Diabetes: Aetiology, Diagnosis and Presentation

Question 1

Describe the difference between the onset of symptoms for Type 1 and Type 2 Diabetes [1]

Answer 1

Type 1: Acute
Type 2: Subacute / nonspecific symptoms (e.g. tiredness

Question 2

State 6 classical symptoms of diabetes [6]

Answer 2

 polyuria
 polydipsia
 nocturia
 weight loss
 fatigue
 blurred vision
 pruritis
 recurrent urinary or genitourinary infections

Question 3

Name 4 complications associated with untreated diabetes

Answer 3

 skin infections – staphylococcal skin abcesses, oral or genital candidiasis

 foot problems – ulcers or neuropathic pain

 retinopathy – perhaps found on routine eye test

 acute myocardial infarct / stroke– diagnosed whilst in hospita

Question 4

State 4 methods for diagnosing diabetes [4]

Answer 4

 Fasting plasma glucose (FPG) (note NOT a capillary glucose [ie. a fingerprick test])

 Random plasma glucose (RPG)

 75 gram oral glucose tolerance test (OGTT / 2hr PG)

 Haemoglobin A1c (HbA1c, glycated haemoglobin)

NOTE: One diagnostic test is enough to diagnose diabetes w/ symptom

Question 5

What HbA1c score is :
- Within normal range [1]
- Pre-diabetes [1]
- Diabetes mellitus [1]

Answer 5

Normal < 42mmol / mol
Pre-diabetes: 42- 47 mmol / mol
DM: > 48 mmol / mol

Question 6

If Ptx has diabetic symptoms, how many diagnostic tests do they require for a diagnosis ? [1]

If Ptx has no diabetic symptoms, how many diagnostic tests do they require for a diagnosis ? [1]

Answer 6

Symptoms: one test
No symptoms: two tests

Question 7

Answer 7

Question 8

Impaired glucose tolerance can only be diagnosed using which diagonostic test?
FPG
2 hr PG
RPG
HbA1c

Answer 8

Impaired glucose tolerance can only be diagnosed using which diagonostic test?
FPG
2 hr PG
RPG
HbA1c

Question 9

Answer 9

Question 10

Which HLA is associated with DMT1? [2]

Answer 10

HLA DR3 & DR4

Question 11

Describe what pancreatic diabetes is [1]

Name 4 causes of pancreatic diabetes [4]

Answer 11

Pancreatic diabetes:
* Severe disease of pancreas causes damage to B cells

Causes:
 Acute / Chronic Pancreatitis
 Trauma / Pancreatectomy
 Neoplasia
 Cystic fibrosis
 Haemochromatosis / Thalassaemia – due to iron overload

Question 12

Name 6 endocrine diseases known to cause diabetes [6]

Answer 12

 Acromegaly (excess growth hormone)
 Cushing’s syndrome (excess cortisol)
 Glucagonoma (excess glucagon)
 Phaechromocytoma (excess adrenaline)
 Hyperthyroidism (excess thyroid hormone)
 Conn’s syndrome (excess aldosterone hormone

Question 13

State 5 causes of drug induced diabetes [5]

Answer 13

 Glucocorticoids

 b-blockers

 Thiazide diuretics

 Tacrolimus (used in transplantation – may cause “New Onset Diabetes after Transplantation” [NODAT])

 Atypical anti-psychotics – eg. olanzapine, risperidone, clozapine

Question 14

Name two congenital viral infections that may cause diabetes [2]

Answer 14

 Congenital rubella
 Cytomegalovirus

Question 15

DMT2 is caused by a combination of which two physiological factors? [2]

Answer 15

Insulin resistance AND B-cell failure

Question 16

Insulin resistance AND B-cell failure are exacerbated by hyperglycaemia:
What is this concept called? [1]
Explain the pathophysiology [2]

Answer 16

Glucose toxicity:

 High levels of glucose lead to poorer b-cell function leading to reduced insulin secretion

 therefore lowering glucose may actually help b-cell function

Question 17

Describe how alpha and beta cell mass changes in diabetic patients [2]

Answer 17

 b-cell mass is relatively preserved (50% at autopsies) - but function declines
 a-cell population increased

Question 18

Which factors contribute to metabolic syndrome? [6]

Answer 18

BMI > 30 kg/m2 , or:
Abdominal Waist Circumference – ethnic specific
Low HDL Concentration
Blood pressure
Fasting glucose
Triglyceride

Question 19

Which antibodies are commonly positive in DMT1? [2]

Answer 19

Usually islet cell [ICA] and glutamic acid decarboxylase [GAD] antibodies positive