Abstract
Background
A healthy diet is key to chronic kidney disease (CKD) prevention; however, which specific dietary components are more beneficial is still unclear. We identified dietary patterns (DPs) analytically through selected risk factors of CKD.
Methods
We included 6215 Cooperative Health Research In South Tyrol (CHRIS) study participants without known kidney disease, hypertension or diabetes. We obtained serum creatinine-based estimated glomerular filtration rate (eGFR) with the 2021 CKD-EPI equation and defined CKD as eGFR<60 ml/min/1.73m^2. Dietary intake was estimated based on the self-administered internationally validated GA2LEN food frequency questionnaire (FFQ). We estimated DPs using RRR, selecting two groups of mediators: the FFQ-derived nutrients (DPN) and selected biomarkers (DPB). Factor loading-based scores, either as continuous or stratified into tertiles (T1-T2-T3), were included in multiply-adjusted regression models for eGFR and CKD. Sex-specific DPs and models were also implemented.
Results
We identified 3 DPN and 2 DPB scores. DPN1 was characterized by high intake of all nutrients and associated with lower eGFR (linear p<0.001, T3vsT2 p=0.042). The T3 of DPN3 (low intakes of potassium and sodium; high intakes of proteins and phosphorus) was protective against CKD risk (T3vsT2 p=0.017). DPB1 reflected the impact of higher levels of all risk biomarkers and was associated with lower eGFR (linear p=0.027). Other DPs showed no evidence of association with eGFR or CKD. Sex-stratified analyses led to similar DPs, and effects on eGFR and CKD differed to some extent between males and females.
Conclusions
In addition to confirming known relationships between nutrient-based DPs and kidney health, biomarker-based DPs highlighted additional food groups related with specific CKD risk factors. Integrating both nutrients and biomarkers risk factors as mediators adds value to the investigation of diet effects on kidney function.