The composite dietary antioxidant index (CDAI) is commonly utilized to assess antioxidant intake across diseases, but its association with kidney stones is unclear. We hypothesized that higher CDAI is associated with reduced kidney stone risk. Using National Health and Nutrition Examination Survey 2007-2020 data, we calculated CDAI based on vitamins A, C, E, selenium, zinc, and carotenoids intake in 29,280 adults. Stone formers had lower CDAI, with significant gender differences. Restricted cubic spline showed an L-shaped curve, with the steepest decline before CDAI of 1.449. In multivariate logistic regression, moderate and high CDAI tertiles were associated with reduced kidney stone odds compared to the lowest tertile (odds ratio [95% CI]): 0.85 [0.73, 0.99], P = .035 and 0.80 [0.66, 0.95], P = .014, respectively). Vitamin C had the highest negative correlation weight with kidney stones. Significant interactions were found for age and diabetes subgroups. In conclusion, higher CDAI may reduce kidney stone risk, especially with adequate vitamin C intake. Further cohort studies are warranted to confirm the causal association.
Nutrition research (New York, N.Y.). 2024 Jun 29 [Epub ahead of print]
Anwen Huang, Weiyan Huang, Yufei Ye, Lulu Liu, Haiyan Wang, Xiaolu Bian, Yingyi Qin, Zhiyong Guo, Wei Chen
Department of Nephrology, First Affiliated Hospital of Naval Medical University, Shanghai Changhai Hospital, Shanghai, China., Department of Health Statistics, Naval Medical University, Shanghai, China., Department of Nephrology, First Affiliated Hospital of Naval Medical University, Shanghai Changhai Hospital, Shanghai, China. Electronic address: .