Muscle Mass Loss Is a Potential Predictor of 90-Day Mortality in Older Adults with Aspiration Pneumonia

ObjectivesTo investigate the association between loss of muscle mass and aspiration pneumonia (AP). DesignProspective observational cohort. SettingAcute geriatric hospital. ParticipantsIndividuals admitted to the hospital for AP (N = 151; mean age 85.9; 49.7% male). MeasurementsAppendicular skeletal muscle index (ASMI; appendicular skeletal muscle mass divided by height squared) was used to evaluate muscle mass. Data on age, sex, body mass index, Mini Nutritional AssessmentShort Form score, Barthel Index score, Charlson Comorbidity Index score, and pneumonia severity (Japanese version of the CURB-65 (C (confusion), U (blood urea nitrogen 20 mg/dL), R (respiratory rate 30 breaths/min), B (systolic blood pressure <90 mmHg or diastolic blood pressure 60 mmHg), 65 (aged 65) severity score (A-DROP)) were obtained. Outcomes included 30- and 90-day mortality. ResultsMild, moderate, severe, and extremely severe AP were observed in 1.3%, 70.2%, 25.8%, and 2.6% of participants, respectively. On Kaplan-Meier analysis, participants in the lowest ASMI quartile for each sex were more likely to die than those in the other quartiles (log-lank test P = .005). Multivariate logistic analyses showed that ASMI and A-DROP were independent predictors of 90-day mortality; only A-DROP was a significant predictor of 30-day mortality (P < .001). Cox regression analysis also showed that the first ASMI quartile was independently associated with mortality (hazard ratio = 2.19; 95% confidence interval = 1.06-4.52; P = .03). ConclusionLow muscle mass is a potential predictor of long-term mortality in individuals with AP. Prospectively preventing muscle mass deterioration may be beneficial for recovery from AP in older adults.