Prevalence, awareness, treatment, control and risk factors of hypertension in Korea: the Ansan study

OBJECTIVES To determine prevalence, awareness, treatment, and control of hypertension, and its risk factors in an urban Korean population. DESIGN AND SETTING A cross-sectional survey in Ansan-city, Korea. SUBJECTS AND METHODS Population-based samples of people aged 18-92 years in Ansan-city, Korea, were selected, yielding 2278 men and 1948 women, and their blood pressures were measured using a highly standardized protocol. Hypertension was defined as a systolic BP > or = 140 mmHg or diastolic BP > or = 90 mmHg or reported treatment with antihypertensive medications, and subclassified according to 1999 WHO-ISH guidelines. Isolated systolic hypertension (ISH) defined as a systolic BP > or = 140 mmHg and diastolic BP < 90 mmHg was also examined. Data were stratified by age and sex. RESULTS The overall prevalence of hypertension in this study was 33.7%. Among these, 64.9% had Grade 1 hypertension, 22.5% Grade 2, and 12.5% Grade 3. Age-specific prevalence of hypertension increased progressively with age, from 14.19% in 18 to 24 year-olds to 71.39% in those 75 years or older. Hypertension prevalence was significantly higher in men (41.5%) than in women (24.5%) (P < 0.001). Isolated systolic hypertension had significantly lower prevalence (4.33%) within the population, although in the elderly aged 55 years or more it rose by 11.13%. Overall, 24.6% of hypertensive individuals were aware that they had high blood pressure, as much as 78.6% were being treated with antihypertensive medications, and 24.3% were under control. Hypertension awareness as well as treatment and control rates varied by sex, with women higher in all three rates. Multivariate analysis revealed that age, body mass index and abdomen circumference were significantly associated with prevalence of hypertension both in men and women. CONCLUSIONS Hypertension is highly prevalent in Korea. Despite the high rate of treatment, the rates of awareness and control are relatively low, suggesting the nationwide demand for preventing and controlling high blood pressure in Korea in order to avert an epidemic of cardiovascular disease.