Subtypes of Hypertension and Risk of Stroke in Rural Chinese Adults

Abstract

Hypertension is a definitive risk factor for stroke. We examined the associations between hypertension subtypes and stroke incidence in rural Chinese adults. We conducted a prospective study in a sample of 38,949 rural Chinese adults aged ≥35 years and free from stroke at baseline. The subtypes of hypertension were defined as isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), systolic and diastolic hypertension (SDH), and managed hypertension (MHT). The relative risks of stroke with the subtypes of hypertension, compared with normotensive subjects, were estimated using the Cox model after adjusting for age, sex, and other confounders. The prevalence of hypertension was as follows: SDH = 18.6%, ISH = 10.2%, IDH = 5.8%, and MHT = 0.4%. During a total of 168,023 person-years of follow-up, 858 subjects developed stroke. The incidence rate per 100,000 person-years of overall first-ever stroke was 510.6. The SDH group was at the highest risk of stroke among all the hypertensive subjects. The hazard ratio was 2.13 (95% confidence interval (CI) = 1.78-2.55) for all stroke, 2.74 (95% CI = 2.08-3.60) for hemorrhagic stroke, and 1.92 (95% CI = 1.50-2.45) for ischemic stroke. SDH patients warrant the most attention for prevent of stroke. However, ISH and IDH are also independent predictors of stroke. The risk factors for stroke, especially hypertension, were not controlled in the rural population we studied. More aggressive efforts to control the risk factors for stroke in rural areas are needed.