Association of Increased Hair Calcium Levels and Enhanced Augmentation Index (AIx): a Marker of Arterial Stiffness

摘要

Arterial stiffness is involved in the pathophysiology of cardiovascular disease, and the degree of arterial stiffness is associated with the extent of vascular calcification. This study aimed to investigate the association of hair calcium levels with augmentation index (AIx), a simple, non-invasive measurement for arterial stiffness. Healthy Koreans (male, n = 34, female, n = 70) were enrolled in this study. Anthropometric parameters, lipid profiles, fasting glucose, hair mineral levels, and AIx were measured. Pearson/partial correlations and multivariate linear regression analyses were used to assess the relationship between hair calcium levels and AIx. AIx positively correlated with hair calcium levels (r = 0.275, p = 0.005), age (r = 0.283, p = 0.004), systolic blood pressure (r = 0.282, p = 0.004), low-density lipoprotein (LDL)-cholesterol (r = 0.255, p = 0.009), and hair magnesium (r = 0.196, p = 0.046), and negatively correlated with heart rate (r = -0.563, p < 0.001) and fasting glucose (r = -0.262, p = 0.005). Hair calcium levels significantly correlated with hair magnesium (r = 0.926, p < 0.001). Significant relationship between AIx and hair calcium levels was maintained after adjustment for sex, age, height, hear rate, blood pressure, total cholesterol, LDL-cholesterol, fasting glucose, and hair magnesium (r = 0.244, p = 0.018). Logistic regression model showed that AIx increased with the increment of hair calcium levels; log-AIx increased by 0.403% (95% CI: 0.139–0.515, p = 0.001) per unit change in log-hair calcium level (sex-adjusted). After adjustment for all the variables above together with triglyceride and high-density lipoprotein-cholesterol, increased significance of the association was 0.513% (p = 0.016)]. This study supports the presence of the independent positive relationship between hair calcium levels and AIx. It suggests the possibility that hair calcium levels may be a useful index for reflecting arterial stiffness.