ESPE Abstracts

Introduction: Bone mineral density (BMD) is affected not only by genetic and enviromental causes, but various hormonal factors. It seems reasonable to seek for dependencies between BMD and paediatric endocrinopathies. The aim of the study was to assess the frequency of decreased BMD in children with several endocrinological disorders and evaluate the influence of selected auxological and hormonal parameters on their BMD.

Materials and Methods: The participants of the study were children diagnosed at our Clinic over the last three years. In each patient additional total body less head (TBLH) and lumbar spine (Spine) DXA examination was carried out, as well as calcium, phosphates, vitamin D, PTH, osteocalcin, crosslaps concentrations were assessed. Basing on the height and body mass of each child, HSDS and BMISDS were calculated and the advancement of puberty was estimated according to the Tanner scale. In most patients TSH, FT4, FT3, IGF-1 (expressed as IGF-1 SDS) were marked and bone age (BA) was graded. The DXA examination was performed among all children.

Results: The analysis consisted of 148 children (73 girls and 75 boys) aged (mean±SD): 11.85 ± 3.34 SD, including 66 patients with short stature and 43 children with obesity. Throughout the group, reduced BMD (Z-Score <-1.0) was found in 53.3% children (based on TBLH) and 37.1% (based on Spine), with the highest frequency of decreased BMD observed in the short-stature group (88% according to TBLH i 53.7% according to Spine). A significant positive correlation was found between Z-score TBLH and: HSDS (r= +0.70), BMISDS (r= +0.64) and IGF-1 SDS (r= +0.49) as well as Z-score spine and: HSDS (r= +0.56), BMISDS (r= +0.55), IGF-1 SDS (r= +0.43). Vitamin D deficiency was found in 104 (69.8%) children (<20 ng/dl - in 44, 20-30 ng/ml - in 60 cases), but suprisingly there was a negative correlation between vitamin D levels and: Z-score TBHL (r= -0.43) and Z-score Spine (r= -0.33). A negative correlation was noted for these parameters in respect to the BA delay severity.

Conclusions: A high incidence of cases with reduced BMD is observed in children with endocrinopathies. It seems that deficient and excess in both height and body mass affect BDM. In children with short stature, these disorders may be additionally associated with reduced IGF-1 levels. On the other hand, in some cases the possibility of overdiagnosing reduced BMD may rise due to the lack of automatic BMD adjustment in the software of the densitometer for anthropometric measurements and BA.