Osteoporosis is associated with an increased risk of dementia, according to German research published in the Journal of Alzheimer’s Disease.

Researchers matched 29,983 cases and the same number of controls, with mean ages of 62.1 years in women and 61.5 years in men. After 20 years, 20.5 per cent of women with osteoporosis and 16.4 per cent of controls had both been diagnosed with dementia. Similarly, 22.0 per cent of men with osteoporosis and 14.9 per cent of controls had dementia.

After allowing for confounders, osteoporosis was associated with a 20 per cent increase in dementia risk in women and a 30 per cent increase in men.

The authors were unable to collect data on bone mineral density, socio-economic status and lifestyle risk factors.

Nevertheless, osteoporosis and dementia might share genetic and other risk factors, including levels of vitamin D and K, thyroid disease and hormones.

Further studies need to establish the underlying mechanisms and confirm the link in countries other than Germany.