Nutritional Risk Assessment in Hemodialysis Patients: A Comparative Analysis of Modified Creatinine Index, Geriatric Nutritional Risk Index and simple Protein-Energy Wasting score with Malnutrition-Inflammation Score.

Abstract

Background and aims: Nutritional status has a great impact on the prognosis of maintenance hemodialysis patients. Therefore, its management should be a priority, and risk screening frequent and easily implemented, based on the biochemical and clinical routine parameters already available, when the use of more comprehensive tools is not possible. Many tools fit these simple criteria, namely the modified creatinine index, geriatric nutritional risk index, and simple protein energy wasting score. These scores are associated with mortality and morbidity risk in hemodialysis patients. This study aims to confirm that these scores are significantly associated with all-cause mortality and to compare them with malnutrition inflammation score.

Methods: Historical cohort study of hemodialysis patients from 25 outpatient clinics. The nutritional and inflammation status was assessed at baseline with malnutrition-inflammation score, geriatric nutritional risk index, modified creatinine index, and simple protein-energy wasting score. Univariable and multivariable Cox additive regression models were used to analyse data. Partial likelihood ratio tests to compare the performance of non-nested Cox models were used.

Results: We analysed 2322 patients, 59% males, 31.7% diabetic, with a median age of 70 years (P₂₅=60, P₇₅=79), during a median follow-up period of 45 months (P₂₅=31; P₇₅=45). All-cause mortality was observed in 778 patients (33.5%). The median of the modified creatinine index was 12.6 mg/kg/day (P₂₅=11.9, P₇₅=13.4), and a higher index value was observed for the surviving patients (p<0.001). Regarding geriatric nutritional risk score, a median of 106.6 (P₂₅=99.4, P₇₅=114.2) was observed, being significantly higher in the survival group (p<0.001). Simple protein-energy wasting score lower scores were more frequent in the group of deceased patients (p<0.001). For the malnutrition-inflammation score, the median was 6 (P₂₅=4, P₇₅=8), and 50.6% of the patients had a score ≥6, with higher scores being more frequent in the group of deceased (p<0.001). Partial likelihood ratio tests showed that the malnutrition-inflammation score only fitted better than the model including simple protein-energy wasting score. All scores had a good discriminative performance with Harrell's C-statistic ranging from 0.71-0.73. Malnutrition-inflammation score and modified creatinine index models attained the highest values.

Conclusion: All the tools were significantly associated with mortality. The geriatric nutritional risk index was the score that performed most similarly to the malnutrition-inflammation score.