title: Gender dimorphism and lack of day/night variation or effects of energy deprivation on undercarboxylated osteocalcin levels in humans.
abstract: OBJECTIVE
  Undercarboxylated osteocalcin (ucOC) is a bone marker with potent metabolic effects. Leptin regulates Esp gene expression and osteocalcin carboxylation in animal models. We aim to elucidate day/night patterns of ucOC levels, whether short-term and/or chronic energy deprivation alters ucOC levels, and whether leptin may mediate these changes in humans.
  
  
  METHODS
  Twelve healthy males and females were studied for 72 h in the fed state to study day/night pattern of ucOC. The six female subjects were also studied in a crossover interventional study in the fasting state for 72 h with administration of either placebo or metreleptin in physiological doses. Blood samples were obtained hourly from 0800 a.m. on day 3 until 0800 a.m. on day 4. In a separate study, eleven obese subjects who underwent bariatric surgery were followed for 24 weeks to examine the effects of postsurgery weight loss on ucOC levels.
  
  
  RESULTS
  Males have higher ucOC levels compared to females. There is no day/night variation pattern of circulating ucOC in humans. Short-term and chronic energy deprivation or leptin administrations do not alter ucOC levels.
  
  
  CONCLUSIONS
  The hypothesis that ucOC plays a role in energy homeostasis or of leptin in regulating ucOC in humans is not supported.
authors.affiliation: Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Joo-Pin
authors.initials: JP
authors.lastname: Foo
authors.forename: Konstantinos N
authors.initials: KN
authors.lastname: Aronis
authors.forename: John P
authors.initials: JP
authors.lastname: Chamberland
authors.forename: Bindiya
authors.initials: B
authors.lastname: Thakkar
authors.forename: Ole-Petter
authors.initials: OP
authors.lastname: Hamnvik
authors.forename: Mary
authors.initials: M
authors.lastname: Brinkoetter
authors.forename: Lesya
authors.initials: L
authors.lastname: Zaichenko
authors.forename: Christos S
authors.initials: CS
authors.lastname: Mantzoros
mesh_terms: D000328:Adult; D050110:Bariatric Surgery; D015992:Body Mass Index; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002940:Circadian Rhythm; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004734:Energy Metabolism / Q000502:physiology*; D005215:Fasting; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood*; D029589:Seminal Plasma Proteins / Q000235:genetics / Q000378:metabolism; D012737:Sex Factors; D015431:Weight Loss; D055815:Young Adult
chemical_list: D002352:Carrier Proteins; D007328:Insulin; D020738:Leptin; C484958:SPESP1 protein, human; D029589:Seminal Plasma Proteins; D015675:Osteocalcin; C415771:metreleptin