Hypertension subtypes and risk of cardiovascular diseases in a Mongolian population, inner Mongolia, China

Background: There have been no reports about the effects of hypertension subtypes on the future cardiovascular events among Mongolian people, China. Methods and results: From June 2003 to July 2012, we conducted a prospective study to assess the association of hypertension subtypes with future risk of cardiovascular events including stroke and coronary heart disease among a Mongolian cohort of 2589 adults in China. According to the baseline blood pressure levels, the subjects were divided into those with normal blood pressure, prehypertension, isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), and combined systolic and diastolic hypertension (SDH). Cox proportional hazards models were used to evaluate the association between blood pressure subtypes and risk of cardiovascular diseases. After adjustment for age and gender, hazard ratios (95% confidence intervals) of cardiovascular diseases were 1.75(0.92–3.33), 2.11(0.95–4.70), 2.14(1.01–4.56) and 5.31(2.86–9.77) for pre-hypertension, ISH, IDH and SDH, respectively, compared with normal blood pressure. Furthermore, after adding other cardiovascular risk factors to adjustment, hazard ratios(95% confidence intervals) of cardiovascular diseases were 1.74(0.92–3.31), 2.00(0.88–4.54), 2.20(1.02–4.74) and 4.92(2.62–9.26) for pre-hypertension, ISH, IDH and SDH, respectively, compared with the normal blood pressure group. Conclusions: IDH and SDH were significantly associated with the increased risk of cardiovascular diseases; this study suggests that carefully monitoring and actively treating the subjects with IDH should be an important strategy for CVD prevention among Mongolian population.