Relevance: Evaluation of bone metabolism is a new scientific direction in the study of the long-term effects of childhood obesity.
Objective: To study markers of bone metabolism in children and adolescents with obesity.
Materials and Methods: 74 children with overweight and obesity in accordance with the WHO criteria and 25 healthy children with an average age of 15.4[11.6;19.2] years and 14.9[11.5;18.3] years, respectively, were surveyed. The levels of markers of osteogenesis (osteocalcin) and bone resorption (β-crosslaps) in the blood by ELISA were determined for all children. Statistical processing was performed using non-parametric methods.
Results: The level of osteocalcin in children with overweight and obesity corresponded to 37.3[12.3;62.3] ng/ml, significantly different from that in the group of practically healthy children (70.4[38.2;102.6], P<0.05). The level below the reference values was observed only in overweight and obese children (54.1%). The level of osteocalcin depended on the duration of the disease: <10 years - 63.0[41.0;85.0] ng/ml, >10 years - 23.7[5.1;42.3] ng/ml (P<0.01), which is also argued by the correlation coefficient (ρ=-0.507, P<0.001). There were no significant differences in the level of the marker, depending on the degree of overweight and the presence of obesity complications.
The level of β-crosslaps in patients with overweight and obesity was also significantly different from the level in healthy children: 0.73[0.24;1.22] ng/ml and 2.05[1.11;2.99] ng/ml, respectively (P<0.01). The level below the reference values was observed only in patients with obesity (2.7%). With an increase in the duration of obesity, the level of the marker decreased: <10 years - 1.00[0.45;1.55] ng/ml, >10 years - 0.53[0.13;0.93] ng/ml (P<0.01), this dependence is confirmed by the correlation coefficient (ρ=-0.464, P<0.001).
The results indicate a low level of bone metabolism in patients with obesity. The balance of bone formation and bone resorption in osteocalcin/β-crosslaps ratio indicates a more significant inhibition of bone resorption in patients with obesity - 51.1[23.0;79.2] (in healthy children - 32.0[22.9;41.1]). However, as the duration of obesity increases, there is a simultaneous decrease in both bone formation and bone resorption: osteocalcin/β-crosslaps with a disease duration of less than 10 years - 56.2[39.3;73.1], over 10 years - 43.2[27,2;59.2], P<0.01.
Conclusion: The results can explain the mechanism of formation of osteopenia in obesity in children.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology