Association of fractures with the incidence of amyotrophic lateral sclerosis.

OBJECTIVE

Elevated bone turnover observed in ALS patients suggests poor bone health and increased fracture risk. We therefore evaluated the relationship of fracture to subsequent ALS risk.

METHODS

We followed 4,529,460 Swedes from 1987 to 2010 and identified ALS and fractures from the Swedish National Patient Register. We examined associations of ALS risk with all fractures, osteoporotic and non-osteoporotic fractures, and traumatic and non-traumatic fractures among individuals aged 30-80 years. We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). We analysed the association of ALS with time since fracture using a Poisson regression model.

RESULTS

All fractures (HR: 1.51, 95% CI 1.39-1.65) as well as osteoporotic (HR: 1.59, 95% CI 1.41-1.79), non-osteoporotic (HR: 1.46, 95% CI 1.31-1.63), traumatic (HR: 1.50, 95% CI 1.37-1.63), and non-traumatic (HR: 1.80, 95% CI 1.35-2.40) fractures were associated with a higher incidence of ALS. Increased ALS incidence was associated with fractures occurring from one (HR: 2.33, 95% CI 2.04-2.66) to 18 (HR: 1.19, 95% CI 1.01-1.43) years before ALS diagnosis.

CONCLUSIONS

Poor bone health may be related to ALS. These findings may offer insight into ALS pathophysiology.