Diabetes mellitus clinical

Question 1

Common symptoms of type 1/type 2 DM (7)

Answer 1

Polydipsia (excessive thirst)
Polyuria (excessive urinating)
Blurred vision
Weight loss (unexplained)
Fatigue
Thrush/genital itching
Increased vulnerability/recurrent infection

Question 2

Diagnostic investigations of diabetes mellitus (4)

Answer 2

Fasting plasma glucose ≥ 7.0 mmol/l

Random plasma glucose ≥ 11.1 mmol/l

Oral glucose tolerance test 2hr after 75g oral glucose load ≥11.1 mmol/l

HbA1c ≥ 48 mmol/mol (type 2 only)

Question 3

People with intermediate hyperglycaemia are at risk of what

Answer 3

future diabetes

Question 4

If have the classic diabetes symptoms, how many diagnostic investigations needed

Answer 4

ONE LAB GLUCOSE

Question 5

If no classic diabetes symptoms, how many/ what diagnostic investigations needed

Answer 5

TWO LAB GLUCOSE (e.g. random and fasting)

or

just HbA1c

Question 6

What is HbA1c

Answer 6

Glycated haemoglobin

Question 7

HbA1C gives an indication of BG levels over what time period

Answer 7

last 3 months

Question 8

Does glucose reversibly or irreversibly bind to Hb

Answer 8

Irreversibly

Question 9

When HbA1c can’t be used for diagnosis (6)

Answer 9

All children
If pregnant
Acutely ill
If have been on mediation that can cause rapid glucose rise <2 months
Acute pancreatic damage/ if had pancreatic surgery
Post-blood transfusion

Question 10

Only hormone that lowers BG

Answer 10

Insulin

Question 11

Summarise the factors which may contribute to beta cell damage and the eventual clinical presentation of type 1 DM (2)

Answer 11

Genetic factors
+
Environmental factors
-e.g. viral infection

Question 12

What are ketones produced from + where

Answer 12

Free fatty acids

produced in liver

Question 13

Symptoms (3)/signs (5) of DKA

Answer 13

Symptoms

• Nausea
• Vomiting
• Abdo pain/tenderness

Signs:
Ketones in breath (acetone breath)
Tachypnoea/kussmaul breathing (rapid deep breathing)
Tachycardia
Hypotension
Dehydration (fluid depletion) –> dry mucous membranes, sunken eyes

Question 14

In type 2 DM, what is wrong with the beta cells

Answer 14

Due to insulin resistance, glucose persists in blood so beta cells compensate for this by increasing insulin secretion

However beta cells become damaged by lipotoxicity and glucotoxicity and eventually can no longer compensate –> hyperglycaemia

Question 15

Summarise what type 2 DM is a result of (2)

Answer 15

insulin resistance and subsequent B cell dysfunction

Question 16

Which type of DM may present with no symptoms

Answer 16

2

Question 17

What sign of DM is present in type 1 but not type 2

Answer 17

Ketones in breath or urine

Question 18

Risk factors of type 2 DM (5)

Answer 18

Overweight
Family history of DM
>40yrs old
Gestational diabetes
Sedentary lifestyle/lack of exercise

Question 19

Other types of diabetes mellitus that are not type 1/2 (3)

Answer 19

Genetic syndrome
-maturity onset diabetes in the young (MODY)

Gestational diabetes

Secondary diabetes

Question 20

What is maturity onset diabetes in the young (MODY)

Answer 20

Single gene defect resulting in reduced insulin production

Most are due to mutations of transcription factor genes

Question 21

Maturity onset diabetes in the young (MODY) is a single gene defect of either … or … (2)

Answer 21

Transcription factor genes

• HNF-1a
• HNF-1b,
• HNF-4a

Glucokinase gene

Question 22

Most common form of maturity onset diabetes in the young (MODY) is due to a single gene defect in what gene

Answer 22

HNF-1a (a transcription factor gene)

Question 23

How does maturity onset diabetes in the young (MODY) due to a glucokinase mutation present

• normal function of glucokinase
• how it presents
• any treatment

Answer 23

Glucokinase helps the body to recognise how high the blood glucose level is so when it isn’t working properly, the body allows the level of blood glucose to be higher than it should be

typically only slightly higher than normal so don’t generally have symptoms

No medical treatment needed

Question 24

How does maturity onset diabetes in the young (MODY) due to a HNF-1a (transcription factor) present

• age onset
• pathology
• any treatment

Answer 24

Usually in adolescence/ early 20s

Reduces insulin production by pancreas

Generally don’t need insulin therapy, but may take sulphonylureas

Question 25

Causes of secondary DM (4)

Answer 25

Drug induced, e.g. corticosteroids

Pancreatic destruction
-e.g. CF, chronic pancreatitis, pancreatectomy

Genetic syndromes
-e.g. Wolfram syndrome

Endocrine disorders
-e.g. Cushing’s syndrome, acromegaly, pheochromocytoma

Question 26

What is gestational diabetes

Answer 26

In females who are not diabetic

-hyperglycaemia during pregnancy due to insulin resistance to some extent

Question 27

What type DM is gestational diabetes more associated with

Answer 27

2

Question 28

When taking the family history of someone with possible DM, what should be asked (2)

Answer 28

If anyone has DM

If anyone has other autoimmune conditions, e.g. thyroid problems, IBD, rheumatoid arthritis

Question 29

Biochemical triad of DKA

Answer 29

Hyperglycaemia
Ketonaemia
Acidaemia

Question 30

Investigations of DKA (4)

Answer 30

Plasma glucose - high
ABG - test arterial pH
Urinalysis - for glucose and ketones
U and Es - low serum sodium, high serum potassium, high serum creatinine

Question 31

DKA is characterised by:

• BG >
• HCO3- <
• pH

Answer 31

> 14mmol/l

<18mmol/l

<7.3

Question 32

Complications of DKA (5)

Answer 32

Hyper/hypokalaemia - due to excessive insulin

Hypoglycaemia - due to excessive insulin

Cerebral oedema - more in children

Arterial or venous thromboembolism

Acute respiratory distress syndrome (ARDS)
-treatment induced reduction in colloid osmotic pressure –> accumulation of water in lungs –> decreased lung compliance –> hypoxaemia

Question 33

The characteristic skin finding associated with type 2 is

Answer 33

acanthosis nigricans - due to increased insulin levels