Key references discussed in the episode:
Key take-home messages from the episode:
- If there is recurrent unexplained hypoglycaemia or diabetic ketoacidosis in a person living with type 1 diabetes (T1D), think Addison’s disease.
- An unexplained reduction of total insulin dose >15–20% (due to frequent hypoglycaemia) in a person living with T1D should also raise suspicion of Addison’s disease.
- Abnormal pigmentation in those with T1D warrants further investigation of adrenocortical function.
- Electrolyte abnormalities are often not present until an advanced stage; 20–30% of individuals do not have hyponatraemia or hyperkalaemia at any time.
- The diagnosis of adrenocortical insufficiency also requires simultaneous investigation of thyroid function and thyroid autoantibodies: 25% of those with Addison’s disease also have hypothyroidism.
- As a “rule of thumb”, double the hydrocortisone dose during illness until recovery and add 5–10 mg to the usual regimen before any strenuous exercise.
- A random cortisol is of limited clinical value when testing for cortisol excess.
- Deficiency is highly unlikely if 9am cortisol >400–475 nmol/L. However, levels of 150–400 nmol/L require further investigation; and levels <150 nmol/L require urgent discussion with, or referral to, endocrinology.
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