Lifestyle: Physical Activity Flashcards
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Best prescription to cure/ prevent diabetes
walking 30 min a day
* Control went on with normal life nd highest prevalence
* Metformin had about 31% reduction
* Lifestyle has even better effect about 60% reduction in instance of diabetes
Why are metformin and lifestyle not additive?
Both act through the same pathway on AMPK
What is an important consideration for those who want to undertake vigorous exercise with T2D?
People with cardiovascular disease or microvascular complications of diabetes, who wish to undertake exercise that is substantially more vigorous than brisk walking, should have medical evaluation for conditions that might increase exercise-associated risk.
* May have underlying conditions hence why brisk walking is the best
What are problems doctors face in reccomending PA and solutions?
What was developed to help physicians prescribe exercise?
What is the goal for PA?
Individuals should strive to achieve 150 minutes per week of moderate-intensity PA combined with 2 days per week of vigorous-intensity PA
Immediate benefits of PA
- lower blood glucose within 1 hour
- improve mood, sleep patterns and energy levels
- Increase effectiveness of insulin your body makes or the insulin your doctor prescribed to you
Long-term benefits of PA
- Improve blood glucose control (HbA1c)
- reduce you body fat
- help keep pancreas, kidneys, eyes and nerves healthy
- reduce the risk of heart attack, stroke and death
Describe the graph
the more obese and less PA the more years of life that are lost
What is the dose relationship between PA and heart failure?
The higher amount of PA the less risk for CVD
What are the goals of aerobic training and resistance training?
- Aerobic training: goal is to increase aerobic capacity (max oxygen uptake), eg. running
- Resistance training: goal is to increase muscle mass, eg. weight lifting
What factors saw significant differences with AT or RT?
- TG: RT, combined vs. AT
- lean mass: RT, combined vs. AT
- abdominal visceral fat: AT
Is AT or RT better?
The combination of PA and reduced energy intake has been found to be more effective than either alone.
* AT is more effective then RT
What are the benefits of PA on T2D?
- Decreases body weight
- Displays protective cardiovascular effects both during exercise as well as at rest → increase in stroke volume, lower resting heart rate, lower blood pressure
- Increases insulin sensitivity
- Stimulates mitochondria biogenesis
- Regulates fat metabolism / TG oxidation
- Stimulates thermogenesis
- Produces different myokines, which in turn promote angiogenesis, neuroprotection, etc.
- Increases bone density
How does PA improve glucose uptake?
Both methods can stimulate pathways of glucose uptake but bypasses the need for insulin
* Mechanical stretch: PA is mechanical so with muscle contraction there is a mechanical stretch which activates signalling pathway to translocate GLUT4, so if insulin resistance is not responding, PA will still transfer GLUT4 to membrane to uptake glucose and therefore glucose disposal.
* Sensing of energy levels: As you work you use ATP to contract muscles and increase AMP/ATP which can activate AMPK and can also translocate GLUT4
Blood flow also increases allowing for better flow of glucose to cells for uptake
How does PA effect glycogen and mitochondria?
cAMP activity increases in response to PA
* cAMP stimulate PKA which then stimulates phosporylase a thus breaking down glycogen to glucose for short-term use. PKA additionally inhibits synthase b, preventing glycogensis
* cAMP → AMP → ↑ AMP/ATP whih stimulate AMPK and this stimulate GLUT4 translocation but also stimulates PGC1a for mito biogenesis for long-term glucose decrease by having more to to utilize glucose during exercise.
How was skeletal muscle discovered to be an endocrine organ?
Myostatin was the first identified myokine in 1997. The concept of myokine was proposed in 2003 when it became apparent that the skeletal muscle possessed endocrine properties and communicated with other organs.
What are hallmark myokines of the muscle?
- Cytokines (IL6, IL8, IL15, …)
- Growth factors (BDNF, FGF21,…)
- Other molecules (Irisin, musclin,…)
Role if Irisin and effect of PA
Muscle secretes irisin hormone with PA which signals adipose tissue to convert white fat to brown fat which is more beneficial because it produces heat and burns calories only for heat.
* increases lipolysis
* may signal neurogensis in the brain
Role of FGF21 growth factor and effect of PA
Acts on tissues (mainly adipocytes) to regulate glucose uptake, fatty acid oxidation and inhibit lipogensis by acting on its receptors
* With obesity FGF21 becomes resistance increasing circulating levels
* PA may improve its activity
Effect of PA on IGF/PI3K/Akt
- stimulates muscle vascularization to increase blood flow and thus more oxygen to muslce by creating new vessels (via VEGF & Fstl1/NOS)
- stimulates FGF21
Effect of PA on PGC-1
With PA, PGC-1 is stimulated by cAMP cascade and get more mitogenesis
Effect of PA in myostatin
PA inhibits secretion of myostatin so can build more muscle cells
Effect of PA on BNDF
- goes to brain and improves neuroplasticity
- stimulates AMPK to increase fat oxidation, glucose uptake, and myogenesis
- may improve motor unit regeneration
How does training adapt muscle to a healthy phenotype?
up-regulation of stress proteins (HO-1, HSPs)
* mitochondriogenesis (pGC-1a up-regulation)
* muscle hypertrophy
* angiogenesis
How does training improve anti-oxidants?
↑ antioxidant network in several tissues: upregulation of antioxidant enzymes/ proteins such as SOD, GPx, GCS, CAT, HO-1, HSP70
* blood, brain, liver, kidneys, gut, muscle fibres, vessels, heart
Overall effect of myokines
Is nutrition or PA more potent in reducing anthropometrics of T2D?
Dietary interventions alone are better with a greater effect on weight, BMI, waist circumference, and body fat than PA alone
* PA is still beneficial but produces only modest weight loss
* Together diet and PA is additive
