title: Bone and metabolism: a complex crosstalk.
abstract: BACKGROUND
  Until recently, communication from metabolism to bone was considered purely unidirectional, involving complex interactions among an adipocyte-derived factor (leptin), the sympathetic nervous system and neuropeptides. However, studies in animal models now show that bone regulates glucose metabolism and fat mass via the uncarboxylated form of an osteoblast-derived factor (osteocalcin). These findings not only demonstrate that energy metabolism regulates bone remodeling through neural relays, but also that the skeleton acts as an endocrine tissue that regulates metabolic homeostasis.
  
  
  CONCLUSIONS
  Further study is needed to understand the physiological role of these complex interactions in man and their implications for human diseases.
authors.affiliation: Laboratory for Experimental Medicine and Endocrinology, Department of Experimental Medicine, Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: Liesbet
authors.initials: L
authors.lastname: Lieben
authors.forename: Filip
authors.initials: F
authors.lastname: Callewaert
authors.forename: Roger
authors.initials: R
authors.lastname: Bouillon
mesh_terms: D000818:Animals; D016723:Bone Remodeling / Q000502:physiology; D001842:Bone and Bones / Q000378:metabolism*; D002490:Central Nervous System / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D053858:Metabolic Networks and Pathways / Q000502:physiology*; D008660:Metabolism / Q000502:physiology*; D008954:Models, Biological