title: Plasma leptin in chronic fatigue syndrome and a placebo-controlled study of the effects of low-dose hydrocortisone on leptin secretion.
abstract: OBJECTIVE
  Previous studies have suggested that chronic fatigue syndrome (CFS) is associated with changes in appetite and weight, and also with mild hypocortisolism. Because both of these features may be related to leptin metabolism, we undertook a study of leptin in CFS.
  
  
  METHODS
  (i) A comparison of morning leptin concentration in patients with CFS and controls and (ii) a randomized, placebo-controlled crossover study of the effects of hydrocortisone on leptin levels in CFS.
  
  
  METHODS
  Thirty-two medication free patients with CFS but not comorbid depression or anxiety. Thirty-two age, gender, weight, body mass index and menstrual cycle matched volunteer subjects acted as controls.
  
  
  METHODS
  We measured basal 0900 h plasma leptin levels in patients and controls. All 32 patients were taking part in a randomized, placebo-controlled crossover trial of low dose (5 or 10 mg) hydrocortisone as a potential therapy for CFS. We measured plasma leptin after 28 days treatment with hydrocortisone and after 28 days treatment with placebo.
  
  
  RESULTS
  At baseline, there was no significant difference in plasma leptin between patients [mean 13.8, median 7.4, interquartile range (IQR) 18.0 ng/ml] and controls (mean 10.2, median 5.5, IQR 11.3 ng/ml). Hydrocortisone treatment, for both doses combined, caused a significant increase in leptin levels compared to placebo. When the two doses were analysed separately, only 10 mg was associated with a significant effect on leptin levels. We also compared the hydrocortisone induced increase in leptin between those who were deemed treatment-responders and those deemed nonresponders. Responders showed a significantly greater hydrocortisone-induced rise in leptin than nonresponders. This association between a clinical response to hydrocortisone and a greater rise in leptin levels may indicate a greater biological effect of hydrocortisone in these subjects, perhaps due to increased glucocorticoid receptor sensitivity, which may be present in some patients with CFS.
  
  
  CONCLUSIONS
  We conclude that, while we found no evidence of alterations in leptin levels in CFS, low dose hydrocortisone therapy caused increases in plasma leptin levels, with this biological response being more marked in those CFS subjects who showed a positive therapeutic response to hydrocortisone therapy. Increases in plasma leptin levels following low dose hydrocortisone therapy may be a marker of pretreatment physiological hypocortisolism and of response to therapy.
authors.affiliation: Department of Psychological Medicine, Guy's, King's and St Thomas' School of Medicine, 103 Denmark Hill, London SE3 8AF, UK. a.cleare@iop.kcl.ac.uk
authors.forename: A J
authors.initials: AJ
authors.lastname: Cleare
authors.forename: V
authors.initials: V
authors.lastname: O'Keane
authors.forename: J
authors.initials: J
authors.lastname: Miell
mesh_terms: D000328:Adult; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D015673:Fatigue Syndrome, Chronic / Q000097:blood* / Q000188:drug therapy; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000627:therapeutic use*; D020738:Leptin / Q000097:blood* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome
chemical_list: D000893:Anti-Inflammatory Agents; D015415:Biomarkers; D020738:Leptin; D006854:Hydrocortisone