Association between Chinese visceral adiposity index and sarcopenia: a China health and retirement longitudinal study (CHARLS)-based longitudinal analysis

Sarcopenia, characterized by a progressive decline in muscle mass and function, is increasingly associated with metabolic dysregulation. However, the relationship between the Chinese visceral adiposity index (CVAI), a reliable indicator for assessing visceral fat, and sarcopenia remains unclear. This study aimed to investigate the association between CVAI and the incidence of sarcopenia among middle-aged and older Chinese adults. Baseline and follow-up data were collected from the 2011 and 2015 waves, respectively, of the China Health and Retirement Longitudinal Study. Sarcopenia was defined based on the 2019 consensus update from the Asian Working Group for Sarcopenia. Multivariate logistic regression models were employed to examine the association between CVAI and sarcopenia. The restricted cubic spline (RCS) models were applied to explore the potential nonlinear associations and dose-response relationships. A total of 4,532 participants were included, of whom 284 (6.27%) developed sarcopenia in the 2015 wave. After adjusting for confounders, higher CVAI levels were associated with a lower risk of sarcopenia. Participants in the highest quartile (Q4, CVAI ≥ 129.74) exhibited the lowest risk of sarcopenia (OR = 0.06; 95% CI: 0.04-0.11). RCS analysis confirmed a linear inverse association between CVAI and the risk of sarcopenia (P for nonlinear = 0.423). Stratified analyses revealed significant interactions between CVAI and age (P = 0.011) and between CVAI and chronic kidney disease (P = 0.038). There is a potential inverse relationship between elevated CVAI levels and the risk of sarcopenia in middle-aged and older Chinese adults.