title: Leptin administration in physiological or pharmacological doses does not alter circulating irisin levels in humans.
abstract: Leptin is an adipokine causing browning of adipose tissue, and it thus increases energy expenditure. The same is true for irisin. We studied whether exogenously administered metreleptin affects serum irisin concentrations in humans, which would suggest a direct interplay between leptin and irisin. We performed two studies: a dose-escalating 1-day-long study and a randomized placebo-controlled study. Study 1: 15 healthy, normal-weight and/or obese male and female individuals participated in three 1-day-long trials of metreleptin administration in the fed state. Metreleptin was administered once at physiological and pharmacological (0.01, 0.1 and 0.3 mg per kg body weight) doses. Study 2: 18 apparently healthy hypoleptinemic young women with hypoleptinemia and secondary amenorrhea took part in this study. Subjects received either metreleptin in replacement doses (0.08 and/or 0.12 mg kg(-1)) or placebo for 16 weeks. Blood samples were analyzed for leptin and irisin. We found no effect of metreleptin administration on irisin levels of subjects studied at either the fasting or the fed state either in the short or the long term. We provide evidence that leptin is not altering circulating irisin levels in humans.
authors.affiliation: Department of Internal Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
authors.forename: A
authors.initials: A
authors.lastname: Gavrieli
authors.affiliation: Department of Internal Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
authors.forename: G
authors.initials: G
authors.lastname: Panagiotou
authors.affiliation: Department of Internal Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
authors.forename: C S
authors.initials: CS
authors.lastname: Mantzoros
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects; D001823:Body Composition / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004734:Energy Metabolism / Q000187:drug effects; D005260:Female; D005353:Fibronectins / Q000097:blood*; D006801:Humans; D020738:Leptin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D009765:Obesity / Q000097:blood; D055815:Young Adult
chemical_list: C577593:FNDC5 protein, human; D005353:Fibronectins; D020738:Leptin; C415771:metreleptin