Cross-sectional association between body fat percentage and arteriosclerosis assessed by Cardio-Ankle Vascular Index in a Chinese population: a retrospective observational study

Objective To evaluate arteriosclerosis using Cardio-Ankle Vascular Index (CAVI) and to explore the relation between the body fat percentage (BFP) and CAVI. Design A retrospective observational study. Setting and participants A total of 1152 patients admitted to a geriatric unit and general practice at a mega hospital in Wuhan, China, from November 2018 to November 2019 were included in this study. Primary outcome Association between BFP and CAVI. Results Multiple linear regression analysis showed that BFP was positively correlated with CAVI after correction for potential confounding variables (beta=0.03; 95% CI: 0.01 to 0.05); this association persisted after BFP was treated by quartile categorical variables and the trend test was statistically significant (p for trend=0.002). Meanwhile, the generalised additive model showed a non-linear association between BFP and CAVI. When BFP<20.6%, BFP is not associated with CAVI for (beta=-0.02; 95% CI: -0.06 to 0.03), but when BFP >= 20.6%, there is a linear positive association between BFP and CAVI (beta=0.05; 95% CI: 0.02 to 0.07). Subgroup analysis showed that there was an interaction between BFP and CAVI in the age stratification (p interaction=0.038). Conclusion BFP was non-linearly correlated with CAVI, with a 0.05 increase in CAVI for every 1% increase in BFP when BFP >= 20.6% and a 0.03 increase in CAVI in those >65 years of age.