Endocrine Abstracts

Aims: To compare bone mineral density (BMD) and stature between women with androgen insensitivity syndrome and women with gonadal dysgenesis.

Settings: Adult Intersex Clinic.

Design: Retrospective cross-sectional study of three groups of women aged 17-58 years with varying degrees of exposure to sex hormones and different combinations of sex chromosomes. Forty-six subjects had complete androgen insensitivity syndrome and 46XY [CAIS(XY)], 18 had gonadal dysgenesis and 46XY [GD(XY)], and 25 had gonadal dysgenesis and 46XX [GD(XX)].

Outcome measures: Oestrogen therapy, karyotype, anthropometry, and BMD.

Results: Multivariate logistic regression analysis (adjusted for age and height) showed that among women with XY karyotype, GD(XY) women were 5.2 times (95% CI: 1.3 to 20.1, P=0.018) more likely than CAIS(XY) women to have a low hip BMD. This difference was not evident among women with gonadal dysgenesis of different karyotypes (P=0.938). Spinal BMD did not differ between subject groups. Further adjustment for oestrogen replacement did not alter these relationships. Height differed between groups (F ratio 5.2, P=0.007), with GD(XX) women being shortest (mean 1.66, S.E. 0.02 m), GD(XY) women tallest (1.74, S.E. 0.02 m) and in between were CAIS(XY) women (1.70, S.E. 0.01 m). Delayed gonadectomy resulted in taller stature and higher spinal BMD.

Conclusions: Androgen rather than Y chromosome may play an important role in cortical bone mineralization subjects with CAIS, probably via oestrogen receptor. Final adult height is determined by age of gonadectomy and oestrogen replacement.