History of Fractures May Help Predict Onset of ALS, Study Reports

Poor bone health that makes people vulnerable to fractures may be a risk factor for the development of amyotrophic lateral sclerosis (ALS), according to a study.

The research, “Association Of Fractures With The Incidence Of Amyotrophic Lateral Sclerosis,” was published in the journal Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration.

Previous studies have demonstrated that ALS patients have poor bone health and are at high risk of fractures. The question is whether the poor bone health preceded ALS, or stemmed from it.

“Fractures may be related to bone health, i.e. to changes in bone density, structure, or strength resulting from aging, physical inactivity, diet, medical conditions such as hyperparathyroidism or bone disease, or medication use,” researchers wrote.

But changes in bone health may occur before the onset of ALS. Indeed, ALS that runs in families has been associated with variations in genes related to bone remodeling. For this reason, researchers wondered whether fractures occurring before ALS diagnosis could be associated with increased risk for this disease.

The team scoured Swedish population and health registers for ALS patients with a history of fractures. The records covered 4,529,460 individuals between 1987 and 2010.

Researchers investigated potential associations between fractures and ALS among individuals 30 to 80 years old. All fracture types were included: osteoporotic, non-osteoporotic, traumatic and non-traumatic. Oosteoporotic fractures are caused by loss of bone density. Traumatic fractures are caused by accidents.

The analysis indicated that a higher incidence of ALS was associated with fractures. Another important finding was that increased ALS incidence was associated with fractures that occurred between one and 18 years before ALS diagnosis.

Together, the results suggested that poor bone health is associated with ALS. That could explain why ALS patients are at high risk of experiencing several types of fractures.

“In conclusion, we found different types of fractures to be associated with increased incidence of ALS,” researchers wrote. “While the association of ALS with fractures occurring up to five years before diagnosis may be due to reverse causation [the disease may promote poor bone health or the other way around], the association with those occurring more than five years before diagnosis suggests that bone changes may be related to ALS and may offer insight into its pathophysiological mechanisms.

“Additional studies exploring the relationship of poor bone health to ALS would be of interest,” they added.