Combining Geriatric Nutritional Risk Index with Total Cholesterol to Predict Pneumonia Mortality Risks in a Cohort of General Older Adults

Abstract

Background/Objectives: To examine the importance of a composite measure incorporating the Geriatric Nutritional Risk Index (GNRI) and total cholesterol (TC), termed TC-GNRI, in predicting pneumonia mortality in community-dwelling aged individuals. Methods: A longitudinal analysis of the Tsurugaya cohort in Japan, including 1124 participants aged 70 years or older, was used for tracking pneumonia-related deaths for an 11-year period. Total cholesterol thresholds were set at 171 mg/dL (males) and 192 mg/dL (females), classified into higher- and lower-groups. GNRI was divided into higher (≥100.64) and lower (<100.64) groups. A combined index (TC-GNRI) was then created by integrating these indices into three levels: high (both values at or above the thresholds), intermediate (one value above and one below), and low (both below). Cox proportional hazards models estimated hazard ratios (HRs) for pneumonia mortality, adjusting for age, gender, smoking, the Timed Up and Go test, %FVC, and tuberculosis, using high groups as references. Results: Kaplan–Meier curves showed that lower total cholesterol and lower GNRI were associated with higher pneumonia mortality than in the respective higher groups. The intermediate- and low-TC-GNRI groups had poorer survival rates than the high group. After adjustment, lower total cholesterol (HR = 3.03, 95% CI 1.41–6.52) and lower GNRI (HR = 2.69, 95% CI 1.21–5.99) were each associated with greater pneumonia mortality than the higher groups. The intermediate- (HR = 2.81, 95% CI 1.18–6.70) and low-TC-GNRI (HR = 6.17, 95% CI 2.15–17.74) groups showed greater pneumonia mortality than the high group. Conclusions: TC-GNRI may provide additional value in indicating pneumonia mortality risk than total cholesterol or GNRI alone. TC-GNRI may be a valuable tool for identifying older adults at particularly high risk of pneumonia mortality.