Association between the composite dietary antioxidant index and sarcopenia among United States adults: A cross-sectional study.

Background: Diets high in antioxidants are associated with decreased prevalence of sarcopenia. This study aimed to investigate whether the composite dietary antioxidant index (CDAI) and sarcopenia have an underlying relationship.

Methods: We used the data from the National Health and Nutrition Examination Survey 2011-2018. According to dietary antioxidant intake, the CDAI was calculated for each individual. Appendicular skeletal muscle mass index was employed to determine sarcopenia. Multivariate weighted logistic models and restricted cubic spline regression analysis was undertaken to determine the association between CDAI and sarcopenia.

Results: A total of 7012 participants were enrolled in this study, including 473 with sarcopenia (weighted percentage, 5.6%). Compared with the lowest tertile, those in the highest tertile of the CDAI exhibited a greater likelihood of being male, with lower body mass index, higher education level and economic standard, and more chance of being single or separated. In multivariate weighted logistic models, model 3 revealed a noteworthy inverse association between the CDAI and sarcopenia (odds ratio = 0.94; 95% CI, 0.91-0.98; P = 0.003). Compared with the lowest tertile, the highest tertile of CDAI was associated with a 0.57-fold risk of sarcopenia (95% CI, 0.42-0.77; P < 0.001). The inverse association between CDAI and sarcopenia strengthened in the participants with elevated education levels (P for interaction = 0.003).

Conclusion: The CDAI was inversely correlated with the prevalence of sarcopenia. As a comprehensive measurement representing antioxidant status, the CDAI may help manage and prevent sarcopenia.