IGF-1 Levels are Dependent on Age, but Not Weight Status in Children

Introduction: The intersecting pathways involved in linear growth, glucose, and lipid metabolism may play a key part in the imbalances leading to the dysmetabolic changes observed in obese children, and later adults. The growth-hormone/insulin growth factor 1 (GH/IGF-1) axis is a prime example in this regard and IGF-1 levels have been shown to correlate with insulin resistance. Objectives: The aim of this study is to examine whether there is a relationship between circulating IGF levels and weight status in children as an independent relationship, regardless of insulin sensitivity. Materials and method: We retrospectively collected data from patients aged 5-12 years referred to the Pediatric Clinical Hospital Sibiu between January 2010 and May 2023, for which IGF-1 levels were documented. We excluded patients with pathologies or medication which could have influenced weight status, glucose and lipid metabolism, or growth hormone secretion, and those with short stature or a growth velocity of under 5 cm a year. Anthropometric measurements were retrieved and BMI Z-score was calculated. Results: Our study included 66 patients (32 females and 34 males) with a mean age of 100,09 months (SD: 24,754 months). Initial bivariate analysis showed a significant negative correlation between BMI Z-score and IGF-1 values. However, adjusting for age indicated that there was in fact no significant relationship between these two parameters. Insulin-like growth factor 1 levels did however vary significantly with patient age. Conclusions: Levels of IGF-1 showed an age-dependent variation which should be accounted for in data analysis. Our study found no correlation between weight status and IGF-1 levels when adjusting for age-dependent variation. Further studies may shed light on the possible role of IGF-1 in discerning between obese children with or without increased insulin resistance.