[Loss of bone mass in patients with anorexia on tube feeding and its prevention with biphosphonates].

Women with long-lasting anorexia nervosa often display osteopenia. Furthermore, we have observed additional marked loss of bone mass under tube feeding in underweight anorexia patients. Such loss of bone substances can lead to spontaneous fractures. Therefore, we investigated in this study whether this undesirable effect of tube-feeding might be prevented by administration of bisphosphonates (Didronel), a substance that inhibits the activity of osteoclasts. Bone density was assessed by a high-precision, low dose, quantitative computed tomography of the distal radius and the distal tibia. A group of 6 anorexia patients (tube feeding with an initial underweight of 74.9 +/- 10.3% of ideal weight, mean +/- SD) treated with bisphosphonates showed only slight loss of trabecular bone (0.8 +/- 0.2%, mean +/- SEM) after 2 months of observation, whereas in 2 control groups a marked diminution of trabecular bone was observed (4.4 +/- 0.7% and 7.6 +/- 1.1% respectively, p less than 0.001 for each comparison). Cortical bone was unchanged throughout. Treatment with bisphosphonates provides effective prevention of bone loss observed in tube-feeding.