Difference in positive relation between cardio-ankle vascular index (CAVI) and each of four blood pressure indices in real-world Japanese population.

This study aimed to investigate the association of cardio-ankle vascular index (CAVI), an arterial stiffness parameter, with four blood pressure (BP) indices, systolic BP (SBP), diastolic BP (DBP), pulse pressure (PP) and mean BP (MBP), in real-world population including untreated hypertension. We analyzed the cross-sectional data from 23,257 Japanese subjects (12,729 men and 10,528 women, aged 47.1 years) without a past history of cardiovascular disease, stroke, hypertension, diabetes or dyslipidemia. Gender differences in four BP indices were slight, but significant for SBP, DBP and MBP. All four BP indices increased linearly with age. After adjusting for confounders comprising gender, age, HDL-C and BMI identified by multiple regression analysis, CAVI was lower in normotensive subjects compared to hypertensive subjects. Trend test detected an almost linear relation of adjusted CAVI with each of four BP indices even within ideal range. Exceptionally, the increment in adjusted CAVI reached its peak over 140 mm Hg range in SBP. Logistic regression models showed that 1-SD increment in each BP index contributed independently to high CAVI (≥90th percentile), whereas that in PP showed a somewhat lower contribution. Subgroup analyses revealed that older age, dyslipidemia and hypertension were independently associated with relatively small contributions to high CAVI per 1-SD increment in SBP. PP might be less useful to assess arterial stiffness compared to other BP indices. Besides, the contribution of SBP increment to arterial stiffening was relatively large in normotensive, normolipidemic non-elderly subjects, whose individual transition of SBP should be noticed.