THE RELATIONSHIP BETWEEN CONNECTIVE TISSUE DYSPLASIA AND OSTEOPENIA IN CHILDREN

The high prevalence of musculoskeletal disorders among children and adolescents determines significant interest from researchers and clinicians in these conditions. Among their causes are reduced bone mineral density (BMD) and undifferentiated connective tissue dysplasia (UCTD). The pathogenesis of both conditions may be associated with trace element imbalances.

To determine the frequency and pathogenetic relationships between UCTD and osteopenic syndrome in children.

The group of examined children included 375 respondents (137 boys and 238 girls) from 3 to 16 years old (average age - 10.8±0.2 years). The diagnosis of UCTD was made according to the criteria of the guidelines for "Hereditary Disorders of Connective Tissue Structure and Function." All children had determined their daily calcium and vitamin D intake. Objective criteria included blood levels of 25-hydroxyvitamin D (25(OH)D), calcium, and magnesium. Densitometry of the calcaneus was performed using a Sunlight 2000 device. The χ2 criterion was used to analyze contingency tables, including for arbitrary tables.

A strong association between osteopenic syndrome and the presence of UCTD was identified. When analyzing the effect of UCTD on the frequency of decreased BMD, the following statistically significant indicators were determined: χ²=37.580, critical value χ²=9.21, p<0.001. This level of significance was found between all three groups-absence of UCTD, grade 1, and grades 2-3. A significant increase in the frequency of insufficient dietary intake of vitamin D was observed in children with reduced BMD (χ²=15.848, critical value χ²=13.277, p=0.004). Similar associations were found for calcium intake (χ²=15.043, critical value χ²=13.277, p=0.005). Reduced magnesium levels were more characteristic of the subgroup of children with UCTD. For all three parameters, the highest frequency of deficiency was found in the group with a combination of osteopenic syndrome and UCTD. Differences compared to the group without pathological conditions were as follows: for 25(OH)D - RR=3.38 (χ²=47.408, critical value in all cases χ²=11.345; p<0.001), for calcium - RR=3.38 (χ²=35.831; p<0.001), and for magnesium - RR=3.38 (χ²=20.802; p<0.001).

The identified features of vitamin D, calcium, and magnesium intake and metabolism in children with combined decreased BMD and UCTD require special attention, as they may represent additional risk factors for the progression of these conditions and the development of complications. Their correction requires comprehensive pharmacological prevention with periodic monitoring of results.