Prevalence of isolated systolic and isolated diastolic hypertension subtypes in China.

BACKGROUND: Isolated systolic hypertension (ISH), more so than any other hypertension subtype, increases the risk for stroke and coronary heart disease. The prevalence of ISH versus other hypertension subtypes in the general Chinese adult population is not known.

METHODS: The prevalence of isolated systolic and isolated diastolic hypertension (IDH) was examined in a representative national sample of 15,540 Chinese adults aged 35 to 74 years. Three seated blood pressure (BP) measurements taken after 5 min of rest were averaged and hypertension subtypes were defined among individuals not receiving antihypertensive therapy as follows: ISH as systolic BP >/=140 mm Hg and diastolic BP <90 mm Hg; IDH as systolic BP <140 mm Hg and diastolic BP >/=90 mm Hg; and combined systolic/diastolic hypertension (SDH) as a systolic BP >/=140 mm Hg and diastolic BP >/=90 mm Hg.

RESULTS: Overall, 7.6% of the Chinese adult population had ISH, 7.4% had SDH, and 4.4% had IDH. The prevalence of ISH increased with age and was more common in older women than in older men. Stage 1 hypertension was much more prevalent than stage 2 hypertension among all hypertension subtypes. The prevalence of SDH, IDH, and ISH (women, only) were higher in northern China than southern. The prevalence of ISH and SDH (women, only) were higher among rural residents versus urban residents.

CONCLUSIONS: These data document high rates of ISH in China. Given the risk of cardiovascular disease associated with ISH, our findings underscore the critical need for enhanced hypertension screening and treatment programs in China.