Age- and Sex-Specific Patterns of Cardio-Ankle Vascular Index in Asymptomatic Adults

BACKGROUND The cardio-ankle vascular index (CAVI) is a blood pressure-independent measure of arterial stiffness. OBJECTIVES The authors aimed to characterize age- and sex-specific CAVI patterns and longitudinal changes and determine the optimal cutoff for predicting the coronary artery calcium score (CACS) > 0 in the Korean cohort. METHODS We included individuals who underwent CAVI during health check-ups between 2010 and 2024. Cross-sectional analyses characterized CAVI distributions by age and sex, whereas longitudinal analyses of participants with serial measurements assessed annual changes. The association between CAVI and CACS > 0 was evaluated using multivariable logistic regression, and a sigmoid spline model determined the optimal cutoff value for predicting CACS > 0. RESULTS Among 15,811 asymptomatic adults, 11,022 (69.7%) were men. The CAVI increased progressively with age, with a more apparent increase in men after their 50s and in women after their 60s. Median CAVI ranged from 6.35 (Q1-Q3: 6.05-6.67) to 9.35 (Q1-Q3: 8.75-10.05) in men and from 6.05 (Q1-Q3: 5.80-6.70) to 9.00 (Q1-Q3: 8.25-9.60) in women across age groups, generally lower than prior reference values. Sensitivity analyses excluding individuals with cardiovascular disease or relevant medications showed similar trends. In the longitudinal subset, the CAVI increased over time, particularly in older men. The CAVI independently predicted CACS > 0 after adjustment for clinical risk factors (OR: 1.071; 95% CI: 1.007-1.139; P = 0.030), with an optimal cutoff of 8.2. CONCLUSIONS This large-scale study provides updated age- and sex-specific CAVI references and longitudinal trajectories in Korean patients. The association between elevated CAVI and subclinical coronary calcification supports its utility as a noninvasive vascular screening tool.