title: Regional bone metabolism at the lumbar spine and hip following discontinuation of alendronate and risedronate treatment in postmenopausal women.
abstract: The aim of this study was to examine the effects of bisphosphonate discontinuation on bone metabolism at the spine and hip measured using (18) F-fluoride PET. Bone metabolism at the spine remained stable following discontinuation of alendronate and risedronate at 1 year but increased in the hip in the alendronate group only.
  
  
  BACKGROUND
  Bisphosphonates such as alendronate (ALN) or risedronate (RIS) have persistent effects on spine BMD following discontinuation.
  
  
  METHODS
  Positron emission tomography (PET) was used to examine regional bone metabolism in 20 postmenopausal women treated with ALN (n = 11) or RIS (n = 9) for a minimum of 3 years at screening (range 3-9 years, mean 5 years for both groups). Subjects underwent a dynamic scan of the lumbar spine and a static scan of both hips at baseline and 6 and 12 months following treatment discontinuation. (18) F-fluoride plasma clearance (K(i)) at the spine was calculated using a three-compartment model. Standardised uptake values (SUV) were calculated for the spine, total hip, femoral neck and femoral shaft. Measurements of BMD and biochemical markers of bone turnover were also performed.
  
  
  RESULTS
  With the exception of a significant decrease in spine BMD in the ALN group, BMD remained stable. Bone turnover markers increased significantly from baseline by 12 months for both study groups. Measurements of K(i) and SUV at the spine and femoral neck did not change significantly in either group. SUV at the femoral shaft and total hip increased significantly but in the ALN group only, increasing by 33.8% (p = 0.028) and 24.0% (p = 0.013), respectively.
  
  
  CONCLUSIONS
  Bone metabolism at the spine remained suppressed following treatment discontinuation. A significant increase in SUV at the femoral shaft and total hip after 12 months was observed but for the ALN group only. This study was small, and further clinical studies are required to fully evaluate the persistence of BP treatment.
authors: Osteoporosis Research Unit, King's College London, Guy's Hospital Campus, Great Maze Pond, London, UK. michelle.frost@kcl.ac.uk
authors: M L
authors: ML
authors: Frost
authors: M
authors: M
authors: Siddique
authors: G M
authors: GM
authors: Blake
authors: A E
authors: AE
authors: Moore
authors: P K
authors: PK
authors: Marsden
authors: P J
authors: PJ
authors: Schleyer
authors: R
authors: R
authors: Eastell
authors: I
authors: I
authors: Fogelman
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D000369:Aged, 80 and over; D019386:Alendronate / Q000008:administration & dosage; D015415:Biomarkers / Q000378:metabolism; D015519:Bone Density / Q000187:drug effects / Q000502:physiology; D050071:Bone Density Conservation Agents / Q000008:administration & dosage; D016723:Bone Remodeling / Q000187:drug effects / Q000502:physiology; D012968:Etidronic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000378:metabolism; D019788:Fluorodeoxyglucose F18 / Q000097:blood; D006615:Hip / Q000000981:diagnostic imaging*; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000378:metabolism; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000378:metabolism*; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals / Q000097:blood; D000068296:Risedronic Acid; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D050071:Bone Density Conservation Agents; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D000068296:Risedronic Acid; D012968:Etidronic Acid; D019386:Alendronate