Effects of Glucocorticoids on Bone: What we can Learn from Pediatric Endogenous Cushing's Syndrome.

Chronic exposure to supraphysiologic levels of glucocorticoids (GCs) is associated with impaired bone mineral density, an increase in fracture rates, and, in growing children, compromised linear growth. GCs inhibit bone formation in part by decreasing the number of osteoblasts and by increasing bone resorption by stimulating osteoclasts. While GCs are used to treat many chronic diseases, it is difficult to isolate the effects of the steroids on the bone from the effects of the underlying disease itself. Investigation into the effects of GC exposure on the bone in endogenous Cushing syndrome have contributed to our understanding of bone microarchitecture, growth, healing, and regeneration. We now know that GCs negatively impact bone marrow derived-mesenchymal stromal cells. In children with Cushing syndrome, the potential reversibility of deleterious effects of chronic GC exposure on bone provides insight into the pathophysiology behind pure GC excess.