How may adrenal insufficiency lead to weakness?
Up to 50% of patients with Addison’s disease have a glucocorticoid-sensitive myopathy with associated cramping.
Adrenal insufficiency results in decreased blood flow to the muscle, reduced muscle carbohydrate metabolism, and altered Na + /K + pump function and potassium homeostasis with resulting reduced intracellular muscle potassium and altered muscle contractility.
Decreased adrenergic sensitivity in patients with Addison’s disease also results in reduced exercise tolerance and exercise-related hypotension.
Abnormalities in potassium homeostasis may additionally result in the episodic appearance of extreme weakness, resembling hyperkalemic periodic paralysis.
