title: Changes in bone mass during the perimenopausal transition in naturally menopausal cynomolgus monkeys.
abstract: OBJECTIVE
  This study measured the differences in bone mineral density and content in relation to changes in serum hormone and bone marker levels during the perimenopausal transition in naturally menopausal cynomolgus monkeys.
  
  
  METHODS
  The bone mineral density and content of premenopausal, perimenopausal, and early (0-< 5 y), mid (5-10 y), and late (> 10 y) postmenopausal monkeys were measured at the distal radius and proximal tibia in both metaphysis and diaphysis. Hormonal and bone marker levels were also measured.
  
  
  RESULTS
  The serum 17β-estradiol level significantly decreased during late postmenopause, whereas the serum follicle-stimulating hormone levels significantly increased from early postmenopause before declining at late postmenopause. Trabecular bone loss at metaphysis occurred once the animals entered into the perimenopausal period, whereas cortical bone loss gradually and continuously decreased, dependent on the time-course after perimenopause, and was greatest in the late postmenopausal period. Serum bone-specific alkaline phosphatase and urinary N-telopeptide of bone type-1 collagen levels were negatively correlated with the trabecular bone mineral content at metaphysis, whereas serum osteocalcin levels showed a negative correlation with the cortical bone mineral density at the diaphysis. The only positive linear correlation observed was between serum follicle-stimulating hormone and urinary N-telopeptide of bone type-1 collagen levels.
  
  
  CONCLUSIONS
  Unlike the ovariectomized monkey models that do not retain the perimenopausal transition, naturally menopausal monkeys elicit different patterns of bone loss during the transition-an abrupt decline in the trabecular metaphysis and a gradual decline in the cortical diaphysis. Naturally menopausal cynomolgus monkeys offer an alternative model for osteoporosis research for postmenopausal women.
authors.affiliation: 1Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand 2Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan 3National Primate Research Center of Thailand, Chulalongkorn University, Saraburi, Thailand.
authors.forename: Donlaporn
authors.initials: D
authors.lastname: Kittivanichkul
authors.forename: Gen
authors.initials: G
authors.lastname: Watanabe
authors.forename: Kentaro
authors.initials: K
authors.lastname: Nagaoka
authors.forename: Suchinda
authors.initials: S
authors.lastname: Malaivijitnond
mesh_terms: D000469:Alkaline Phosphatase / Q000097:blood; D000818:Animals; D015519:Bone Density / Q000502:physiology*; D024042:Collagen Type I / Q000652:urine; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D008252:Macaca fascicularis; D008593:Menopause / Q000502:physiology*; D023421:Models, Animal; D015675:Osteocalcin / Q000097:blood; D015663:Osteoporosis, Postmenopausal / Q000097:blood / Q000652:urine; D010455:Peptides / Q000652:urine; D047648:Perimenopause / Q000097:blood* / Q000502:physiology* / Q000652:urine; D017698:Postmenopause / Q000097:blood / Q000652:urine; D017697:Premenopause / Q000097:blood / Q000652:urine; D011884:Radius / Q000503:physiopathology; D013977:Tibia / Q000503:physiopathology
chemical_list: D024042:Collagen Type I; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D015675:Osteocalcin; D004958:Estradiol; D005640:Follicle Stimulating Hormone; D000469:Alkaline Phosphatase