Regulation Of Insulin Sensitivity By Reactive Oxygen Species
Funder
National Health and Medical Research Council
Funding Amount
$564,644.00
Summary
In morbid obesity and type 2 diabetes chronic levels of reactive oxygen species (ROS) are detrimental and diminish insulin's ability to maintain normal blood glucose levels. Paradoxically, ROS also promote insulin action by inhibiting enzymes known as protein tyrosine phosphatases (PTPs). This proposal will determine whether the promotion of ROS for the inhibition of PTPs early in the progression of type 2 diabetes may be of therapeutic benefit.
Nutrient And Hormone Delivery To Muscle: Interactions Between Insulin And Exercise
Funder
National Health and Medical Research Council
Funding Amount
$304,375.00
Summary
Exercise is known to be beneficial in the treatment and prevention of Type 2 diabetes and in particular muscle insulin resistance. Also, exercise and insulin share similar acute actions on muscle. Firstly, muscle contraction has a well established action to increase glucose uptake, and secondly, both muscle contraction and insulin act to increase capillary recruitment. This latter phenomenon is thought to enhance nutrient delivery and waste product removal. There is evidence that the increase in ....Exercise is known to be beneficial in the treatment and prevention of Type 2 diabetes and in particular muscle insulin resistance. Also, exercise and insulin share similar acute actions on muscle. Firstly, muscle contraction has a well established action to increase glucose uptake, and secondly, both muscle contraction and insulin act to increase capillary recruitment. This latter phenomenon is thought to enhance nutrient delivery and waste product removal. There is evidence that the increase in capillary flow due to muscle contraction is accompanied by increases in total blood flow. For insulin action we now have preliminary data to indicate that capillary recruitment occurs within a 5-10 min application of a physiologic dose of insulin independent of a change in total blood flow suggesting a redistribution of flow. Muscle contraction also increases capillary recruitment and it raises the question of whether similar mechanisms underlie insulin- and muscle contraction-induced capillary recruitment or whether there are distinct and complementary pathways. In this project we plan to define the mechanisms responsible for contraction- and insulin-induced capillary recruitment in muscle. We hypothesize that similar mechanisms are operative, with both insulin and muscle contractions acting via NO-dependent mechanisms. Because of capillary reserve, and different initial steps of the signalling systems stimulated by insulin and exercise, capillary recruitment by combined contraction and insulin stimuli will be additive at both sub maximal and perhaps at maximal insulin pathway stimulation. Signalling mechanisms will be compared and the role of non-nutritive route as a flow reserve assessed.Read moreRead less
Dietary Protein Effects In Elderly Women: Musculoskeletal, Renal, Cardiovascular And Body Composition Endpoints
Funder
National Health and Medical Research Council
Funding Amount
$478,946.00
Summary
Fractures and falls of the elderly are major health problems in our community in terms of disability and cost. It is critical to the future health of our aging population to develop non-pharmaceutical interventions to maintain health into old age. Epidemiologic studies have shown that relatively high protein intake is associated with increased bone mineral mass and reduced incidence of osteoporotic fracture in elderly people. Low protein intakes can lead to loss of muscle mass. To date there hav ....Fractures and falls of the elderly are major health problems in our community in terms of disability and cost. It is critical to the future health of our aging population to develop non-pharmaceutical interventions to maintain health into old age. Epidemiologic studies have shown that relatively high protein intake is associated with increased bone mineral mass and reduced incidence of osteoporotic fracture in elderly people. Low protein intakes can lead to loss of muscle mass. To date there have been no randomised trials of sufficient duration to examine the effects of increased dietary protein intake on bone and muscle health of the elderly. The aim of this study is to examine the effectiveness of protein supplementation for the prevention of osteoporosis and muscle wasting in elderly women, and the safety of such an intervention through monitoring renal function and risk factors for cardiovascular disease. Two hundred and twenty women will be recruited to this study and be assigned to protein group or placebo group. Women in the protein group will received 250 ml high protein drink (containing 30 g protein) per day and women in the placebo group will receive placebo drink containing the same amount of energy, calcium but no additional protein. Bone structure, muscle mass, body composition, renal function and risk factors for cardiovascular disease will be monitored during the 2 year study period. The results of this randomised, controlled study will clarify the role of protein on bone mass and structure, muscle mass and body composition in the elderly. At the same time, the safety of such intervention on renal and cardiovascular endpoints will also be evaluated. It is envisaged that the results of this study if positive will translate into both immediately applicable intervention strategies that are relevant at a program and an individual level.Read moreRead less