S4: Introduction to Ageing and Disease Flashcards
Describe demographic ageing trends in last 50 years
- In today’s modern era there is more chance of living to old age than ever before and when we get to old age there is a now a higher chance one will live longer in old age (i.e. life expectancy in old age is increased).
- Infant mortality has fallen significantly from around 35 to 6 from 1948 to 1996.
- As well as this, in the last 50yrs the proportion of the population that dies before 65 has decreased again drastically from 40% to 7%.
- Life expectancy at birth in the last 100 years has gone from the late 40s to late 70’s/early 80s.
- These changes in length of life have understandably led to a change in the population structure.
Describe changes in population size over last 50 years in England and Whales
- Overall population size has increased by 20%, 0-4 age group only by 9% but the 80+ group by 240%!
- By 2007 there were more people over the age of 65 than under 18 and the over 85’s are the fastest growing segment of the population and set to double by 2020.
- This is not worrying as the younger people coming into employment help with physical care and taxes to elderly.
- The population has reached 56.1 million, up by 3.7 million in a decade.
- The percentage of the population aged 65 and over was the highest seen in any census - at 16.4%.
- There were 430,000 residents aged 90 and over in 2011 compared with 340,000 in 2001 and 13,000 in 1911.
What are Population Pyramids?
Population pyramids are a graphical representation of the age demographics of a society. Populations divided into different age groups and stacked on top of each other (youngest at bottom, oldest at top).
Population pyramid of steady death across life
. . . . . .
Population pyramid as death rates reduce
- Pyramid becomes more square.
- If there is then a fall in fertility rates then we start seeing the pyramid invert with a more barrel shaped.
- Here the age group that is the largest starts to be around the 50/60 mark.
- Now the smaller younger generations have to sustain and look after the larger more dependent generations as they age.
What is a survival curve?
Graphical representation of population survival with age. We can plot survival and ageing onto curves.
Describe the 3 main types of logarithmic survival curve
- The logarithmic curve below depicts a population of animals or humans who live in severe environment where none reach old age and there isn’t much ageing.
- As populations start developing and are able to look after their young, individuals start to live longer with some people surviving to old age but most dying prematurely.
- Finally with further improvements in living conditions and in prevention of adult onset disease and premature death. This compacts all death to old age and is called squaring of the rectangle. This is the ideal although it will never be reached, that everyone lives until they reach a certain old age and then die
Describe squaring of the rectangle in the UK
In the UK this squaring of the rectangle has been occurring, where greater numbers of people survive into old age and then start to die, due to a number of contributing factors but mostly further improvements in living conditions. Major factors in increasing survival of old age (squaring):
- A decreasing infant mortality.
- Increasing standard of living.
- Improvements in public health.
- Improvements in sanitation.
- Improved diet (abolition of corn laws in 1842, could then import cheap food from USA).
Describe how life expectancy at older age is also increasing
As well as life expectancy at birth increasing, life expectancy at older age also increases. In other words if you reached age 80 in 1980 you would be expected to have another 5.8yrs of life. If you reached age 80 in 2000 you would be expected to have another 7 years of life.
Thus more years of retirement and older age. Length of life spent in retirement has increased by 4-8 fold since 1870, this is almost completely due to increased life expectancy. Average length of retirement increased by 5 years between 1981 and 2001.
What is the significance of life expectancy at older age increasing?
An important question to ask however is that are these extra years that we have added to old age are they actually significant and are they good or are they spent quite miserably.
Describe the theoretical gloom in older age
The issue is that although older people may have more time to enjoy their retirement there is an exponential relationship between age and prevalence of disability. In other words the older one gets the more likely they are to have a disability of some kind. There is also a exponential relationship between age and chronic disabling diseases. Some chronic disabling diseases that increase in prevalence with age include:
- Stroke
- Alzheimers
- Parkinson’s
- Osteoarthritis
An example is that the highest prevalence of epilepsy is in old age, thus advancing age does come with a physiological problems. Epilepsy high in old people brought on by stroke.
What makes disability more common in elderly?
As one ages a combination of physiological ageing, acute illness, chronic illness and isolation and poverty all contribute to disability and make it more common in older people.
Describe dependency profile of elderly people by age and 4 possible quality of life scenarios as a result
Graph demonstrates the dependency (need for someone else to help you) with various tasks at different ages and we can see that as we age we become more dependent on others as disability becomes more prominent. So with the extra years that we have managed to add to older life through changes in public health, the four possible scenarios with regards to the quality of this extra life:
- With every year of life gained it is going to be spent in a dependent state (1 year of additional woe),
- With every year of life gained, some of it will be spent in dependent state (less than 1 year of additional woe).
- With every year of life gained there is no change in dependency (no additional woe.
- With every year of life gained, there is actually less period of dependency (less woe). This is known as Fries Compression of morbidity.
What is the actual quality of life scenario due to older population in UK 1981-2001?
It appears that as well as life expectancy at 65 increasing over the past 20 years e.g. 13.0 to 16.1 in women. The healthy life expectancy (life that is free from long standing illness) is also increasing, for women 7.6 to 8.9. The global health survey which analysed trends over last 20 yrs found no change in the proportion of elderly people reporting their health as good, fairly good and not good. No change means that despite people living longer and potentially living longer with illness, this doesn’t appear to be occurring rather people are living longer and not experiencing an additional period of ill health as a result.
Does days spent in hospital before death change with older population?
Generally whether you die very old or relatively young, it is very likely that the last 3yrs of your life you would have spent a significant amount of time in hospital.
The median number of days spent in hospital 3yrs prior to death is 23 and this did not rise with age above 45.
- So it is not the age you die , but the last three years before death where most medical services used regardless of age.
Describe projected numbers of people over 65 in UK unable to perform activities of daily living
Ageing to the rescue process means with time, the no. of people unable to perform daily activates decreases with increasing ageing over. Normal function can happen in extreme old age as long as their is no pathology. If you get sick in old age, reserves are low and you get sick dramatically and it is much harder to recover.
When does our eyesight have maximum function?
Our eye has maximum function at age 14 and then signs of ageing occur.
Describe and define ageing
- The progressive and generalised impairment of function (i.e. doesn’t happen suddenly and it is not specific to one structure or organ).
- Ageing results in a loss of the body’s adaptive response to stress (ageing itself doesn’t make people dependent, but when exposed to pathology the bodies ability to adapt and compensate is severely reduced, leading to dependency).
- Ageing comes with a growing risk of age related diseases (such as the ones mentioned earlier e.g. stroke).
- Ageing is non-focal (i.e. not one structure, all body systems are affected) and symptom free (i.e. no pain, nausea etc.).
Describe Fraility
- Frailty is a new concept, it is a physiological syndrome characterised by decreased reserve and diminished resistance to stressors, resulting from cumulative decline across multiple physiological systems and causing vulnerability to adverse outcomes.
- We diagnose physical frailty in clinic by using signs like grip strength, weight loss, fatigue and slow gait etc.
- Frailty is distinct from ageing, the majority of elderly people are NOT frail, but it is the age group where frailty is most common. So you can be young and frail.
Describe Strechler’s concepts for true afeing provess
Strehler identified things that constitute a true ageing process and thus may help in differentiating disease and ageing. These concepts therefore mean that in order to be true ageing, the following must be met:
- Universal (changes present in every species).
- Intrinsic (changes are not due to exogenous source).
Progressive (changes continue progressively over time).
-Deleterious (should eventually be harmful to organism).
Describe how ageing is universal
The change must be present in all members of a species even though it may affect individuals to a different extent. Examples include collagen cross links in skin and loss of calcium from the bones.
Describe how ageing is intrinsic
Must not require an exogenous source to make process happen, e.g. changes in skin of axilla these are changes of endogenous origin, changes in the face would be due to light so this is photo-ageing not true ageing.
Describe how ageing is progressive
May occur at different rates but occurs over time, e.g. loss of muscle power, greying of hair.
Describe how ageing is deleterious
Most controversial of the concepts, reduced visual acuity is bad, but is greying hair bad?
