Prevalence of isolated diastolic hypertension and the risk of cardiovascular mortality among adults aged 40 years and older in northeast China: a prospective cohort study

OBJECTIVES: Little is known about the prevalence and impact of isolated diastolic hypertension (IDH) in northeast China. We aimed to investigate the current epidemiology of IDH and to illustrate whether IDH accounted for cardiovascular disease (CVD) mortality. DESIGN: A prospective cohort study. SETTING: A population-based study carried out in northeast China. PARTICIPANTS: We built a community-based study of 18 796 residents aged ≥40 years who were living in northeast China with blood pressure measurements between September 2017 and March 2019. OUTCOME MEASURES: Information on CVD death was obtained from baseline until 31 July 2021. IDH was defined as a diastolic blood pressure ≥90 mm Hg together with systolic blood pressure <140 mm Hg among hypertensive population. RESULTS: The overall prevalence of IDH was 3.9%, which decreased significantly with advancing age (p<0.001) and ranged from 7.2% (95% CI: 6.3% to 8.2%) among participants 40-49 years to 1.5% (95% CI: 1.1% to 2.0%) among participants ≥70 years. Moreover, the IDH prevalence was higher in men than in women (5.2% vs 3.1%, p<0.001). The awareness and treatment rates of IDH were 25.7% and 17.7%, respectively, which were significantly lower than those of patients with non-IDH (50.1% and 21.7%, p=0.009, respectively). During a median follow-up of 3.2 years, 314 subjects died due to CVD (rate 4.84/1000 person-years). IDH and non-IDH were both significantly associated with an increased risk of CVD death (HR: 2.55, 95% CI: 1.35 to 4.82; HR: 2.48, 95% CI: 1.81 to 3.38) when compared with participants with non-hypertension. CONCLUSIONS: IDH was mainly prevalent among young and middle-aged populations, and the awareness and treatment rates in IDH were lower than those in non-IDH hypertension. Additionally, IDH and non-IDH were significantly related to an increased risk of CVD mortality. Early management of IDH is urgently required in northeast China.