title: Changes in serum vitamin D and PTH values using denosumab with or without bisphosphonate pre-treatment in osteoporotic patients: a short-term study.
abstract: BACKGROUND
  Denosumab is a fully human monoclonal antibody that inhibits receptor activator of nuclear factor kappa-β ligand (RANKL). Previous reports have shown that denosumab treatment of osteoporotic patients decreases bone resorption and fracture risk, but there have been no clinical studies on changes in bone turnover markers, 1,25(OH)2D3, or parathyroid hormone (PTH) in denosumab therapy with or without bisphosphonate (BP) pre-treatment in Japan.
  
  
  METHODS
  Here, we report such findings in 22 patients (11 in the denosumab alone group and 11 in the BP pre-treated group) with osteoporosis following 4 months of treatment. Bone metabolism had been inhibited by prior BP administration in the BP pre-treated group.
  
  
  RESULTS
  The bone resorption markers serum tartrate-resistant acid phosphatase type 5b and urinary type I collagen cross-linked N-telopeptide were significantly decreased from baseline values for the entire study period in both groups. The bone formation marker bone alkaline phosphatase was significantly decreased at 4 months in the denosumab alone group only, and N-terminal propeptide of type 1 procollagen was significantly decreased at 2 and 4 months in the denosumab alone group versus no remarkable change in the BP pre-treated group. In the denosumab alone group, 1,25(OH)2D3 and PTH were significantly increased at 1 week and decreased gradually thereafter, but these did not change notably in the BP pre-treated group.
  
  
  CONCLUSIONS
  Our results suggest that treatment with denosumab causes a strong inhibitory effect on bone resorption markers and mild inhibitory effect on bone formation markers. 1,25(OH)2D3 and PTH were significantly increased by denosumab but these did not change in the BP pre-treated group.
  
  
  BACKGROUND
  Current Controlled Trials NCT02156960. Registered 31 May 2014.
authors.affiliation: Department of Orthopedic Surgery, Shinshu University, Asahi 3-1-1, Matsumoto, 390-8621, Japan. yxn14@aol.jp.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: Center of Osteoporosis and Spinal Disorders, Kamimura Orthopaedic Clinic, Kotobuki 595-17, Matsumoto, 399-0021, Japan. mikamimura@hotmail.com.
authors.forename: Mikio
authors.initials: M
authors.lastname: Kamimura
authors.affiliation: Department of Orthopedic Surgery, Shinshu University, Asahi 3-1-1, Matsumoto, 390-8621, Japan. sh.ikegami@gmail.com.
authors.forename: Shota
authors.initials: S
authors.lastname: Ikegami
authors.affiliation: Department of Orthopedic Surgery, Shinshu University, Asahi 3-1-1, Matsumoto, 390-8621, Japan. kmuka836@yahoo.co.jp.
authors.forename: Keijiro
authors.initials: K
authors.lastname: Mukaiyama
authors.affiliation: Department of Orthopedic Surgery, Shinshu University, Asahi 3-1-1, Matsumoto, 390-8621, Japan. sigeuti@shinshu-u.ac.jp.
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Uchiyama
authors.affiliation: Department of Oral and Maxillofacial Radiology, Matsumoto Dental University, Gobara 1780, Shiojiri, 399-0781, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Taguchi
authors.affiliation: Department of Orthopedic Surgery, Shinshu University, Asahi 3-1-1, Matsumoto, 390-8621, Japan. hirokato@shinshu-u.ac.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kato
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D015519:Bone Density / Q000187:drug effects*; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D016723:Bone Remodeling / Q000187:drug effects; D000069448:Denosumab / Q000627:therapeutic use*; D004164:Diphosphonates / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007564:Japan; D008297:Male; D010024:Osteoporosis / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D010281:Parathyroid Hormone / Q000097:blood*; D016896:Treatment Outcome; D014807:Vitamin D / Q000097:blood*
chemical_list: D015415:Biomarkers; D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D010281:Parathyroid Hormone; D014807:Vitamin D; D000069448:Denosumab