Muscle dysfunction is associated with poorer health-related quality of life in adults with sickle cell anaemia

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 ${}^{\circ }$ /s. There was a significant correlation between the peak torque (PT) at 240 ${}^{\circ }$ /s and the physical component summary (SF-36 ${}_{\text{PCS}}$ ) 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 ${}^{\circ }$ /s and the SF-36 ${}_{\text{PCS}}$ ( $r=$ 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.