For the study, researchers conducted and analyzed MRI scans of 40 girls aged 16 to 20. Half of the girls suffered from anorexia and half did not. The researchers found that the anorexic girls had significantly higher levels of fat in the marrow of their knees, thighs and upper shin bones, as well as significantly less red marrow.
Earlier studies have also confirmed that malnourished individuals experience hormonal changes that cause the bone marrow's mesenchymal stem cells to turn into fat cells rather than bone-forming cells. This change may help to explain why some anorexic individuals develop osteoporosis.
Dr. Catherine Gordon, an endocrinologist and director of the Bone Health Program at Children's Hospital Boston, explained the phenomenon in a hospital news release: "It's counterintuitive that an emaciated young woman with almost no subcutaneous [below the skin] fat would be storing fat in her marrow. Bone formation is very low in girls with anorexia, and that's a particular problem because they are growing adolescents who should be maximally forming bones.
"But because of the hormonal alterations induced by malnutrition, the bone marrow stops yielding the needed cells to form bone. Instead, the stem cells are pushed toward fat formation."
Experts hypothesize that the body makes this change in a "last ditch" effort to preserve body fat and increase body temperature. With little or no body fat, anorexics often suffer from dangerously low body temperatures (hypothermia) and must be hospitalized because of it.
(Source: www.businessweek.com)
Labels: anorexia, osteoporosis
Posted By: Aspen Education Group