Diabetes

Question 1

What is diabetes

Answer 1

 A metabolic disorder characterized by the presence of hyperglycemia due to:

• defective insulin secretion and/or
• Defective insulin action

Question 2

what are the longterm complication of diabetes

Answer 2

• kidney, eye, nerves, heart, and blood vessels

Question 3

what % of the population has diabetes

how many people will have it in 2019?

what % is undiagnosed

Answer 3

 Prevalence is ~6.3% of the population (all ages and males/females grouped together).
 This is expected to be 3.7 million by 2019.
 Estimated that up to 20% of diabetes cases are undiagnosed.

Question 4

Type 1 is also increasing but why is type 2 more?

Answer 4

due to:

• Population is again
• Obesity rate are rising
• Sedentary lifestyle
• Aboriginal people are 3-5x more likely to develop type 2 diabtes
• 77% of new Canadians come from pepulations at increased risk for type 2 diabetes. Eg. Hispanics, asina, south Asian, African descent.

Question 5

what is type 1

Answer 5

primarily a result of pancreatic beta cell destruction and is prone to ketoacidosis.

Question 6

what is type 2

Answer 6

may range from predominant insulin resistance with relative insulin deficiency to a predominant secretory defect with insulin resistance.

Question 7

What is GESTATIONAL DIABETES MELLITUS (GDM)

Answer 7

) refers to glucose intolerance with onset or first recognition during pregnancy.

Question 8

there are other uncommon forms of diabetes- what do they consist of

Answer 8

specific genetically defined forms of diabetes – NOT common (eg. Single gene defect)

Question 9

diabetes can also stem from other diseases:

Answer 9

Pancreatitis
Pancreatic cancer and surgical removal of pancrease
Cystic fibrosis
Excess glucocorticoids
- chronic administration as a drug eg. Prednisone
- excess endogenous production (cushing’s syndrome- overactivity of adrenal cortex)

Question 10

Type 1:
what % of all diabetes
who does it affect

Answer 10

 ~5-10% of cases of diabetes
 Usually but not always < 30 years of age
 Occurs more commonly in people of European descent. Marked geographic variation in annual incidence.
 Insulin deficient (production).

Question 11

what are other characteristics of type 1: how much is it increasing per year
how does it appear

Answer 11

 Prone to development of ketosis.(excess production of ketones- can progress to ketoacidosis- (low blood ph due to excessive ketones)
 Typical Type 1 patient is a child or adolescent at onset
 Disease appears more suddenly with severe symptoms.
 Less common in pre-school age children but incidence is ing.
 Incidence overall is ing at a rate of 3%/year
- Dupports the role of environment etiology.

Question 12

What causes type 1: etiology

Answer 12

idiopathic (unknown)
 Genetic defects plus environmental factors necessary.(they interact) (polygenic)
 Genetic pattern transmits (many genes involved) transmit predisposition to diabetes.
 # of susceptibility genes under study.|(already have the susceptibility but what triggers it) e.g. candidate =
 Environmental factors that have been studied: eg. Vitamin D
 viruses – e.g. enteroviruses, rotavirus, rubella but evidence is mostly against
 dietary factors. e.g. exposure to cows’ milk protein
 vitamin D intake

Question 13

what is TEDDY

Answer 13

The Environmental Determinants of Diabetes in the Young
 large international study to follow high risk infants from birth to adolescence to try to establish the importance of specific environmental factors.

Question 14

Pathogenesis of type 1

Answer 14

 Autoimmune destruction of insulin-producing beta cells in the pancreas by CD4+ and CD8+ T cells and macrophages infiltrating the islets.
 When fully developed  little or no insulin is produced

Question 15

what is the treatment for type 1

Answer 15

diet insulin and exercise

Question 16

Type 2:
who does it affect,
who prevalent compared all diabetes
clinical symptoms
what happenes

Answer 16

 Usually middle aged or elderly at onset
 ….But recent alarming  incidence in childhood
- Predominimantly adolecents
- Especially in aboriginal population

 Most are not ketosis prone (a small proportion are). (but a small proportion is)
 Clinical symptoms often subtle and unnoticed by the patient
 Accounts for majority of DM (~ 90% )
 Patient has a combination of:
- Insulin resistance: diminished tissue response to insulin ( impaired insulin signaling arising from postreceptor defects) AND
- An insulin secretion defect (metabolic defect) (different than type 1)- the dgree of these two in people varies-

 Relative importance of insulin resistance versus secretion defect varies among patients
 Thus, a heterogenous group of disorders with the common endpoint of hyperglycemia.

Question 17

Etiology and pathogenesis

Answer 17

Etiology and Pathogenesis
 Genetic predisposition (polygenic) PLUS environmental factors.(interacting)
 Recall basic endocrine physiology.
 How does an endocrine hormone such as insulin exert its action? – it’s a protein- it needs to bind to a receptor on the surface of the cell.
 How is it determined which are the target tissues or cells? – the cells with the insulin receptors.

Question 18

normal glucose tolerance

Answer 18

ability to remove a specified glucose load from the blood and within a defined period of time. Means that their body put out insulin to keep their glucose normal

Question 19

what is  Fasting hyperglycemia

Answer 19

caused by abnormally high hepatic glucose output due to hepatic resistance to insulin action.

Question 20

what are the pathways in the liver

Answer 20

gluconeogenesis and glycogenolysis