Fig. 2

Associations between dietary iron intake and diabetic retinopathy by sex using restricted cubic spline model. A. Male; B. Female. Graphs show odds ratio (OR) for any DR according to dietary iron level adjusted for age, race, education, marital status, poverty income ratio, body mass index, smoking status, alcohol consumption, duration of diabetes, HbA1c level, hypertension, hypercholesterolaemia, history of comorbidities, including congestive heart failure, heart attack and stroke. Data were fitted by a logistic regression model, and the model was conducted with 4 knots at the 5th, 35th, 65th, 95th percentiles of iron intake (reference is the 5th percentile). Solid lines indicate ORs, and shadow shape indicate 95% CIs. OR, odds ratio; CI, confidence interval