Cardiovascular Risk of Isolated Systolic or Diastolic Hypertension in Young Adults

Background: Little is known regarding health outcomes associated with isolated systolic hypertension (ISH), isolated diastolic hypertension (IDH), or systolic and diastolic hypertension (SDH) among young adults with stage 1 hypertension, defined using the 2017 American College of Cardiology/American Heart Association blood pressure (BP) guideline. Methods: From a nationwide health screening database, we included 6 424 090 participants, aged 20 to 39 years, who were not taking antihypertensive medication at the baseline examination in 2003 to 2007. Participants were categorized as having normal BP (untreated systolic BP [SBP] <120/diastolic BP [DBP] <80 mm Hg; n=2 665 310); elevated BP (SBP 120-129/DBP <80 mm Hg; n=705 344); stage 1 IDH (SBP <130/DBP 80-89 mm Hg; n=1 271 505); stage 1 ISH (SBP 130-139/DBP <80 mm Hg; n=255 588); stage 1 SDH (SBP 130-139/DBP 80-89 mm Hg; n=711 503); and stage 2 hypertension (SBP >= 140, DBP >= 90 mm Hg; n=814 840). The primary outcome was composite cardiovascular disease (CVD) events, including myocardial infarction, stroke, heart failure, and CVD-related death. Results: The median age of the participants was 30 years and 60.9% were male. Over a median follow-up of 13.2 years, 44 070 new CVD events occurred. With normal BP as the reference, multivariable-adjusted hazard ratios (95% CIs) for CVD events were 1.14 (1.09-1.18) for elevated BP, 1.32 (1.28-1.36) for stage 1 IDH, 1.36 (1.29-1.43) for stage 1 ISH, 1.67 (1.61-1.72) for stage 1 SDH, and 2.40 (2.33-2.47) for stage 2 hypertension. Conclusions: Among young adults, stage 1 ISH, IDH, and SDH were all associated with higher CVD risks than normal BP. The CVD risks of stage 1 ISH and IDH were similar to each other but lower than the risk of stage 1 SDH. Categorizing young adults with stage 1 hypertension further into stage 1 ISH, IDH, and SDH may improve risk stratification for identifying high-risk individuals.