Epidemiology

Question 1

what is Epidemiology?

Answer 1

Epidemiology is the study of the distribution and determinants of health-related states or events (including disease), and the application of this study to the control of diseases and other health problems.

Question 2

what is the purpose of Epidemiology?

Answer 2

The purpose of epidemiology is to search for the causes of disease, or how it is spread, and to identify a system for surveillance of its occurrence.

Question 3

how to measure Epidemiology?

Answer 3

Various methods can be used to carry out
epidemiological investigations:

• Surveillance and descriptive studies can be used to study distribution;
• Analytical studies are used to study determinants.

Question 4

what are the fundamental assumptions of Epidemiology?

Answer 4

1. Human disease is NOT random
2. Human disease has causal and preventative factors that can be identified through scientific investigation of different populations or subgroups of individuals within a population (Hennekens, 1987)

Question 5

Physical activity Epidemiology?

Answer 5

• …focuses on physical activity within populations
and investigates how physical activity levels impact on health and disease, and consequently decrease mortality and morbidity

• …typically incorporates both the assessment of
physical activity, as well as, intervention efforts
focusing on increasing physical activity

Question 6

Hippocrates – “Father of Medicine” why is he important?

Answer 6

First Epidemiologist

• Based his medical practice on observations and study of the human body.

• Kept records of associations between
disease and climate, living conditions
and habits such as diet and exercise

Question 7

what is does-response?

Answer 7

Relationship in which a change in the amount, intensity or duration of exposure is associated with a change in risk of a specified outcome

Question 8

what is the does in physical activity?

Answer 8

• Mode
• Frequency
• Intensity
• Duration
• Total Volume

Question 9

what are the risks of inactivity?

Answer 9

676,000 deaths each year
were down to inactivity vs.
337,000 from carrying too
much weight

Eliminating inactivity in
Europe would cut mortality
rates by nearly 7.5%, or
676,000 deaths, but
eliminating obesity would cut rates by just 3.6%.

Question 10

Medical complications of INactivity?

Answer 10

Depression
Stroke
Coronary heart disease
Diabetes
Dyslipidaemia
Hypertension 
Cancer
Osteoporosis
Overweight

Question 11

what were the number of obese adults in 1995?

Answer 11

200 million

obese adults

Question 12

what were the number of obese adults in 2000?

how many u5s are obese?

Answer 12

> 300 million
obese adults

18 million u5s
overweight

Question 13

what were the number of obese adults in 2016?

how many u5s are obese?

Answer 13

650 million
obese adults

41 million u5s
overweight

Question 14

what is the prevalence of obesity in the UK?

Answer 14

England 26.2% (prevalence of obesity) 61.4% (Prevalence of Obesity
or overweight)

Scotland 29.0% (prevalence of obesity) 65.0% (Prevalence of Obesity
or overweight)

Wales 23.0% (prevalence of obesity) 59.0% (Prevalence of Obesity or overweight)

Question 15

What is the prevalence of obesity for children in the UK?

Answer 15

England 9.6% (prevalence of obesity) 22.6% (Prevalence of Obesity or overweight)

Scotland 10.0% (prevalence of obesity) 22.0% (Prevalence of Obesity or overweight)

Wales 11.7% (prevalence of obesity) 26.2% (Prevalence of Obesity or overweight)

Question 16

how many people on average in 2020 will be obese?

Answer 16

8-10 men

7-10 women

Question 17

why is obesity increasing?

Answer 17

Is it because we have drastically reduced our physical activity (decreasing energy expenditure), tried to compensate by ‘dieting’ (decreasing energy intake) – and can’t get that low…?

Question 18

what happens in the body during inactivity?

Answer 18

• When dietary intake exceeds energy expenditure for a prolonged period of time
• Chronic positive energy balance
• Energy converts to triglycerides
• Stored in adipose tissue depots and expand in size EXCESSIVE FAT STORAGE

Question 19

obesity can also lead to what?

Answer 19

Musculoskeletal Disease
• Osteoarthritis: Inflammation of one or more joints.

Alzheimer Disease • Alzheimer Disease: type of brain disorder that causes problems with memory, thinking and behaviour

Question 20

what is feast and famine?

Answer 20

In time of famine-genes for fat accumulation promoted survival

in times of feast-they promote chronic disease.

Question 21

Our Genes expect what?

Answer 21

Physical activity:
Failure to maintain gene expression at the expected level

Genes requiring physical activity are also disease-susceptibility genes

inhibition of health proteins activation of disease proteins

Question 22

Gene-environment interaction

Answer 22

Environmental disease: g + E

Common disease: G + E

Genetic disease: G + e

Question 23

how does Genetic Predisposition lead to obesity?

Answer 23

Energy intake increases+ Energy expenditure= Energy storage facilitating fat+ Adipogenesis= overweight=obesity

its also affected by external; factors such as food intake, no exercise, viruses, alcohol, home , prenatal factors, lactation, nutrition, physical environment, economic factors

Question 24

Evidence of environmental influences

Answer 24

• Pima Indians from Sierra Madre/ Maycomb of Mexico are isolated leading a traditional lifestyle
• Whereas in Arizona, western influences have caused a high fat diet and sedimentary lifestyle
• Resulting in an obesity epidemic over the previous 50 years

Question 25

Evidence of genetic influences in humans?

Answer 25

• Familial clustering:
• Obesity in families
• Twin studies:
• Greater concordance in MZ twins
• Family studies:
• Variety of statistical models consistent with this

Question 26

Amish lifestyle and obesity linked with it?

Answer 26

• Farming/subsistence
community

• No motorised transport
– only animals

• High calorie, high fat
diet

• ~3% Obesity

Question 27

Physical Activity Exposures and Outcomes

Answer 27

Exposure:          
volume              
frequency
intensity
duration 
mode    

Risk factors:
Blood pressure
Cholesterol
Insulin resistance
metabolic syndrome
Arterial stiffness
bone density

Morbidity:
CHD
Stroke
Cancer
mental health
Osteoporosis
Diabetes
Obesity

Mortality:
death

Question 28

what is the Additive effects of physical activity?

Answer 28

“With the possible exception of diet, we know of no single intervention with greater promise than physical exercise to reduce the risk of virtually ALL chronic disease simultaneously…”