Association Between Geriatric Nutrition Risk Index and 90-Day Mortality in Older Adults with Chronic Obstructive Pulmonary Disease: a Retrospective Cohort Study.

Background: Malnutrition adversely affects prognosis in various medical conditions, but its implications in older adults with Chronic Obstructive Pulmonary Disease (COPD) in the ICU are underexplored. The geriatric nutritional risk index (GNRI) is a novel tool for assessing malnutrition risk. This study investigates the association between GNRI and 90-day mortality in this population.

Methods: We selected older adults with COPD admitted to the ICU from Medical Information Mart for Intensive Care (MIMIC)-IV 2.2 database. A total of 666 patients were categorized into four groups based on their GNRI score: normal nutrition (>98), mild malnutrition (92-98), moderate malnutrition (82-91), and severe malnutrition (≤81) groups. We employed a restricted cubic spline (RCS) analysis to assess the presence of a curved relationship between them and to investigate any potential threshold saturation effect.

Results: In multivariate Cox regression analyses, compared with individuals had normal nutrition (GNRI in Q4 >98), the adjusted HR values for GNRI in Q3 (92-98), Q2 (82-91), and Q1 (≤81) were 1.81 (95% CI: 1.27-2.58, p=0.001), 1.23 (95% CI: 0.84-1.79, p=0.296), 2.27 (95% CI: 1.57-3.29, p<0.001), respectively. The relationship between GNRI and 90-day mortality demonstrates an L-shaped curve (p=0.016), with an approximate inflection point at 101.5.

Conclusion: These findings imply that GNRI is a useful prognostic tool in older adults with COPD in the ICU. An L-shaped relationship was observed between GNRI and 90-day mortality in these patients.