Objective <p>Low levels of Insulin-like Growth Factor 1 (IGF-1) are known risk factors for cardiovascular diseases. Left Ventricular Mass Index (LVMI) serves as an early predictor of adverse cardiovascular events. Obese children have relatively low concentrations of IGF-1 in their blood. To date, there is no research on whether there is a correlation between IGF-1 levels and LVMI in obese children. This study aims to investigate the potential correlation between IGF-1 and LVMI in obese children at a single center.</p> Methods <p>A total of 104 obese children were selected as the case group, while 61 healthy children undergoing physical examinations served as the normal control group. Anthropometric measurements, assessments of IGF-1, and cardiovascular metabolic factors were conducted. Echocardiographic examinations were also performed to calculate the LVMI.</p> Results <p>Compared to the control group, the obese group had significantly higher LVMI and significantly lower standard deviation scores for Insulin-like Growth Factor 1 (IGF-1 SDS). After controlling for confounding factors including total cholesterol (TC), triglycerides (TG), and uric acid (UA), there was a significant linear negative correlation between IGF-1 SDS and LVMI, and a significant linear positive correlation between homeostasis model of assessment for insulin resistance (HOMA-IR) and LVMI. Each unit increase in IGF-1 SDS resulted in a 16.1% decrease in LVMI (β = -0.161; <i>p</i> = 0.046), and each unit increase in HOMA-IR resulted in a 24.1% increase in LVMI (β = 0.241; <i>p</i> = 0.007).</p> Conclusion <p>IGF-1 and LVMI exhibit an independent negative correlation. Monitoring IGF-1 levels might provide valuable insights into the cardiovascular health of obese children, facilitating early identification and management of cardiovascular risk factors.</p> Clinical trial number <p>Not applicable.</p>