Background: What affects the efficacy of alendronate for prevention of glucocorticoid-induced (GI) fractures remains unclear. We aimed to explore the factors affecting alendronate's efficacy, and further identify subgroup effects of alendronate in preventing GI fractures.
Methods: We searched 3 databases. Random-effects meta-analysis was conducted to synthesize risk ratio (RR) and 95% confidence interval (CI) for each endpoint. Meta-regression analysis was used to explore sources of heterogeneity, and subgroup analysis was used to address heterogeneity and evaluate subgroup effects. We detected publication bias using funnel plots and Egger tests.
Results: We included 13 papers from 12 unique studies involving 46431 participants. Glucocorticoid (GC) dosage (P = .053) and proportion of previous vertebral fracture (PVF) (P = .047) were probably 2 sources of heterogeneity in meta-analysis for vertebral fractures, while GC duration (P = .020) was probably 1 for nonvertebral fractures. Alendronate reduced vertebral fractures in the high dosage subgroup (RR 0.61, 95% CI 0.44-0.86), but didn't in the low dosage subgroup (RR 1.56, 95% CI 0.20-12.02). Alendronate reduced vertebral fractures (RR 0.53, 95% CI 0.40-0.68) in the subgroup of PVF proportion <5%, but didn't (RR 0.76, 95% CI 0.42-1.37) in the subgroup of this proportion ≥5%. Alendronate reduced nonvertebral and hip fractures, whether in primary or in secondary prevention subgroup.
Conclusions: The findings in our study support that alendronate is used for the primary and secondary prevention of GI fractures, but do not support that alendronate is recommended as a first-line agent for patients receiving a low dose of GCs or patients with PVF.