Optimal office blood pressure levels in younger (<50 years old) Korean hypertensive patients: a nationwide cohort study in South Korea

BACKGROUND: It is unclear what thresholds and targets of office blood pressure (BP) for treatment are appropriate in younger (<50 years old) hypertensive patients. Thus, the aim of this study was to evaluate associations of office BP levels with major cardiovascular events (MACEs) in these patients. METHODS: Using the Korean National Health Insurance Service database, data of 98 192 younger (<50 years old) hypertensive patients having BP measurements available without any history of cardiovascular events from 2002 to 2011 were extracted. This cohort study evaluated associations of BP levels (<120/<70, 120-129/70-79, 130-139/80-89, 140-149/90-99, and ≥150/≥100 mmHg) with MACEs. The study outcome was MACE, a composite of cardiovascular death, myocardial infarction, stroke, and heart failure. RESULTS: In all patients, those treated with antihypertensive medication accounted for 34.7% and those who achieved BP less than 130/80 mmHg accounted for 35.5%. During a mean follow-up of 9.5 ± 2.8 years, 4918 (5%) MACEs were documented in our cohort. The risk of MACE was the lowest [adjusted hazard ratio: 0.77, 95% confidence interval (CI) 0.66-0.89] for those with BP level of less than 120/less than 70 mmHg. It was the highest (hazard ratio 2.0, 95% CI 1.83-2.19) for those with BP level of at least 150/at least 100 mmHg in comparison with those with BP level of 130-139/80-89 mmHg. These results were consistent for all age groups (20-29, 30-39, and 40-49 years) and both sexes. CONCLUSION: Elevated BP level from less than 120 mmHg/less than 70 mmHg is significantly correlated with an increased risk of MACE in younger (<50 years old) Korean hypertensive patients. Lowering BP to less than 120 mmHg/less than 70 mmHg is needed for these patients.