Regional bone metabolism at the lumbar spine and hip following discontinuation of alendronate and risedronate treatment in postmenopausal women

• Published in: Osteoporosis international 2012-08, Vol.23 (8), p.2107-2116
• Main Authors: Frost, M. L., Siddique, M., Blake, G. M., Moore, A. E., Marsden, P. K., Schleyer, P. J., Eastell, R., Fogelman, I.
• Format: Article
• Language: English
• Subjects: Absorptiometry, Photon; Aged; Aged, 80 and over; Alendronate - administration & dosage; Alendronic acid; Biochemical markers; Biomarkers - metabolism; Bisphosphonates; Bone Density - drug effects; Bone Density - physiology; Bone Density Conservation Agents - administration & dosage; Bone mineral density; Bone Remodeling - drug effects; Bone Remodeling - physiology; Bone turnover; Bones; Drug therapy; Endocrinology; Etidronic Acid - administration & dosage; Etidronic Acid - analogs & derivatives; Female; Femur; Femur - diagnostic imaging; Femur - metabolism; Fluorodeoxyglucose F18 - blood; Hip; Hip - diagnostic imaging; Humans; Lumbar Vertebrae - diagnostic imaging; Lumbar Vertebrae - metabolism; Medicine; Medicine & Public Health; Menopause; Middle Aged; Original Article; Orthopedics; Osteoporosis; Osteoporosis, Postmenopausal - diagnostic imaging; Osteoporosis, Postmenopausal - drug therapy; Osteoporosis, Postmenopausal - metabolism; Positron emission tomography; Positron-Emission Tomography - methods; Post-menopause; Radiopharmaceuticals - blood; Rheumatology; Risedronate Sodium; Risedronic acid; Spine (lumbar); Tomography; Treatment Outcome
• ISSN: 0937-941X; 1433-2965
• DOI: 10.1007/s00198-011-1805-9

Summary 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. Introduction 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.