Association of Calcium and Phosphate Balance, Vitamin D, PTH, and Calcitonin in Patients With Adolescent Idiopathic Scoliosis

STUDY DESIGN: A cross-sectional study of 2 groups of patients with scoliosis, and an age-matched control group was conducted. Each of the groups such as patients with adolescent idiopathic scoliosis (AIS) as well as control group were divided additionally into 2 groups: premenarcheal and postmenarcheal girls. OBJECTIVE: The aim of the study was to determine the levels of 25-OH-vitamin D3, calcium and phosphate, parathyroid hormone (PTH), and calcitonin in serum of pre- and postmenarcheal girls with AIS and corresponding groups of scoliosis-free controls. SUMMARY OF BACKGROUND DATA: The primary etiology and pathogenesis of AIS remains unknown. It is assumed that vitamin D deficiency and genetic predisposition, for example, polymorphisms of vitamin D receptor, have a great significance. Vitamin D plays a key role in skeletal development and prevents bone atrophy, affects the absorption of calcium, maintains calcium-phosphate homeostasis, and the bone matrix mineralization. Its deficiency can result in a wide variety of skeletal deformities, low bone mass, and then leads to the disappearance of bone. Defects in trabecular bone structure and/or bone mineralization are the main features of scoliosis. Some studies have reported that Vitamin D deficiency is common among patients with AIS. The mechanism of Vitamin D action on scoliosis development is still unclear. METHODS: Determination of serum 25-OH-D3 levels was performed using high-performance liquid chromatography chromatography; concentrations of calcium and phosphate were measured using colorimetric methods, and concentration of PTH and calcitonin was measured using ELISA system. RESULTS: Reduction in the serum levels of 25-OH-D3 and calcitonin in girls with AIS compared with healthy girls was demonstrated. CONCLUSION: The phosphate-calcium balance and PTH level seem to be normal in patients with AIS. The calcitonin level in girls with AIS is 2-fold lower than in healthy subjects. It is possible that the deficiency of vitamin D can be involved in AIS. LEVEL OF EVIDENCE: 4.