Antioxidant supplement in FSHD helps muscle strength, life quality
Findings of small trial suggest supplements as new treatment strategy
Treatment with an antioxidant supplement led to improvements in muscle strength and quality of life for people with facioscapulohumeral muscular dystrophy (FSHD) in a small clinical trial.
The use of such supplements was particularly seen to improve the muscle quality of patients’ quadriceps — a group of muscles found on the front of the thigh.
By increasing physical functioning, supplementation was found to improve life quality for those with this form of muscular dystrophy, which typically most impacts the upper body and face.
“Our data suggest that antioxidant supplementation may represent a new strategy for improving the daily lives of patients with FSHD,” the researchers wrote.
Their study, “Muscle strength, quantity and quality and muscle fat quantity and their association with oxidative stress in patients with facioscapulohumeral muscular dystrophy: Effect of antioxidant supplementation,” was published in Free Radical Biology and Medicine.
Use of antioxidant supplement seen to improve strength in leg muscles
FSHD is caused by mutations that result in abnormal production of the DUX4 protein, which is toxic to cells. Although the exact mechanisms of how abnormal DUX4 production drives muscle cell dysfunction in FSHD are not fully understood, it’s thought that oxidative stress may play a major role.
Oxidative stress is a type of cell damage caused by reactive oxygen species, which are molecules made as a byproduct of cellular energy production. Antioxidants are molecules that can neutralize radical oxygen species, thereby reducing oxidative damage.
If oxidative stress is a major driver of disease in FSHD, then it follows that antioxidant treatment may be a useful strategy to slow disease progression. That theory led a team of scientists, primarily from the University Hospital of Montpellier, in France, to launch a clinical trial (NCT01596803) in 2012 to explore the idea.
The trial enrolled a total of 53 adults with FSHD, and participants were randomly assigned to take an antioxidant supplement or a placebo for about four months. The supplement specifically included 500 mg of vitamin C, 400 mg of vitamin E, 25 mg of zinc gluconate, and 200 micrograms of selenomethionine.
The study’s main goal was to assess whether the antioxidant treatment improved patients’ walking ability, and strength in their quadriceps, which are four individual muscles in the thigh. The results, published in 2015, showed the supplement led to significant increases in muscle strength. However, walking tests were not significantly different in patients receiving the treatment versus the placebo.
In this new study, the researchers presented analyses of MRI data from a subset of patients who had participated in the trial: 10 each from the antioxidants supplement and the placebo groups.
For these analyses, the team separately compared each patient’s stronger or weaker leg.
The results showed that the antioxidant treatment led to significant improvements in muscle volume in patients’ weaker (nondominant) legs. In patients’ stronger (dominant) legs, the antioxidant treatment was associated with improvements in muscle quality — that is, muscle strength per unit of muscle.
Antioxidants may be a relevant therapeutic option in patients with FSHD and should be considered in future treatment protocols.
Other biomarker data from these patients suggested that taking the antioxidant supplement led to reductions in oxidative stress, as designed. These results “suggest that the antioxidant response can be improved by antioxidant supplementation to reduce oxidative stress and increase the antioxidant defenses,” the scientists wrote.
The researchers also presented quality of life data from these patients, as measured with a standard questionnaire (SF-36) that assesses physical functioning, role limitations, bodily pain, general health perceptions, vitality, social functioning, role limitations, and mental health.
Patients given the antioxidant supplement reported significant improvements in life quality, relative to those given the placebo, the results showed.
Looking more closely at these scores, the researchers noted that the improvement in life quality for patients given the supplement “was explained by decreased difficulties in walking long distances, stair climbing, and lifting/carrying groceries.”
The team noted that the study was limited by its small sample size.
But overall, the scientists said, these data suggest that “antioxidants may be a relevant therapeutic option in patients with FSHD and should be considered in future treatment protocols.”
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