Non diabetes causes of hypoglycaemia

Question 1

What are the autonomic and neuroglycopenic symptoms of hypoglycaemia?

Answer 1

Autonomic - Sweating, palpitations, pallor, tremor, nausea, irritability and hunger (in most people without diabetes this occurs at 3mmol/L)
Neuroglycopenic - Inability to concentrate, confusion, drowsiness, personality change, slurred speech, incoordination, weakness, dizziness, visual impairments, headaches, seizure and coma.

Question 2

What is Whipple’s triad?

Answer 2

• Symptoms which are consistant with hypoglycaemia
• Low plasma glucose,
• Relief of those symptoms once plasma glucose is raised.
  Basically determines if someone is having a hypo because some people can have BMs of 2mmol/L and be asymptomatic

Question 3

What else is important to know in context of hypoglycaemia?

Answer 3

Whether symptoms occur in the fasting period or the post prandial state (after a meal). This determines what diagnostic tests you preform

Question 4

What are the different non-blood related investigations for hypoglycaemia?

Answer 4

• If post prandial symptoms then do a mixed meal test up to 5 hours.
• If fasting symptoms then do 72 hour fast. Finish the fast when plasma glucose is at 2.5mmol/L with symptoms, if 72 hours have passed or if plasma glucose is below 3mmol/L and whipples triad previously documented

Question 5

What are the different blood test investigations for hypoglycaemia?

Answer 5

• Glucose,
• Insulin,
• C peptide (co released with insulin)
• Screen for sulphonureas,
• Beta hydroxybutyrate (keto body - low in insulinoma)
• Insulin antibodies

Question 6

What are the different imaging techniques for endogenous hyperinsulinaemic hypoglycaemia?

Answer 6

• CT or MRI of pancreas or endoscopic ultrasound.
• Arterial calcium stimulation (distinguishes focal (insulinoma) from diffuse disease (islet cell hypertrophy). This is preformed when imaging is negative.

Question 7

What are the Pancreatic causes of spontaneous hypoglycaemia?

Answer 7

• Insulinoma,
• Non insulinoma pancreatogenic hypoglycaemia (hypertrophy of cells)
• MEN1

Question 8

What are non isclet cell tumour hypoglycaemias?

Answer 8

• Insulin growth factor 2 secreting tumours,
• Lymphomas/myelomas/leukaemias,
• Metastatic cancer

Question 9

What are different autoimmune causes of hypoglycaemia

Answer 9

• Autoimmune insulin syndrome,
• Anti insulin receptor

Question 10

What are some drugs that can induce hypoglycaemia?

Answer 10

• Insulin,
• Sulfonylureas,
• Repaglinide,
• Salicylates,
• Beta blockers,
• Trimethoprim,
• Levofloxacin

Question 11

What are some dietary toxins which can induce hypoglycaemia?

Answer 11

• Alcohol,
• Mushrooms causing acute liver failure

Question 12

What are some organ failure causes of hypoglycaemia

Answer 12

• Severe liver disease,
• end stage renal disease
• Renal dialysis,
• Congestive cardiac failure

Question 13

What endocrine diseases can cause hypoglycaemia?

Answer 13

Hypopituitarism,
- Adrenal failure,
Hypothyroidism

Question 14

What are some other miscellaneous causes of spontaneous hypoglycaemia?

Answer 14

• Sepsis,
• Starvation,
• Anorexia nervosa,
• Total parental nutrition,
• Severe excercise excess

Question 15

What is the likely causes of hypoglycaemia in ill or medicated patients?

Answer 15

1. Look at drug history for precipitating cause,
2. Look to see if they have a critical illness which may have caused the hypoglycaemia eg, organ failure or sepsis,
3. Hormone deficiencies (cortisol)
   - Non islet cell tumour

Question 16

What are the likely causes of a spontaneous hypoglycaemia in a seemingly well patient

Answer 16

1. Endogenous hyperinsulinism either from insulinoma, functional islet cell disorders (nesidioblastosis) such as noninsulinoma pancreatogenic hypoglycaemia, insulin autoimmune hypoglycaemia.
2. Accidental or Malicious hypoglycaemia