Osteoporosis Drugs Tied to 24% Lower Dementia Risk in 120,000 Patients
A Hong Kong study of more than 120,000 older adults found a 24% lower dementia risk with bisphosphonates. It is observational and cannot prove cause.
Older adults who took a common class of osteoporosis drugs had a 24% lower risk of dementia than patients on other osteoporosis medications, according to a University of Hong Kong study of more than 120,000 people. The study was published in the journal Alzheimer’s & Dementia. It is observational, so it shows an association and does not prove the drugs prevent dementia.
The drugs are nitrogen-containing bisphosphonates (NBPs), including alendronate and zoledronate. They slow the breakdown of bone tissue and are widely prescribed to reduce fractures.
How the researchers tested the link
The team at HKUMed’s LKS Faculty of Medicine analyzed electronic medical records from across Hong Kong. The records covered patients aged 60 and older who had osteoporosis or fragility fractures (breaks from relatively minor injuries, caused by weakened bones). The data ran from 2005 through 2020.
Compared with patients who received no osteoporosis medication, those taking NBPs had a 16% lower risk of Alzheimer’s disease and related dementias. Compared with patients taking other types of osteoporosis drugs, the risk was 24% lower. The associations looked particularly strong in women and in patients who had suffered hip fractures.
The researchers also estimated that treating 48 patients with NBPs over five years could potentially prevent one case of dementia.
Why bones and brains might be connected
Osteoporosis and dementia often affect the same people and share risk factors such as older age, being female and low physical activity. The same team previously found that osteoporosis and fractures are independent risk factors for dementia, and that people with dementia are more likely to fall and break bones. The authors say some biological processes affected by these drugs may also be involved in the development of Alzheimer’s disease, though the study did not test a mechanism.
What is still unclear
Because patients were not randomly assigned to take the drugs, other differences between the groups could explain part of the result. The researchers state that the findings do not establish that the drugs themselves prevent dementia. Further studies are needed to determine whether NBPs can directly prevent or delay the disease. The paper reports results from one population, in Hong Kong.
Why it matters
More than 55 million people worldwide live with dementia, and the number is projected to reach 139 million by 2050. The first drugs designed to slow Alzheimer’s disease have recently been approved, but the researchers cite their high cost, limited suitability for some patients and questions about effectiveness. That has increased interest in existing medications that might lower risk before symptoms appear.
Professor Cheung Ching-lung, who led the study, said the results give “an empirical basis” for future research on whether NBPs can prevent or delay cognitive decline. NBPs are already widely available and have a long record of use in osteoporosis, which is why researchers see them as a candidate worth testing. The study does not recommend that anyone take them for dementia prevention.
The first author was Dr. Sing Chor-wing. The paper, “Bisphosphonates and the risk of dementia in patients with osteoporosis or fragility fracture: A population-based study in Hong Kong,” carries the DOI 10.1002/alz.70503.
Source: ScienceDaily
