Introduction to Diabetes

Question 1

How has diabetes increased in America and worldwide?

Answer 1

• America: 5.0% in 1980 up to 8.3% in 2014
• Worldwide: 4.7% in 1980 up to 8.5% in 2014

Question 2

Why is diabetes taking epedemic proportions?

Answer 2

It is fueled by obesity which is a huge risk factor and hence why it is increasing → it mirrors obesity

Question 3

What is the expected increase in diabetes worldwide?

Answer 3

46% by 2045

Question 4

Social and economic burden of diabetes

Answer 4

• affects 8% of the world (both type I & II)
• 10% of healthcare dollars (25% of taxes goes towards healthcare so 2.5 towards diabetes)

Question 5

Prevalance of diabetes in Canada

Answer 5

• > 8% of Canadians have been diagnosed with diabetes → an additional one million Canadians have undiagnosed diabetes.
• Diabetes Canada estimates that 20% of the population has pre-diabetes.
• This number is expected to double in the next 20 years.
• In Canadian hospitals, one bed out of five is currently occupied by a diabetic patient.

Question 6

Costs of diabetes in Canada

Answer 6

The costs to treat diabetes and its complications are estimated at $16B, annually, in Canada
* health concern, economic concern, social burden

Question 7

How does diabetes prevalence change with age and gender?

Answer 7

More at risk for develop diabetes with age and males more prone

Question 8

Where is diabetes most prevalent in Canada

Answer 8

Newfoundland and Labradour with 6.5%

Question 9

Where we donate disease vs. disease that kills us

Answer 9

Major discrepancy with little money raised even though it is a leading cause of death
* May be because it is the individual fault and may be reluctant to put money towards research or treatment

Question 10

The thrifty gene hypothesis

Answer 10

Ancient humans in Africa migrated and populated globe and throughout journey suffered famine and scarcity and posed that selection for individuals to accumulate energy fast and retain it and survive times of scarcity so we were selected for our ability for fat reserves. Now know hypothesis is wrong and have sequenced the human genome and know there is not a thrifty gene nor a combination to drive you to accumulate fat or obesity.
* Proposed by geneticist James Neel (U. Michigan) in 1962 in the American Journal of Human Genetics.

Question 11

Other hypothesis of diabetes

Answer 11

• thrify phenotype
• drifty gene hypothesis (mutations)
• unknown foods
• aggression control (psychological)

Question 12

How has nutritional intake changed?

Answer 12

We eat more food and more calories and more nutrients of lesser quality

Question 13

Describe the Land of Cokaigne picture

Answer 13

Painting from medieval times and depicts heaven showing paradise with foreign merchant with different spices and 3 different individual of people classes (soldier, peasant, noble) that just had a feast together and abundance of food with pig running with knife etc. shows at thi time that the only thing in their mind is food, harvesting, planting and life revolved around agriculture. Different from our times because we can get food very easily
* Pieter Bruegel, 1567

Question 14

Ancient history of diabetes

Answer 14

• Described in ancient egypt
• Hindu physician first to describe sweetness of urine
• term diabetes was coined by Aretaeus c. 250 BC (from Greek = syphon); insipidus, tasted nothing; mellitus tasted sweet

Question 15

History of diabetes from 17th century

Answer 15

• In the 17th century, authors reported on the increased prevalence of the disease.
• Matthew Dobson was the first to described hyperglycemia after he evaporated the urine of one of his patient to a “white cake” that could not be distinguished from sugar (1776).
• In the 19th century: first use of the adjective “mellitus” (vs insipidus).
• In the 1870’s, Claude Bernard, a French physiologist posited that diabetes could have a pancreatic origin after noticing atrophy or injury in post-mortem exams.
• Around that time, Etienne Lancereaux was the first to distinguish between Diabète maigre (lean) and Diabète gras (fat)

Dont need to know names and dates, just general idea

Question 16

Breakthrough of diabetes

Answer 16

A breakthrough occurred in 1889, when Joseph von Mering and Oskar Minkowski performed total pancreatectomy on dogs. The dogs displayed all the symptoms of diabetes and died shortly afterwards showing it was a pancreatic disease
* 4 years later, Gustave Laguesse speculated on the putative “internal secretions” produced by these “islands” previously discovered by Paul Langerhans.

Question 17

Discovery of insulin

Answer 17

Insulin was discovered in Toronto in 1921 by Frederick Banting (surgeon) and Charles Best (student) reversed diabetes in dogs by giving them a pancreatic extract.
* First patient treated with insulin in 1922.

Question 18

Simple definition of diabetes

Answer 18

High concentrations of circulating glucose

Question 19

Clinical definitions of diabetes

Answer 19

Needs a particular window to be optimal
* low- can go to coma
* High - lots in circulation

Question 20

What is considered pre-diabetes?

Answer 20

impaired fasting glucose → means fasting glucose is a tiny bit elevated

Question 21

Tests to diagnose diabetes

Answer 21

Always need to be done at least twice and fail consecutively to be diagnosed accurately
* fasting glucose test
* OGTT → Oral Glucose Tolerance Test
* HbA1c → Glycated Hemoglobin

Question 22

OGTT

Answer 22

Oral glucose tolerance test → show up fasted and drink sweetened beverage and test glucose at different time points and what should happen is it will go up and then body will use it and store it and should go down to normal levels. Measured after 2 hours
* Would run this test twice and would need to fail twice

Question 23

What is HbA1c?

Answer 23

glycated hemoglobin → Glucose in circulation is sticky so it can bind Hb proteins (through collision) and so the more you have the more collision and glycation that can occur and so lots of proteins can become glycated
* non-enzymatic and slow process, and its intensity mirrors glucose levels
* Glycated hemoglobin reflects the circulating concentrations of glucose over the last 3 months (half-life)

Question 24

What are the negatives of HbA1c?

Answer 24

costs, influenced by conditions that affect blood cell turnover (ethnicity, diseases, etc.), availability

Question 25

What level of HbA1c is considered diabetes?

Answer 25

6.5%
* Means on average last 3 months have experience spikes of glucose that are very high

Question 26

Correlation between glycemia and HbA1c

Answer 26

Question 27

Diabetes classifications

Answer 27

Question 28

Comparison: type 1 and type 2 diabetes

Answer 28

Question 29

How has understanding of type I diabetes changed?

Answer 29

Type 1 diabetes was considered a “simple” T- cell-mediated autoimmune disease in which >90% of the beta-cells are destroyed but recently discovered they may just be absent
* Individuals with long- duration disease display measurable levels of c- peptide
* A majority of T1D patients exhibit persistent beta-cells even decades after diagnosis

Question 30

What is the “honeymoon phase” of type I diabetes?

Answer 30

When diagnosed they start insulin treatments right away but they then experience a honeymoon state where they are cured of diabetes, the pancreas naturally starts to secrete again where they dont need to inject at all but only lasts a few days to a year (variable) in the remission phase, which tells us the islets are still there just dont know why they stopped.
* Changes in islets way before autoimmunity arises so maybe the islets are messed up and triggering reaction against themselves but dont really know that much about TI

Question 31

What are the hallmarks of T2D to recognize it?

Answer 31

1. insulin resistance (usually linked to obesity)
2. beta-cell impairment

Question 32

In what way is T2D similar to cancer?

Answer 32

multifactorial disease
* hereditary and environmental factors

Question 33

What have twin studie shown about the genetics components of T2D?

Answer 33

Once 1 twin is diagnosed, the probability of the other one getting it increases
* This shows a genetic component, and risk if diabetes runs in the family

Question 34

How have Pima Indians shown environmental influences on T2D development?

Answer 34

Studies First Nations in Mexico and the at border of Texas. Those in Mexico had lower chances of T2D but once across border into America the chances go up significantly.
* This shows the effect of the environment/ culture

Populations on pacific islands -> the grandfathers not diabetic nor fathers but children were at 80% more chance

Question 35

Other types of diabetes

Answer 35

• Monogenic forms of diabetes from single mutated gene (e.g. MODY)
• Mitochondrial diabetes
• Pancreatic diseases (e.g. pancreatitis, cancer)
• Injury
• Drugs and chemicals (e.g. glucocorticoids) effecting blood glucose
• Endocrinopathies and syndromes associated with diabetes (e.g. Cushing, Prader-Willi) which typically effect hormone balance
• Infections
• Gestational with hormonal changes