Association between remnant cholesterol and isolated diastolic hypertension in young adults: a cross-sectional study in China

Remnant cholesterol, the cholesterol content of triglyceride-rich lipoproteins, has emerged as a novel cardiovascular risk factor. However, its relationship with isolated diastolic hypertension, particularly among young adults, remains unclear. This study aimed to investigate the association between remnant cholesterol levels and isolated diastolic hypertension in a population aged under 45 years. A total of 6,153 participants aged 18–44 years who underwent routine health check-ups at Chinese PLA General Hospital were included after exclusion of secondary or non-isolated hypertension. Participants were categorized into remnant cholesterol tertiles (T1 ≤ 0.6 mmol/L, T2 0.6–0.88 mmol/L, T3 > 0.88 mmol/L). Multiple linear and logistic regression models were used to assess associations between remnant cholesterol and blood pressure levels as well as isolated diastolic hypertension, with progressive adjustment for demographic, metabolic, inflammatory, and renal factors. Restricted cubic spline analysis further examined the dose–response relationship between remnant cholesterol and isolated diastolic hypertension. Higher remnant cholesterol levels were significantly associated with increased systolic and diastolic blood pressure (both P < 0.001). Compared with the lowest remnant cholesterol tertile, participants with remnant cholesterol > 0.88 mmol/L showed higher odds of isolated diastolic hypertension in both unadjusted and fully adjusted models (OR = 1.73, 95% CI: 1.12–2.68, P = 0.003). Restricted cubic spline analysis revealed a linear positive correlation. Subgroup analyses showed consistent associations across sex, age, body mass index, hyperuricemia, and diabetes status (all P for interaction > 0.05). Elevated remnant cholesterol is independently associated with higher blood pressure and greater odds of isolated diastolic hypertension in young adults, suggesting remnant cholesterol may contribute to early diastolic blood pressure elevation.