Response to oral bisphosphonates in subgroups of younger and older postmenopausal women.
BACKGROUND
Although the effects of bisphosphonates in bone are known for postmenopausal women, it is not known if younger postmenopausal women have a similar response. Furthermore, it is not known if the effects of alendronate and risedronate differ in postmenopausal women in regard to age, specifically in women at or younger than the mean age of natural menopause. Our aim was to examine the effects of two oral bisphosphonates in postmenopausal women by age.


METHODS
This was a post-hoc analysis of postmenopausal women <55 or > or =55 years old with low bone mineral density (BMD), randomized to once weekly alendronate 70 mg or risedronate 35 mg for 1 year with 1-year extensions in U.S. and International Fosamax Actonel Comparison Trials.


RESULTS
In both age subgroups of postmenopausal women, alendronate produced significantly greater mean BMD increases from baseline than risedronate at hip trochanter, lumbar spine, total hip, and femoral neck. Changes in BMD were not significantly different between younger and older alendronate-treated women, although treatment differences favoring alendronate were numerically greater for younger than older postmenopausal women at all sites. Significantly greater reductions in bone turnover markers also occurred with alendronate vs. risedronate in both subgroups. Tolerability was similar between treatments.


CONCLUSIONS
In this post-hoc subgroup analysis of older and younger postmenopausal women receiving alendronate or risedronate, larger treatment differences in BMD gain in younger compared with older women suggest that patient age may affect the relative efficacy of these antiresorptive drugs.
Department of Obstetrics and Gynecology, Endocrine Research, VCU Medical Center, Richmond, Virginia, USA. ds2as@hscmail.mcc.virginia.edu
Dale W
DW
Stovall
Mary K
MK
Beard
Suzanne
S
Barbier
Erluo
E
Chen
Elizabeth
E
Rosenberg
Anne E
AE
de Papp
D000328:Adult; D000367:Age Factors; D000368:Aged; D019386:Alendronate / Q000009:adverse effects / Q000627:therapeutic use*; D000704:Analysis of Variance; D015519:Bone Density / Q000187:drug effects*; D050071:Bone Density Conservation Agents / Q000009:adverse effects / Q000627:therapeutic use*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D012968:Etidronic Acid / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D005260:Female; D005269:Femur / Q000033:anatomy & histology / Q000187:drug effects; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy*; D000068296:Risedronic Acid
D050071:Bone Density Conservation Agents; D000068296:Risedronic Acid; D012968:Etidronic Acid; D019386:Alendronate