Background: The new ACC/AHA hypertension guideline lower the definition of hypertension from 140/90 mmHg to 130/80 mmHg and eliminate the category of prehypertension thus increasing the prevalence of hypertension. A purpose of this study is to explore the applicability of the new guidelines in rural China.
Methods: In total, 3229 participants aged ≥35 years and free of stroke at baseline were followed for up to 4.8 years during 2012 to 2017 in a rural community-based prospective cohort study of Xifeng County. The hazard ratio (HR) and 95% Confidence interval (CI) of different blood pressure (BP) levels for risk of incident stroke were analyzed by multivariable Cox proportional hazard models.
Results: During the follow-up, 81 new strokes occurred among the 3229 participants. Compared with normal BP (Systolic BP (SBP)<120 mmHg and Diastolic BP (DBP)<80 mmHg), stage 2 hypertension (SBP ≥ 140 mmHg or DBP ≥ 90 mmHg) had approximately 2.1 greater risks for stroke (HR: 2.10, 95% CI: 1.13 to 3.91, P = 0.020). However, there was no significant association between elevated (SBP:120-129 mmHg and DBP<80 mmHg), stage1 hypertension (SBP:130-139 mmHg or DBP:80-89 mmHg) and stroke incidence (HR: 0.93, 95% CI: 0.33 to 2.61, P = 0.888; HR: 0.96, 95% CI: 0.46 to 2.02, P = 0.920, respectively). An increase of the SBP by 1-SD increases the risk for stroke by 56% (HR: 1.56, 95%CI: 1.29 to 1.88, P < 0.001). An increase of the SBP by 20 mmHg increases the risk for stroke by 51% (HR: 1.51, 95%CI: 1.27 to 1.80, P < 0.001).
Conclusions: Compared with normal BP, the stage 2 hypertension based on 2017 ACC/AHA guideline significantly increases the risk of stroke incidence, but this association was not observed between elevated, stage1 hypertension and stroke incidence in Chinese rural adults.
Keywords: Blood pressure; Incidence; Prospective study; Rural area; Stroke.