Abstract: Objective  To investigate the association between the Geriatric Nutritional Risk Index (GNRI) and the progression of renal impairment in patients with chronic kidney disease (CKD).  Methods  A secondary analysis was conducted using data from the CKD-ROUTE study available in the DRYAD open database. Based on baseline clinical data, patients were categorized into a high GNRI group (GNRI ≥ 98) and a low GNRI group (GNRI<98). A Cox proportional hazards model was used to evaluate the association between GNRI and CKD progression, defined as a ≥50% decline in estimated glomerular filtration rate (eGFR) or initiation of renal replacement therapy. Subgroup analyses were also performed.  Results   A total of 996 patients with CKD stages G2 to G5 were included. The mean baseline GNRI was 97.28±10.28. The high GNRI group consisted of 562 patients (56.4%), while the low GNRI group had 434 patients (43.6%). Compared to the high GNRI group, the low GNRI group had older age (t =-4.245; P <0.001), higher prevalence of hypertension (Z=10.433; P=0.001), diabetes (Z=31.137; P<0.001), and cardiovascular disease (Z=14.934; P< 0.001), as well as higher rates of baseline hematuria (t =40.894; P<0.001) and proteinuria (t =102.023; P< 0.001). However, baseline eGFR (t =-7.859; P <0.001), hemoglobin (t =14.368; P <0.001), and albumin levels (t =35.454; P<0.001) were lower in the low GNRI group. CKD progression occurred in 264 patients, with a cumulative incidence of 26.5%. Cox regression analysis showed that, compared to the high GNRI group, the low GNRI group had a hazard ratio of 1.563 (95% CI: 1.166～2.095, P<0.001) for CKD progression. Subgroup analysis revealed that the association between low GNRI and increased risk of CKD progression was consistent across different genders (HR=1.477, 95% CI: 1.035～2.107, P=0.032), presence or absence of type 2 diabetes (HR =1.793, 95% CI: 1.154～2.786, P =0.009), history of cardiovascular disease (HR =1.413,     95% CI: 1.010～1.978, P=0.044), and varying levels of hemoglobin (HR =1.557, 95% CI: 1.144～2.119, P= 0.005) and systolic blood pressure (HR =1.578, 95% CI: 1.004～2.479, P =0.048).  Conclusion  Low GNRI is an independent risk factor for the progression of renal impairment in non-dialysis CKD patients. Regular screening and appropriate nutritional interventions may help improve their prognosis. 

Key words: Chronic kidney disease, Geriatric nutritional risk index, Progression of renal impairment, Risk factors