Decreased bone mineral density (BMD) in anorexia nervosa (AN) can be detected easily by dual-energy X-ray absorptiometry (DXA). This study was designed to assess the prevalence of osteoporosis and osteopenia in AN, identify predictors, and determine the diagnostic yield of screening with DXA.
DXA was used to screen 59 unselected adult patients with a history of AN.
Osteoporosis was identified in 18 patients (31%) and osteopenia in 30 (51%). The spine had a lower mean T-score than either the hip or femur. BMI significantly predicted T-score (p = 0.0006) and the odds of having osteoporosis (p = 0.0188). There was a significant association between use of oestrogens and the presence of osteoporosis or osteopenia (p = 0.0491). There was no significant association between duration of AN and T-score. A duration of AN of less than 1 year was found in 12% of those with osteoporosis.
BMI is a strong predictor of BMD in AN. DXA is an effective screening tool and should probably be offered routinely.