# Bone Mineral Density Assessment by Dual-Energy X-Ray Absorptiometry (DEXA) Versus Serum Tartrate-Resistant Acid Phosphatase 5b (TRAP-5b) in Children With Classic Salt-Losing Congenital Adrenal Hyperplasia

## TL;DR

This study compares DEXA scans and TRAP-5b levels to assess bone health in children with adrenal hyperplasia on steroid therapy.

## Contribution

The study introduces TRAP-5b as a potential diagnostic marker for bone disease in children with congenital adrenal hyperplasia.

## Key findings

- Children with CAH had significantly lower BMD in the vertebrae and femoral neck.
- TRAP-5b levels were significantly higher in patients with abnormal BMD, indicating increased bone resorption.

## Abstract

Chronic glucocorticoid (cGC) therapy is a leading cause of drug-induced osteoporosis, often resulting in severe bone loss. Bone mineral density (BMD) is maintained by a dynamic balance between bone formation and resorption, regulated by various hormones, vitamin D, and cytokines. BMD is typically measured using dual-energy X-ray absorptiometry (DEXA). Tartrate-resistant acid phosphatase 5b (TRAP-5b) serves as a biomarker of bone resorption and is utilized to assess osteoclast activity. Objectives: This study aimed to evaluate BMD by measuring serum TRAP-5b levels in patients with congenital adrenal hyperplasia (CAH) receiving steroid therapy. Methods: Forty patients with CAH underwent DEXA scans to assess BMD. Patients were then divided into two groups: one with normal BMD (n=14) and the other with abnormal BMD (n=26). Serum TRAP-5b levels were measured as a marker of bone turnover. Results: Children with CAH had significantly lower BMD in both the vertebrae and femoral neck. TRAP-5b levels were significantly higher in the abnormal BMD group (2.95 U/L) compared to the normal BMD group (p<0.001), indicating increased bone resorption in CAH. Conclusions: Serum TRAP-5b activity may be a significant diagnostic and prognostic marker for bone disease in CAH.