GC2 Flashcards
What are the three types of ageing?
Normal ageing - gene related decline
Pathological ageing - accelerated decline due to disease states
Successful ageing - maintenance of physical and mental health in absence of disease
What is the effect of exercise on ageing?
Increased functional reserve
Increased lifespan and longevity
What are ADLs and is it considered as exercise?
Activities of daily living
e.g. getting dressed, walking around, cleaning etc
Physical activity is involved but generally not much. Exercise defined as planned, structured physical activity, and this is what benefits ageing
What is the definition of exercise
Physical activity that is structured and/or planned and is performed to maintain health or fitness
What percentage of the elderly report taking part in any regular physical activity?
29%
And this may be an exaggeration
What does lack of regular exercise in the elderly suggest about ageing?
Perhaps ageing is a state of chronic exercise deficiency?
What is sarcopenia?
Loss of muscle mass. Sarcopenia increases with age.
Decrease in muscle cells are lost as a result of atrophy and loss
What are the consequences of sarcopenia?
Decreased resting energy expenditure Decreased insulin sensitivity Decreased muscle mass and strength Increased risk of falls and disability Increased risk of mortality
What are the benefits of exercise (regardless of age)?
Weight loss (decrease in adipose and increase in lean body mass) Decreased blood pressure Increased aerobic capacity increased strength Increased insulin sensitivity Increased bone mass Increased emotional well being
What are benefits of exercise in the elderly?
Decreases rate of sarcopenia
Improves cardiovascular/aerobic capacity - which has further effect on sacopenia
Any exercise maintains functional reserve
What is effect of exercise on muscle oxidative enzyme capacity?
Increases muscle oxidative enzyme capacity
What is the effect of exercise on muscle protein synthesis?
Stimulates muscle protein synthesis
What would be the effect of exercise and high protein diet on muscle protein synthesis?
Increase
What is protein homeostasis a balance between and how is this imbalanced in ageing muscle cells?
Protein homeostasis is balance between protein synthesis and degradation
In ageing, balance is skewed so that more protein is degraded than is being synthesis
What can rebalance the impaired protein homeostasis seen in ageing muscle cells?
Exercise
Exercise increases protein synthesis in aging muscle cells
What does mTOR stand for and how may it be involved in age related changes in protein synthesis?
Mechanistic target of rapamycin
Major regulator of protein synthesis
Damage or mutations in mTOR may result in reduced protein synthesis
What signalling pathway is mTOR thought to be involved in and how might this link to aging?
mTOR is downstream of insulin like growth factor (IGF-1) receptor
Production of IGF-1 stimulated by GH. GH reduced in aging, causing less mTOR activation. mTOR is major regulator of protein synthesis, so GH reduction may be responsible for reduced protein synthesis
What is inflammaging?
Chronic low grade systemic inflammation that occurs during physiological ageig
What is the inflammatory effect of adipose accumulation between tissues and in muscle?
Increases release of proinflammatory proteins and cytokines
Exercise would prevent accumulation of fat between tissues and in muscles, so could reduce these proinflammatory effects
What is the effect of IL-6 on IGF-1 and what is this effect associated with?
IL-6 inhibits the anabolic effects of IGF-1 in muscle
This is associated with weakness in the obese elderly
How does exercise counteract inflammaging?
Exercise causes decreased adipose and increased lean muscle mass
Adipose accumulation between tissues and in muscle causes release of proinflammatory proteins and cytokines such as IL-6
What is the possible target of reservatrol?
SIRT1, member of the sirtuins family of enzymes
What type of enzyme is SIRT1 and what does it do?
NAD histone dependent deacetylase
Decetylates diverse histone and non-histone proteins
What are the anti-aging effects of SIRT1?
Thought to mediate effects of calorie restriction on longevity and cell metabolism
Down regulation of NFKB-dependent pro-inflammatory cytokine expression
What is the effect of SIRT1 on inflammation and how does it cause this?
Reduces inflammation
Down regulation of NFKB-dependent pro-inflammatory cytokine expression
What was aim of Lanza 2008 experiment and what were results?
To find out if mitochondrial dysfunction and insulin desensitivity were normal aspects of aging or secondary to physical inactivity
Reduced insulin insensitivity probably due to increased adiposity and physical inactivity
Normal age-related mitochondrial activity could be nomalised by endurance training
The longevity promoting effects of exercise are thought to occur through pathways shared with what other longevity promoting technique?
Calorie restriction
What are potential therapeutic methods of preventing sarcopenia?
Antioxidants
HSP inducers
