Osteopenia as a feature of the androgen insensitivity syndrome

OBJECTIVE The syndrome of androgen insensitivity, a paradigm of a hormone resistance syndrome, manifests as failure of masculinization despite normal or high concentrations of serum testosterone. The defect in these 46 XY patients resides in the androgen receptor gene, with consequent defective androgen action and abnormal sexual differentiation. We sought to evaluate whether the adverse sequelae of androgen resistance may extend to skeletal tissue by measuring bone mineral density In SIX patients with androgen Insensitivity. DESIGN A cross-sectional retrospective study. MEASUREMENTS Bone mineral density was measured by means of a Dexa (Hologic QDR 1000 scanner). The diagnosis of androgen Insensitivity was confirmed in each patient by karyotype and assay of sex hormones. RESULTS The five adult patients with androgen insensitivity had been exposed to both defective androgen action and variable periods of oestrogen deficiency. The latter resulted from the low circulating oestrogen concentrations (for premenopausal females) before gonadectomy and inadequate oestrogen replacement afler gonadectomy. All five adults with androgen insensitivity had osteopenia in both the lumbar spine (T-score ?1.52 to ?3.85) and femoral neck (T- score ?1.34 to ?4.91). CONCLUSIONS Osteopenia in patients with androgen insensitivity may relate to defective androgen action, oestrogen deficiency or a combination of the two. These observations have implications for the management of patients with androgen insensitivity and may provide insight into the effects of androgens on the female as well as the male skeleton.