Negative association of composite dietary antioxidant index and peripheral artery disease in US participants

The association between the composite dietary antioxidant index (CDAI) and peripheral artery disease (PAD) remains inadequately explored. Elucidating this link is crucial for developing targeted nutritional strategies to mitigate PAD risk at both individual and public health levels. This analysis sought to evaluate the relationship between CDAI scores and the prevalence of PAD. We conducted a cross-sectional analysis utilizing data from the National Health and Nutrition Examination Survey (1999–2004). Participant demographics (age, sex, race, education, marital status, income-to-poverty ratio) and health-related factors (physical activity, body mass index, smoking status, total cholesterol, C-reactive protein, glycosylated hemoglobin, and histories of cardiovascular disease, hypertension, and diabetes) were collected. The association was examined using logistic regression, smoothed curve fitting, and interaction analyses. The study included 6018 individuals, with a PAD prevalence of 5.9% (n = 358). After comprehensive covariate adjustment, a significant inverse association between CDAI and PAD prevalence was observed (odds ratio [OR] = 0.96, 95% confidence interval [CI]: 0.92–1.00). When CDAI was analyzed as tertiles, participants in the middle tertile (T2) showed significantly lower odds of PAD compared to the lowest tertile (T1) (OR = 0.74; 95% CI = 0.56–0.98). The highest tertile (T3) also exhibited reduced odds, though not statistically significant (OR = 0.93; 95% CI = 0.69–1.24). Subgroup analyses consistently demonstrated this inverse trend, with no significant interaction effects detected (all P for interaction > .05). Our findings indicate that a higher CDAI is independently associated with a lower prevalence of PAD in United States adults. Future research is warranted to confirm these results and explore the underlying mechanisms.