The relation between mortality, intramuscular adipose tissue and sarcopenia in hospitalized geriatric patients

Introduction: One of the biggest healthcare challenges that arises with increasing age expectations is sarcopenia. However, as a multi-dimensional construct with both neurological and musculoskeletal factors involved, the exact contribution of these different components of sarcopenia to mortality outcomes is not clear. Therefore, in mortality assessment, it is advisable to use subitems of sarcopenia such as the intramuscular adipose tissue (IMAT), instead of using sarcopenia as a construct itself. IMAT is negatively correlated with strength and performance, and positively correlated with mortality, both all-cause and cardiovascular. In this study, IMAT and its relation to long-term mortality, muscle strength and function is studied.

Materials and methods: Patients admitted to the University Geriatrics Department during 6 months were screened for muscle mass, strength and function through computed tomography (upper leg), Jamar dynamometer and short physical performance battery, respectively. After 4 years, health status (mortality) was obtained by telephone.

Results: Three hundred and two patients were included (69.6% female). Mean IMAT was 29.3 ± 12.3%. There was a positive correlation between IMAT and mortality in the male 70-79-year-old age group (n = 20), but not in the whole cohort. IMAT was negatively correlated with muscle strength and function.

Conclusion: IMAT is negatively correlated with muscle strength and muscle function. IMAT is correlated with mortality in a specific subgroup of this cohort. This data adds to the discussion of the value of IMAT in the construct of sarcopenia. More studies need to be done regarding the evolution of IMAT in function of time and functional decline.