title: A retrospective analysis of nonresponse to daily teriparatide treatment.
abstract: Some patients with osteoporosis do not respond to teriparatide treatment. Prior bisphosphonate use, lower bone turnover marker (BTMs) concentrations, and lower early increases in BTMs were significantly associated with a blunted lumbar spine (LS) bone mineral density (BMD) response to daily treatment with teriparatide, although the impact was limited.
  
  
  
  Some osteoporosis patients do not respond to teriparatide treatment. To better understand the factors underlying treatment nonresponses, we compared nonresponders' and responders' characteristics.
  
  
  
  We retrospectively analyzed 354 male and female patients with osteoporosis who were administered teriparatide (20 μg/day) for 24 months. The patients were categorized as responders (≥3 % lumber spine (LS) bone mineral density (BMD) increase) or nonresponders (<3 % LS BMD increase), and the groups were compared.
  
  
  
  The univariate analyses determined that prior bisphosphonate use, a lower baseline procollagen type I N-terminal propeptide (PINP) concentration and a lower urinary N-telopeptide of type I collagen (uNTX) concentration at baseline were significantly associated with teriparatide nonresponses, but these factors were not significant following multivariate analysis. Diminished early increases in the bone turnover markers (BTMs) were also related to nonresponses after teriparatide treatment began. In the nonresponders, the mean (standard deviation (SD)) absolute LS and femoral neck (FN) BMD changes were -0.002 g/cm(2) (0.032) and -0.010 g/cm(2) (0.045), respectively. In the responders, the mean (SD) absolute LS and FN BMD changes were 0.118 g/cm(2) (0.056) and 0.021 g/cm(2) (0.046), respectively. The serum PINP and uNTX levels increased rapidly in both groups, but the responders showed higher early absolute serum PINP and uNTX increases.
  
  
  
  The factors associated with nonresponses were prior bisphosphonate use, lower baseline BTM levels, and lower early increases in the BTMs after starting teriparatide treatment, but the impact of these factors on achieving a ≥3 % LS BMD increase at 24 months was limited.
authors.affiliation: Department of Orthopaedic Surgery, Tomidahama Hospital, 26-14, Tomidahamacho, Yokkaichi, Mie, 510-8008, Japan. furikakefuri@hotmail.co.jp.
authors.forename: R
authors.initials: R
authors.lastname: Niimi
authors.affiliation: Department of Orthopaedic Surgery, Tomidahama Hospital, 26-14, Tomidahamacho, Yokkaichi, Mie, 510-8008, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kono
authors.affiliation: Department of Orthopaedic Surgery, Tomidahama Hospital, 26-14, Tomidahamacho, Yokkaichi, Mie, 510-8008, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Nishihara
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Mie University, Tsu, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Hasegawa
authors.affiliation: Department of Orthopaedic Surgery, Tomidahama Hospital, 26-14, Tomidahamacho, Yokkaichi, Mie, 510-8008, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kono
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Mie University, Tsu, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Sudo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D015519:Bone Density; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D024042:Collagen Type I / Q000652:urine; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000188:drug therapy*; D010455:Peptides / Q000652:urine; D012189:Retrospective Studies; D019379:Teriparatide / Q000627:therapeutic use*; D017211:Treatment Failure
chemical_list: D015415:Biomarkers; D050071:Bone Density Conservation Agents; D024042:Collagen Type I; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D019379:Teriparatide
keywords: Bone mineral density; Bone turnover marker; Nonresponders; Responders; Teriparatide