McArdle Disease Treatment by Ketogenic Diet

McArdle's disease or Glycogen storage disease type 5 (GSD5), the most common muscle glycogenosis, is a rare disabling condition with no effective treatment. There are indications that a special dietary regimen could positively influence the disease manifestations. After contradictory indications for protein rich vs carbohydrate rich diets, several preliminary studies and more and more patients own experiences are now pointing to a low carbohydrate ketogenic diet (LCKD) as possibly effective in improving exercise tolerance and reducing muscle damage. The investigators propose a multicentre randomized single blind controlled trial testing efficacy of an individualized LCKD in GSD5. The investigators will test the ability of a 6 months dietary regimen with a 3:1 LCKD inducing a BOHB blood concentration of 1.5-4 mmol/l to improve the aerobic capacity as measured by peak VO2 at exercise testing in GSD5 patients. Thirty molecularly defined MCA adults will be enrolled: to half of them randomly selected the dietary regimen will be prescribed, while subjects in the control group will follow their usual balanced diet. The evaluators will be blinded to the diet followed by the examined patient