A circulating marker of bone remodelling is associated with cognition in older age

Steven Bradburn is a PhD student at Manchester Metropolitan University. His research interests focus on age-related cognitive decline and physical functioning in later life. He recently published Association between Osteocalcin and Cognitive Performance in Healthy Older Adults in Age and Ageing journal.

Cognitive decline and reductions in bone health regularly co-manifest during advancing age. Previous studies have shown relationships between bone mineral density and risks of Alzheimer’s disease and cognitive decline, especially in older women. This raises the possibility that factors related to bone regulation and function may also influence cognitive wellbeing.

In our study, using the cross-sectional MyoAge cohort, we evaluated the relationship between bone mineral density and proteins related to bone metabolism in the blood with measures of cognitive functioning in physically and mentally healthy older adults. Despite finding no association between bone mineral density and cognitive performance, we did detect a positive relationship between osteocalcin, a marker of bone formation, with multiple measures of cognitive performance in older women.

Released solely by the osteoblasts, the specialized cells responsible for bone synthesis, osteocalcin is the major protein component of the bone matrix. Interestingly, rodent studies have previously shown that osteocalcin can cross the blood-brain barrier to promote the birth of new neurons (neurogenesis), support spatial learning and memory and increase the synthesis of neurotransmitters.

The finding that bone regulatory proteins, but not bone mineral density, correlate with cognitive performance in the older adults suggests that these molecular alterations may precede the reductions in bone density loss. Reductions in bone health may ultimately contribute, either directly and/or indirectly, to cognitive dysfunctions. Interventions, particularly longitudinally, to maintain or improve bone health with a view to promote cognitive reserve should be considered in future research.

Read the Age and Ageing paper Association between Osteocalcin and Cognitive Performance in Healthy Older Adults