Nutritional Prevention of Exertional Muscle Dysfunction
Condition: Muscle Dysfunction; Exertional Rhabdomyolysis; Muscle Strength
MeSH terms: Rhabdomyolysis
Study type: Interventional

Summary: 
      The investigators want to find out whether a choline supplement can protect muscle health in
      young men with very common genetic vulnerabilities. Men, who respond to a brief, but intense
      set of arm exercise and have a common genetic profile, will be asked to use a choline
      supplement for three weeks and a placebo for three weeks. Before the begin of the
      supplementation study and after 3 and 6 weeks the investigators will test response to the
      exercise challenge and ask that all consumed foods are recorded.
    

Detailed description: 
      An initial screening questionnaire will determine general eligibility. The investigators will
      screen white young males with low to moderate choline intake (<450 mg/d) for CK response to
      exercise (high/low) by having them do intense eccentric exercise (12 elbow flexor
      contractions of non-dominant arm with dumbbell at 100% maximal lift capacity) and then 72
      hours (3 days) later draw 250 μl capillary blood by finger stick for CK, metabolomic and
      genetic measurements.

      The investigators plan to recruit 30 CK responders with an 1958 A allele of the
      methylenetetrahydrofolate dehydrogenase 1 (MTHFD1), which is present in about 60% of
      Caucasian males.

      All participants will be asked to complete on three days 24-hour diet interviews with an
      online automated program provided by the National Cancer Institute. Participants of the
      intervention study will also have to be complete interviews on the final three days of the
      two intervention periods The recruited candidates will do an initial exercise challenge with
      no intervention, then a second challenge after three weeks with the first supplement
      (randomized choline or placebo), then a third challenge after another three weeks with the
      complementary second supplement (choline if they had placebo first, placebo if they had
      choline first).

      Samples identified only by code will be stored indefinitely at the UNC Nutrition Research
      Institute to permit the analysis of additional genetic markers related to muscle health and
      choline metabolism when the capacity for the analysis of such markers becomes available. Such
      analyses may be carried out at the University of North Carolina Nutrition Research Institute
      (UNC NRI) or at external laboratories providing the service for the PI. Samples will be
      destroyed once no such additional analyses are intended or feasible anymore or if the
      investigators do not continue this research. Storage of the samples is not optional.
    

Intervention name(s): Choline; Placebo
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): 4 capsules with 480 mg choline per day
Intervention MeSH terms: Choline
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Supportive Care
Keywords: muscle; muscle dysfunction; choline; exercise; exertional rhabdomyolysis; rhabdomyolysis