Geriatric Nutritional Risk Index as a Possible Predictor of Decline in Kidney Function in Older People.

Background: The Geriatric Nutritional Risk Index (GNRI) is associated with morbidity and mortality in older individuals. Our study explored the relationship between GNRI, decline in kidney function, and all-cause mortality in older individuals.

Methods: This retrospective cohort study analyzed data from participants aged ≥60 years who underwent a general health checkup between 2002 and 2018. The primary exposure was the GNRI, divided into quartiles. The primary and secondary outcomes were a decline in kidney function assessed using the 5-year estimated glomerular filtration rate (eGFR) and all-cause mortality, respectively.

Results: The analysis included a total of 1,599 participants (median age, 63 years; interquartile range [IQR], 61-67; 54% males). The mean±standard deviation of GNRI was 114±7. Compared with the highest GNRI quartile, the lower GNRI quartiles were associated with steeper 5-year slopes in eGFR, with a fully adjusted beta coefficient and 95% confidence intervals (CIs) of -0.50 (-0.86, -0.14), -0.29 (-0.63, 0.05), and -0.19 (-0.53, 0.14) for the first, second, and third GNRI quartiles, respectively. The median follow-up duration was 7.4 years (IQR, 4.6-12.4). During this period, we identified 108 deaths (7.8 per 1,000 person-years). The first GNRI quartile was associated with all-cause mortality compared to the highest GNRI quartile (hazard ratio of 2.20; 95% CI 1.23, 3.95).

Conclusion: Nutritional status, as evaluated using the GNRI, was associated with 5-year changes in kidney function and all-cause mortality in older individuals.