ESPE Abstracts

Vitamin D is a steroid hormone, essential for the immune system and bone health. Given that sun exposure is meant to provide at least 80% of daily vitamin D requirements, the COVID-19 pandemic is likely to have a considerable influence on calcium metabolism We retrieved anonymized data on calcium metabolism parameters assessing the occurrence of subclinical hyperparathyroidism – subclinical nutritional rickets (PTH ≥ 45 pg/ml with normal serum Ca ≤ 10.5 mg/dl) in children and adolescents in the post-COVID-19 period (2022, 2023). Vitamin D [25(OH)D] cut-offs were defined as deficiency ≤20 ng/ml, insufficiency <30 ng/ml and sufficiency ≥30 ng/ml. 1138 children seen for the first time in the outpatient pediatric endocrinology clinic were enrolled, assessed for any reason, after excluding patients with any pathology that could interfere with calcium and vitamin D metabolism. Overall, 60.8% of children had 25(OH)D values <30 ng/ml: Notably, 18.3% and 42.5% of children had vitamin D deficiency and insufficiency, respectively. A statistically significant positive correlation was found between the incidence of vitamin D deficiency and age (P <0.05). Specifically, it was found that the age groups 6-11 and 12-16 had a lower mean value of vitamin D: 29.5±11.5 and 28.7±12.16 respectively, compared to the group 1-5: 31.1±13.6, while 40% of infants (<1 year of age) had vitamin D concentrations <30 ng/ml (38.7±19.3). In preadolescence, no differences were found between genders in vitamin D concentrations, however, in adolescence mean 25(OH)D was 2 ng/ml higher in males (P <0.05). A statistically significant negative correlation was found between BMI and 25(OH)D (R²=0.02, P <0.05). As expected, 25(OH)D levels decreased over the winter and autumn but increased in the summer and spring. Overall, 21.5% of patients had hyperparathyroidism (PTH > 45 pg/ml), 20.9% of them subclinical hyperparathyroidism (PTH ≥45 pg/ml and normal serum Ca levels). 45.1% and 28.4% of patients with hyperparathyroidism had vitamin D insufficiency and deficiency respectively. Linear regression was negatively statistically significant between 25(OH)D and PTH (R²=0.036, P <0.01). Our investigation identified a substantial number of patients with subclinical hyperparathyroidism (20.9%) whereas in a relevant study of our group, conducted before the COVID-19 pandemic (2016-2018), among 3060 children only 5% had subclinical hyperparathyroidism MON-541 Successful Treatment of Normocalcemic Hyperparathyroidism in Children. The COVID pandemic dramatically deteriorated Ca metabolism with possible unforeseen consequences in bone health, infections, autoimmune diseases, metabolic syndrome and cancer.