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Ageing concept

  2. Aging Concept • Aging is a pattern of life changes that occurs as one grows older. • Gerontology is the study of individual and collective aging processes – Biological age – Psychological age – Social age – Legal age – Functional age
  3. Normal Aging  Who is old? • Biological and psychological aging changes usually occur gradually, over years or decades, and as a result, there is no single age at which people in general can be said to be old. • Commonly people older than 65 are called ‘OLD’ • Gerontologists often draw finer chronological demarcations: • Young-old: <75 • Old-old: >75 • Oldest-old: >85
  4. Cognitive Abilities in Later Life: A Processing Resource Model • Declines in three fundamental cognitive-processing resources: 1. Processing Speed: reduced speed of information processing and response- most predictable 2. Working Memory: refers to short-term retention and manipulation of information held in conscious memory, a type of “online” cognitive processing. exa. Examples include consciously recalling a telephone number long enough to write it down 3. Sensory and Perceptual changes: decrements in visual and auditory acuity and other perceptual changes.
  5. Explanations of Cognitive Aging Changes • Neuropathological and neuroimaging studies: changes in brain with aging • generalized atrophic and white matter changes as well as region- specific variations in the extent of cell loss • Affected areas: Within the cortex, the prefrontal lobes are disproportionately affected, Hippocampus and entorhinal cortex are affected but data are conflictual • Subcortical monoaminergic cell populations, are also subject to prominent decline in aging • Spared areas: Temporo-parietal association areas • Areas in which there is relative sparing with age: the globus pallidus, the paleocerebellum, the sensory cortices, and the pons
  6. General Aging Trends
  7. General Aging Trends
  8. Factors That Influence Cognitive Aging
  9. Personality and Emotional Changes 1. Coexisting Stability and Change: • Developmental optimism: subjective growth in personality 2. Influences on Adult personality: three developmental forces: - Social clock - grand adaptive strategy: individual’s desire for continuity in personal past and present - genetic factors: A study of elderly twins and multigenerational families found a genetic contribution to negative affect but not to positive affect • Eriksonian Psychosocial developmental stages • Late adulthood: integrity vs despair • Virtue: wisdom
  10. Personality and Emotional Changes 3. Personality and Perceptions of Health: Older adults’ perceptions of their health have been linked to a variety of objective health outcomes, including mortality • Depression: affects subjective health concerns • Neuroticism: is inversely associated with self-perceptions of good health • Extraversion: is positively associated these associations were stronger among persons age 75 and older than among persons in their 60s and early 70s (Duberstein et al. 2003) 4. Emotions, Coping, and Well-Being: Emotions: old age is an emotionally rich and complex phase of life, and the salience of emotion, increases in later years have better control over emotions than do younger adults
  11. Personality and Emotional Changes • Coping: older people tend to cope with stressful events in different ways • rely more on emotion-focused forms of coping, as opposed to active, problem-solving approaches • Emotion-focused coping is more passive than confrontational, individual than interpersonal, and is oriented toward control of distressing feelings rather than toward alteration of stressful situations • Wellbeing: Specific stressful events have less of an effect on subjective well-being in old age than does attainment of personal goals or the onset of physical disability • A model relates resilience in old age (i.e., maintaining adaptive behavior in the face of stress and recovering from adversity) to a process of selective optimization, in which goals are reshaped to fit current limitations and environments, and resources are spared for personally important activities that sustain self-esteem
  12. Social Context of Aging • Old age is accompanied by role change and, often, role loss • expect transformations in occupational, family, and community roles 1. Education, Work, and Financial Status • Education: changes perception and thinking about life and health • Work: lack of work, loss of income, continuous work help physically as well as financially • Financial status: retirement, loss of income • Source of income: pension plans, social security, personal earnings, asset incomes 2. Marriage and Widowhood: 3. Retirement and Grandparenthood: 4. Extended Families, Friends, and Group Involvement:
  13. Biological Aging • What is Aging? • definition of aging was proposed by Birren and Zarit (1985): “Biological aging, senescing, is the process of change in the organism, which over time lowers the probability of survival and reduces the physiological capacity for self-regulation, repair and adaptation to environmental demands” • Modern gerontologists distinguish • Primary aging, which is postulated to reflect an intrinsic, presumably genetically preprogrammed limit on cellular longevity, • Secondary aging, which is due to the accumulated effects of environmental insult, disease, and trauma. • Primary aging seems to account for the relatively constant maximum life span observed in almost all animal species studies, • secondary aging explains much of the variability among individual members of a species.
  14. Theories of aging • Aging theories can be divided into • Organ-based, • Physiological, • Genomic hypotheses • Organ-based theories hypothesize that human aging results from incremental loss of organ function driven by the immune system or alterations in neuro-endocrine function of the CNS. • Physiological theories suggest that toxic levels of cellular waste products accumulate over time resulting from free radical damage, incapacitation of neuroprotective mechanisms, or cross-linkage of vital molecules, for example, collagen, deoxyribonucleic acid (DNA), and vital proteins.
  15. Genomic Hypothesis • hypothesize aging as the consequence of somatic mutations, multiple genetic errors, or programmed cell death • Evidence that the “Hayflick phenomenon” is under genetic control includes 1) a fair correlation between the doubling limit and the maximum species-specific life span of the cell donor and 2) a reduced doubling limit in cells cultured from patients with genetic diseases of accelerated aging • The precise mechanism underlying the observed limits on normal cellular division is not completely known, but several lines of evidence point to telomeric shortening as at least one likely “clock” mechanism. • A conceptual disagreement exists between theories that human senescent brain alterations result from disuse versus overuse (i.e., the “use it or lose it” theory) and those that attribute aging to cumulative damage (i.e., the “wearing it out” theory)
  17. Observed Changes in the Heart • Deposits of the "aging pigment," lipofuscin accumulate. • The valves of the heart thicken and become stiffer. • The number of pacemaker cells decrease and fatty & fibrous tissues increase around the SA node. These changes may result in a slightly slower heart rate • A slight increase in the size of the heart, especially the left ventricle, is common. The heart wall thickens, so the amount of blood that the chamber can hold may actually decrease. • The heart may fill more slowly. To compensate, elderly subjects demonstrate a doubling of percent atrial contribution to filling.
  18. EFFECT OF CHANGES • Under normal circumstances, the heart continues to adequately supply all parts of the body. However, an aging heart may be slightly less able to tolerate increased workloads. • Examples of stressors include: illness, infections, emotional stress, injuries, and extreme physical exertion.
  19. Observed Changes in the Vessels • Blood vessels – Arteries » thickening & stiffening in the media of large arteries is though to be caused by collagen cross-linking » smaller arteries may thicken/stiffen minimally; their ability to dilate & constrict diminishes significantly – Veins » age-related changes are minimal and do not impede normal functioning
  20. Observed Changes in the Vessels • The aorta becomes thicker, stiffer, and less flexible. This makes the blood pressure higher resulting in LV hypertrophy. • Increased large artery stiffness causes a fall in DBP, associated with a continual rise in SBP. Higher SBP, left untreated, may accelerate large artery stiffness and thus perpetuate a vicious cycle. Circulation. 1997;96:308-315 • Baroreceptors (stabilize BP during movement/activity) become less sensitive with aging. This may contribute to the relatively common finding of orthostatic hypotension.
  21. Observed Hematologic Changes • A decrease in total body water is observed with aging. Blood volume therefore decreases. • The number of red blood cells are reduced, but not significantly. • Most of the white blood cells stay at the same levels, but lymphocytes decrease in number and effectiveness.
  22. Observed Hematologic Changes • Overall, cell counts and parameters in the peripheral blood are not significantly different from in young adult life. • However, the cellularity of the bone marrow decreases moderately. For example, 30% cellularity on an iliac crest biopsy (which would be very low for a young adult) is not unusual in an older person.
  23. The Immune System
  24. Age and the Immune System • The efficiency of the immune system declines with age, but this is variable among persons. • Nonspecific defenses become less effective • The ability of the body to make antibodies diminishes. • Autoimmune disorders are increased in older adults. Not everyone believes that the increased incidence of autoimmune disease is an expected part of aging. – but all acknowledge the increase in findings of positive rheumatoid factor, anti-nuclear antibody, and false-positive syphilis screens in healthy older adults. • The thymus gland (which produces hormones that activate T cells) atrophies throughout life. • The peripheral T-cells (J. Immunol. 144: 3569, 1990) proliferate much less exuberantly in old age.
  25. The Result…. • Common infections are often more severe with slower recovery & decreased chances of developing adequate immunity.
  26. Take a Deep Breath…….
  27. Observed Changes in the Lungs • The number of cilia & their level of activity is reduced. • Glandular cells in large airways are reduced. • Decreased number of nerve endings in larynx. • The cough reflex is blunted thus decreasing the effectiveness of cough. • Decreased levels of secretory IgA in nose & lungs  decreased ability to neutralize viruses. • The number of alveoli do not change significantly.
  28. Observed Changes in the Lung • The number of FUNCTIONAL alveoli decreases as the alveolar walls become thin, the aveoli enlarge, are less elastic. • Decreased elasticity of the lungs may be due to collagen cross-linking. • The loss of elasticity accounts for "senile hyperinflation"; unlike in smokers, there is little or no destruction of the alveoli.
  29. Observed Changes in the Lungs • Combine less functional alveoli with slightly thickened capillaries  decreased surface area available for O2-CO2 exchange  lower O2 to supply vital organs, especially in setting of acute respiratory illness.
  30. Observed Changes in the Lungs • The respiratory muscles lose strength & endurance. • There is increased stiffness of chest wall (ie, decreased compliance). • Pulmonary vasculature becomes less elastic, pulmonary artery thickens & enlarges  increased resistance to blood flow in lungs  increased pulmonary artery pressure.
  31. Another Breather…..
  32. Observed Changes in the Kidney • Renal blood vessels become smaller & thicker reducing renal blood flow. • Decreased renal blood flow from about 600ml/min (age 40) to about 300ml/min (age 80) • Kidney size decreases by 20-30% by age 90. – This loss occurs primarily in the cortex where the glomeruli (# of gloms decrease by 30-40% by age 80) are located. • Decreased GFR. Typically begins to decline at about age 40. By age 75 GFR may be about 50% less than young adult. Current research shows that this is not true for all elders, however.
  33. Observed Changes in the Kidney • There is a decline in the number of renal tubular cells, an increase in tubular diverticula, & a thickening of the tubular walls  decreased ability to concentrate urine & clear drugs from the body. • Overall kidney function, however, remains normal unless there is excessive stress on the system.
  34. The Bladder & Such….
  35. Observed Changes in the Bladder & Such…. • The muscular ureters, urethra, & bladder lose tone & elasticity. The bladder may retain urine. – This causes incomplete emptying. • Decline in bladder capacity from about 500- 600mL to about 250ml  less urine can be stored in the bladder. – This causes more frequent urination. – The warning period between the urge and actual urination is shortened or lost as one ages.
  36. Let’s see Those Muscles!!!
  37. Observed Changes in the Musculoskeletal System….. • Muscles – Sarcopenia (↓ muscle mass & contractile force) occurs with age. Some of this muscle-wasting is due to diminished growth hormone production (NEJM 323: 1, 1990), – exactly how much is due to aging versus disuse is unclear. – Sarcopenia is associated with increased fatigue & risk of falling (so may compromise ADLs). – Sarcopenia affects all muscles including, for example, the respiratory muscles (↓ efficiency of breathing) & GI tract (constipation).
  38. Observed Changes in the Musculoskeletal System….. • Bone/Tendons/Ligaments – Gradual loss of bone mass (bone resorption > bone formation) starting around age 30s. – Decreased water content in cartilage • the “wear-&-tear” theory regarding cartilage destruction & activity doesn’t hold up as osteoarthritis is also frequently seen in sedentary elders. – Decreased water in the cartilage of the intervertebral discs results in a ↓ in compressibility and flexibility. This may be one reason for loss of height. – There is also some decrease in water content of tendons & ligaments contributing to ↓ mobility.
  39. Yummy, Yummy, in my Tummy…
  40. Observed Changes in the GI Tract • Some sources claim that one can expect atrophy & decrease in the number of (especially) anterior (salty/sweet) taste buds, but this is controversial NEJM 322: 438, 1990 • Basal and maximal stomach acid production diminish sharply in old age. At the same time, the mucosa thins. Very little seems to happen to the small bowel (J. Clin. Path. 45: 450, 1992) • Decline in number of gastric cells  decreased production HCL (an acidic environment is necessary for the release of vitamin B12 from food sources) • Decrease in amount of pancreatic enzymes without appreciable changes in fat, CHO, or protein digestion. • Diminished gastric (eg pepsinogen) & pancreatic enzymes result in a hinderance to the absorption of other nutrients like iron, calcium, & folic acid. • Hepatic blood flow, size & weight decrease with age. Overall function, however, is preserved, but may be less efficient in the setting of drug overload. • Decreased tone in stomach & intestines result in slower peristalsis  constipation.
  41. Hmmm….The Nervous System
  42. Observed Neurologic Changes • There is neuronal loss in the brain throughout life (the amount & location varies). J. Ger. 47: B26, 1992. – Loss is chiefly gray matter not white matter – there is some evidence that although some neuronal loss occurs with age, many neurons have ↑ dendrite growth which may (at least partially) compensate for neuronal loss in some areas of the brain. • Slowed neuronal transmission • Loss of brain weight and volume in most studies • Loss of dendritic arbor, with reduced interneuronal connectivity • Interneuronal accumulation of lipofuscin and loss of organelles • Neurofibrillary degeneration of neurons; accumulation of senile plaques, especially in hippocampus, amygdala, and frontal cortex
  43. Observed Neurologic Changes • The lens of the eye loses fluid and becomes less flexible, making it more difficult to focus at the near range. • Dry eyes • Changes in sleep cycle: takes longer to fall asleep, total time spent sleeping is less than their younger years, awakenings throughout the night, increase in frequency of daytime naps • Sense of smell markedly decreases
  44. Neurobiology of aging
  45. Neurobiology of aging
  46. Observed Hair Changes – Men: • men loose the hair about their temples during their 20s • hairline recedes or male pattern baldness may occur • increased hair growth in ears, nostrils, & on eyebrows • loss of body hair – Women • Usually do not bald, but may experience a receding hairline • hair becomes thinner • Increased hair growth about chin & around lips • loss of body hair
  47. Observed Toenail Changes – Become thicker & more difficult to cut – Grow more slowly – May have a yellowish color
  48. Observed Skin Changes - Epidermis • The number of epidermal cells decreases by 10% per decade and they divide more slowly making the skin less able to repair itself quickly. • Epidermal cells become thinner making the skin look noticeably thinner. • Changes in the epidermis allows more fluid to escape the skin.
  49. In Between • The rete-ridges of the dermal-epidermal junction flatten out – making the skin more fragile and making it easier for the skin to shear. – This process also decreases the amount of nutrients available to the epidermis by decreasing the surface area in contact with the dermis. = slower repair/turnover
  50. Observed Skin Changes - Dermis These changes cause the skin to wrinkle and sag. • The dermal layer thins • Less collagen is produced • The elastin fibers that provide elasticity wear out. --------- • ↓ function of sebaceous & sweat glands contribute to dry skin
  51. Observed Skin Changes – SubQ • The fat cells get smaller – This leads to more noticeable wrinkles and sagging
  52. Endocrine Changes
  53. Endocrine System • Because the endocrine system is so complex & interrelated it is difficult to discern the effects of aging on specific glands
  54. Age-Related Changes in the Endocrine System • In most glands there is some atrophy & decreased secretion with age, but the clinical implications of this are not known. • What may be different is hormonal action.
  55. Age-Related Changes in the Endocrine System Hormonal alterations are variable & gender- dependent • Most apparent in: – glucose homeostasis – reproductive function – calcium metabolism • Subtle in: – adrenal function – thyroid function
  56. Age-Related Changes in the Reproductive System Women • The “climacteric” occurs (defined as the period during with reproductive capacity decreases (ie, ovarian failure) then finally stops = loss of estrogen & progesterone; FSH & LH ↑↑). This is also described as the transition from perimenopause (~age 40s) to menopause. • thinning & graying of pubic hair • loss of subQ fat in external genitalia giving them a shrunken appearance • ovaries & uterus decreases in size & weight • skin is less elastic + loss of glandular tissue gives breasts a sagging appearance • other physical changes may include hot flashes (can cause sleep deprivation if they occur at night), sweats, irritability, depression, headaches, myalgias. Sexual desire is variable. The symptoms are typically present for about 5 years • atrophy of vaginal tissues due to low estrogen levels = thinning & dryness occurs;
  57. Age-Related Changes in the Reproductive System Men • Testosterone decreases, testes become softer & smaller • Erections are less firm & often require direct stimulation to retain rigidity • Though fewer viable sperm are produced & their motility decreases, men continue to produce enough viable sperm to fertilize ova well into older age. • Less seminal fluid may be ejaculated • they may not experience orgasms every time they have sex • the prostate gland enlarges; this often results in compression of the urethra which may inhibit the flow of urine.
  58. Stay Active…..
  59. Integrity vs despair • Psychosocial Conflict: Integrity versus despair • Major Question: "Did I live a meaningful life?“ • Basic Virtue: Wisdom • Important Event(s): Reflecting back on life • Integrity: the state of being whole and undivided • Despair: the complete loss or absence of hope • This stage occurs during late adulthood from age 65 through the end of life. • During this period of time, people reflect back on the life they have lived and come away with either a sense of fulfillment from a life well lived or a sense of regret and despair over a life misspent.
  60. THE END “healthy children will not fear life if their elders have integrity enough not to fear death.”

Notes de l'éditeur

  1. Biological age is the relative age or condition of a person’s organs and body systems. Psychological age refers to a person’s adaptive capacities. Social age refers to a person’s habits and roles relative to society’s expectations. Legal age is based on chronological years. Functional age is how people compare physiologically to others of similar age.
  2. Prospective memory (i.e., memory for actions intended in the future) Implicit: Incidental facts or features (e.g., the color of someone’s dress) Explicit: like someone’s name
  3. When older adults compare their current and past selves, they usually perceive more growth than decline in personality; that is, desirable traits are perceived as outweighing undesirable traits to an increasing degree through middle age and early old age. Social clock: societies have rather firm beliefs about age appropriateness of various actions. Continuity has been described as “a grand adaptive strategy” promoted by individual preference and reinforced by social approval (Atchley 1989). In late adulthood, the primary tasks concern integrity versus despair; that is, each person is faced with making sense of his or her actions over a lifetime and with judging the purpose and effect of these actions.
  4. elderly individuals tend to have smaller social networks and less frequent interpersonal contacts. Older people rely more heavily than younger adults on family members and long-term friendships for input on important matters.
  5. Hayflick and associates (Hayflick 1965; Hayflick and Moorhead 1961) in a series of experiments that established the maximum number of cell divisions (doublings) that would occur in carefully cultured normal human cells at about 50±10. Telomeres are unique protein- DNA structures that make up the terminal region of chromosomes in eukaryotic cells. The telomere section of the chromosome does not contain genetic information; rather, it is composed of repeated stretches of six nucleotides (TTAGGG in vertebrates) that seem to perform a stabilizing or protective function for the end of the chromosome
  6. Those who feel proud of their accomplishments will feel a sense of integrity. Successfully completing this phase means looking back with few regrets and a general feeling of satisfaction. These individuals will attain wisdom, even when confronting death Those who are unsuccessful during this phase will feel that their life has been wasted and will experience many regrets. The individual will be left with feelings of bitterness and despair. Erikson (1982) defines wisdom as a kind of &amp;quot;informed and detached concern with life itself in the face of death itself