Bone mineral density and anorexia nervosa in women

OBJECTIVE: A review of reports of reduced bone mineral density in women with anorexia nervosa was undertaken in order to profile specific risk factors, which could then be used as the basis for suggestions for future research and treatment. METHOD: Thirteen research studies and four case studies of reduced bone mineral density and fractures in women with anorexia nervosa were reviewed. The relationships between bone mineral density and amenorrhea, estrogen, calcium intake, physical activity, parathyroid hormone, alkaline phosphatase, 1,25- dihydroxyvitamin D, cortisol, and growth hormone were examined in the reports of these studies and other reports of altered physiology during anorexia nervosa. RESULTS: The average spinal, radial, and femoral bone mineral density in anorexic women was significantly lower than it was in normal control subjects. Concurrent with the low intake of nutrients by individuals with anorexia nervosa, low body weight, early onset and long duration of amenorrhea, low calcium intake, reduced physical activity, and hypercortisolism appeared more likely to contribute to decreased bone mineral density than did other abnormal aspects of the disorder. CONCLUSIONS: Future research needs to address how such factors as amenorrhea and hypercortisolism affect bone mineral density in anorexia nervosa. Since no controlled trials of estrogen replacement or calcium supplementation in anorexia nervosa have been reported, the proper treatment for decreased bone mineral density is not known. However, the most obviously important intervention is to encourage medical stabilization and weight gain.