How does chronic stress induce bone loss?

https://www.eurekalert.org/pub_releases/2020-09/caos-hdc091120.php

News Release 11-Sep-2020
Chinese Academy of Sciences Headquarters

Clinical studies have found that bone mineral density in patients with anxiety or depression is lower than in ordinary people.

The brain, commander of the body, receives and processes external signals, and then sends instructions to peripheral bones. But how does anxiety induce a decline in bone mineral density?

Researchers from the Shenzhen Institutes of Advanced Technology (SIAT) of the Chinese Academy of Sciences and their collaborators now have an answer. They found that a central neural circuit from the forebrain to the hypothalamus mediates chronic stress-induced bone loss via the peripheral sympathetic nervous system. 

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The researchers found that isolation can significantly increase anxiety levels, thus inducing bone loss in human subjects.

Biochemical analysis showed that prolonged isolation increases the concentration of norepinephrine and decreases osteogenic markers in serum. These changes were consistent with the observation of elevated anxiety and reduced bone formation in subjects.

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