Lecture 3 - Metabolic Syndrome & Population Health

Question 1

Compare ‘incidence’ and ‘prevalence’

Answer 1

Incidence: rate at which new cases occur in a population during a specific period

Prevalence: proportion of people in a specific population with a given disease at a point in time

Question 2

What is a ‘Risk Factor’?

Answer 2

Something that increases one’s changes of getting a disease

Can be:
• Something you do (e.g. smoking)
• Unavoidable (e.g. old age)

Question 3

What is nosology?

Answer 3

Branch of medical science dealing with the classification of disease

Question 4

Why was population health important for medicine in the 19th century?

Answer 4

Fundamental to modern medicine, through the measuring of diseases and conditions in populations

Challenged the idea that every individual’s sickness is unique to that individual

Question 5

Describe the first epidemiological study

Answer 5

John Snow, Cholera Epidemic in London, 1850’s

He mapped cases of cholera and traced the source back to the water pump in Broad strew

Question 6

What are the questions to be asked when looking at disease epidemiologically?

Answer 6

• Who?
• Where?
• What?

Question 7

Briefly describe metabolic syndrome

Answer 7

• Chronic condition
• Triggered by weight gain
• Associated with middle-aged, overweight females
• Predisposes to DM

Question 8

Describe the trends in obesity in the US from 1985 - 2010

Answer 8

1985: mostly < 10% of people 30 lbs overweight
2010: most states with 30 lbs overweight prevalence of 25-29%

Differences of prevalence between ethnicities: black higher than hispanic, which is higher than white

Question 9

Compare prevalence of obesity between countries

Answer 9

Different countries have vastly different prevalences of obesity
Highest: US: 30%
Lowest: South Korea & Japan: 3.2%

Question 10

Describe the connection between inequality and obesity

Answer 10

More adults are obese in more unequal rich countries:
• US very unequal, most obese
• Japan quite equal, least obese

‘Diabetes is a disease of poverty amidst affluence’

Question 11

What are some possible explanations for the rising prevalence of metabolic syndrome / obesity

Answer 11

• Increasing inequality

* Nutrition transition (i.e. changing diets)

Question 12

Describe the HFCS story

Answer 12

• The growing of corn in the US was heavily subsidised in the second half of the 20th century
• HFCS55 emerges
• The use of HFCS55 in sweet drinks and fast food as a cheaper replacement for sugar lead to a decrease in the price of fast food
• 80% of supermarket products contain HFCS55
• Foods with HFCS55 are cheaper, tastier and easier

Question 13

What is the problem with fructose?

Answer 13

Metabolic shunting

Fructose bypasses the usual complex digestion and goes straight to the liver

It is contended that metabolic shunting produces more rapid insulin resistance

Results in a huge increase in sugar load in the body which is not broken down

Question 14

Describe the Palm oil story

Answer 14

Palm oil imported in deal on free trade

New technologies in the mid 70’s made it possible to use for commercial fat (frying oil, margarine, bread etc)

Features of palm oil:
 • Very dense and saturated
 • Cheap
 • More stable (longer shelf life)
 • Good mouth-feel
 • Doesn't biodegrade in the body

Effects on the body:
• Increased BP
• Increased cholesterol
• Increased body fat

Question 15

What were the economic ramifications of Palm oil and HFCS55?

Answer 15

• Fall in food prices
• Higher profits from food
• Dramatic ecological changes (new deadly salmonella → antibiotic resistance through overuse)
• Changing food production practices

Question 16

What is the role of changing activity patterns over the past 40 years?

Can this explain the obesity epidemic?

Answer 16

Physical activity habits have not changed that much

The decline in walking happened much earlier

Overweight people are still doing hard manual labour, using their arms etc.**

Changing food habits is playing a greater role