The relationship of pre-sarcopenia (low muscle mass) and sarcopenia (loss of muscle strength) with functional decline in individuals with intellectual disability (ID)

The aim was to determine the association between loss of muscle mass, loss of muscle strength, and physical ability in individuals with ID. Upper and lower extremity strength, muscle mass and muscle quality (MQ) were calculated. Physical ability was measured according to the Katz activities of daily living (ADL), stair climb test, and sit-to-stand test. We found a strong correlation between quadriceps strength and physical ability in ADL (r = 0.92 for males, and r = 0.88 for females), and a low-moderate correlation between hand grip strength and physical ability in ADL (r = 0.40 for males, and r = 0.46 for females). MQ showed a strong relationship between pre-sarcopenia and sarcopenia. Quadriceps strength is a promising measure of age-related muscle changes and it is strongly associated with physical and functional decline.