Association between the Geriatric Nutritional Risk Index and all-cause mortality in older adults with obstructive sleep apnea symptoms: A retrospective cohort study

Nutritional status assessment is crucial for managing comorbidities and improving outcomes in older patients with obstructive sleep apnea (OSA) symptoms, but it is often neglected. The Geriatric Nutritional Risk Index (GNRI) is an objective tool to assess nutritional health. This study aimed to explore the association between GNRI and all-cause mortality in older patients with OSA symptoms. The analysis used data from 1642 older patients with OSA symptoms from the National Health and Nutrition Examination Survey during 2005 to 2008 and 2015 to 2018. We assessed GNRI’s correlation with all-cause mortality using weighted survival analysis and Cox regression models, evaluating GNRI both quantitatively and categorically. The stability of the results was evaluated using propensity score matching. To gauge robustness, we computed the E-value – the smallest confounder odds ratio capable of nullifying the GNRI–mortality link. Among the 1642 participants, 20.03% died after weighting was applied. The cohort had a median age of 71 years, with 53.07% being women. With a GNRI threshold <98, 13.2% of participants were in the low-GNRI group. Weighted Kaplan–Meier analysis indicated higher all-cause mortality among those with low GNRI. After full adjustment in the weighted Cox regression analysis, GNRI demonstrated a hazard ratio of 0.94 (95% confidence interval: 0.91–0.97, P < .001). Further subgroup evaluations revealed no substantial interaction effects involving GNRI and all-cause mortality. The E-values corresponding to the point estimate and upper confidence limit for all-cause mortality among older patients with OSA symptoms were 2.7 and 1.97, respectively. In older patients with OSA symptoms, lower GNRI is linked to higher mortality risk.