Expansion
Raises glucose, breaks down protein and fat, suppresses immunity, and maintains vascular tone
Expansion
Metabolic
- Increases gluconeogenesis and hepatic glycogen, and causes peripheral insulin resistance, so blood glucose rises
- Protein catabolism in muscle, skin and bone, providing amino acid substrate
- Lipolysis peripherally with central fat redistribution
Cardiovascular
- Permissive effect on catecholamines, maintaining vascular tone and blood pressure. Its absence causes the hypotension of Addison disease
- Weak mineralocorticoid activity at high concentrations
Immune and inflammatory
- Suppresses inflammation, reduces lymphocytes and eosinophils, raises neutrophils by demargination
Other: bone resorption, reduced calcium absorption, impaired wound healing, mood change, and inhibition of growth in children.
The features of Cushing syndrome are all predictable from this list: hyperglycaemia, central obesity with thin limbs, proximal myopathy, thin skin with striae and easy bruising, osteoporosis, hypertension, infection risk and poor healing.
Cortisol shows a diurnal rhythm, peaking in the early morning, which is why timing matters when it is measured.