Diabetes - Clinical Flashcards
What symptoms may present in hyperglycaemia?
Polyuria Polydipsia Blurred vision Difficulty concentrating Fatigue Weight loss (due to insulin deficiency/insensitivity) Infections
What symptoms may present in hypoglycaemia?
Anxiety, sweating, chilld, clamminess Irritability, impatience Confusion (may become delirium) Rapid heartbeat Lightheadedness, dizziness Hunger, nausea Fatigue, weakness, shakiness
How is diabetes diagnosed?
Lab glucose - 1 diagnostic test plus symptoms - 2 diagnostic tests without symptoms Oral glucose tolerance test (OGTT) HbA1c (glycated haemoglobin)
What blood glucose levels are diagnostic for diabetes?
Fasted glucose > 7.0mmol/L
Random glucose > 11.1mmol/L
Describe how an OGTT can be used to diagnose diabetes
Venous plasma glucose is measured 2 hours after taking 75g of anhydrous glucose (dextrose)
Blood glucose > 11.1mmol/L is diagnostic of diabetes
How can HbA1c be used to diagnose diabetes? What else can it be used for?
HbA1c > 48mmol/mol (6.5%) is diagnostic of diabetes
- the normal range in 4-6%
Can also be used to monitor long term control as it can indicate blood glucose levels over the last 8-12 weeks
Describe the role of urine dipstick in diagnosing diabetes
Dipstick is a very useful screening test but is not sufficient for a diagnosis
What are the normal ranges for blood glucose and blood ketones?
Blood glucose: 4.2 - 6.3 mmol/L
Ketones: < 0.6
What is the threshold for hypoglycaemia?
Blood glucose < 3 mmol/L
What are the indications for a patient with newly diagnosed diabetes to be admitted to hospital?
If they are clearly unwell (or present with DKA)
Ketones are present in urine
Blood glucose is greater than 25 mmol/L
All children should be admitted
Describe the initial investigations that should be done in a patient with suspected diabetes
Height, weight, BMI
Urinalysis - test for ketones, protein, glucose
CVS examination; smoking status, BP, ECG, lipids
Diabetic foot examination
ACR (albumin:creatinine ration) to test for microalbuminuria
Renal function tests
U&E, LFTs
What are the options for long term management of type 1 diabetes?
All will need insulin
Basal-bolus regimens vs continuous subcutaneous insulin infusion (insulin pump)
Basal bolus regimen options:
- twice daily
- three times daily
- four times daily
Give two types of rapid acting insulin
Humalog (lispro)
Novorapid (aspart)
Give two types of short-acting insulin
Actrapid
Humulin S
(both are human soluble insulins)
Give three types of intermediate acting insulin
Insulatard
Hypurin isophane
Humulin I
(all are isophane insulins)
Give three types of long-acting insulin
Lantus (glargine)
Levemir (determir)
Tresiba (degludec)
How long do rapid acting insulins take to kick in? How long do they last for?
Onset: 10-20 minutes
Duration 2-5 hours
How long do short acting insulins take to kick in? How long do they last for?
Onset: 30-60 minutes
Duration: 8 hours
How long do intermediate acting insulins take to kick in? How long do they last for?
Onset: 2 hours
Duration: 8-14 hours
How long do long acting insulins take to kick in? How long do they last for?
Onset: 1 hour
Duration: 18-24 hours
Describe the general measures that should be taken in the long term management of diabetes
Optimise blood glucose control (measure HbA1c)
Optimise blood pressure control
Manage cardiovascular risk factors (stop smoking, control cholesterol)
Screen for early detection of complications (feet, eyes, kidneys)
Describe the initial investigation of a patient with suspected diabetic ketoacidosis
Rapid ABCDE assessment - IV access, vital signs, clinical assessment, full exam Investigations - Blood glucose, ketones - Venous blood gas - Urinalysis - U&E, FBC - Blood/urine culture - ECG - Consider CXR
What are the three main signs of DKA?
Hyperglycaemia: [BG] > 11mmol/L
Ketonaemia: blood ketones > 3mmol/L
Acidosis: pH < 7.3 (venous) OR bicarbonate < 15mmol/L
What are the symptoms of DKA?
Polyuria, polydipsia Weight loss Weakness Nausea, vomiting Abdominal pain Breathlessness
What are the signs of DKA?
Dry mucous membranes Sunken eyes Hypotension and tachycardia Ketotic breath Kussmaul respiration Altered mental state Hypothermia
Describe the potential complications of DKA
Cerebral oedema (and raised ICP) Pulmonary oedema Hyperkalaemia Hypernatraemia Cardiac dysarhuthmia Venous thromboembolism Aspiration pneumonia Acute Respiratory Distress Syndrome (ARDS) Iatrogenic hypoglycaemia
Describe the management of DKA
Give IV saline; 5 litres over 24 hours Give IV insulin; drives glucose AND potassium into cells (monitor carefully for hypokalaemia) Give IV potassium in saline May need antibiotics Consider heparin Consider NG tube
What should be included in the initial management of a patient with newly diagnosed diabetes?
If patient is acutely unwell, presents with DKA and/or is a child, they should be admitted to hospital
Patient education
Dietary advice
Blood pressure management
Blood glucose monitoring and targets (HbA1c)
What lifestyle measures should be recommended to a patient with diabetes?
Quit smoking
Lipid control
Blood pressure control
Diet and exercise
What is the first line treatment for type 2 diabetes?
Metformin
or Sulfonylurea
How often should HbA1c be reviewed?
Every 3 - 6 months
Give three examples of sulfonylureas
Glimepiride
Glicalazide
Glipizide
What class of drugs does metformin belong to? How does this drug work?
Biguanide
Improves insulin action on muscle and liver by improving receptor function.
Inhibits gluconeogenesis and decreases fatty acid synthesis in the liver.
Decreases glucose absorption from intestine.
How do sulfonylureas work?
Increase insulin secretion from beta-cells in the pancreas.
List some second/third line glucose-lowering drugs
(Sulfonylureas)
Thiazidolidinediones - e.g. Pioglitazone
DPP IV inhibitors - sitaglyptin, saxaglyptin
GLP-1 analogues - lixisenatide, liraglutide, exenatide
SGLT2 inhibitors - canagliflozin, empagliflozin, dopagliflozin
(Insulin)
Why might sulfonylurea be used as a first line diabetes treatment instead of metformin?
Metformin is contraindicated in renal impairment (eGFR<30), but sulfonylureas are not.
Which glucose-lowering drugs can also contribute to weight loss:?
GLP-1 analogues
SGLT2 inhibitors
What is MODY?
Maturity Onset Diabetes in the Young
- autosomal dominant, single gene defect
- causes problems with glucokinase which impairs beta-cell function
- level of glucose at which cells are stimulated to produce insulin is higher
- glucose level stays relatively constant but is just above the normal range
What are the potential causes of secondary diabetes?
Pancreatic disease (CF, pancreatitis, cancer) Endocrine causes (Cushing's, acromegaly, thyrotoxicosis, phaeochromocytoma, glucagonoma) Drug-induced (thiazide diuretics, corticosteroids others) Genetics conditions (Wel fram's, Friedreich's ataxia, Haemachromatosis)
Which diabetes drugs work by influencing the incretin pathway?
GLP-1 analogues - are agonists of the incretin hormone GLP-1 so act directly on pancreas and liver.
DPP4 inhibitors - inhibit DPP4 enzymes. DPP4 enzymes inhibit GLP-1, therefore DPP4 inhibitors increase the action of GLP-1 so act indirectly on the pancreas and liver.
Which drugs increase the risk of hypoglycaemia?
Those which act on the pancreas to increase insulin secretion:
- sulfonureas
- GLP-1 agonists
- DPP4-inhibitors
