Physical activity and muscle metabolism in old obese adults.
Research type
Research Study
Full title
Influence of increasing physical activity on body composition, metabolic health and muscle anabolism in overweight older adults.
IRAS ID
127842
Contact name
Leigh Breen
Contact email
Research summary
Two independent, but inter-related conditions that have a growing impact on healthy life expectancy and health care costs in developed nations are the age-related loss of muscle mass (sarcopenia) and obesity. Sarcopenia affects approximately one-third of adults over 60 years of age and more than 50% of those over 80 years, which is of concern when one considers that the most rapidly expanding population demographic in the UK is adults >80 years of age. Skeletal muscle is important in regulating blood glucose and insulin sensitivity. Thus, sarcopenia may play a role in exacerbating insulin resistance and progression toward Type II diabetes (T2D). Indeed, the highest incidence of T2D in the UK has been noted to occur in adults >65 years. Obesity is a major risk factor for chronic diseases including T2D and cardiovascular disease. Progression towards obesity is associated with a concomitant decrease in muscle mass, producing an unfavorable ratio of fat to muscle. Thus, obesity in old age may exacerbate the progression of sarcopenia.
For the proposed study we will conduct preliminary laboratory tests to characterize body composition, insulin sensitivity, systemic inflammation, aerobic capacity and muscle protein metabolism (in the fasted and fed-state) in healthy older and obese older adults. Following preliminary assessments obese older participants will complete 21 days of increased physical activity (PA), completing 8-10,000 steps per day, representing an increase of 200-400% above habitual step-count levels. Following the intervention preliminary tests will be repeated to determine the impact of increased PA improves body composition (i.e. ratio of fat to lean mass), insulin sensitivity, aerobic fitness and inflammatory status). Furthermore, we will measure muscle protein metabolism to determine whether the PA intervention enhances muscle protein metabolism; a mechanism that may explain the beneficial effects of the PA intervention the metabolic health parameters outlined above.
REC name
West Midlands - Black Country Research Ethics Committee
REC reference
13/WM/0429
Date of REC Opinion
3 Dec 2013
REC opinion
Further Information Favourable Opinion