ESPE Abstracts

Introduction: Mucopolysaccharidoses (MPS) are lysosomal storage diseases. The frequency of endocrinological problems such as osteoporosis and hypothyroidism among children with MPS is not known and there are limited studies. In this study, the clinical findings, bone health and other endocrine functions of patients with MPS diagnosis and access to current treatments were retrospectively evaluated.

Materials and Methods:This is a single-center prospective study.44 patients with a diagnosis of MPS were included. All patiens were performed following parameters: body mass index (BMI), BMI-SDS, hormonal analysis, the clinical findings. The relationship between 25-hydroxyvitamin D3(25(OH)D3) level and dual energy X-ray absorptiometry (DEXA) results, height growth rates were evaluated in patients. 25(OH)D3 levels were defined as normal for> 20 ng/ml, insufficiency for 12–20 ng/ ml, and deficiency for<12 ng/ml. Bone mineral density(BMD) measurements for the lumbar spine (L1–L4) were obtained using DEXA.

Results: The mean age of the 44 patients was 7.55± 4.18 years. Twenty-one (47.7%) were male. Thirty-nine patients were receiving enzyme replacement therapy. (4 with MPS-I, 2 with MPS-II, 2 with MPS-III, 11 with MPS-IVA, and 25 with MPS-VI). At the last control of the patients, height-SDS weight-SDS, BMI-SDS were as follows:-3.96±3.00,-2.22±2.36,0.65±1.20. Height-SDS was statistically lower than pre-treatment height-SDS(P=0.016). In total thirty-two(%72.72) patients had a short-stature, and twenty-two(50%) of them were underweight for their age. twenty-five(%56.8) had deficiency and insufficient level of 25(OH)D3. DEXA was performed in thirty-eight of these patients. BMD z-score of patients was-3.15±2.25. In twenty-five(%67,57) patients, it was <-2. However, after correction for height-for-age z score (HAZ), adjusted BMD z score was -1.02±1.28. In eight(21.6%) patients, it was <-2. The mean 25(OH)D3 level of the patients in whom DEXA could be performed was 19.64±8.43(<10-44.65)ng/mL. While the 25(OH)D3 level was 17.57±6.56 in patients with an age adjusted DEXA z-score below normal, it was 20.09±9.17 in those with a normal DEXA z-score. Although 25(OH)D3 level was found to be lower in those with a DEXA z-score below normal, the difference was not statistically significant (p =0.39).

Conclusion: The low BMD z-score prevalence reported with DEXA was misleadingly higher in children with MPS and short stature. To prevent exposure to unnecessary antiresorptive treatments in these children, the effect of severe short. No serious dysfunction was seen in other endocrine organs.