Your bones could hold clues about what is happening in your brain, and a common imaging test could help uncover them, according to a new study that found people with lower bone density in their spine were more likely to experience faster decline in thinking ability. The study, published in Radiology, also found that lower spinal bone density was associated with worsening changes in the brain’s white matter over time. Researchers from Johns Hopkins University analyzed data from 2,086 people from an existing study, using CT scans to estimate vertebral volumetric bone mineral density (vBMD) in the thoracic, or upper and middle, spine. Of those participants, 715 also had brain MRI scans and cognitive testing that could be used to examine how bone density related to changes in the brain and thinking ability. People who had a lower vBMD at the beginning of the study tended to show a faster decline in overall cognitive ability. They also had greater progression of certain changes in the brain. These included an increase in white matter hyperintensities in the corpus callosum. These abnormalities can be seen on MRI scans and were associated with cognitive decline and a higher risk of dementia. Dr. Sara Momtazmanesh, a postdoctoral research fellow in the Department of Radiology and Radiological Sciences at Johns Hopkins University in Baltimore, Maryland, cautioned that the findings should not be interpreted as evidence that bone loss directly causes brain decline. “I would not want readers to come away thinking that bone loss causes brain aging, because an observational study cannot show that. Our data best fit shared vulnerability, meaning the same underlying processes that weaken bone also damage the brain,” she told Newsweek. The study also found a greater decline in fractional anisotropy in the anterior limb of the internal capsule, a measure related to changes in the microscopic organization of white matter. Some of the brain regions involved in these associations are important for functions such as working memory, attention, and executive function. The researchers suggest that biological factors could potentially contribute to changes in both bone and brain health. They point to possible shared metabolic factors, dyslipidemia, and menopausal changes. However, the study also did not prove that these factors explain the association. Dr. Momtazmanesh said two participant groups appeared to stand out, although she emphasized that the analyses were exploratory and based on small subgroups, meaning the findings require further study before firm conclusions can be drawn. She explained: “The clearest was people with diabetes. Among them, lower bone density was linked to faster accumulation of white matter hyperintensities, the bright spots on MRI that reflect damage to small blood vessels, while we saw essentially no association in participants without diabetes. “The association between lower bone density and loss of white matter integrity also appeared stronger in women than in men, although that difference was borderline. For cognition, people in the lowest quarter of bone density declined faster on our global cognitive score than those in each of the three higher quarters.” In the study, the researchers used an artificial intelligence system to estimate thoracic spine bone density from CT scans. This raises the possibility that routine CT scans could provide information about bone health beyond the reason the scan was originally performed. Dr. Momtazmanesh said the finding was potentially significant because chest CT scans were among the most common imaging tests in older adults. “Bone density can be measured from the same scan automatically, with no extra imaging, no extra radiation and no extra time for the patient. That is what makes the idea appealing: a number that already exists in a routine scan might one day help identify people at higher risk of faster brain aging. We are not there yet,” she said. However, she warned that the findings still needed to be confirmed before they can be used in clinical practice. “It is not a dementia test, and nothing in our study should be read as a recommendation to patients or their physicians.” Reference: Momtazmanesh et al. Deep Learning-derived Bone Mineral Density and Longitudinal White Matter Microstructure and Cognitive Decline: Multi-Ethnic Study of Atherosclerosis. Radiology. Contact Newsweek editors on this story: Kara Dolman and Cristina Diciu.

Original source: US