The Relationship between Low Skeletal Muscle Mass and Subsequent Oral Intake Ability among the Aged Population

This study aimed to determine the relationship between skeletal muscle mass in an aged population with limited oral intake upon admission and functional oral intake at the subsequent 3-month follow-up. Methods: This was a retrospective cohort study using the Japanese Sarcopenia Dysphagia Database involving older adults (≥60 years) with limited oral intake (Food Intake Level Scale [FILS] level of ≤8). People without skeletal muscle mass index (SMI) data, unknown methods of SMI evaluation, and SMI evaluation by DXA were excluded. Data for 76 people (47 women, 29 men) were analyzed (mean [standard deviation] age: 80.8 [9.0] years; median SMI: women, 4.80 kg/m²; men, 6.50 kg/m²). There were no significant differences in age, FILS upon admission and methods of nutrition intake between the low (n = 46) and the high skeletal muscle mass groups (n = 30), although the proportion of sex between the two groups was different. The FILS level at the time of follow-up differed significantly between the groups (p < 0.01). The SMI upon admission (odds ratio: 2.99, 95% confidence interval: 1.09-8.16) were significantly associated with the FILS level at the time of follow-up after adjustment for sex, age, and history of stroke and/or dementia (p < 0.05, power = 0.756). Conclusion: A low skeletal muscle mass is a disadvantage for achieving a subsequent fully functional oral intake ability among the aged population with limited oral intake upon admission.