Intro

Question 1

What are the features of vascular disease in diabetic foot

Answer 1

Pale discoloration
Loss of hair
Absent pulses (begin in foot and proceed to legs)
Reduced capillary refill time
Cool temperature
Evidence of gangrene or infection

Question 2

Features of neuropathy in diabetic foot?

Answer 2

Clawing of toes, loss of plantar arch
Joint deformity (charcot’s joint)
Glove and stocking sensory loss
Loss of vibration sense, proprioception and pain
Loss of ankle jerk
Neuropathic ulcers

Question 3

What is the most common cause of death in diabetic patients?

Answer 3

Heart disease

Question 4

Which molecules are used in gluconeogenesis?

Answer 4

The liver combines three-carbon molecules derived from the break-down of fat (glycerol), muscle glycogen (lactate) and protein into six-carbon glucose molecules.

Question 5

Organs of gluconeogenesis

Answer 5

Liver
Kidney

Question 6

Is glucose uptake by the brain insulin-dependent?

Answer 6

No, it is obligatory

Question 7

Regulated pathway of insulin release

Answer 7

Ribosomes manufacture pre-proinsulin
the hydrophobic “pre” portion allows it to transfer to the Golgi apparatus where it is cleaved off
proinsulin is packaged into secretory granules in the Golgi apparatus
They mature and pass toward the cell membrane where they are stored before release
The proinsulin molecule folds back on itself and stabilized by disulfide bonds
C (connecting) peptide splits off from proinsulin in the secretory process leaving insulin as a complex of two linked peptide chains
Equimolar quantities of insulin and c-peptide are released into the circulation

Question 8

Regulated pathway of insulin release

Answer 8

Bypasses secretory granules

Question 9

What happens to glucose taken up by muscles

Answer 9

Stored as glycogen or metabolized to lactate or carbon dioxide and water

Question 10

What happens to glucose taken up by fat cells

Answer 10

Becomes a substrate for triglyceride synthesis. In the process of lipolyses, fatty acids from triglycerides are released together with glycerol, a substrate for hepatic gluconeogenesis

Question 11

Which glucose transporter is insulin dependent

Answer 11

GLUT-4
It is normally present in the cytoplasm, but after insulin binds to its receptor, GLUT-4 moves to the cell surface where it creates a pote for glucose entry

Question 12

Function of insulin in the fasting state?

Answer 12

Regulate glucose release by the liver

Question 13

Function of insulin in the postprandial state

Answer 13

Promotes glucose uptake by fat and muscles

Question 14

Counter regulatory hormones that antagonize the action of insulin

Answer 14

Glucagon
NE
Cortisol
Growth hormone
Increase hepatic glucose production and reduce its utilization in fat and muscle for any given insulin concentration

Question 15

Secondary diabetes can be subdivided into:

Answer 15

Diabetes secondary to genetic defects
Diabetes secondary to exocrine pancreatic disease
Diabetes secondary to endocrine disease
Diabetes secondary to drugs and chemicals
Diabetes secondary to infection
Uncommon forms of immune-mediated diabetes
Other genetic syndromes sometimes associated with diabetes

Question 16

What is latent autoimmune diabetes in adult (LADA)

Answer 16

Is a slow-burning variant of type 1A diabetes with slower progression to insulin deficiency occurring later in adulthood

Question 17

Immune mediated organ specific diseases

Answer 17

Type 1 diabetes
Autoimmune thyroid disease
Coeliac disease
Addison’s disease
Pernicious anaemia

Question 18

Pathophysiology of type 1 diabetes

Answer 18

Triggering of selective autoimmune destruction of the insulin producing cells in a genetically susceptible individuals
Asymptomatic loss of beta cell secretory capacity histologically characterized by a chronic inflammatory mononuclear cell infiltrate of of T lymphocytes and macrophages in the islets, known as insulitis
Diabetes symptoms start to develop when the remaining beta cells are no longer able to produce enough insulin to meet the body’s needs

Question 19

Autoantibodies are directed against the following islet antigens (in type 1 DM)

Answer 19

Insulin
Glutamic acid decarboxylase (GAD)
Protein tyrosine phosphatase (IA-2, aka ICA512)
The cation transporter ZnT8
Tetraspanin 7

Question 20

Genes involved in type 1 diabetes

Answer 20

HLA-DR3-DQ2
HLA-DR4-DQ8
Or both

Question 21

Risk factors for developing type 2 DM

Answer 21

Obesity
Diet
Physical inactivity
Others: urbanization, poverty, abnormal sleep pattern, environmental toxins, mental illness

Question 22

Pathogenesis of type 2 diabetes

Answer 22

Abnormalities of insulin action (insulin resistance)
Abnormalities of insulin secretion
Other hormonal abnormalities (increased glucagon secretion and impaired incretin effects)
Glucose réabsorption in the kidney

Question 23

Insulin resistance

Answer 23

Inability of insulin to produce its usual biological effects at physiological concentrations. It is characterized by an impaired ability of insulin to:
-inhibit hepatic glucose output
-stimulate glucose uptake into skeletal muscle, and
-suppress lipolysis in adipose tissue

Question 24

Incretin effect

Answer 24

Mediated by two hormones, glucagon like peptide-1 (GLP-1) and glucose-dependent insulinotrophic polypeptide (GIP), which are released by the GI tract following eating. They increase insulin secretion, reduce glucagon secretion, slow gastric emptying and induce satiety. Both hormones have short half-lives and are degraded within minutes by dipeptidyl peptidase-4 (DPP4)