Diabetes Mellitis

Question 1

Difference between diabetes mellitus and diabetes insipidus

Answer 1

DM = deficiency of insulin, resistant to effects of insulin
DI = deficiency of ADH

Question 2

What is insulin?

Answer 2

peptide hormone released into the bloodstream
produced in B cells of Islets of Langerhans of the pancreas; also produce glucagon and pancreatic polypeptide
regulates glucose uptake and metabolism
skeletal muscles/fat cells require insulin to absorb glucose (large carb reserves)

Question 3

Actions of insulin

Answer 3

uptake of glucose by cells
uptake of amino acids by cells
increases glycogen synthesis
increases synthesis of fatty acids
decreases lipolysis, proteinolysis, gluconeogenesis

Question 4

Control of insulin release

Answer 4

Mainly direct feedback
Some autonomic control
Also released by cholecystokinin

Question 5

Acute consequences of insulin deficiency

Answer 5

Hyperglycaemia
Ketosis (increased levels of ketones)
Acidosis
Hyperosmolar state (severe dehydration = coma and death)

Question 6

Chronic consequences of insulin deficiency

Answer 6

CV disease
Nephropathy
Neuropathy
Retinopathy

Question 7

Name the 4 types of diabetes

Answer 7

type 1
type 2
gestational
secondary

Question 8

DM Type 1

Answer 8

autoimmune destruction of B cells = pancreas cant produced insulin ? triggered by infection eg rubella
susceptibility partly dependant on HLA gene subtypes
classically starts in childhood
symptoms: polyuria (increase volumes of urine), polydipsia (thirst), hunger, weight loss

Question 9

DM Type 2

Answer 9

formally known as non-insulin dependant diabetes/obesity related/adult-onset diabetes
- peripheral insulin resistance
- B cell response to glucose delayed/absent
- insulin concs normal or high
strong association with lifestyle eg obesity

Question 10

Gestational diabetes

Answer 10

genetic predisposition 
become insulin resistant triggered by hormonal changes in pregnancy
resolves with delivery 
risk factors:
- maternal age
- family history of type 2
- previous GB
- previous baby over 4kg
- smoking

Question 11

Dangers of gestational diabetes

Answer 11

Mother: greater risk of diabetes later in life, hypertension, pre-clampsia, obstructed
Child: greater risk of diabetes later in life, risk of obesity, jaundice, hypoglycaemia

Question 12

Secondary diabetes

Answer 12

diabetes that develops as a result of another condition

• chronic pancreatitis
• cystic fibrosis
• pancreatic surgery
• endocrine disease eg. Cushing’s syndrome
• drug therapy eg. corticosteroids

Question 13

Biochemical diagnosis of DM

Answer 13

fasting plasma glucose level at or above 7mmol/l
plasma glucose at or above 11.1mmol/l or 2 hours after a 75g oral glucose dose
random plasma glucose at or above 11.2mmol/l

Question 14

Ketoacidosis

Answer 14

rapid breakdown of fat and protein releases ketones (inc acetone) and acids into the bloodstream
type 1, rarely type 2
can lead to coma and DEATH

Question 15

Hyperosmolar nonketotic state

Answer 15

severe dehydration
type 2
can lead to coma and DEATH

Question 16

Hypogylcaemia

Answer 16

insulin overdose = decreases levels of glucose dramatically
generally accidental
can lead to coma and DEATH

Question 17

Diabetic foot

Answer 17

generalised sepsis and death

Question 18

Chronic presentations of DM

Answer 18

Macro-vascular:
- ischaemic heart disease
- stroke
- peripheral vascular disease
Micro-vascular:
- retinopathy
- neuropathy
- nephropathy
Cataracts

Question 19

Diabetic retinopathy

Answer 19

proliferation of blood cells in the retina (retinal haemorrhages)
macular oedema (fluid exudation into retina)

Question 20

Diabetic neuropathy

Answer 20

macroangiopathy of vasa nervosum (disease of blood vessels)

• peripheral numbness/tingling
• neuropathic pain
• muscle weakness
• autonomic neuropathy = vomiting, diarrhoea, incontinence, constipation, impotence

Question 21

Diabetic nephropathy

Answer 21

Macroangiopathy if glomerular capillaries

clinical = chronic renal failure, nephrotic syndrome, hypertension

Question 22

Infections in diabetes mellitus

Answer 22

osteomyelitis
septicaemia
post-op infections
rectal abscesses
pyelonephritis (upper UTI infection - kidneys and ureters affected)