title: Evaluation of pituitary function in the fatigued patient: a review of 59 cases.
abstract: OBJECTIVE
  The aim of this study was to review the results of dynamic pituitary testing in patients presenting with fatigue.
  
  
  METHODS
  We reviewed clinical histories and insulin tolerance test (ITT) results of 59 patients who presented with fatigue and other symptoms of glucocorticoid insufficiency over a 4-year period. All patients referred for ITT had an early-morning cortisol level of <400 nM and a low or normal ACTH level.
  
  
  RESULTS
  Peak cortisol and GH responses following insulin-induced hypoglycaemia were normal in only seven patients (12%). Median age of the remaining 52 patients was 47 years (range, 17-67 years); all but five were female. Common presenting symptoms were neuroglycopaenia (n = 47), depression (n = 37), arthralgia and myalgia (n = 28), weight gain (n = 25), weight loss (n = 9), postural dizziness (n = 15) and headaches (n = 13). Other medical history included autoimmune disease (n = 20; particularly Hashimoto's thyroiditis, Graves' disease and coeliac disease), postpartum (n = 8) and gastrointestinal (n = 2) haemorrhage and hyperprolactinaemia (n = 13). 31 subjects had peak cortisol levels of <500 nM (suggestive of ACTH deficiency; 18 of whom had levels < 400 nM) and a further six had indeterminate results (500-550 nM). The remaining 15 subjects had normal cortisol responses (median 654 nM; range, 553-1062 nM) but had low GH levels following hypoglycaemic stimulation (5.9 mU/l; 3-11.6 mU/l).
  
  
  CONCLUSIONS
  Our results suggest that patients presenting with fatigue and symptoms suggestive of hypocortisolism should be considered for screening for secondary adrenal insufficiency, particularly in the presence of autoimmune disease or a history of postpartum or gastrointestinal haemorrhage. Whether physiological glucocorticoid replacement improves symptoms in this patient group is yet to be established.
authors.affiliation: Department of Endocrinology, St Vincent's Hospital and St Vincent's Clinic and the Garvan Institute of Medical Research, Sydney, Australia.
authors.forename: Jerry R
authors.initials: JR
authors.lastname: Greenfield
authors.forename: Katherine
authors.initials: K
authors.lastname: Samaras
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001327:Autoimmune Diseases / Q000150:complications; D001786:Blood Glucose / Q000378:metabolism; D002940:Circadian Rhythm; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood; D015673:Fatigue Syndrome, Chronic / Q000503:physiopathology*; D005260:Female; D019382:Human Growth Hormone / Q000097:blood; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology; D007328:Insulin; D008297:Male; D008875:Middle Aged; D010901:Pituitary Function Tests; D010902:Pituitary Gland / Q000503:physiopathology*; D010913:Pituitary-Adrenal System / Q000503:physiopathology; D012189:Retrospective Studies
chemical_list: D001786:Blood Glucose; D007328:Insulin; D019382:Human Growth Hormone; D019314:Dehydroepiandrosterone Sulfate; D006854:Hydrocortisone