title: Assessment of adrenal function in cirrhotic patients: salivary cortisol should be preferred.
abstract: OBJECTIVE
  Adrenal insufficiency is a common disorder among cirrhotic patients. Adrenal function is usually assessed with serum total cortisol assays. Free cortisol (active fraction) represents only 10% of serum total cortisol, the remaining 90% being linked to cortisol-binding globulin (CBG) and albumin. In cirrhotic patients, the synthesis of these proteins is reduced, which could lead to an overestimation of the prevalence of adrenal insufficiency. Salivary cortisol assessment adequately reflects free cortisol plasma concentration. However, this method has never been validated in cirrhotic patients. The objectives of this report were to assess the following parameters by a prospective observational study: (1) correlation between salivary, serum total and free cortisol, (2) adrenal insufficiency prevalence using salivary and serum assays, (3) parameters associated with a discrepancy between both tests, and (4) adrenal insufficiency risk factors among cirrhotic patients.
  
  
  METHODS
  Salivary and serum total cortisol were assessed before and 1h following an injection of corticotropin (250 microg) in patients hospitalized for cirrhosis complications without shock. CBG was measured and free cortisol was assessed by the Coolens formula.
  
  
  RESULTS
  Eighty-eight patients were included in the study (Child-Pugh C: 68.2%). Free cortisol was more strongly correlated with salivary than with serum total cortisol (Spearman coefficient=0.91 vs. 0.76, respectively, p<0.001). Among included patients, 9.1% had adrenal insufficiency according to salivary cortisol and 33.0% had adrenal insufficiency according to serum total cortisol (p=0.001). Hypoalbuminemia was the only factor associated with a discrepancy between the results of both tests. Adrenal insufficiency risk factors were ascites and low HDL-cholesterol plasma concentration.
  
  
  CONCLUSIONS
  Using serum total cortisol assays overstate adrenal insufficiency prevalence among cirrhotic patients, mainly because of inaccurate concentrations related to hypoalbuminemia. Salivary cortisol assays should be preferably used in these patients.
authors.affiliation: Université Pierre et Marie Curie, Service d'hépato-gastroentérologie, Hôpital de la Pitié-Salpêtrière (AP-HP), Paris, France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Galbois
authors.forename: Marika
authors.initials: M
authors.lastname: Rudler
authors.forename: Julien
authors.initials: J
authors.lastname: Massard
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Fulla
authors.forename: Abdelhai
authors.initials: A
authors.lastname: Bennani
authors.forename: Dominique
authors.initials: D
authors.lastname: Bonnefont-Rousselot
authors.forename: Vincent
authors.initials: V
authors.lastname: Thibault
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Reignier
authors.forename: Anne
authors.initials: A
authors.lastname: Bourrier
authors.forename: Thierry
authors.initials: T
authors.lastname: Poynard
authors.forename: Dominique
authors.initials: D
authors.lastname: Thabut
mesh_terms: D000309:Adrenal Insufficiency / Q000175:diagnosis / Q000453:epidemiology / Q000378:metabolism; D000324:Adrenocorticotropic Hormone / Q000008:administration & dosage / Q000097:blood; D000328:Adult; D002352:Carrier Proteins / Q000097:blood; D005260:Female; D006728:Hormones / Q000008:administration & dosage / Q000097:blood; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000378:metabolism*; D008103:Liver Cirrhosis / Q000097:blood* / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D015203:Reproducibility of Results; D012307:Risk Factors; D012463:Saliva / Q000378:metabolism*; D012709:Serum Albumin / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D006728:Hormones; D012709:Serum Albumin; C027091:cortisol binding globulin; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone