A cross-sectional study of the association between dietary inflammatory index and glaucoma prevalence in a US population

To assess the relationship between dietary inflammatory index (DII) and prevalence of glaucoma among individuals aged 40y and above in the United States.

Participants were drawn from 2 cycles of the National Health and Nutrition Examination Survey (NHANES, 2005-2008) for a cross-sectional study. DII was calculated from 24-hour dietary recall questionnaire conducted by experienced researchers and data analyzed in R according to the NHANES user guide, “Stratified Multi-stage Probability Sampling”. The relationship between DII and glaucoma was evaluated by multi-factor logistic regression analysis and the existence of a non-linear association examined by restricted cubic spline (RCS) analysis.

A total of 5359 subjects were included and the cross-sectional analysis weighted to represent the US population of 109 million. DII was elevated in glaucoma patients (P<0.001) and smoking and alcohol use contributed to significant differences (P<0.001). DII correlated negatively with Healthy Eating Index (HEI)-2015 (Spearman rank correlation coefficient, r=-0.49). RCS analysis showed a linear relationship between DII and glaucoma risk (P of non-linear relationship =0.575).

An increased DII is strongly associated with high risk of glaucoma and diet-induced inflammation should be controlled to delay glaucoma progression.