The Association between Rice Intake and Chronic Kidney Disease: the Toon Health Study

Background and objectives: Almost one in eight Japanese adults have chronic kidney disease (CKD). Although rice intake may increase the risk of diabetes which is one of the major risk factors for CKD, the association between rice intake and CKD remained unknown. The objective of our study was to examine the association between rice intake and CKD in Japanese adults. Methods: This cross-sectional study included 1665 Japanese men and women aged 30-84 years who participated in the Toon Health Study. We calculated estimated glomerular filtration rate (eGFR), and defined CKD as eGFR =30mg/L. Rice intake was assessed by food frequency questionnaire, and adjusted for energy intake by residual method. The participants were divided into sex-specific quartiles according to rice intake. We calculated the multivariable-adjusted odds ratio (OR) and 95% confidence intervals (95%CIs) of CKD and albuminuria according to the quartiles of rice intake using the logistic regression model. Results: We found no significant association between rice intake and CKD. The multivariable-adjusted OR of CKD was 0.87 (95%CI: 0.60-1.25, p for trend =0.44) for the highest quartile of rice intake compared with the lowest quartile. However, we found that higher rice intake tended to be associated with lower odds of albuminuria; the OR of albuminuria was 0.59 (95%CI 0.32-1.08, p for trend =0.09). After stratification by current drinking status, the OR of CKD for the highest quartile was 0.88 (95%CI 0.53-1.47, p for trend =0.63) and albuminuria was 1.00 (95%CI 0.41-2.49, p for trend =0.99) in the non-drinking group; but in the current drinking group, the OR of CKD for highest quartile was 0.82 (95%CI 0.48-1.39, p for trend =0.45) and albuminuria was 0.37 (95%CI 0.15-0.91, p for trend =0.03). This association in the current drinking group remained significant after further adjustment for ethanol intake. Conclusion: Higher rice intake may be associated with a lower presence of albuminuria for individuals with a drinking habit (or who consumes alcohol).