Modification of diet is a convenient and cost-effective approach proved to be beneficial for population with Chronic kidney disease (CKD). Nutritional status is closed related to the frailty status and both of them are associated with health outcomes. However, in population with CKD, the prognostic value of different dietary indices in survival and how frailty will influence their association remains unclear. The objectives of our analysis were 1) assess the associations between frailty with seven dietary indices in population with CKD; 2) evaluate the mortality risk of frailty and different dietary scores in CKD; 3) explore the association between dietary scores and mortality after adjustment for frailty index. Methods: 4445 participants with CKD (≥ 20 years) from the 2007–2016 cohorts of the National Health and Nutrition Examination Survey (NHANES) were enrolled. Nutrition index (NI), Dietary Inflammatory Index (DII), Healthy Eating Index-2020 (HEI-2020), Mediterranean Diet Score (MED), Dietary Approaches to Stop Hypertension (DASH), Dietary Acid Load (DAL), Composite Dietary Antioxidant Index (CDAI) were calculated based on dietary intake information from the first 24-hour recall data. Linear regression models were performed to evaluate the association between different dietary scores and frailty index (FI).
Cox regression models were utilized to identify the associations of dietary indices and frailty with mortality. Results: FI was significantly higher in participants with CKD compared with the overall population. There was significant relationship between DII, NI, CDAI, HEI-2020 and MED scores with frailty in CKD patients. Frailty index, DII, NI and HEI-2020 scores were significantly associated with increased mortality risk in individuals with CKD. The relationship between DII score, NI score, HEI-2020 score and mortality changed when adjustment for frailty. Conclusions: In individuals with CKD, frailty was related to DII, NI, CDAI, HEI-2020 and MED scores and higher FI was significantly associated with increased risk of all-cause mortality. Higher DII, NI and lower HEI-2020 scores were related to mortality risk. After adjustment for frailty index, only higher NI score (3-year and 5-year mortality) and lower HEI-2020 (3-year and 8-year mortality) score were associated with higher mortality risk.