Steroid diabetes must be distinguished from stress hyperglycemia , hyperglycemia due to excessive intravenous glucose, or new-onset diabetes of another type. Because it is not unusual for steroid treatment to precipitate type 1 or type 2 diabetes in a person who is already in the process of developing it, it is not always possible to determine whether apparent steroid diabetes will be permanent or will go away when the steroids are finished. More commonly undiagnosed cases of type 2 diabetes are brought to clinical attention with corticosteroid treatment because subclinical hyperglycemia worsens and becomes symptomatic. Generally, steroid diabetes without preexisting type 2 diabetes will resolve upon termination of corticosteroid administration.
Cells of the zona fasciculata and zona reticularis lack aldosterone synthase (CYP11B2) that converts corticosterone to aldosterone, and thus these tissues produce only the weak mineralocorticoid corticosterone. However, both these zones do contain the CYP17A1 missing in zona glomerulosa and thus produce the major glucocorticoid, cortisol. Zona fasciculata and zona reticularis cells also contain CYP17A1, whose 17,20-lyase activity is responsible for producing the androgens, dehydroepiandosterone (DHEA) and androstenedione. Thus, fasciculata and reticularis cells can make corticosteroids and the adrenal androgens, but not aldosterone.