Lower geriatric nutritional risk index is associated with a higher risk of all-cause mortality in patients with chronic obstructive pulmonary disease: a cohort study from the National Health and Nutrition Examination Survey 2013–2018

OBJECT: Malnutrition negatively affects patients with chronic obstructive pulmonary disease (COPD). This study aimed to explore the potential association between malnutrition, as defined by the Geriatric Nutritional Risk Index (GNRI), and all-cause mortality in patients with COPD using the National Health and Nutrition Examination Survey (NHANES). METHOD: The data of 579 adults with COPD during NHANES 2013–2018 were analysed. Each patient was assigned to one of the two groups according to GNRI values: normal nutritional status (GNRI>98) and malnutrition status (GNRI≤98). Survival curves and Cox regressions were applied to evaluate the association between nutritional status and mortality. RESULTS: Overall, the mean age was 63.4±0.5 years, and 53.9% of the patients were women. The prevalence of malnutrition was 6.6%, and the Kaplan-Meier curves for all-cause mortality according to nutritional status showed that malnutrition was associated with a higher incidence of all-cause mortality. The Cox regression analysis found that in the unadjusted model, the HR was 2.30 (95% CI 1.24 to 4.27, p=0.01). In the fully adjusted model, the adjusted HR was 2.47 (95% CI 1.36 to 4.5, p=0.003). Furthermore, subgroup analysis revealed that the risk of death due to malnutrition increased more than threefold in the low education and cancer subgroups. CONCLUSION: A low GNRI was an independent risk factor for all-cause mortality in patients with COPD.