Inverse relationship of cardioankle vascular index with BMI in healthy Japanese subjects: a cross-sectional study

Objective: The objective of this study is to investigate the association of body mass index (BMI) with arterial stiffness assessed by cardioankle vascular index (CAVI). Subjects and methods: A retrospective cross-sectional study was conducted in 23,257 healthy Japanese subjects (12,729 men and 10,528 women, aged 47.1 +/- 12.5 years, BMI 22.9 +/- 3.4 kg/m(2)) who underwent health screening between 2004 and 2006 in Japan. Exclusion criteria were current medication use and a past history of cardiovascular disease, hypertension, stroke, diabetes, and nephritis. Results: Male subjects showed significantly higher BMI, CAVI, and triglycerides and lower high-density lipoprotein (HDL)-cholesterol compared with female subjects. Next, the subjects were divided into tertiles of BMI: lower, middle, and upper, in a gender-specific manner. After adjusting for confounders including age, systolic blood pressure, and HDL-cholesterol identified by multiple regression analysis, the mean CAVI decreased progressively as BMI tertile increased in both genders. Furthermore, a negative inverse relationship between BMI and adjusted CAVI was observed throughout the BMI distribution. Multivariate logistic regression model for contributors of high CAVI (>= 90th percentile) identified obesity (odds ratios (95% confidence interval): 0.804 (0.720-0.899)], older age [15.6 (14.0-17.4)], male gender [2.26 (2.03-2.51)], hypertension [2.28 (2.06-2.54)], impaired fasting glucose [1.17 (1.01-1.37)], and low HDL-cholesterol [0.843 (0.669-1.06)] as independent factors. Conclusion: We demonstrated an inverse relationship between CAVI and BMI in healthy Japanese subjects, suggesting that systemic accumulation of adipose tissue per se may lead to a linear decrease of arterial stiffness in nonobese and obese subjects without metabolic disorders.