Association between the Composite Dietary Antioxidant Index and Nonalcoholic Fatty Liver Disease: Evidence from National Health and Nutrition Examination Survey 2005-2016

Abstract Importance: Oxidative stress is an important contributor to the progression of nonalcoholic fatty liver disease (NAFLD), however, the relationship between Composite Dietary Antioxidant Index (CDAI) and NAFLD in US adult population remains unclear. Objective: To access whether CDAI is associated with NAFLD in US adults. Design, setting, and participants: This population-based cross-sectional study used data on US adults from the National Health and Nutrition Examination Survey (NHANES) 2005-2016 cycles. Data were analyzed from January to February 2024. Exposures: CDAI obtained from the dietary intake questionnaire. Main outcomes and measures: The main outcome was NAFLD which defined by the US fatty liver score (USFLI) ≥ 30. Sampling weights were calculated according to NHANES guidelines. Results: Among 9746 adults included in this study (mean age, 48.3 years; 4662 [47.6%] males), 3324 (33.0%) were classified as having NAFLD using USFLI. In the fully adjusted of multivariable logistic regression, CDAI was negative associated with NAFLD (odds ratio [OR], 0.95; 95% CI, 0.93-0.98). Furthermore, the highest quartile CDAI were 34% less likely to have NAFLD than those with the lowest quartile (OR, 0.66; 95% CI, 0.52-0.85). In subgroup analyses, CDAI was associated with NAFLD among participants who were male (OR, 0.94; 95% CI, 0.92-0.97), without diabetes (OR, 0.95; 95% CI, 0.93-0.97), and without metabolic syndrome (OR, 0.93; 95% CI, 0.91-0.96). In addition, the negative correlation between CDAI and NAFLD was robust in sensitivity analyses that excluded potential hepatotoxic medication use (OR, 0.95; 95% CI, 0.93-0.98), or non-Hispanic Black participants (OR, 0.95; 95% CI, 0.93-0.98), defined NAFLD based on the hepatic steatosis index score (HSI) (OR, 0.97; 95% CI, 0.95-0.99), and used unweighted logistic analysis (OR, 0.96; 95% CI, 0.94-0.98). Conclusions and relevance: In this cross-sectional study based on six cycles (2005-2016) of the NHANES, CDAI was negative associated with NAFLD in US adult population. This association may provide a new approach to explore the factors affecting dietary interventions to reduce the incidence of NAFLD.