Sarcopenia and malnutrition in relation to mortality in hospitalised patients in geriatric care - predictive validity of updated diagnoses.

Background and aim: The definition of sarcopenia was recently updated by the European Working Group on Sarcopenia (EWGSOP2), and consensus criteria for the diagnosis of malnutrition have been presented by the Global Leadership Initiative on Malnutrition (GLIM). The aim of this study was to investigate prevalence and mortality related to categorisation of patients according to these definitions in a geriatric hospital setting. Method: Fifty-six consecutive geriatric inpatients (84y (SD 7.3), 68% women) underwent test of handgrip strength (HGS) and five-rise chair stand test (5CST). Muscle mass and fat free mass (FFM) were evaluated by Dual X-ray Absorptiometry (DXA). Calf circumference (CC) was recorded. Probable sarcopenia was defined, according to EWGSOP2, as low HGS (<27/16 kg for men/women) and/or 5CST >15 s; sarcopenia was confirmed when coupled with low appendicular skeletal muscle index (ASMI <7.0 and <5.5 kg/m2 (m/w)). Malnutrition was defined according to GLIM as weight loss >5% (past 6 mo); BMI <20/22 kg/m2 (<70/>70y); and FFM-index <17/15 kg/m2 (m/w) combined with reduced food intake and/or disease burden/inflammatory condition. Alternatively, CC <31 cm was used as a proxy for low muscle mass for both sarcopenia and malnutrition. One- and two-year mortality was registered.

Results: All participants displayed probable sarcopenia; 46% and 20% were sarcopenic depending on whether muscle mass was estimated by DXA or CC. Malnutrition according to the GLIM criteria was prevalent in 64% or 60% (muscle mass by DXA or CC, respectively). Nine in ten with sarcopenia were also malnourished. Twenty-six participants (46%) died within two years. Sarcopenia defined by CC <31 cm, but not by DXA, was associated with increased mortality; e.g. 2-y mortality HR was 3.19 (95% CI 1.31-7.75). Similarly, malnutrition according to GLIM related to increased 1-y mortality (HR 4.83, 95% CI 1.04-22.39) when DXA was used for muscle mass estimation. All of the participants with CC <31 cm were categorised as both sarcopenic and malnourished.

Conclusion: In this small set of well-characterised geriatric inpatients all displayed probable sarcopenia. Prevalence of sarcopenia (EWGSOP2) and malnutrition (GLIM) was 20-46% and 60-64%, respectively. Both conditions related to mortality. CC <31 cm hold promises to be an acceptable alternative for DXA as a proxy for low muscle mass.