HLTB01H3S: Health, Aging and the Life Cycle
Department of Health Studies
University of Toronto at Scarborough
Instructor: Anna Walsh.
Term: Winter 2010 Mondays 3 p.m. - 5 p.m.
Lecture Room: Room AA112.
Theories of Aging.
28 year old woman died
An 83 year old woman killed a 23 yearold woman through a car accident.
23 year old woman pushed the stroller out of the way
Toyota, went through this red light.
POINT: looks at the Rights of public and rights of individual.
Haiti: people are suffering as we speak.
Proffesor story: Her son sustained an injury and broke left wrist. Spoke about waiting
times. Budgets in health care system, where schalli case had to do with waiting times.
We pay tax money for public health but we are being told we have to wait. Son had to
wait 6 hours in emergency. She can’t really do anything about it. Policy needs to be
Its not really called health care system we call it ministry health care however people
think someone is caring. But she thinks we should call it health business public
misunderstands the intention out there.
Hospital standardized mortality ratio
Used to track hospitals mortality over time.
relates to adverse events
ratio of actual deaths compared to expected deaths
Adverse events = negligence (something that is done and forgot to get done)
100 is more than expected average= not a good thing
recognizing that we have a right to know, it is displayed publicly
Idea behind this is transparency related to disclosure. Forces hospitals to look at their
risks. Ever since rates have been posted, the rates of preventable deaths are decreasing.
Therefore making hospitals accountable forces them to prevent adverse events.
Just because there are adverse risks doesn’t mean we can sue a hospital
It is very difficult to sue a hospital. Issues of evidence are important. Getting a doctor to
testify against another doctor is difficult
1 2004 study indicated 7.5% were suffering an adverse event in hospital. This was
associated with 9000 –24 000 preventable deaths.
2006 : 917 law suits against Canadian doctors. About 1/3 would get compensation.
Were told 2% of people who suffer injury receive compensation.
2007: humber river region hospital have highest rate of HSMR =136/1000
Same year scarborough general hospital had a rate of 102/1000
Reasons we have misconceptions are due to theories.
What is a theory? An idea that is tested by research. Research proves a theory until
someone disproves a theory. A theory is not etched in stone. Does have an impact on how
we look at the elderly.
A&G: Chapter 3- Theories of Aging: Biological and Psychosocial Theories.
Progressive loses of biological functions ….(look at chapter 3) Textbook shows a
negative way. Certain things we did when we were kids we wouldn’t be able to.
Injure yourself as a kid heal a lot faster. Now break a bone, healing a lot slower.
Aging processes occur at different levels
And social levels
Genders are predictors of life expectancy
Women live longer than males, because women are more likely to go to doctors.
In adulthood, men are more likely to take risks. As men advance in age, they
develop heart conditions. Females have a protective affect due to estrogen. Once
women reach menapause the lose the protection.
Homeostatis refers to balance. Have this ability in our body. When looking at theories of
aging, the kind of approach is important
Biological process= looks at biology. Ie damaged DNA, oxidation, free radical theory
Free radicals damage DNA. Free radicals are counteracted by antioxidants.
What can we do to restore function.
CBS news= advice on healthy aging.
• Gerontology-has provided facts that are based on systematic observations that
may be loosely grouped into models, but rarely provide any conclusive theory.
• Models and theories are often times not carefully distinguished from one another
in the literature and create this ongoing problem.
• Aging is usually defined as the progressive loses of biological function
accompanied by decreasing fertility and increasing mortality with advancing age.
This process usually occurs after sexual maturation and continues up to the time
2 of maximum longevity (life span) for members of a species. Death is the final
event. Although age-related changes occur in every individual in a given species,
different species are known to a, at different rates. Note: The rate of aging can
vary between individuals of the same chronological age.
Lifestyles also exert additional influence on the aging process. Aging is caused
by the accumulation of damage to the cells. Some of the causes are unavoidable
such as ultraviolet radiation, free radicals and genetic effects, while others involve
environmental and behavioral influences.
• Many theories and models have been advanced to better explain the aging process
that reflect both the genetic and environmental factors associated with aging.
Theories of Aging
• Aging processes occur at the biological, psychological and social levels.
• There are different theories that reflect each discipline with no general consensus.
• Although we are beginning to appreciate the underlying causes and the factors
that regulate or govern the rate of aging, we are still not certain about why we age.
• Bengtson, Rice and Johnson (1999) They argued that different theories
emphasized different aspects such as: characteristics of the aging population, the
development or aging process and the way in which age is incorporated into
elements of the social structure.
• Gender is one of the strongest predictors of life expectancy with women living
longer than men. Better conditions in sanitation and medical procedures such as
the risk to women in childbirth offered greater improvement for women’s
longevity. The continued difference in life expectancy between men and women
is due to a number of biological, behavioural and environmental factors.
• If change occurs, mechanisms typically exist for countering that change and
returning that organism to a steady state. Classic examples include blood pressure
regulation, heart rate, respiratory rate, glucose regulation and DNA repair. Once a
system has been displaced and homeostasis (steady state; regulation; balance) has
been affected, the deviation amplification mechanisms can take over, accelerating
the change or imbalance Once a system is removed out of homeostasis, then
deviation amplification mechanisms can take over, accelerating the change or
imbalance. Biological processes relevant to aging fall into 2 categories: those that
promote homeostasis (steady state; regulation; balance) and decelerate the aging
process and those that increase the aging process such as that which results from
the effects of free radical damage.
• Psychosocial theories often advance positive and negative changes with age.
• There are many biological theories of aging: 1. Genetic Theory: the maximum life
span of a human being is 120 years. The life span differs between species. 2.
Deviation Amplification Theory: Theory that deals with problems of aging. i.e., a
death gene that regulates suicide cell death = Apoptosis (programmed cell death).
Apoptosis is one mechanism for the destruction of cells i.e. the destruction seen in
3 the immune system with T-cells. There may be a positive correlation between the
life span of a species and the # of times that a cell will replicate. Telomeres
consist of specialized ends of DNA strands that help them during the stages of
mitosis. In humans the # of times somatic cells can replicate is partially regulated
by telomeres. Telomeres can be restored by an enzyme called telomerase.
Cancer cells have longer telomeres and more active telomerase than normal cells.
The number of times that a cell replicates may also be affected by genes.
• There are certain theories such as that of Hayflick who has argued that there may
be a limited # of times that a cell can replicate without error. DNA repair
mechanisms can be used to correct errors. The DNA in mitochondria may be
particularly susceptible to damage. Mitochondria (part of the cell that deals with
oxidation). DNA damage can occur from a variety of environmental factors such
as radiation as well as from internal processes such as oxidation.
DNA Repair Mechanisms
• Damaged DNA can be repaired which can be considered a deviation countering
mechanism for aging. Damage tends to activate transcription and replication. If
an error is discovered, replication can cease to occur so repairs can be made. The
primary errors include: base extension repair, mismatch repair and repair of strand
breaks. Sometimes the errors escape detection, but at other times the damage can
be tolerated and the cell will use replication bypass (presumably, it simply skips
over the error).
• Free radical theory is based on the belief that free radicals are generated during
the oxygen process in cells. There molecules have an unpaired electron that
makes them unstable and chemically very reactive. Free radical damage increases
with age because (a) more free radicals are generated in aging cells (b) there
appears to be a decreased ability for the cells to generate antioxidants (c) cellular
repair mechanisms becomes less effective.
• Aging cells also accumulate waste matter called lipofuscin = a dark mixture of