Introduction: It is well known that low birth weight in children (born small for gestational age, SGA) predisposes them to the occurrence of obesity, insulin resistance (IR) and lipid disorders, observed even through the whole first decade of life. Thus, early diagnostics and prevention are very important. The HOMA index is used to assess insulin resistance (IRIHOMA). However, in some cases, high, prolonged postprandial insulin secretion is observed despite the low, adequate fasting glucose and fasting insulin levels. This can easily be assessed during the oral glucose tolerance test (OGTT). One of the indicators that properly analyses glucose and insulin levels during OGTT is Belfiore IR index (IRIBelfiore) in the modification intended for the pediatric population.
The aim of the study was to compare IRIHOMA (which evaluates fasting glucose and insulin) with IRIBelfiore (which evaluates glucose and insulin areas under the curve during OGTT) in children born SGA, being in the prepubertal period, in the first decade of life, in order to determine the usefulness of IRIBelfiore in the diagnosis of children with SGA.
Material and Methods: 126 children born as SGA, aged 6-8 years, with normal height were enrolled in the study. In each child, OGTT was performed after administering 1.75 g/kg of oral glucose. The glucose and insulin serum concentrations were evaluated at 0, 60th and 120th minute of the test. Based on the results, the IRIHOMA and IRIBelfiore were calculated. In addition, the body mass index (BMI), waist to height ratio (WHtR), lipids profile and blood pressure were assessed. IRIHOMA higher than 2.0 and IRIBelfiore higher than 1.27 was considered abnormal.
Results: No elevated IRIHOMA was observed in any of the children, while elevated IRIBelfiore was found in 13 children. The insulin concentration at 0 and 120th minute during OGTT showed a strong positive correlation with each other. What is more, a strong correlation was demonstrated between IRIHOMA as well as IRIBelfiore and: HDL-cholesterol, triglycerides, BMI, WHtR, and blood pressure.
Conclusions: Despite the normal fasting insulin concentration in children with SGA, there is an IR tendency, which can be demonstrated on the basis of OGTT results. In such cases, it seems advisable to use some methods to prevent IR complications already at this stage of children's lives. The result of the IRIHOMA is not a reliable diagnostic tool for children with SGA in the first decade of life.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology