Affiliations: [a] Rehabilitation Sciences Post-Graduation Programme, Augusto Motta University, Rio de Janeiro, Brazil | [b] Admiral Adalberto Nunes Physical Education Center (Brazilian Navy), Rio de Janeiro, Brazil | [c] Medical Sciences Post-Graduation Programme, School of Medical Sciences, State University of Rio de Janeiro, Rio de Janeiro, Brazil
Correspondence:
[*]
Corresponding author: Agnaldo José Lopes, Rehabilitation Sciences Post-Graduation Programme, Augusto Motta University, Praça das Nações, 34, Bonsucesso, 21041-010, Rio de Janeiro, Brazil. Tel./Fax: +55 21 21 2576 2030; E-mail: agnaldolopes.uerj@gmail.com.
Abstract: BACKGROUND: It is known that episodes of microvascular obstruction and oxidative stress in sickle cell anaemia (SCA) can damage muscle tissue. As a consequence, deterioration in muscle function may potentially contribute to poor health-related quality of life (HRQoL) in subjects with SCA, particularly those who do not use long-term treatment. OBJECTIVES: To evaluate muscle function in adults with SCA, to study the correlations between muscle function and HRQoL and to analyse the impact of hydroxyurea treatment. METHODS: Twenty-two adults with SCA and 20 matched controls were subjected to Short Form-36 (SF-36), respiratory muscle strength measurement, isometric hand grip strength (iHGS) measurement and knee isokinetic dynamometry. RESULTS: In relation to their healthy peers, adults with SCA had lower SF-36 scores, respiratory muscle strength and iHGS. Regarding the isokinetic test, adults with SCA showed lower values, especially in the variables measured in flexion and with an angular velocity of 240∘/s. There was a significant correlation between the peak torque (PT) at 240∘/s and the physical component summary (SF-36PCS) in both extension (r= 0.77; p< 0.001) and flexion (r= 0.82; p< 0.001). Significant correlations were also observed between the agonist/antagonist ratio at 240∘/s and the SF-36PCS (r= 0.50; p< 0.001). The use of hydroxyurea led to higher scores on the SF-36 and higher values in knee isokinetic dynamometry. CONCLUSIONS: Adults with SCA have muscle dysfunction, especially with regard to endurance of the knee flexor muscles. In these patients, there is a significant association between muscle function and HRQoL. Moreover, the use of hydroxyurea is associated with better HRQoL and less muscle dysfunction.
