Does alendronate reduce the risk of fracture in men? A meta-analysis incorporating prior knowledge of anti-fracture efficacy in women.
BACKGROUND
Alendronate has been found to reduce the risk of fractures in postmenopausal women as demonstrated in multiple randomized controlled trials enrolling thousands of women. Yet there is a paucity of such randomized controlled trials in osteoporotic men. Our objective was to systematically review the anti-fracture efficacy of alendronate in men with low bone mass or with a history of prevalent fracture(s) and incorporate prior knowledge of alendronate efficacy in women in the analysis.


METHODS
We examined randomized controlled trials in men comparing the anti-fracture efficacy of alendronate to placebo or calcium or vitamin D, or any combination of these. Studies of men with secondary causes of osteoporosis other than hypogonadism were excluded. We searched the following electronic databases (without language restrictions) for potentially relevant citations: Medline, Medline in Process (1966-May 24/2004), and Embase (1996-2004). We also contacted the manufacturer of the drug in search of other relevant trials. Two reviewers independently identified two trials (including 375 men), which met all inclusion criteria. Data were abstracted by one reviewer and checked by another. Results of the male trials were pooled using Bayesian random effects models, incorporating prior information of anti-fracture efficacy from meta-analyses of women.


RESULTS
The odds ratios of incident fractures in men (with 95% credibility intervals) with alendronate (10 mg daily) were: vertebral fractures, 0.44 (0.23, 0.83) and non-vertebral fractures, 0.60 (0.29, 1.44).


CONCLUSIONS
In conclusion, alendronate decreases the risk of vertebral fractures in men at risk. There is currently insufficient evidence of a statistically significant reduction of non-vertebral fractures, but the paucity of trials in men limit the statistical power to detect such an effect.
Sawka
Anna M
AM
Department of Medicine, St, Joseph's Healthcare and McMaster University, Hamilton, Ontario, Canada. sawkaam@yahoo.com
Papaioannou
Alexandra
A
Adachi
Jonathan D
JD
Gafni
Amiram
A
Hanley
David A
DA
Thabane
Lehana
L
D000328:Adult; D000368:Aged; D019386:Alendronate / Q000627:therapeutic use*; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D005260:Female; D050723:Fractures, Bone / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic; D012306:Risk; D040242:Risk Reduction Behavior; D012737:Sex Factors; D016103:Spinal Fractures / Q000517:prevention & control
D050071:Bone Density Conservation Agents; D019386:Alendronate