Several forms of hypertension are associated with a higher risk of cardiovascular disease events, even in young adults, according to a study published in Circulation.
Categorizing young adults with hypertension into sub-types may improve risk stratification for identifying and treating high-risk individuals, according to Donald Lloyd-Jones, MD, the Eileen M. Foell Professor, chair of Preventive Medicine and a co-author of the study.
“Clinicians have typically not treated younger patients with hypertension as intensively as older patients, but these results suggest that greater attention should be paid to all forms of hypertension in young adults,” said Lloyd-Jones, who is also a professor of Pediatrics and of Medicine in the Division of Cardiology.
Blood pressure is evaluated using two measurements: systolic blood pressure (the numerator) and diastolic blood pressure (the denominator).
Systolic blood pressure measures the force of blood against artery walls while the left ventricle — the main pumping chamber of the heart — contracts, pushing blood out to the rest of the body. Diastolic blood pressure measures the baseline pressure inside the arteries as the heart relaxes.
Isolated systolic hypertension occurs when systolic blood pressure is in the hypertensive range, but diastolic blood pressure is normal. Conversely, isolated diastolic blood pressure is hypertensive diastolic blood with normal systolic blood pressure.
Isolated systolic hypertension is highly prevalent in older adults but less prevalent in young adults, though incidence has been increasing during the last decade in part due to rising rates of obesity, according to the authors.
Little has been known about the difference in cardiovascular outcomes between young adults with different types of hypertension, so the investigators set out to measure differential cardiovascular disease risk.
Using health screening data from the Korean National Health Insurance database, the authors identified nearly 6.5 million adults aged 20 to 39 who underwent a health checkup between 2003 and 2007. People with a history of heart attack or stroke were excluded.
Hypertension was measured at a baseline checkup and stratified into ascending classifications: normal, elevated blood pressure, stage one and two hypertension — both stages including isolated systolic and diastolic subtypes. Cardiovascular disease events included hospitalizations for heart attack, stroke or heart failure through 2017.
Cumulative incidence of cardiovascular disease events was highest in young adults with stage two hypertension (both systolic and diastolic hypertension), followed by people with stage two isolated systolic hypertension and then stage two isolated diastolic hypertension, respectively. The pattern held for people with stage one hypertension: incidence of cardiovascular disease events in people with isolated systolic hypertension was slightly higher than those with isolated diastolic hypertension.
Overall, even stage one hypertension — whether with isolated systolic or diastolic — was associated with significantly higher risk for cardiovascular disease events and mortality in comparison to those with normal blood pressure. While the underlying mechanisms for isolated systolic versus diastolic blood pressure may differ, both conditions signal a need for drug intervention and lifestyle changes, according to the authors.
This work was supported in part by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health and Welfare, Republic of Korea, grant HI13C0715.