Association between dietary saturated fatty acid intake and rheumatoid arthritis: A cross-sectional study based on NHANES

This study aimed to investigate whether there is an association between saturated fatty acid (SFA) intake and the risk of rheumatoid arthritis (RA). A cross-sectional study was conducted on 15,885 participants from the National Health and Nutrition Examination Survey between 2003 and 2023. A multivariate logistic regression model was used to assess the relationship between SFA and RA. Additionally, receiver operating characteristic curves and sensitivity analyses were employed to evaluate the predictive ability and stability of the model. Furthermore, restricted cubic spline analysis was used to explore the nonlinear relationship between SFA and RA. Results showed a significant negative correlation between SFA intake and RA risk (odds ratio [OR] = 0.801, 95% confidence interval [CI]: 0.720-0.890, P < .001). After adjusting for confounding factors such as age, gender, race, education level, body mass index, poverty income ratio, smoking status, alcohol intake, and total energy intake, Model 2 (OR = 0.872; 95% CI: 0.775-0.981, P = .023), and Model 3 (OR = 0.798; 95% CI: 0.695-0.917, P = .002) showed that the same significant negative correlation between SFA intake and RA persisted. Receiver operating characteristic and sensitivity analyses confirmed the robustness of the results (area under the curve = 0.78). Restricted cubic spline analysis results suggested that there was a nonlinear relationship between SFA intake and RA risk (P for non-linearity = .0273). These results suggest that a low SFA intake may have a protective effect against RA and significantly reduce the risk of developing RA.