HSE320 Week 7 Lecture 2022 PDF

8/28/2022 HSE320 Exercise, Health and Disease Ageing and Sarcopenia Part A: Understand Ageing and the Physiological...

8/28/2022 HSE320 Exercise, Health and Disease Ageing and Sarcopenia Part A: Understand Ageing and the Physiological Changes that occur Throughout Life 1 Learning Objectives On completion of this presentation, you should be able to:  Have an understanding of the ageing process and its definition(s).  What are the consequences of ageing.  Identify some of the theories that are currently used to explain ageing.  Briefly discuss whether the ageing process can be slowed.  Identify the key physiological changes associated with ageing. 2 What is Ageing? One of the certainties of life is that everyday everyone grows older, but they do so in different ways and at different rates. Ageing is not a disease Life expectancy has changed dramatically in this century: a baby born in 1900 lived to 47 years. A baby born between 2010‐12 can expect to live to 79.9 years (boy) and 84.3 years (girl). Maximum lifespan (100 years) has not changed. 3 1  8/28/2022 Ageing Population - Australia Grey Tsunami – The world faces a wave of ageing  From 1973 to 2013, the number of people aged 65+ years tripled, from 1.1 to 3.3 million.  There was a 6‐fold increase in the number of people aged 85+ years. 4 Chronic Disease and Ageing More likely to have: Distribution of selected long-term  CAD condition by age group, 2004-5  Arthritis  Hypertension  Type 2 Diabetes  Alzheimer's / Dementia  Cancer Increased risk of:  Obesity  Osteoporosis  Hypertension  Poor CV fitness  Poor balance  Vision/ hearing problems  Neuromuscular disorders 5 What is Ageing? Ageing refers to a process or group of processes occurring in living organisms that with the passage of time lead to a loss of adaptability, functional impairment, and eventually death. Strehler (1962) outlined five criteria’s for ageing:  Cumulative: Effects of ageing increase with time.  Universal: All members of a species display signs of ageing.  Progressive: Ageing is a series of gradual changes.  Intrinsic: Changes would take place even in a “perfect” environment.  Deleterious: Changes which occur compromise normal biological functions. 6 2  8/28/2022 Contemporary Theoretical Frameworks for Ageing Paradigm Shift in How Ageing is Conceptualised – Different Frameworks  Active Ageing ‘The process of optimizing opportunities for physical, social and mental well‐being throughout the life course, in order to extend healthy life expectancy, productivity and quality of life in older age’ (WHO, 2002).  Healthy Ageing ‘Ability to continue to function mentally, physically, socially, and economically as the body slows down its processes’ (Hansen‐Kyle, 2005).  Productive Ageing ‘Any activity by an older individual that produces goods or services, or develops the capacity to produce them, whether they are to be paid for or not (Bass, Caro and Chen, 1993).  Successful Ageing ‘Low probability of disease and disease‐related disability; high cognitive and physical functioning and active engagement with life’ (Minkler and Fadem, 2002). 7 What Causes Ageing? Little is known about the cause of ageing, but a number of theories are proposed: Damage (Error) theory: Ageing is a result of external or environmental assaults that damage cells or organs so they can no longer function properly  Rate of living theory  Free radical theory  Cross linking theory  Wear and tear theory  Theory of error catastrophe  Somatic mutation theory Programmed theory Human body is designed to age and there is a certain biological timeline.  Endocrine theory  Programmed senescence theory  Immunological theory Jin K. Aging Dis. 1(2): 72–74, 2010 8 Leading Causes of Death in Australia 2003 2007 2012 http://www.abs.gov.au/ausstats/[email protected]/Lookup/3303.0main+features100012012 Ischaemic heart disease: includes angina, blocked arteries of the heart and heart attacks. Cerebrovascular diseases: include haemorrhages, strokes, infarctions and blocked arteries of the brain 9 3  8/28/2022 Factors Contributing to Chronic Disease 10 Why Some People Live Longer? Super seniors in three widely separated regions share a number of key habits, despite many differences in backgrounds and beliefs 11 What May Slow Ageing?  Calorie restriction? Decrease in serum insulin or insulin‐like growth factor‐ 1 (IGF‐1)?  Antioxidants? Antioxidants are naturally occurring chemicals in foods that counter the negative impact of free radicals in our bodies.  Resveretrol? Resveratrol is a member of a group of plant compounds called polyphenols. These compounds are thought to have antioxidant properties.  Hormone therapy Estrogen (HRT), testosterone, growth hormone?  Regular exercise? 12 4  8/28/2022 Physiological Changes with Age Source Undetermined 13 Age-related Changes in Exercise Capacity Change in Running and Swimming Time in Men and Women Tanaka et al J Appl Physiol 2003 14 Cardiovascular Change with Ageing   Maximal Oxygen Update Overall decline averages 0.4 to 0.5 mL/kg/min per year (10% per decade), regardless of activity status.   Max Heart Rate Maximum HR decreases by about 5‐10 beat per decade (little change in resting HR) due to decreased sympathetic nervous system activity and changes in cardiac conduction; slowed HR response at exercise onset.   Cardiac Output / Stroke Volume Decrease in maximal cardiac output and reduced (or unchanged) stroke volume (can be maintained with training); decrease in (a‐v)O2 difference due to loss of contractile strength, stiffened heart wall (decrease in SV). 15 5  8/28/2022 Cardiovascular Change with Ageing   Blood Pressure Blood pressure at rest (especially systolic) increases with age.   Blood Volume and Composition Reduced total and plasma volume; small increase in haemoglobin concentration;  kidney function.  Vascular / Endothelial Function Aorta and its major branches stiffen; vasodilator capacity and endothelium‐dependent dilation of most peripheral arteries decreases; increase in left ventricular wall thickness.  Regional blood flow and capillary density Leg blood flow is generally reduced at rest (and with submaximal and maximum exercise); capillary density decreased. 16 Pulmonary Changes with Ageing  Ventilation Total lung capacity remains unchanged, but there is a decrease in lung compliance and chest wall thickness: ‒ Increase in chest wall stiffness ‒ Decrease in static elastic recoil of the lungs ‒ Decrease in expiratory muscle strength Vital capacity decreases progressively with age (loss of up to 40‐50% by age 70); FEV1 decreases; maximum voluntary ventilation diminishes by up to 50% with age, while residual volume  30 to 50%.  Gas Exchange Loss of alveoli and increased size of alveoli reduces surface area for O2 and CO2 exchange in the lungs. Pulmonary gas exchange does not usually limit exercise performance in older adults. 17 Body Composition and Muscle Function Decreased  Height (1 cm per decade from age 40‐50 yrs)  Bone density and strength  Muscle mass and size  Muscle strength  Muscle power  Muscle contraction velocity (type II fibres, esp lower body)  Muscle endurance / fatigability  Muscle mitochondrial function  Muscle oxidative enzyme capacity  Resting metabolic rate (related to  muscle mass), muscle protein synthesis and fat oxidation  Gait speed, balance and mobility Increased  Weight  Visceral fat mass  Total body fat  Intramuscular lipid accumulation NB: more detailed information to come in next presentations. 18 6  8/28/2022 Other Physiological Changes with Age  Proprioception Decreased sense of limb position and movement (esp foot and ankle); decreased vibratory sensation in feet, and reduced vestibular system function.  Cartilage, Tendons, Ligaments Collagen cross‐linkage, thinning cartilage, tissue elasticity; some decrease in water content of tendons & ligaments contribu ng to ↓ mobility.  Immune Function Efficiency of immune system tends to decline with age; non‐specific defenses become less effective; ability of the body to make antibodies diminishes.  Brain and Neurological Function Loss of gray matter; slowed neural transmission; decrease size of motor units (decreased reaction time); decreased cognitive processing speed, attention span and memory. Campbell et al., (1973) J Neurol Neurosurg Psych 36:74‐182. 19 Other Physiological Changes with Age 20 Self Assessment Quiz  Question Briefly outline how ageing if often described, and the different theoretical frameworks currently proposed.  True or False? Dementia and Alzheimer’s disease is now one of the top three causes in death in Australia.  Question Briefly explain the difference between the Damage (Error) and Programme theory of ageing.  Question Briefly explain some of the proposed factors that may increase an individuals longevity.  True or False? VO2 max does not decrease with age if you maintain an active lifestyle.  Question Describe at least 5 cardiovascular and 5 musculoskeletal changes that typically occur with ageing. 21 7  8/28/2022 HSE320 Exercise, Health and Disease Ageing and Sarcopenia Part B: Importance of Muscle for Health and the Consequences and Mechanisms Underlying Sarcopenia and Dynapenia 22 Learning Objectives On completion of this presentation, you should be able to:  Understand the importance of muscle for physical and metabolic health.  Understand the clinical importance of age‐related changes in muscle mass, strength, power and function.  Have an understanding of the major factors contributing to sarcopenia and dynapenia. 23 24 8  8/28/2022 25 Muscle Physiology and Function  Largest mass of tissue in the human body  Essential for locomotion and maintaining posture  Assists to maintain the integrity and structure of bone  Significant reserve of energy (amino acids stored as protein)  Primary site of glucose disposal, fat use and protein stores  Major site of hormone action (insulin) 26 Pathway To Age Associated Disability Reid and Fielding Sports Med 40(1):4‐12, 2012 27 9  8/28/2022 Age-related Muscle Loss Heterogeneity in the Timing and Rate of Muscle Loss 28 ‘Anabolic Resistance’ of Ageing Understanding muscle gain and loss Balance between Muscle Protein Synthesis (MPS) and Breakdown (MPB) The primary reason for muscle loss in healthy older adults is the inability of older muscles to mount a robust 'youthful' protein synthetic response to anabolic stimuli (e.g. protein, exercise) above that seen in the basal-state Breen and Phillips. Nutrition Metab 2011; 8:68. 29 Sarcopenia Classical Definition In 1989, Irwin Rosenberg proposed the term ‘sarcopenia’ (Greek: sarx‐flesh, penia‐loss) to describe age‐related muscle loss. Updated Definition Loss of muscle mass, strength and/or impaired function 30 10  8/28/2022 Dynapenia Dynapenia is the age‐associated loss of muscle strength that is not caused by neurologic or muscular diseases. Rates of loss in leg muscle strength is about 2‐4 fold greater than leg muscle mass Ferrucci L. et al. J Gerontol A Biol Sci Med Sci (2012) 67A(1):13‐16BH 31 Functional Impairment Risk of Poor Physical Performance or Disability in Adults with Low Muscle Strength or Muscle Mass Relative risk (RR) of poor physical performance, functional limitation or physical disability is:  2.2‐fold for low muscle strength  1.4‐fold for low muscle mass Manini TM and Clark DC. J Gerontol A Biol Sci Med Sci 2011 32 33 33 11  8/28/2022 34 34 Age-related Changes in Muscle Function Differences in the age at which strength, balance and gait begin to decline Changes in graphs represent the mean change after 10 years in those that when from 50 to 60, 60 to 70 and 70 to 80 years of age. All analyses were performed adjusting for: height, rural/urban living, change in self reported disability, change in disease/medication use, change in habitual physical activity, menopause status, smoking history, and baseline values for the respective measurements Daly et al. BMC Geriatrics 2013 35 Impaired Function and Fracture Risk Poor physical function is associated with an increased risk of hip fracture in older men, independent of BMD 4.0 3.6  risk 3.5 Hazard Ratio of Hip Fracture 3.0 2.5 2.4  risk 2.0 1.6  risk 1.5 1.2  risk Ref Ref Ref Ref 1.0 0.5 0.0 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Chair stands Leg power Gait speed Grip strength Quartiles of Physical Performance Measures MrOs study: 5995 men aged 65+ yrs; Adjusted for age, clinical center, femoral neck bone mineral density, body mass index, history of heart attack and history of stroke. Cawthorn et al. J Bone Miner Res 23(7): 1037‐44, 2008 36 12  8/28/2022 Age-related Loss in Muscle Power Muscle Power (Force x Velocity) = Ability to Produce Force Rapidly Muscle power is required for everyday tasks like stepping quickly; Jumping Muscle Power (W Kg) movement (contraction) velocity is a sensitive risk factor for falls. Muscle power begins to decline from ~30 years of age, and is much more rapid than muscle strength. Lose up to 70‐75% from the age of 20 to 70+ years. Linear decrease in muscle power from the age of ~30 years. Age (years) Lose up to 70‒75% from the age of Runge et al. Clin Physiol Funct Imaging 2004; 24(6):335‒40. 30 to 70+ years. 37 Muscle Atrophy and Type II Fibres Reduced muscle mass with aging is mainly due to smaller type II muscle fiber size Nilwik R et al. Exp Gerontol 48:492‐98, 2013 38 Clinical Consequences of Muscle Loss 39 13  8/28/2022 Metabolic Consequences of Muscle Loss Adapted from Nair al. Am J Clin Nutr 2005;81:953‐63 40 Metabolic Double Jeopardy Does Obesity Contribute to Sarcopenia? 41 Metabolic Double Jeopardy Does Sarcopenia Contribute to Obesity?  Muscle is metabolically more active than fat and is responsible for about 30% of energy expenditure.  The energy released as a result of muscle protein synthesis varies by muscle mass: – Young adult ∼2000 kJ/d (480 kcal/d) – Elderly active ∼500 kJ/d (120 kcal/d)  A 10‐kg difference in lean mass would lead to differences in energy expenditure equal to ∼420 kJ/d (100 kcal/d). Over the course of a year this would lead to a potential gain of 4∙7 kg in fat mass. Vincent et al. Ageing Research Review, 2012 42 14  8/28/2022 Mechanisms Underlying Sarcopenia Scheme of the etiological sarcopenia mechanisms and their consequences Indirect Sarcopenia Beas‐Jiménez et al. Rev Andal Med Deporte. 2011;4(4):158‐166 43 Dynapenia Importance of neural changes to muscle loss Clark and Manini J Gerontology: Med Sci 2008;63A;8:829‐34 44 Self Assessment Quiz  Question Define dynapenia and explain how it differs from sarcopenia?  True or False? After the age of 40, the rate of loss in muscle power is greater than the loss in muscle strength which is greater than the decline in muscle mass.  Question List at least 5 reasons as to why skeletal muscle is important for both physical and metabolic health.  True or False? An increase in fat mass (obesity) has been shown to be associated with a loss in muscle mass (sarcopenia)?  Question Describe at least 5 factors which may contribute to development of muscle loss and sarcopenia? 45 15  8/28/2022 HSE320 Exercise, Health and Disease Ageing and Sarcopenia Part C: Sarcopenia and Frailty Diagnosis and Management Approaches 46 Learning Objectives On completion of this presentation, you should be able to:  Define sarcopenia and how it is diagnosed (along with sarcopenic obesity).  Have an understanding of some of the limitations associated with the current criteria used to diagnose sarcopenia.  Describe the clinical consequences of sarcopenic obesity.  Understand the differences between sarcopenia and frailty.  Have an understanding of some of the key lifestyle approaches that can be used to prevent and manage sarcopenia. 47 Sarcopenia – More than Mass No universal consensus on the definition of sarcopenia 2010 European Consensus Definition ‘Sarcopenia is a syndrome characterised by progressive and generalised loss of skeletal muscle mass and strength with a risk of adverse outcomes such as physical disability, poor quality of life and death.’ Diagnosis based on documentation of the following criterion: 1. Slow gait speed 2. Low muscle strength 3. Low muscle mass 48 16  8/28/2022 Algorithm for Sarcopenia Slowness + Weakness + Low Lean Mass 1. Physical Function – Gait speed 1.2g/kg body weight/d) is advised  Most older people who have acute or chronic diseases need even more dietary protein (i.e. 1.2‒1.5 g/kg body weight/d)  Per‐meal anabolic threshold dietary protein intake (or post‐exercise) is higher in older individuals: 25‒30 g protein per meal Bauer J et al. J Am Med Dir Assoc 2013; l8:542‒59. 77 Strategies for Sarcopenic Obesity In 2005, the ASN and the NAASO (Obesity Society) recommended: “…. obese older person engage in weight loss regimens that will minimise the loss of lean mass if they are afflicted by functional limitations or medication complications as a result of obesity”. Adverse effects often associated with weight loss in older adults: ‒ Loss of lean tissue mass ‒ Decrease muscle function ‒ Loss of bone density Weinheinmer et al. Nutr Rev 2010 Villareal et al. N Eng J Med 2011;364:1218‐29 78 26  8/28/2022 Self Assessment Quiz  Question Describe some of the current limitations associated with the criteria used to diagnose sarcopenia.  True or False? Sarcopenia is defined as low total body lean mass, low muscle strength and slow gait speed.  Question Describe the key differences between sarcopenia and frailty.  True or False? Increasing dietary protein intake to >1.2 g/kg/d is an effective approach to stop age‐related muscle loss.  Question Describe some of the key lifestyle strategies which can be used to help prevent and/or manage sarcopenia and sarcopenia obesity. 79 27