Association of dietary iron intake with diabetic kidney disease among individuals with diabetes

The current study investigated the correlation between dietary iron intake and diabetic kidney disease among diabetic adults.

This cross-sectional study enrolled 8118 participants who suffered from diabetes from the National Health and Nutrition Examination Survey (NHANES) 1999–2018. Dietary iron intake was obtained from 24 h recall interviews, and diabetic kidney disease was defined as eGFR < 60 mL/min per 1.73 m² or albumin creatinine ratio (ACR) ≥ 30 mg/g. Three weighted logistic regression models were utilized to investigate odd ratio (OR) and 95% CIs for diabetic kidney disease. Stratified analyses were performed by gender, age, BMI, HbA1c, hypertension status, and smoking status, and diabetes types.

Among 8118 participants (51.6% male, mean age 61.3 years), 40.7% of participants suffered from diabetic kidney disease. With the adjustment of potential covariates, we found that ≥ 12.59 mg of dietary iron was related to a lower risk of diabetic kidney disease (OR = 0.78, 95% CI: 0.63 to 0.96; OR = 0.79, 95% CI: 0.63 to 0.98). In stratified analyses, higher iron intake was negatively related to diabetic kidney disease, especially among those who were male, < 60 years, those with hypertension, those with HbA1c < 7.0%, and those who were ex-smokers. The result remained robust in sensitivity analyses.

We found that ≥ 12.59 mg of dietary iron is associated with a lower risk of diabetic kidney disease, especially in those who were male, younger, heavier weight, have better blood sugar control, and those who were ex-smokers.