Forearm immobilization, metabolic health, and muscle loss

  • Research type

    Research Study

  • Full title

    The impact of Acipimox and Salbutamol supplementation on the development of insulin resistance and anabolic resistance during forearm immobilization in healthy, young volunteers

  • IRAS ID

    250839

  • Contact name

    Marlou Dirks

  • Contact email

    m.dirks@exeter.ac.uk

  • Sponsor organisation

    University of Exeter

  • Clinicaltrials.gov Identifier

    NCT03866512

  • Duration of Study in the UK

    2 years, 0 months, 1 days

  • Research summary

    Summary of Research

    Short periods of muscle disuse, which for instance occur during hospitalisation or limb immobilisation, lead to rapid muscle loss. The cause is currently unknown, but how our muscles use food energy may be crucial. Therefore, in the
    present study we will investigate how the availability of foodstuffs (carbohydrates, fat, and protein) in muscle affects the development of disuse-induced muscle loss. Healthy, young (18-40 y) males and females will undergo two days of forearm immobilisation in a cast, during which two different drugs (compared to a placebo) will be used to alter muscle foodstuff availability. The study will take place in the Clinical Research Facility on the RD&E hospital site, under well-controlled laboratory conditions. By taking blood samples from the forearm, we will measure how the altered foodstuff availability affects muscle loss. As such, this study will gain important insight in the roles of muscle disuse and nutrition in muscle health, and can be used to develop targeted interventions to preserve muscle mass and health during disuse.

    Summary of Results

    Periods of physical inactivity, such as a period of arm or leg immobilization, are often required for the recovery from injury. Such periods lead to loss of muscle mass, called muscle atrophy. The reason is likely linked to an impaired ability of muscles to extract important nutrients from blood. We believe that lowering the concentration of plasma lipids and/or stimulating glucose metabolism in muscle tissue will improve the muscle’s sensitivity to nutrients, and thereby attenuate muscle atrophy. We have measured how arm muscles of young people obtained nutrients from their blood after they were made physically inactive and fed a normal diet, combined with lipid-lowering medication, medication that stimulates glucose metabolism in muscle, or placebo, for 2 days.
    We showed that inactivity reduces the amount of glucose muscles take up by 40%. We also showed that lipid-lowering medication reduced the amount of glucose taken up when looked at on the whole-body level, and the medication that stimulates glucose metabolism increased this. The medication did not have an effect on the amount of glucose that the inactive muscles took up.

  • REC name

    Wales REC 4

  • REC reference

    18/WA/0330

  • Date of REC Opinion

    13 Nov 2018

  • REC opinion

    Further Information Favourable Opinion