Bone Abstracts

Background/aims: Glucocorticoid treatment may influence bone and muscle development in patients with congenital adrenal hyperplasia (CAH). This study evaluates bone mineral density (BMD), bone geometry and muscle mass longitudinally throughout childhood.

Methods: Eighteen patients (ten males, eight females) with classical CAH were included. BMD, bone geometry and muscle mass were measured using peripheral quantitative computed tomography (pQCT) in prepubertal, midpubertal and postpubertal years.

Results: Mean age at first measurement was 9.70±1.95 years, at second 13.94±0.98 years and at third 17.03±1.11 years respectively. The corresponding bone ages were within a range of ±1 years for chronological age. In all, mean S.D. score for trabecular BMD decreased (from 0.77±1.24 to −0.32±1.12), whereas mean cortical BMD increased (from −0.40±1.39 to 0.74±1.18). Mean SD scores at first measurement for total (0.86±1.12) and medullary cross-sectional area (CSA) (2.10±1.17) were significantly elevated, also at all further time points, but decreased with time (Δ−0.802 and Δ −0.61 respectively; P<0.001). In all patients, S.D. score for relative cortical CSA (−1.32±01.16) was stable on a reduced level throughout childhood. After adjustment for lower height, muscle CSA was normal in all.

Conclusion: From childhood to adolescence we observed a reduction of trabecular BMD. There is an enlarged total and medullary CSA in CAH patients that decrease with time. Relative cortical CSA was reduced in all CAH patients. These longitudinal changes in bone geometry may have a long-term impact on bone stability.

Disclosure: The authors declared no competing interests.