title: The associations of serum serotonin with bone traits are age- and gender-specific.
abstract: BACKGROUND
  Serotonin plays a potential role in bone metabolism, but the nature and extent of this relationship is unclear and human studies directly addressing the skeletal effect of circulating serotonin are rare.
  
  
  OBJECTIVE
  The study aimed to investigate the associations between serum serotonin and bone traits at multiple skeletal sites in women and men.
  
  
  METHODS
  Subjects were part of the CALEX-family study and comprised 235 young women, 121 premenopausal women, 124 postmenopausal women, and 168 men. Body composition was assessed using DXA, as was areal bone mineral density (aBMD) of spine, femur and whole body. In addition, pQCT was used to determine bone properties at tibial midshaft and distal radius. Fasting serum serotonin concentration was assessed using a competitive enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Serum serotonin declined with advancing age both in females and males (all p<0.01). Serotonin was negatively correlated with weight, BMI, lean and fat mass in women (r = -0.22 to -0.39, all p<0.001), but positively with height and lean mass in men (all p<0.01). In the premenopausal women, serotonin was negatively correlated with lumbar spine aBMD (r = -0.23, p<0.05) but the statistical significance disappeared after adjustment for weight. Conversely, in postmenopausal women, serotonin was positively correlated with whole body and femur aBMD, as well as with distal radius bone mineral content and volumetric BMD (r = 0.20 to 0.30, all p<0.05), and these associations remained significant after adjustment for weight. In men, no significant associations were found between serotonin and bone traits.
  
  
  CONCLUSIONS
  Serum serotonin is positively associated with bone traits in postmenopausal women, but not in premenopausal women or men. This partially supports the idea of circulating serotonin playing a role in the regulation of bone metabolism, but also indicates the importance of gender and age specific factors.
authors.affiliation: Department of Endocrinology, West China Hospital of Sichuan University, Sichuan, China; Department of Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Endocrinology, West China Hospital of Sichuan University, Sichuan, China.
authors.forename: Decai
authors.initials: D
authors.lastname: Chen
authors.affiliation: Department of Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
authors.forename: Patrick
authors.initials: P
authors.lastname: Nicholson
authors.affiliation: Department of Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
authors.forename: Shumei
authors.initials: S
authors.lastname: Cheng
authors.affiliation: Department of Medical Rehabilitation, Oulu University Hospital and Institute of Health Sciences, University of Oulu, Oulu, Finland.
authors.forename: Markku
authors.initials: M
authors.lastname: Alen
authors.affiliation: Department of Sport and Physical Education, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Lijian
authors.initials: L
authors.lastname: Mao
authors.affiliation: Department of Health Sciences, University of Jyväskylä, Jyväskylä, Finland; Department of Sport and Physical Education, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Sulin
authors.initials: S
authors.lastname: Cheng
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001823:Body Composition / Q000502:physiology*; D015519:Bone Density / Q000502:physiology*; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D017698:Postmenopause / Q000502:physiology; D011859:Radiography; D012701:Serotonin / Q000097:blood*; D012737:Sex Factors
chemical_list: D012701:Serotonin