A common drug used to treat Alzheimer’s has shown potential in mice models to prevent bone fractures. The findings were discovered by researchers at Saitama Medical University in Japan. Researchers are hopeful that the Alzheimer’s drug has the potential to treat osteoporosis and periodontitis.
With an aging population, Alzheimer’s disease is the most common form of dementia and the number of cases continues to grow. Loss of bone density is not only found in aging, but is also part of the early stages of Alzheimer’s disease which can increase a person’s risk of bone fractures.
Lead author Dr. Tsuyoshi Sato said, “We think that donepezil can improve cognitive function and increase bone mass, making it a very useful drug for patients with dementia and osteoporosis. From the viewpoint of medical economics, this dual purpose could reduce the cost of treating these diseases.”
Two kinds of cell control determine bone mass and density: osteoblasts make bone and osteoclasts absorb it. Acetylcholine – a molecule – causes osteoblasts to die and acetylcholinesterase – an enzyme – breaks down the molecule (the effects of this are largely unknown).
A common Alzheimer’s drug stops the acetylcholinesterase process from occurring which increases acetylcholine in the brain. Previous research on the Alzheimer’s drug revealed those who took it had a reduced risk of hip fractures – the results, though, were determinant on the level of dosage.
The researchers examined how the drug works in mice bone marrow and found “more acetylcholinesterase is produced when osteoclasts are being made, which leads to even more osteoclasts being made.” When acetylcholinesterase is stopped, osteoclasts is prevented.
Studies have shown that acetylcholinesterase activity increases with age which speeds up bone loss in seniors. Dr. Sato added, “Our findings are very promising and suggest that there is a role for donepezil in increasing bone mass in elderly patients with inflammation and dementia. There is still work to be done and we look forward to observing the effect of this drug in patients.”