Ask a Scientist
The Muscular Dystrophy Campaign research team is always available to answer any questions about research. Questions we don't know the answer to, we refer to our network of scientists and clinicians working in the field. In this article we posed someof the questions we have received recently to top researchers for further expert opinions.
Q. Our 14 year old son has Duchenne muscular dystrophy. The doctors have suggested using the supplement creatine based on a report by 'The Cochrane Collaboration' published in February 2011. Is there any recommended protocol or dosing regimen for the use of creatine?
Geoffrey and Fiona McMullen, Northern Ireland.
A. Creatine is a naturally occurring substance in the body that helps to supply energy to muscle and nerve cells. We get approximately half of our creatine supply from food, especially meat and fish, and our liver and kidneys produce the rest. Athletes and body builders have used creatine supplements for decades to improve their performance.
The Cochrane Collaboration independently and systematically reviews research into human health care. In their review "Creatine for treating muscle disorders" they analysed the results of 14 randomised controlled trials of creatine treatment involving 364 participants with a wide variety of muscle conditions. They concluded that creatine treatment increased muscle strength in muscular dystrophies but not in metabolic myopathies (lipid and glycogen storage diseases and mitochondrial myopathies).
In the review, three trials of creatine for Duchenne muscular dystrophy were included because they were considered of high enough quality. One of the studies also included three Becker muscular dystrophy patients. In total 60 trial participants took creatine and 61 took a placebo. When the trials were considered separately some of the results were inconclusive but by pooling the results in the Cochrane review they found that there was about a nine percent improvement in muscle strength in the treatment group (for example by measuring hand grip strength).
The Cochrane review commented that long-term studies (greater than one year) are not currently available to assess the safety of creatine supplementation in people with muscle conditions. However, in studies up to six months in duration there did not appear to be any significant side effects. Creatine is sold as 'creatine monohydrate' in pharmacies and health food stores. The usual dose is four grams daily for adults (e.g. two grams twice daily) and two grams daily for children (e.g. one gram twice daily) dissolved in a glass of liquid. If taking creatine supplements you should make sure you drink plenty of liquid throughout the day. If you are taking any supplements, you should always mention this to your doctor.
Professor Volker Straub, Newcastle University, TREAT-NMD Project Coordinator.
Q. If exon skipping becomes available as a treatment for Duchenne muscular dystrophy in the future, will it reverse the damage already done to the muscle? If not do you think anything could be done to help rebuild the damaged muscle?
The muscle wasting in Duchenne muscular dystrophy is caused by break down of the muscle tissue. This causes inflammation and eventually the muscle is replaced with scar tissue. Restoring dystrophin through exon skipping should stabilise the muscle and prevent further destruction and muscle wasting. This in turn will decrease inflammation - this has already been shown in the clinical trial conducted by AVI Biopharma - which will prevent further scar tissue formation. Thus the progression of Duchenne muscular dystrophy should stop and we hope there will be an improvement in muscle function as a direct result of the presence of dystrophin. The body has the potential ability to remodel some of the scar tissue once inflammation has stopped so there should be some further improvement in function. However, it might not lead to the formation of new muscle fibres or reduce the amount of existing scar tissue.
Clinicians and researchers think that a combination of treatment approaches might be needed to significantly improve muscle function in Duchenne muscular dystrophy. Once we understand how well exon skipping works to successfully halt the progression of Duchenne muscular dystrophy then we can look at ways to build up the remaining muscle. For example, researchers are currently working on finding ways to block myostatin (a protein that regulates muscle weight). It has been shown in animal models that this could increase the size of the remaining muscle. At present it is not clear whether we will be able to reverse the damage that has already been done to the muscle.
Professor Dominic Wells, Professor in Translational Medicine, Royal Veterinary College, University of London