Anorexia nervosa: Slow regain of bone mass

In a retrospective study of women aged 18-30 years, aimed at assessing fact ors associated with peak bone mass (PBM), 13 of 239 study cases reported ha ving had anorexia nervosa. The mean total femoral;md lumbar bone mineral de nsity (BMD) values were not significantly lower in women who had had anorex ia than in the pooled group (mean Z-scores of -0.60 and -0.48). Cases with less than 6 years since the anorexia had on average a present weight 5.7 kg less than their premorbid weights, while cases with more than 6 years sinc e the eating disorder had an average weight 22.5 kg above their pre-morbid weights. The cases who had not regained their weight had BMD values signifi cantly lower than the pooled material (mean Z-scores -1.15 and -0.9 in the lumbar spine and total femur respectively). Those who had regained their we ight had BMD values as predicted from their present anthropometric data, wh ile those who had not regained their weight had BMD values that were substa ntially below that predicted from their present weight. Anorexia nervosa se ems to be associated with a low BMD which is even lower than that which can be predicted from the weight loss alone. This suggests that weight loss an d other factors, such as menstrual dysfunction and estrogen deficiency, are independent and thus additive causes of bone loss in anorexia nervosa. Rec overy of BMD seems slow, but the BMD may become as predicted from the anthr opometric data after restoration of body weight and menses. The potential f or recovery of BMD seems intact :for several years after menarche.