Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant disease characterized by progressive weakness and atrophy of specific skeletal muscles. As growing evidence suggests that oxidative stress may contribute to FSHD pathology, antioxidants that might modulate or delay oxidative insults could help maintain FSHD muscle function. The main objective of this study was to test whether oral administration of vitamin C, vitamin E, zinc gluconate and selenomethionine could improve the physical performance of patients with FSHD. Adult patients with FSHD (n=53) were enrolled at Montpellier University Hospital (France) in a randomized, double-blind, placebo-controlled pilot clinical trial. Patients were randomly assigned to receive 500mg vitamin C, 400mg vitamin E, 25mg zinc gluconate and 200μg selenomethionine (n=26) or matching placebo (n=27) once a day for 17 weeks. Primary outcomes were changes in the two-minute walking test (2-MWT), maximal voluntary contraction and endurance limit time of the dominant and non-dominant quadriceps (MVCQD, MVCQND, TlimQD and TlimQND, respectively) after 17 weeks of treatment. Secondary outcomes were changes in the antioxidant status and oxidative stress markers. Although 2-MWT, MVCQ and TlimQ were all significantly improved in the supplemented group at the end of the treatment compared to baseline, only MVCQ and TlimQ variations were significantly different between groups (MVCQD: P=0.011; MVCQND: P=0.004; TlimQD: P=0.028; TlimQND: P=0.011). Similarly, the vitamin C (P<0.001), vitamin E as α-tocopherol (P<0.001), vitamin C / vitamin E ratio (P=0.017), vitamin E γ/α ratio (P=0.022) and lipid peroxides (P<0.001) variations were significantly different between groups. In conclusion, vitamin E, vitamin C, zinc and selenium supplementation has no significant effect on the 2-MWT, but improves MVCQ and TlimQ of both quadriceps by enhancing the antioxidant defences and reducing oxidative stress.
