DXA Derived Low Bone Mass in a Cohort of Prepubertal Eastern Indian Girls With Turner Syndrome Disappeared Following Adjustment for Short Stature.

INTRODUCTION

Whereas hypergonadotropic hypogonadism is incriminated for poor bone mass in adults with Turner syndrome (TS), studies are limited on bone mass acquisition in pubertal girls with this condition. In previous studies reporting low bone mass in pubertal girls with TS, the bone-mineral-density (BMD) was not adjusted for height, a major determinant of BMD in this group. The present study was designed to address this knowledge gap by looking at the effect of height-adjustment on BMD in pre-pubertal girls with TS.

MATERIALS AND

METHODS

Eighty pre-pubertal girls with TS aged 12-18 years who did not receive GH or pubertal induction before the study, and 85 age-matched controls underwent BMD assessment by dual-energy X-ray absorptiometry (DXA) followed by stature corrections as per ISCD official positions. Bone turnover markers, P1NP (formation) and beta-CTX (resorption) were also assessed.

RESULTS

TS patients had lower BMD both at lumbar spine (0.763 ± 0.116 gm/cm2 vs. 0.938 ± 0.153 gm/cm2, p < 0.001), total-body-less-head (0.696 ± 0.087 gm/cm2 vs. 0.761 ± 0.187 gm/cm2, p = 0.002) and non-dominant distal radius (0.592 ± 0.063 gm/cm2 vs. 0.690 ± 0.081 gm/cm2, = 0.006) compared to healthy controls. However, the differences disappeared at all sites following adjustment of the BMD values for stature using the bone mineral apparent density (BMAD) (0.275 ± 0.032 gm/cm3 vs. 0.286 ± 0.047 gm/cm3, p = 0.357) and height adjusted Z scores (-0.9 ± 1.3 vs. -1.5 ± 3.9, p = 0.496). The lower beta-CTX values in TS indicated reduced bone resorption. (0.81 ± 0.37 ng/mL vs. 1.05 ± 0.59 ng/mL, p = 0.036).

CONCLUSION

When adjusted for stature, bone mineral density in Turner Syndrome is not different from that of healthy girls of the same age.