Ageing and Healthcare

Question 1

Describe the molecular theory of ageing

Answer 1

• ageing is influenced by the changes in gene expression (‘programming’ by epigenetic modifications)
• histone modification and gene methylation
• accumulation of mutations = ageing
• while there are mechanisms in place in the body to repair/remove damage, their efficiency is not 100% and also declines with age

Question 2

Describe the cellular theory of ageing

Answer 2

• telomeres sit at the end of DNA strands, containing no genetic material, acting as protection to prevent chromosome ends from fusing with one another
• with each replication, due to the imperfect nature of the mechanism, not all of the chromosome is replicated and telomeres shorten with each replication
• telomere shortening results in progressive loss of chromosome caps
• free radical generation damages DNA
• DNA damage = apoptosis (ageing)

Question 3

Describe the environmental theory of ageing

Answer 3

• wear and tear theory: ageing is a result of the accumulation of UV and ionising radiation damage over the years
• disposable soma theory: an organism only has limited resources to be allocated to its cellular processes. So greater investment in growth and reproduction results in decreased investment in DNA repair maintenance leading to increased DNA damage, shorted telomeres, mutations etc. which all contribute to ageing

Question 4

What is the consequences of ageing in the context of disease incidence and the health system?

Answer 4

• with increasing age, most will have chronic illnesses - each requiring the prescribing of multiple medications (for symptomatic treatment and risk reduction)
• ageing also comes with increased multimorbidity, with disease burden increasing linearly with the deprivation index (smoking/alcohol/diet/obesity/housing).
• taking all of this into account, social and healthcare costs rise with age

Question 5

What is frailty?

Answer 5

A clinically recognisable state of increased vulnerability due to age-associated decline in reserve and function across multiple physiological systems such as the ability to cope with everyday/acute stressors

Characterised by:

• unintentional weight loss
• reduced muscle strength
• reduced gait speed
• self-reported exhaustion
• low energy expenditure
• some will have additional issues (vision/hearing problems, cognitive decline etc.)