Uncontrolled Blood Pressure in Hypertensive Patients with High Medication Adherence: A Korean Nationwide Population-Based Study

BACKGROUND: Uncontrolled blood pressure (BP) is relatively common despite treatment with antihypertensive medication. This study aimed to investigate factors associated with uncontrolled systolic BP (SBP) and diastolic BP (DBP) separately in hypertensive patients with high medication adherence in Korea. METHODS: This population-based cross-sectional study included 3,236 participants in the Korea National Health and Nutrition Examination Survey from 2013 to 2015. Hypertensive patients with high medication adherence were defined when they stated that they were taking antihypertensive medication daily. “Uncontrolled SBP and DBP” were defined as SBP ≥140 mm Hg and DBP ≥90 mm Hg, respectively. Data were analyzed using logistic regression to determine the association between uncontrolled SBP or DBP and various factors. RESULTS: The prevalence of uncontrolled SBP and uncontrolled DBP was 23.3%, and 9.0%, respectively. In multivariate analysis, uncontrolled SBP was positively associated with older age, female sex, blue-collar occupation or no work (vs. white-collar), presence of a spouse, short sleep duration, frequent heavy alcohol drinking, longer hypertension duration, diabetes, stroke, and missing antihypertensive medication on the examination day, but negatively associated with high stress. Uncontrolled DBP was positively associated with frequent heavy alcohol drinking, but negatively associated with older age, blue-collar occupation or no work (vs. white-collar), and diabetes. CONCLUSION: After excluding low medication adherence, we identified various factors associated with uncontrolled SBP or DBP in Korean adults with treated hypertension. There were differences between factors associated with uncontrolled SBP or DBP. Separate analysis of SBP and DBP may help understand the factors involved in BP control.