RESUMEN
OBJECTIVE: To assess whether the composite dietary antioxidant index (CDAI) is associated with osteoporosis (OP) in middle-aged and older US populations. METHODS: We conducted a cross-sectional survey and identified individuals aged 40-85 years (n=11,664) from secondary datasets from the 2007-2010, 2013-2014, and 2017-2018 National Health and Nutrition Examination Survey (NHANES). Dual-energy X-ray absorptiometry was used to measure bone mineral density (BMD), and OP was defined as a BMD T-score ≤-2.5 at the femoral neck or lumbar spine. The CDAI score was calculated based on dietary data from the first NHANES 24-hour dietary recall. Multivariate logistic regression models were used to evaluate the association between CDAI and OP. RESULTS: Among the 11,664 participants, the average age was 60.3 (11.8), 5,898 (50.6%) were female, and 925 (7.9%) had OP. The median CDAI was -2.0 (interquartile range, -6.9 to 4.2). After adjusting for age, sex, race, family income, body mass index, physical activity, calorie intake, estimated glomerular filtration rate, smoking and drinking status, hypertension, and diabetes, the CDAI was associated with OP (odds ratio (OR), 0.98; 95% CI: 0.96-0.99). Participants in the highest CDAI quantile were at low risk of osteoporosis (OR, 0.61; 95% CI: 0.44-0.85) versus those in the lowest quantile. Moreover, this association was stable in the subgroup and sensitivity analyses. CONCLUSION: Dietary antioxidant ability assessed by using the CDAI was inversely associated with OP among US adults aged 40-85 years.