Although no satisfactory biomedical explanation for CFS exists, recent research suggests that adrenal under-stimulation may be a factor. Working out of the Trinity College Dublin Medical School at St. James's Hospital in Ireland, six researchers set out to determine whether CFS patients who had evidence of adrenal hypofunctioning (decreased or insufficient function) had altered adrenal gland size. Participants for the study were recruited from a fatigue clinic and tested under the CDC criteria for CFS. Those who met the criteria were then given a 1 microgram adrenocorticotropin (ACTH) stimulation test, which is a test of adrenal gland functioning.

Eight participants (5 males, 3 females) who showed a subnormal response to the adrenal gland function test were given a computed tomography (CT) adrenal gland assessment. CT is a process by which a three dimensional image of a body structure (in this case, the adrenal gland) is compiled using computer images. The adrenal gland measurements of the eight participants were measured against those from a group of 55 healthy subjects. The results were that the eight CFS patients showed a 50% decrease in adrenal gland size – a significant adrenal gland atrophy.

It is important to remember that these eight patients showing this atrophy had existing abnormal endocrine parameters. It is yet to be determined whether a larger sampling or testing of those without endocrine abnormalities would result in such dramatic adrenal reduction results.

Researchers recommend that a larger, randomized study of CFS patients is necessary and could help determine not only the causes but also treatments of CFS.

Source: Scott LV, Teh J, Reznek R, Martin A, Sohaib A, Dinan TG. "Small adrenal glands in chronic fatigue syndrome: a preliminary computer tomography study." Department of Psychiatry, Trinity College Sublin Medical School, St. James's Hospital, Ireland.