Linking the dietary inflammation index to sarcopenia in diabetes: mediation by body roundness index and evidence from complementary analyses.

BACKGROUND

This study investigates whether dietary inflammatory index (DII) is associated with sarcopenia risk in diabetes and the mediating role of body roundness index (BRI). Two-sample Mendelian randomization (MR) was additionally employed to provide genetic evidence complementing these relationships.

METHODS

Data from 2252 participants were sourced from the National Health and Nutrition Examination Survey. The DII was evaluated using a 24-hour dietary recall, whereas data for the sarcopenia index were acquired through dual-energy X-ray absorptiometry. Multivariate regression and mediation analysis examined associations. In parallel, these results were indirectly supported through two-sample MR analyses and animal experiments.

RESULTS

Adjusted logistic regression analysis indicates that a higher DII is significantly linked to an increased prevalence of sarcopenia as opposed to the lowest DII category (odds ratio [OR] = 1.97, 95% confidence interval [CI]: 1.37 to 2.82). A restricted cubic spline model revealed a positive linear relationship between DII and sarcopenia incidence in diabetics. BRI significantly mediated this association (P = 0.038), while BMI showed no significant mediation (P = 0.314). MR suggests anti-inflammatory foods (fruits, vegetables, vitamin C) protect against muscle loss, while saturated fatty acids accelerate it. Simultaneously, studies on animals demonstrated that a diet high in inflammatory foods leads to muscle deterioration.

CONCLUSIONS

Higher DII scores correlated with increased sarcopenia risk in diabetes, a link partially mediated by BRI. Anti-inflammatory dietary components were protective; saturated fatty acids were associated with muscle loss. DII may help identify at-risk patients.