Objective
Chronic Kidney Disease (CKD) is nowadays a public health challenge worldwide. Accordingly, this study is aiming to evaluate the association between long-term intake of total polyphenol and its subclasses, and the incidence of CKD.
Methods
A sample of 3021 Iranian Adults (47% men) were selected from the the Tehran Lipid and Glucose Study population. The participants aged 20–79 years and had no diagnosis of CKD at baseline. Total polyphenol intake and its major subclasses including flavonoids, phenolic acids, stilbenes, and lignans, was assessed by a validated and reliable Food Frequency Questionnaire (FFQ). The of the were broadly categorized as flavonoids, phenolic acids, stilbenes, and lignans. The Modification of Diet in Renal Disease Study equation was used to calculate the Estimated Glomerular Filtration Rate (eGFR), and, CKD was defined as eGFR < 60 mL/min/1.73 m2. Hazard ratio and 95% confidence intervals of CKD by total polyphenols quartiles were assessed by Cox-regression analysis.
Results
In this study, we documented 355 cases of diagnosed CKD over 11,058.464 person-years. The mean ± SD age of participants was 37.3 ± 12.6 years at baseline. After adjustment of the potential confounders, it was revealed that a moderate intake of lignans (≤ 6.8 mg) was negatively associated with the incidence of CKD, whereas there was no significant association between the higher amounts of lignan intake and CKD. No significant associations were observed between the consumption of total polyphenols and the incidence of CKD (HR: 0.97, 95% CI 0.67–1.40).
Conclusions
Data of the current study suggest that in the case of lignan with protective properties, a moderate amount of lignan favorably reduced the incidence of CKD by approximately 32%, whereas higher amounts possessed a null effect.