Clinical Benefit of Treatment of Stage-1, Low-Risk Hypertension: Korean National Health Insurance Database Analysis

Abstract

Evidence about the benefits of treating uncomplicated, low-risk, stage-1 hypertension is lacking. The study aimed to investigate the association between mean blood pressure (BP) and clinical outcomes, and to determine optimal BPs in treated, low-risk, stage-1 hypertension. From the National Health Insurance Service Health Examination Database, patients with stage-1 hypertension between 2005 and 2006 were selected. They had a systolic BP of 140 to 159 mmHg or diastolic BP of 90 to 99 mmHg. Patients were grouped as controlled (mean BP <140/90 mmHg; n=99301) and uncontrolled (mean BP 140/90 mmHg; n=49460) according to their mean BP recorded during the follow-up health examination. All-cause mortality and cardiovascular outcomes were examined. Mean BPs in the controlled and uncontrolled groups were 131.1/80.9 and 144.6/86.8 mmHg, respectively. Controlled BP was associated with significantly lower risks of all-cause mortality, all stroke, hemorrhagic stroke, ischemic stroke, and end-stage renal disease. Subgroup analysis demonstrated benefits of controlled BP in hypertensive patients aged <50 years for all-cause mortality, all stroke, hemorrhagic stroke, ischemic stroke, and end-stage renal disease, with no significant interaction according to age. The BP associated with the lowest risk of all-cause mortality was 120 to <130 mmHg (systolic BP) and 70 to <80 mmHg (diastolic BP). There was an increased risk of myocardial infarction in patients with mean systolic BP <120 mmHg and diastolic BP <80 mmHg. BP <140/90 mmHg was associated with a significant reduction in the risk of mortality, stroke, and end-stage renal disease, with the lowest mortality risk at BP ranges of 120 to <130 and 70 to <80 mmHg.