Prevalence, awareness, treatment, and control of hypertension in Japanese rural communities]

BACKGROUND: In Japan, a national survey indicated that only 7% of hypertensive patients had a blood pressure less than 140/90 mmHg. There have been no reports of studies investigating all of the prevalence of hypertension, the percentage of subjects who are aware of hypertension, the percentage being treated, and the percentage that are well-controlled (awareness, treatment and control, respectively) among hypertensives in the Japanese general population. OBJECTIVE: To investigate the prevalence of hypertension, and awareness, treatment and control of hypertension among hypertensives in a Japanese rural population. DESIGN: A cross-sectional analysis of base-line data of the Jichi Medical School Cohort Study. SETTING: Twelve rural communities is 8 prefectures in Japan. PARTICIPANTS: Community-dwelling people who participated in the health examination program in 1992-1995. MAIN OUTCOME MEASURES: Blood pressure (BP) measured once in the sitting position after a 5-minute rest using oscillometric automatic BP monitors (BP203RV-II; Nippon Colin, Japan), and history of hypertension assessed using a self-administered questionnaire. RESULTS: We analyzed data from 11,302 subjects (4,415 men and 6,887 women). The mean (standard deviation) age was 55(12) years for men and 55(11) years for women. Mean systolic BP and diastolic BP levels were, respectively, 131(21) mmHg and 79(12) mmHg for men and 128(21) mmHg and 76(12) mmHg for women. Prevalence of hypertension (systolic BP > or = 140 mmHg or diastolic BP > or = 90 mmHg or on antihypertensive medication) was 37% for men and 33% for women. Percentages for awareness (on medication or present past history), treatment and control (both systolic BP < 140 mmHg and diastolic BP < 90 mmHg) were, respectively, 39%, 27% and 10% for men and 46%, 38% and 13% for women. CONCLUSIONS: About one third of the study popUlation were hypertensive, and awareness, treatment and control of hypertension among the hypertensives were 43%, 34% and 12%, respectively. Less than half of the hypertensives were well-controlled even when measurement bias was considered. In the rural Japanese population, improvements are required with regard to awareness, treatment and control of hypertension.