ESPE Abstracts

Background: A positive association between osteoprotegerin (OPG) levels and cardiovascular morbidity and mortality has been recently reported. Additionally, there is evidence that OPG in obese adults participates in the pathogenesis of atherosclerosis and cardiovascular diseases by promoting inflammation, which is known to be linked to insulin resistance (IR). There is few data regarding the relationship among obesity-IR-OPG, in youth.

Objective and hypotheses: To assess serum OPG levels in obese children/adolescents and investigate possible association with IR.

Methods: A total of 160 participants (85 obese/75 healthy controls) aged 10.7 years (ranged: 2.6–17.8) were enrolled. Obese participants underwent an oral glucose tolerance test (OGTT), whereas IR was evaluated according to the homeostasis model assessment-IR index (HOMA-IR). Anthropometric measurements and serum OPG levels were assessed.

Results: Osteoprotegerin levels were increased in obese compared to controls, but this difference was not statistically significant (P=0.133). During correlation analysis, OPG levels were positively correlated to BMI-SD (r=0.24, p=0.028), fasting insulin levels (r=0.293, p=0.007), area under the curve for insulin during OGTT (r=0.224, p=0.046), HOMA-IR (r=0.289, p=0.009) and negatively associated to age (r=−0.22, p=0.043) among obese. Only obese-IR exhibited significantly higher serum OPG levels compared to controls and to obese-nonIR individuals, even after adjustment for BMI-SD and age (P=0.001). Serum OPG levels did not correlate to impaired glucose metabolism.

Conclusion: Insulin resistance may influence OPG levels in childhood obesity indicating a new interplay between them.