EMBARGOED FOR RELEASE UNTIL 10 AM ET, April 27, 2004
Creatine is Safe, but not Effective, in Pediatric Neuromuscular Disease
San Francisco -
The muscle supplement creatine can be safely taken by children with neuromuscular diseases, but does not improve strength or muscle mass, according to research that will be presented at the American Academy of Neurology 56th Annual Meeting in San Francisco, Calif., April 24 – May 1, 2004. Creatine stores energy within muscles, and creatine supplements are a mainstay of high-performance athletes and others trying to improve muscle output. “Patients with neuromuscular disorders have been found to have reduced concentrations of phosphocreatine, which is a marker for total creatine,” according to study author Jonathan Strober, MD. Strober is Director of the Pediatric Neuromuscular Program at the University of California San Francisco. Results of previous studies of creatine supplementation in neuromuscular diseases have been mixed. Some have shown mild benefit while others have shown none. Two reports indicated a worsening of pre-existing kidney dysfunction, but others have shown no significant side effects. Because of the recognized phosphocreatine deficiency, and because it is thought that children with neuromuscular diseases may benefit from increased strength, Strober tested the safety of creatine supplementation in five children with neuromuscular disorders: two boys with Duchenne muscular dystrophy (DMD), two girls with limb-girdle muscular dystrophy (LGMD), and one girl with chronic inflammatory demyelinating polyneuropathy (CIDP). All three conditions are characterized by muscle weakness. All the patients were between six and 10 years old. The patients took an initial loading dose of 25 milligrams per kilogram of body weight of creatine monohydrate, four times per day. After five days, they cut back to 50 milligrams per kilogram for the next 30 days. These doses are about a tenth of the doses used by high-performance adult athletes in training. Strober tested the safety of the creatine supplementation with a variety of blood and urine tests, given before, during, and 30 days after supplementation. Strength and motor function were also monitored throughout the study. All five children completed the study without significant side effects, indicating creatine supplementation appears to be safe in this population. However, creatine did not improve strength, muscle mass, or motor function for any of the children. The one patient with CIDP did have an increase in hip extension (range of motion) that lasted throughout the study, but three of the muscular dystrophy patients had decreased range of motion over the same period. “While creatine monohydrate appears to be safe in children with neuromuscular disorders, preliminary data suggest no short-term benefits in muscle mass, gross motor function, or strength,” said Strober.