Influence of body composition and muscle strength on functional outcomes in post-acute stroke

Abstract

Despite skeletal muscle is the main effector organ of disability in stroke, there is a paucity of data on skeletal muscle disorders in stroke. In addition to loss of muscle mass as a result of normal ageing, reduced physical activity, poor nutrition, and hormonal changes can play a role in the development of sarcopenia in stroke. This preliminary study was aimed to determine the influence of body composition and muscle function on functional outcomes in patients with post-acute stroke. Within 2 weeks of stroke onset, 45 subjects (66.1 ± 8.8; 32 men) with a first ischemic stroke event were prospectively assessed during in-patient rehabilitation hospitalization. The main variables were fat-free mass and fat-mass (in kg and as a percentage of reference values) assessed with electrical impedance, body mass index (BMI), maximal isometric handgrip strength of non-paretic upper limb, and functional status assessed with the Barthel Index (BI) at hospital discharge. According to BMI, patients were classified in low weight ( n = 2), normal weight ( n = 10), overweight ( n = 20) and obesity ( n = 13). Fat-free mass was reduced in 3 patients and fat-mass in 8. Obese patients had lower BI (mean difference: 22.7, 95% CI: 8.6–36.8, P = 0.002, at admission; 14.9, 95% CI: 0.58–29.1, P = 0.042, at discharge). Twenty-eight patients had reduced strength of the non-paretic handgrip; these patients had lower BI (mean difference 15.2, 95% CI: 0.8–29.6, P = 0.039), but no differences in BI improvements at discharge were detected. Strength in the non-paretic hand is reduced in 62% of the sample. Obesity and reduced handgrip strength are associated with worse functional status during stay in a neurorehabilitation ward. Further studies are required to assess the influence of body composition and muscle strength on functional outcomes.