Objective: The Global Leadership Initiative on Malnutrition (GLIM) criteria suggest alternative methods for assessment of muscle mass, and which of these methods is more strongly associated with adverse outcomes remains an issue to be clarified. Our primary outcome was to report malnutrition prevalences defined by 6 different GLIM approaches and study their relationship with mortality.

Methods: This retrospective follow-up study included the data of outpatients admitted to a tertiary hospital. We used 6 different approaches for GLIM, based on methods used to identify reduced muscle mass: i) skeletal muscle mass (SMM)/height², ii) SMM/ body mass index (BMI), iii) handgrip strength (HGS), iv) calf circumference (CC), v) CC adjusted for BMI, and vi) GLIM without third phenotypic criterion (P3). We evaluated survival in malnutrition with Kaplan–Meier log rank test. The Cox proportional hazards model was used to identify the relationships of different GLIM versions with mortality.

Results: The study population included 224 older individuals, with a median age of 72, and female predominance (68.8%). The prevalences with different GLIM versions ranged between 4.0% and 34.1%. During a median follow-up period of 31 months, 14 (6.3%) participants died. According to unadjusted analyses, only GLIM (SMM/h²), GLIM (HGS), GLIM (CC), and GLIM (without P3) were significantly associated with increased mortality risk [Hazard Ratio (95% CI) were 3.8 (1.1-13.7), 4.3 (1.4-12.8), 4.6 (1.3-16.7), and 7.3 (2.0-26.5), respectively]. After final adjustments were made for age and sex, it was revealed that none of the versions were the predictors of mortality in older outpatients.

Conclusion: The GLIM criteria have room for improvement as different options for muscle mass assessment are allowed, and this study aimed to fill the gap in the literature on whether malnutrition diagnosed by alternative GLIM definitions had predictive validity in community-dwelling older adults. Further outcome studies using larger cohorts and different pragmatic approaches are needed to detect the ideal GLIM definition for malnutrition assessment.

Keywords: Older adults, malnutrition, mortality, sarcopenia, survival