Bone Abstracts

Objectives: Increased fracture risk and decreased bone mineral density (BMD) have been demonstrated by several studies in Turner syndrome (TS). Affected females have short stature and present with primary amenorrhea. Good densitometric predictor of fractures and longitudinal data on BMD development in childhood and adolescence are still lacking.

Patients and methods: Single tertiary care endocrinology center longitudinal study was performed. Peripheral quantitative CT (pQCT) scans at the forearm were performed in 33 girls with TS (median age 12.1 year, range 6.0–16.4 year) biannually for a period of 6 years. Trabecular volumetric BMD (vBMD) and cortical thickness were assessed at the 4 and 65% site, respectively. z-scores were calculated based on published references. The 6-year changes of both parameters were investigated in girls with TS with regard to reference data, the participant’s age of first measurement and an interview based fracture history. All TS girls were treated with recombinant human growth hormone. Oral oestrogen substitution was given to 27 participants, while the remaining six had spontaneous puberty.

Results: There were seven girls with prevalent fractures while three girls sustained at least one fracture during the follow up. The mean 6-year decrease in trabecular vBMD z-scores was 1.0±1.16 SDS (P<0.001), with no association with the ages of the first pQCT assessment (95% CI of beta estimate: −0.19–0.17) of the TS participants. There was no difference in 6-year change in trabecular vBMD between girls with and without positive fracture history (mean z-scores −0.73±0.81 and −1.08±1.24; P=0.42). We observed no significant 6-year changes in cortical thickness z-scores (−0.31±0.94, P=0.09) and no association of these changes with the ages of the first pQCT assessment (95% CI: −0.08–0.21). The fractured TS girls did not show different cortical thickness changes over 6 years of observation compared with the changes in non-fractured TS girls (mean z-score changes −0.15±0.56 and −0.35±1.03; P=0.55).

Conclusions: This longitudinal vBMD study in TS girls demonstrates that trabecular vBMD decreases with age, which may be due to the hypogonadism, despite providing the girls with widely accepted oral oestrogen substitution. Nor trabecular vBMD neither cortical thickness seem to be suitable for fracture prediction in TS.

Grant support: This work was supported by the Project (Ministry of Health, Czech Republic) for Conceptual Development of Research Organisation 00064203 (University Hospital Motol, Prague, Czech Republic).

Disclosure: The authors declared no competing interests.