Soy foods, isoflavone intake, and diabetic kidney disease: The Fukuoka Diabetes Registry

Aims/Introduction Soy foods are traditional components of the Japanese diet; however, evidence of their association with diabetic kidney disease remains limited. This study examined the association of soy food and isoflavone intake with decreased eGFR and albuminuria in Japanese patients with type 2 diabetes. Materials and Methods Overall, 4,922 individuals with type 2 diabetes were enrolled in this cross‐sectional analysis. Soy food and isoflavone intakes were assessed using a self‐administered diet history questionnaire. Odds ratios for decreased cystatin C‐based eGFR (eGFR cys <60 mL/min/1.73 m 2 ) and albuminuria (urinary albumin‐to‐creatinine ratio ≥30 mg/g) were calculated using logistic regression. Results Frequent consumption of natto, miso soup, and tofu was associated with lower prevalence of decreased eGFR cys . The multivariable‐adjusted odds ratios for the highest vs. lowest frequency categories were 0.49 (95% CI: 0.37, 0.65), 0.63 (0.42, 0.95), and 0.52 (0.30, 0.88), respectively. More frequent natto consumption, but not miso soup or tofu consumption, was inversely associated with albuminuria. Higher isoflavone intake was associated with lower odds of both outcomes. Conclusions Higher soy food consumption was associated with a lower prevalence of decreased eGFR, whereas natto and isoflavone intake were also associated with a lower prevalence of albuminuria. Habitual soy intake may be clinically relevant to kidney health.