title: Low bone mineral density is associated with bone microdamage accumulation in postmenopausal women with osteoporosis.
abstract: Marked suppression of bone turnover by bisphosphonates is associated with increased bone microdamage accumulation in animal models. The purpose of this study was to test the hypothesis that long-term treatment with alendronate (ALN) results in accumulation of microdamage in bone in women after menopause. Sixty-six postmenopausal women with osteoporosis (mean age of 68.0 years and mean BMD T-score of -1.7 at total hip and -2.8 at lumbar spine; 62% with prevalent fractures) were evaluated in this cross-sectional analysis. Thirty-eight had been treated previously with ALN (10 mg/day or 70 mg/week for a mean duration of 63.6 months) while twenty-eight were treatment naive (TN). Without adjustments, crack surface density (Cr.S.Dn) and crack density (Cr.Dn) were not different between ALN and TN patients. After adjustment for potential confounders (age, prevalent fractures, femoral neck BMD, activation frequency and center), Cr.Dn was elevated in ALN patients (P=0.028 and P=0.069 for Cr.S.Dn). In ALN patients only, lower femoral neck BMD (Cr.S.Dn, r=-0.58, P=0.003; Cr.Dn, r=-0.54, P=0.005) and increased age (Cr.S.Dn, r=0.43, P=0.03; Cr.Dn, r=0.43, P=0.03) were associated with microdamage accumulation. Among potential confounders, femoral neck BMD was the only independent predictor for these correlations (P=0.04 for Cr.Dn and P=0.03 for Cr.S.Dn). We conclude that increased microdamage accumulation may occur in low BMD patients treated with alendronate.
authors.affiliation: Institute of Rheumatology, Charles University, Faculty of Medicine, Prague, Czech Republic. jstepan@vol.cz
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Stepan
authors.forename: David B
authors.initials: DB
authors.lastname: Burr
authors.forename: Imre
authors.initials: I
authors.lastname: Pavo
authors.forename: Adrien
authors.initials: A
authors.lastname: Sipos
authors.forename: Dana
authors.initials: D
authors.lastname: Michalska
authors.forename: Jiliang
authors.initials: J
authors.lastname: Li
authors.forename: Astrid
authors.initials: A
authors.lastname: Fahrleitner-Pammer
authors.forename: Helmut
authors.initials: H
authors.lastname: Petto
authors.forename: Michael
authors.initials: M
authors.lastname: Westmore
authors.forename: David
authors.initials: D
authors.lastname: Michalsky
authors.forename: Masahiko
authors.initials: M
authors.lastname: Sato
authors.forename: Harald
authors.initials: H
authors.lastname: Dobnig
mesh_terms: D000367:Age Factors; D000368:Aged; D019386:Alendronate / Q000009:adverse effects*; D015519:Bone Density / Q000187:drug effects / Q000502:physiology*; D050071:Bone Density Conservation Agents / Q000009:adverse effects*; D001842:Bone and Bones / Q000187:drug effects* / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy*; D017698:Postmenopause
chemical_list: D050071:Bone Density Conservation Agents; D019386:Alendronate