Diabetes Mellitus Flashcards
What defines diabetes?
Elevation of blood glucose above a diagnostic threshold
What are the thresholds for diagnosis of diabetes:
- fasting glucose levels
- 2hr plasma glucose
- HbA1c
fasting = 7mmol/l
2hr plasma glucose after glucose tolerance test = 11.1mmol/l
HbA1c = 48mmol/l
If someone is asymptomatic what must be considered when trying to diagnose diabetes?
Repeat confirmatory test is required
The thresholds for diabetes diagnosis are based on what?
This is different in gestational diabetes. What is that threshold levels based on?
Risk of developing retinopathy
Gestational = risk to foetus/neonate
How is endogenous insulin secretion measured?
C-peptide levels
What causes type 1 diabetes?
Pancreatic autoantibodies can be used to aid diagnose. Name the 3 antibodies used
Autoimmune destruction of pancreatic beta cells
GAD
Znt8
IA-2
Diabetes can cause microvascular and macrovascular complications.
What one refers to “diabetes specific” complications?
Give 3 examples of each
Microvascular
- retinopathy
- neuropathy
- nephropathy
Macrovascular
- MI/ACS
- Stroke
- PVD
Diabetes can present asymptomatically esp. in type 2.
How would it present symptomatically though? (6)
- Polyuria
- Increased thirst
- Genital thrush
- Fatigue
- Blurred vision
- Weight loss
Why must you always rule out type 1 diabetes first in diagnosis?
Can be fatal if left untreated
What is HbA1c?
It can be used to show blood sugar levels over past 90 days. How?
Hb that has bound with glucose in RBC
HbA1c lasts as long as RBC lasts
What is used to monitor diabetes?
HbA1c
How much weight loss can result in remission in T2?
10-15% weight loss
In diabetes what is the HbA1c target?
This changes if the patient is on insulin/triple oral therapy. What does it change to?
7%/53 mmol/l
Triple therpay/insulin - 58mmol/l
For diabetic inpatients what is the desirable and what is the accepted blood glucose levels?
Desirable = 6-10mmol/l
Acceptable = 4-12mmol/l
How often should patients with subcutaneous insulin have blood glucose tested vs. IV insulin patients?
Subcutaneous - prior to each injection
IV - hourly
Who should have their blood glucose levels monitored twice daily as opposed to once daily when an inpatient. Patients on sulphonylureas or metformin?
Sulphonylureas - twice daily
Metformin - once
What impact can corticosteroids have on blood glucose and why?
Leads to impaired insulin sensitivity -> hyperglycaemia
Diabetic patients stay in hospital longer than non-diabetics. True or flase?
True
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+
- complications
- active foot problem
- new T1 diagnosis
- pregnant
- ketoacidosis
- recurrent/severe hypoglycaemia
- insulin initiation
- poor control
Where are the 4 sites of injection for insulin?
Abdomen
Upper outer thigh
Buttock
Upper outer arm
Why is it important to rotate site of injection?
Reduce risk of lipohypertrophy
What layer must insulin injection go into?
Subcutaneous tissue
Insulin must be documented on two forms. True or false?
True
What insulin should not be kept in the fridge?
Opened vials can be stored at room temp for up to 1month
Describe the pathophysiology of T2 diabetes?
With link to obesity and genetics
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
What tests must be done on a patient with a raised blood glucose in clinic?
- Ketones
- HbA1c
- Pancreatic autoantibodies
Under what circumstances MUST a ketone test be done?
What number of ketones is high?
If patient presents with blood sugar >15mmol/l
> 3 (anything <1 is ok)
When is a C-peptide test used?
3 years after diagnosis - confirms T1 diabetes
T1DM is still producing insulin after 3-5 years - shown by still having C-peptide. What needs to now be considered?
Their initial diagnosis was wrong - this is very unlikely to be T1DM
What type of diabetes is more likely to present with evidence of microvascular disease?
T2 due to regularly being undiagnosed for many years
What is LADA?
latent autoimmune diabetes of adult (late onset T1) - often misdiagnosed as T2
What resp disease has a strong association with diabetes?
CF
esp. those with (delta)508 mutation
What is acanthosis nigricans?
In what conditions would it be seen?
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
What does MODY stand for?
Maturity onset diabetes of the young
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?
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
What are the transcription factors that can be damaged in MODY?
HNF-…
