Age-stratified association between isolated diastolic hypertension and carotid intima-media thickness: results from the Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) Study

Background: The clinical significance of isolated diastolic hypertension (IDH), particularly in relation to subclinical vascular changes, remains unclear and may vary across age groups. This study evaluated the age-stratified association between IDH and carotid intima-media thickness (IMT).Methods: This cross-sectional study included 6,759 Korean adults aged 30–64 years from the Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) cohort. Participants with a history of cardiovascular disease or use of antihypertensive medication were excluded. Blood pressure was classified according to the 2017 American College of Cardiology/American Heart Association guidelines into four categories: no hypertension, IDH, isolated systolic hypertension, and systolic diastolic hypertension. Carotid IMT was measured by B-mode ultrasonography, and vascular thickening was defined as IMT ≥0.857 mm (75th percentile). Multivariable logistic regression analyses were performed with age stratification.Results: Among participants younger than 50 years, IDH was significantly associated with carotid IMT thickening after adjustment for age, sex, body mass index, educational attainment, physical activity, smoking, diabetes, total cholesterol, high-density lipoprotein cholesterol, lipid-lowering drug use, C-reactive protein, and study site (odds ratio [OR], 1.57; 95% confidence interval [CI], 1.10–2.26). No significant association was observed in participants aged 50 years or older (OR, 0.89; 95% CI, 0.72–1.09). Both isolated systolic hypertension and systolic diastolic hypertension were associated with carotid IMT thickening in all age groups.Conclusions: IDH was associated with subclinical vascular changes in younger adults but not in older adults. These findings highlight the age-specific nature of the association of IDH with cardiovascular risk.