Osteoporosis and normal weight bulimia nervosa--which patients are at risk?

This study assesses the degree of bone mineral loss in women with active DSM IIIR bulimia nervosa. The subjects in this study were 20 GP-referred female patients of normal weight who met criteria for bulimia nervosa and 16 healthy age, sex and weight matched controls. Dual energy X-ray densitometry of lumbar L1-L4 vertebrae was performed on all subjects. The patients with bulimia nervosa had a significantly lower mean lumbar bone mineral density (0.964 g/cm2) than the control group (1.043 g/cm2, p < 0.01). Within the patient group only subjects with a past history of anorexia nervosa had a significantly lower mean bone mineral density (BMD) than the controls. Small sample sizes limit the power of the study, however significant correlations were found between duration of amenorrhoea, low BMI and lumbar BMD. Bulimic patients do suffer from osteoporosis. Risk factors for this may be; a past history of anorexia nervosa, prolonged secondary amenorrhoea, and a persistently low body mass index.