Autonom cortisol secretion- cause of metabolic syndrome?
Incidental finding of an adrenal tumor or thickening of the adrenal cortex is a common finding in imaging (CT and NMR) for unrelated problems. Theser are called adrenal incidentalomas and is found in around 5% of the adult population. Studies have shown that 5-30% of patients with incidentalomas have an eleveated secretion of the stress hormone cortisol foom the adrenals, knowns as autonomous cortisol secretion (ACS).
The degree of cortisol overproduction varies from lightly elevated to fulminant disease - also called Cushings syndrome. There is association between cortisol overproduction in ACS and metabolic complications such as elevated blood pressure, type 2 diabetes, overweight and osteoporosis. Several studies have also shown an increase in cardiovascular diseases and cardiovascular related deaths in this patient group.
ACS diagnostics is difficult, as the diagnostic tests available have a high degree of uncertainty giving both false positive and false negative results. As such several tests has to be perfomed, sometimes even repeating the same test several times before a diagnosis can be confirmed or disproved. Today the diagnostics is mainly based on blood samples and dynamic adrenal testing, however going forwards steroid profiling (simultaneous measurements of precursors and metabolites of cortisolsynthesis) of blood and urine, and genetic analysis will be important additions of the examination.
Our knowledge of the implications of the long term effects of mild ACS is limited, as there are few studies with long term structured follow up of these patients. Cortisol has several effects on both gene expression and inflammation processes. Biopsies of fat with genetic evaluation and studies of inflammationmarkers in ACS patients compared with healthy controls will improve our understanding of the condition on a cellular level.
Treatmen of the condition is up for debate and usually there is a individual evaluation based on the patients own wishes and the metabolic complications. The treatment options are to surgically remove one or both of the adrenals, alternatively to monitor conservatively and treat only complications of the disease (intensive monitoring of blood pressure, glucose levels and hypercholesterolemi, and possibly wheight reduction).