The association between dietary inflammation index and peripheral neuropathy: Insights into the role of biological aging from a cross-sectional NHANES study

OBJECTIVES: Peripheral neuropathy (PN) is a prevalent neurological disorder with significant health and socio-economic burdens. The Dietary Inflammatory Index (DII) systematically assesses the proinflammatory characteristics of dietary patterns. This study aimed to elucidate the complex relationships among DII, biological aging, and PN, and to deepen the understanding of the potential factors driving these associations, thereby providing novel insights for prevention and clinical intervention. METHODS: This study investigated the National Health and Nutrition Examination Survey 1999-2004 data. The linear association between DII and PN was assessed using binary logistic regression, while restricted cubic splines were employed to evaluate potential nonlinear relationships. Furthermore, mediation analysis was conducted to quantify the contribution of biological age in this association. RESULTS: This study enrolled and analyzed 7860 participants. DII revealed a significant correlation with the prevalence of PN (the odds ratio [OR] = 1.07, 95% confidence interval [CI]: 1.03-1.30, p < 0.001). A J-shaped nonlinear association was identified between DII and the PN (p = 0.0079), with an inflection point at 1.295. Beyond this threshold, OR significantly increased to 1.16 (95% CI: 1.03-1.30). Biological age contributed to 19.95% of the total association between DII and PN. CONCLUSIONS: This study demonstrates a J-shaped association between DII and PN, which is partially accounted for by biological aging. These findings provide a new perspective for preventing PN through a low-inflammation diet.