Diabetes Mellitus

Question 1

What defines diabetes?

Answer 1

Elevation of blood glucose above a diagnostic threshold

Question 2

What are the thresholds for diagnosis of diabetes:

• fasting glucose levels
• 2hr plasma glucose
• HbA1c

Answer 2

fasting = 7mmol/l

2hr plasma glucose after glucose tolerance test = 11.1mmol/l

HbA1c = 48mmol/l

Question 3

If someone is asymptomatic what must be considered when trying to diagnose diabetes?

Answer 3

Repeat confirmatory test is required

Question 4

The thresholds for diabetes diagnosis are based on what?

This is different in gestational diabetes. What is that threshold levels based on?

Answer 4

Risk of developing retinopathy

Gestational = risk to foetus/neonate

Question 5

How is endogenous insulin secretion measured?

Answer 5

C-peptide levels

Question 6

What causes type 1 diabetes?

Pancreatic autoantibodies can be used to aid diagnose. Name the 3 antibodies used

Answer 6

Autoimmune destruction of pancreatic beta cells

GAD
Znt8
IA-2

Question 7

Diabetes can cause microvascular and macrovascular complications.

What one refers to “diabetes specific” complications?

Give 3 examples of each

Answer 7

Microvascular

• retinopathy
• neuropathy
• nephropathy

Macrovascular

• MI/ACS
• Stroke
• PVD

Question 8

Diabetes can present asymptomatically esp. in type 2.

How would it present symptomatically though? (6)

Answer 8

• Polyuria
• Increased thirst
• Genital thrush
• Fatigue
• Blurred vision
• Weight loss

Question 9

Why must you always rule out type 1 diabetes first in diagnosis?

Answer 9

Can be fatal if left untreated

Question 10

What is HbA1c?

It can be used to show blood sugar levels over past 90 days. How?

Answer 10

Hb that has bound with glucose in RBC

HbA1c lasts as long as RBC lasts

Question 11

What is used to monitor diabetes?

Answer 11

HbA1c

Question 12

How much weight loss can result in remission in T2?

Answer 12

10-15% weight loss

Question 13

In diabetes what is the HbA1c target?

This changes if the patient is on insulin/triple oral therapy. What does it change to?

Answer 13

7%/53 mmol/l

Triple therpay/insulin - 58mmol/l

Question 14

For diabetic inpatients what is the desirable and what is the accepted blood glucose levels?

Answer 14

Desirable = 6-10mmol/l

Acceptable = 4-12mmol/l

Question 15

How often should patients with subcutaneous insulin have blood glucose tested vs. IV insulin patients?

Answer 15

Subcutaneous - prior to each injection

IV - hourly

Question 16

Who should have their blood glucose levels monitored twice daily as opposed to once daily when an inpatient. Patients on sulphonylureas or metformin?

Answer 16

Sulphonylureas - twice daily

Metformin - once

Question 17

What impact can corticosteroids have on blood glucose and why?

Answer 17

Leads to impaired insulin sensitivity -> hyperglycaemia

Question 18

Diabetic patients stay in hospital longer than non-diabetics. True or flase?

Answer 18

True

Question 19

Select from the list below the following circumstances where you would refer to diabetic team in 24hrs:

• Complications
• Active foot problem
• Vomiting
• Treatment with corticosteroid
• Ketoacidosis
• Pregnant
• new T1 diabetes
• recurrent/ severe hypoglycaemia
• insulin initiation
• poor control
• sepsis
• IV insulin use for 48hrs+

Answer 19

• complications
• active foot problem
• new T1 diagnosis
• pregnant
• ketoacidosis
• recurrent/severe hypoglycaemia
• insulin initiation
• poor control

Question 20

Where are the 4 sites of injection for insulin?

Answer 20

Abdomen
Upper outer thigh
Buttock
Upper outer arm

Question 21

Why is it important to rotate site of injection?

Answer 21

Reduce risk of lipohypertrophy

Question 22

What layer must insulin injection go into?

Answer 22

Subcutaneous tissue

Question 23

Insulin must be documented on two forms. True or false?

Answer 23

True

Question 24

What insulin should not be kept in the fridge?

Answer 24

Opened vials can be stored at room temp for up to 1month

Question 25

Describe the pathophysiology of T2 diabetes? | With link to obesity and genetics

Answer 25

``` Exceed the fat storage threshold -> Increase in FFAs and visceral fat -> LIPOTOXICITY -> vulnerable beta cells *due to genetics* -> inability to produce sufficient insulin -> T2 diabetes ```

Question 26

What tests must be done on a patient with a raised blood glucose in clinic?

Answer 26

1. Ketones 2. HbA1c 3. Pancreatic autoantibodies

Question 27

Under what circumstances MUST a ketone test be done? What number of ketones is high?

Answer 27

If patient presents with blood sugar >15mmol/l >3 (anything <1 is ok)

Question 28

When is a C-peptide test used?

Answer 28

3 years after diagnosis - confirms T1 diabetes

Question 29

T1DM is still producing insulin after 3-5 years - shown by still having C-peptide. What needs to now be considered?

Answer 29

Their initial diagnosis was wrong - this is very unlikely to be T1DM

Question 30

What type of diabetes is more likely to present with evidence of microvascular disease?

Answer 30

T2 due to regularly being undiagnosed for many years

Question 31

What is LADA?

Answer 31

latent autoimmune diabetes of adult (late onset T1) - often misdiagnosed as T2

Question 32

What resp disease has a strong association with diabetes?

Answer 32

CF | esp. those with (delta)508 mutation

Question 33

What is acanthosis nigricans? | In what conditions would it be seen?

Answer 33

Insulin driven epithelial overgrowth - darkened discolouration in body folds and creases Seen in cases with v high insulin in blood Obesity - most common Severe insulin resistant T2 Monogenic diabetes

Question 34

What does MODY stand for?

Answer 34

Maturity onset diabetes of the young

Question 35

MODY is caused by genetic mutations. There are two main causes of MODY, mutations in transcription factors and mutations in glucokinase. Describe them both in terms of the following factors; - Onset - Gets progressively worse? - Complications common? - Able to manage through diet alone? - Response to OGTT (oral glucose tolerance test) - Beta cells damaged?

Answer 35

Glucokinase - onset from birth - stable hyperglycaemia - complications rare - diet alone - manage a OGTT - no damage to beta cells Transcription factors (more common) - onset from adolescene/YA - gets progressively worse - complications common - needs managed through drugs and diet - poor response to OGTT - beta cells damaged

Question 36

What are the transcription factors that can be damaged in MODY?

Answer 36

HNF-...