Weight, Not Estrogen Use, Correlates with Bone Density

Estrogen supplementation does not improve bone density among patients with anorexia nervosa, according to researchers at Massachusetts General Hospital, Boston. Instead, they found that weight was highly correlated with bone density.

Dr. David Herzog and co-workers used bone density screening by dual-energy x-ray absorptiometry (DEXA) and correlates of low bone density among 94 women with anorexia nervosa. The women, who were 18 to 40 years of age, had very low bone density; for example, the mean anteroposterior spine T score was –1.5 (1.5 standard deviations below mean bone density scores for this age range). The lifetime estrogen use for each patient was also established: 24 women had received estrogen (mean lifetime duration of use was 13+ months), and 70 had never used estrogens.

Estrogen use did not increase bone density

The researchers found that bone density was not different in patients who had used estrogen and those who hadn’t had been prescribed estrogen. In contrast, they established a highly significant correlation between bone density and body mass index. Thus, weight, a measure of overall nutritional status, was highly correlated with bone density. The authors note that although the cause of bone loss among anorexic patients is still unknown, these data are new evidence of the important and independent effect of malnutrition upon bone loss among these patients. More than half of all women with anorexia nervosa have bone loss greater than 2 standard deviations below normal, they added. Dr. Herzog’s group presented their findings at the November meeting of the Eating Disorders Research Society.