Adrenal fatigue does not exist: a systematic review

Abstract

BackgroundThe term “adrenal fatigue” (“AF”) has been used by some doctors, healthcare providers, and the general media to describe an alleged condition caused by chronic exposure to stressful situations. Despite this, “AF” has not been recognized by any Endocrinology society, who claim there is no hard evidence for the existence. The aim of this systematic review is to verify whether there is substantiation for “AF”.MethodsA systematic search was performed at PUBMED, MEDLINE (Ebsco) and Cochrane databases, from the beginning of the data until April 22nd, 2016. Searched key words were: “adrenal” + “fatigue”, “adrenal” + “burnout”, “adrenal” + “exhaustion”, “hypoadrenia”, “burnout” + “cortisol”, “fatigue” + “cortisol”, “clinical” + “burnout”, “cortisol” + “vitalility”, “adrenal” + “vitality”, and “cortisol” + “exhaustion”. Eligibility criteria were: (1) articles written in English, (2) cortisol profile and fatigue or energy status as the primary outcome, (3) performed tests for evaluating the adrenal axis, (4) absence of influence of corticosteroid therapy, and (5) absence of confounding diseases. Type of questionnaire to distinct fatigued subjects, population studied, tests performed of selected studies were analyzed.ResultsFrom 3,470 articles found, 58 studies fulfilled the criteria: 33 were carried in healthy individuals, and 25 in symptomatic patients. The most assessed exams were “Direct Awakening Cortisol” (n = 29), “Cortisol Awakening Response” (n = 27) and “Salivary Cortisol Rhythm” (n = 26).DiscussionWe found an almost systematic finding of conflicting results derived from most of the studies methods utilized, regardless of the validation and the quality of performed tests. Some limitations of the review include: (1) heterogeneity of the study design; (2) the descriptive nature of most studies; (3) the poor quality assessment of fatigue; (4) the use of an unsubstantiated methodology in terms of cortisol assessment (not endorsed by endocrinologists); (5) false premises leading to an incorrect sequence of research direction; and, (6) inappropriate/invalid conclusions regarding causality and association between different information.ConclusionThis systematic review proves that there is no substantiation that “adrenal fatigue” is an actual medical condition. Therefore, adrenal fatigue is still a myth.

Off-Label Use and Misuse of Testosterone, Growth Hormone, Thyroid Hormone, and Adrenal Supplements: Risks and Costs of a Growing Problem

“…The endocrine community, including the Endocrine Society and the Hormone Health Network, does not recognize "adrenal fatigue" as a legitimate medical condition (11). According to some online content not authorized by medical professionals, the diagnosis of "adrenal fatigue" is based upon questionnaires and biochemical hormonal testing.…”

“…These questionnaires usually cover a multitude of nonspecific symptoms, vary in length, scoring, and interpretation, and are often biased in the direction of adrenal fatigue. A systematic review of 58 studies found 19 different types of questionnaires and scores reported, including the Maslach Burnout Inventory, SF-36, Chalder Fatigue Scale, the Multidimensional Fatigue Inventory, General Fatigue Scale, and others (11).…”

“…In individuals with normal thyroid function tests, thyroid hormone and/or thyroid supplements or boosters are sometimes taken for fatigue, obesity, depression, cognitive impairment, impaired physical performance, and infertility (10). Finally, over-the-counter supplements are commonly used by individuals who believe that they suffer from a constellation of common nonspecific symptoms related to "adrenal fatigue," an entity that has not been recognized as a legitimate medical diagnosis (11). "Adrenal fatigue" describes a condition resulting from the supposed "overuse" of the adrenal glands.…”

“…"Adrenal fatigue" describes a condition resulting from the supposed "overuse" of the adrenal glands. A Google search conducted in December 2019 for "adrenal fatigue" yielded 3,090,000 results, an increase from 640,000 results in 2016 (11). Many of the websites found in the search provide information on the self-diagnosis of "adrenal fatigue," commercialize informational products, and sell supplements to treat this condition (12,13).…”

Erratum to: Adrenal fatigue does not exist: a systematic review

“…Following publication of the original version of this article in BMC Endocrine Disorders [1] it was brought to our attention that the comment section for row 12 in Table 1 should be blank. Please find the corrected table below.…”