Researchers at Children’s Hospital Boston found that females who are anorexic may look emaciated on the outside, but on the inside they may be storing excess fat in their bone marrow.
The recent study results are important for several reasons. First, girls and women who are anorexic typically lose bone mass, making them at great risk for osteoporosis and bone fractures. The National Institute of Arthritis and Musculoskeletal and Skin Diseases has already reported that girls with anorexia are less likely to achieve their maximum bone density and therefore may place themselves at increased risk for osteoporosis and fractures early and throughout their lives.
In Children’s Hospital study, researchers took magnetic resonance images (MRIs) of the knees of 20 16 year old girls with anorexia and 20 healthy girls of the same age. The images were read by radiologists who did not know the patients’ condition. When the images of the anorexic girls were compared with those of the controls, the patients with anorexia had markedly increased fat, or “yellow marrow,” and less than half as much healthy red marrow in their knees. This was obvious in both the lower thigh bone and upper shinbone.
One hypothesis is that the body is attempting to store energy and preserve warmth, as anorexics often have low body temperatures because they lack insulating fat.
