension and the success of blood pressure control in patients receiving antihypertensive drugs. A total of 1334 subject s (mean age+/-SD, 53.8+/-17.3 years 8-91 years) participated in the sc reening and home blood pressure measurement program. They measured blo od pressure at home at least 3 times (mean measurement frequency, 20.8 +/-8.3 times). Of these 1334 subjects, 314 (65.1+/-8.9 years) were tak ing drugs (treated group) while 1020 (50.3+/-17.8 years) were not(untr eated group). The WHO criteria were used to categorize screening blood pressure. Criteria for diagnosis of hypertension by home blood pressu re measurements were as follows: definitely hypertensive (systolic blo od pressure greater than or equal to 144 mmHg and/or diastolic blood p ressure greater than or equal to 89 mmHg) and normotensive (104<systol ic blood pressure less than or equal to 131 mmHg and 60<diastolic bloo d pressure less than or equal to 79 mmHg). Of the 1018 subjects identi fied as normotensive on screening measurements, home measurements indi cated that 73 (7.2 %) were hypertensive and 765 (74.7 %) were normoten sive or lower. Of the 112 subjects identified as hypertensive on scree ning measurements, home measurements showed that 42 (37.5 %) were hype rtensive and 30 (26.8 %) were normotensive or lower. Of the 314 treate d subjects, 45 (14.3 %) were identified as hypertensive by screening m easurements and 88 (28.0 %) as hypertensive by home measurements; Only 20 (44.4 %) of the former 45 subjects were also defined as definitely hypertensive by home measurements. Of the 1020 untreated subjects, 67 (6.6 %) were hypertensive by screening measurements and 84 (8.2 %) by home measurements. Only 22 (32.8 %) of the former 67 subjects were cl assified as hypertensive by home measurements. Of the 67 untreated sub jects identified as hypertensive by screening measurements, 20 (29.9%) were normotensive or lower by home measurements, suggesting that thes e subjects were ''white coat'' hypertensives. The study fil st confirm ed based on the large community data that there are large discrepancie s between screening(casual) blood pressure and home blood pressure mea surements for recognition of hypertension and normotension. Determinat ion of blood pressure levels by home blood pressure measurements may p redict prognosis of hypertension differently from that by screening bl ood pressure measurements. Further prospective study is needed to vali date the prognostic value of home blood pressure measurements.