Osteoporosis 5- Chronic Stress

There are 2 types of stress responses in our lives; a short term response and a long term response.  The short term response is considered to be governed by the sympathetic nervous system.  The long term response characteristically involves the release of glucocorticoids, namely cortisol. 

We've already discussed the fact that many people have overactive sympathetic nervous systems.  This has an immediate impact on bone.  We saw in a previous post that sympathetic dominance will inhibit osteoblast activity and increase bone resorption (breakdown).   In fact, much has been written about the more typical stress response seen in America; a prolonged short term response layered over an ongoing long term response.  It's worth noting here the influence of the long term response on bone health.

A 2008 paper does a good job describing the role of stress.
"Cortisol excess inhibits bone formation, increases bone resorption, impairs calcium absorption from the gut, and affects the secretion of several hormones (in particular gonadotropins and GH), cytokines, and growth factors, influencing bone metabolism." 

Remember that cortisol is considered a "stress hormone" and is released in times of physical, emotional or psychological stress.  It is a normal response but in a stressed out world, tends to get hyperactive.  The authors continue,

"Subclinical hypercortisolism, a condition of impaired hypothalamic-adrenal axis homeostasis without the classical signs and symptoms of glucocorticoid excess, is a recently defined entity, which has been shown to be associated to increased bone resorption, bone loss, and high prevalence of vertebral fractures regardless of gonadal status."

You could still ask, "is this common or a rare event?"  The authors conclude,

"recent data suggest that subclinical hypercortisolism is a common and underrated finding in patients with established osteoporosis."   J Endocrinol Invest 2008 Mar;31(3):267-76

There are scores of papers the describe the role of stress in degrading bone health.  Attempts to manage osteoporosis without considering the stress response will likely fall short.