Endocrine Abstracts

JOINT3639

Background: Precocious puberty (PP) is defined as the early onset of pubertal development, often leading to accelerated bone maturation and potential alterations in mineral metabolism. Understanding the interplay between bone mineral density (BMD) and calcium-phosphate homeostasis in this population is crucial for assessing long-term skeletal health. This study aims to evaluate factors influencing BMD and differences in calcium-phosphate metabolism among children with PP.

Methods: A cohort of 34 children (30 girls and 4 boys) diagnosed with PP underwent a comprehensive assessment, including dual-energy X-ray absorptiometry (DXA) to measure BMD at the spine (BMD Spine) and Total Body Less Head (BMD TBLH). Height-adjusted Z-scores (HAZ) were also analyzed. In addition, hormonal levels (IGF-1, androgens such as DHEAS, androstenedione, testosterone, 17-OH progesterone, and estradiol) and responses to an LHRH stimulation test at three time points were evaluated. Markers of calcium-phosphate metabolism—including total calcium, parathyroid hormone (PTH), alkaline phosphatase, inorganic phosphates, urinary calcium excretion, and vitamin D levels—were also analyzed. Statistical tests assessed correlations between these parameters and BMD.

Results: Decreased BMD was found in 10 out of 34 children, defined as HAZ <-1 (among which all 10 patients had reduced HAZ TBLH, and 5 of them had also reduced HAZ Spine). A significant positive correlation was observed between bone age, calendar age, body mass, PTH, and BMD Spine. Additionally, BMD TBLH showed strong positive correlations with bone age, testosterone, and IGF-1 levels. Children with reduced HAZ TBLH had higher levels of DHEAS compared to those with normal HAZ TBLH. However, no statistically significant differences were found in IGF-1, PTH, vitamin D levels, or other hormonal markers between children with reduced BMD and those with normal BMD. Furthermore, no significant impact of vitamin D insufficiency (<20 ng/ml) on bone mineralization parameters was observed (P>0.05).

Conclusion: Bone age, testosterone, and IGF-1 levels were strongly correlated with BMD in children with PP, highlighting their potential role in skeletal development. While vitamin D levels did not significantly affect BMD, distinct hormonal differences, particularly in DHEAS, were observed in children with lower BMD, indicating complex regulatory mechanisms in bone health in PP. These findings underscore the need for further longitudinal studies to assess the long-term impact of metabolic alterations on skeletal integrity.