Effects of teriparatide [rhPTH (1-34)] treatment on structural geometry of the proximal femur in elderly osteoporotic women.
BACKGROUND
We evaluated effects of teriparatide (rDNA origin) injection [teriparatide, rhPTH (1-34), TPTD] on hip structure among a subset 558 postmenopausal women enrolled in the Fracture Prevention Trial.


METHODS
Patients were randomized to once-daily, self-administered subcutaneous injections of placebo (N = 189), teriparatide 20 mug (TPTD20; N = 186), or 40 mug (TPTD40; N = 183) for a median of 20 months. Repeated dual energy X-ray absorptiometry (DXA) hip scans were analyzed with the Hip Structure Analysis (HSA) program to derive structural geometry.


CONCLUSIONS
There were no significant differences in age or body size between groups at baseline, 1 year, or study termination. At the femoral neck, teriparatide increased bone mass and improved bone geometric strength in both treatment groups compared to the placebo group, with the response being dose-related. The mean difference (95% CI) in bone cross-sectional area (CSA) in the TPTD20 was 3.5% (1.8% to 5.3%), and 6.3% (4.5% to 8.2%) in TPTD40 at study termination, compared to placebo controls. Teriparatide treatment increased bending strength, with the mean difference in section modulus being 3.6% (1.4% to 5.8%) and 6.8% (4.6% to 9.1%) greater in the TPTD20 and TPTD40 groups, respectively. Compared to placebo, local cortical instability characterized by the buckling ratio decreased by 5.5% (3.5% to 7.5%) and 8.6% (6.6% to 10.5%) in the TPTD20 and TPTD40 groups, respectively, during the study period. The changes at the intertrochanteric region were comparable to those at the narrow neck although between-group differences were slightly smaller. Except for an inconsequential (1%) improvement in section modulus in TPTD20, teriparatide effects did not reach significance at the femoral shaft. In conclusion, teriparatide treatment improved axial and bending strength, and increased cortical thickness and stability at the femoral neck and intertrochanteric region. Teriparatide treatment effects were not apparent at the purely cortical femoral shaft.
Uusi-Rasi
Kirsti
K
Department of Radiology, The Johns Hopkins University School of Medicine, Outpatient Center, 601 N. Caroline Street, Baltimore, MD 21287-0849, USA.
Semanick
Lisa M
LM
Zanchetta
Jose R
JR
Bogado
Cesar E
CE
Eriksen
Erik F
EF
Sato
Masahiko
M
Beck
Thomas J
TJ
D000368:Aged; D001835:Body Weight / Q000187:drug effects; D015519:Bone Density / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D004311:Double-Blind Method; D005260:Female; D005269:Femur / Q000187:drug effects* / Q000473:pathology; D005272:Femur Neck / Q000187:drug effects / Q000473:pathology; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy* / Q000473:pathology; D019379:Teriparatide / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D016896:Treatment Outcome
D050071:Bone Density Conservation Agents; D019379:Teriparatide