Background: Patients with the sugar metabolism disorder, Glycogen Storage Disease Type V, have insufficient breakdown of sugar stored as, glycogen, within the cells. The investigators know from previous studies with McArdle patients, that they not only have a reduced sugar metabolism, both also have problems in increasing their fat metabolism during exercise to fully compensate for the energy deficiency. Studies on Triheptanoin diet used in patients with other metabolic diseases have shown that Triheptanoin can increase metabolism of both fat and sugar. In these patients, Triheptanoin has had a positive effect on the physical performance and has reduces the level of symptoms experienced by patients. Aim: To investigate the effect of treatment with the dietary oil, Triheptanoin, in patients with McArdle disease on exercise capacity. Methods: 20-30 adult patients will be recruited through Rigshospitalet in Copenhagen, Denmark, Hopital Pitié-Sapêtrière in Paris, France and through The University of Texas Southwestern Medical Center in Dallas, Texas. 1. Pre-experimental testing (1 day): Baseline blood samples are collected to obtain baseline values of safety parameters: Plasma-acylcarnitines, free fatty acids and creatine kinase. Subjects perform a max-test to determine their VO2max 2. Treatment period #1 (2 weeks): Subjects follow a diet consuming a dietary treatment oil. Neither patients nor members of the study group know who receive which type of oil. 3. Washout period (1 week): Subjects receive no treatment 4. Treatment period #2 (2 weeks): Subjects who received Triheptanoin oil in the first treatment period, now receive placebo oil and vice versa. Assessments: Before and after each treatment periods, subjects perform a 30-minutes exercise test on a cycle ergometer, comprising of 20-22 minutes of constant load exercise and 6-8 minutes increasing load to peak. Subjects will complete a Fatigue Severity Scale questionnaire and metabolic products will be measured in blood and urine.
Age range
18 Years – 65 Years
Sex
ALL
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Change in heart rate during constant load cycling exercise (HRconst) with Triheptanoin vs. placebo treatment
Timeframe: Day 14 and day 28