Cushing syndrome is relatively uncommon in the general population, with an incidence of 1.8 to 3.2 per million population per year.[11]Hakami OA, Ahmed S, Karavitaki N. Epidemiology and mortality of Cushing's syndrome. Best Pract Res Clin Endocrinol Metab. 2021 Jan;35(1):101521.
http://www.ncbi.nlm.nih.gov/pubmed/33766428?tool=bestpractice.com
However, studies of high-risk groups report a significantly greater prevalence.[8]Sharma ST, Nieman LK, Feelders RA. Cushing's syndrome: epidemiology and developments in disease management. Clin Epidemiol. 2015 Apr 17;7:281-93.
https://www.dovepress.com/cushing39s-syndrome-epidemiology-and-developments-in-disease-managemen-peer-reviewed-fulltext-article-CLEP
http://www.ncbi.nlm.nih.gov/pubmed/25945066?tool=bestpractice.com
Hypercortisolism has been reported in 0.5% to 1% of patients with hypertension, 2% to 3% of patients with uncontrolled diabetes, 5% to 10% of patients with adrenal masses, and 11% of patients with osteoporosis and vertebral fractures.[8]Sharma ST, Nieman LK, Feelders RA. Cushing's syndrome: epidemiology and developments in disease management. Clin Epidemiol. 2015 Apr 17;7:281-93.
https://www.dovepress.com/cushing39s-syndrome-epidemiology-and-developments-in-disease-managemen-peer-reviewed-fulltext-article-CLEP
http://www.ncbi.nlm.nih.gov/pubmed/25945066?tool=bestpractice.com
[12]Anderson GH Jr, Blankeman N, Streeten DH. The effect of age on prevalence of secondary forms of hypertension in 4429 consecutively referred patients. J Hypertens. 1994 May;12(5):609-15.
http://www.ncbi.nlm.nih.gov/pubmed/7930562?tool=bestpractice.com
[13]Omura M, Saito J, Yamaguchi K, et al. Prospective study on the prevalence of secondary hypertension among hypertensive patients visiting a general outpatient clinic in Japan. Hypertens Res. 2004 Mar;27(3):193-202.
https://www.jstage.jst.go.jp/article/hypres/27/3/27_3_193/_pdf
http://www.ncbi.nlm.nih.gov/pubmed/15080378?tool=bestpractice.com
[14]Vaidya A, Hamrahian A, Bancos I, et al. The evaluation of incidentally discovered adrenal masses. Endocr Pract. 2019 Feb;25(2):178-92.
http://www.ncbi.nlm.nih.gov/pubmed/30817193?tool=bestpractice.com
[15]Chiodini I, Mascia ML, Muscarella S, et al. Subclinical hypercortisolism among outpatients referred for osteoporosis. Ann Intern Med. 2007 Oct 16;147(8):541-8.
http://www.ncbi.nlm.nih.gov/pubmed/17938392?tool=bestpractice.com
It is unclear if this increase in prevalence is due to higher-sensitivity testing, a greater recognition of disease in high-risk groups, or variability in the diagnostic criteria between historical and more-recent studies.
Cushing syndrome occurs 3 times more commonly in women than in men, and Cushing's disease (adrenocorticotrophic hormone-secreting pituitary tumour) has a 3:1 to 5:1 female-to-male predominance.[1]Lacroix A, Feelders RA, Stratakis CA, et al. Cushing's syndrome. Lancet. 2015 Aug 29;386(9996):913-27.
http://www.ncbi.nlm.nih.gov/pubmed/26004339?tool=bestpractice.com
No ethnic disparities in prevalence have been identified. The majority of adults are diagnosed between the ages of 20 and 50 years, although it can occur at any age. Cushing syndrome in children is unusual but well documented.[1]Lacroix A, Feelders RA, Stratakis CA, et al. Cushing's syndrome. Lancet. 2015 Aug 29;386(9996):913-27.
http://www.ncbi.nlm.nih.gov/pubmed/26004339?tool=bestpractice.com
Exogenous corticosteroid exposure is the most common cause of Cushing syndrome, but no data exist as to the exact epidemiology of exogenous disease. All currently reported statistics include only patients with endogenous Cushing syndrome.