The impact of insulin resistance and glycaemic control on Insulin like growth factor-1 in patients with type 2 diabetes: A cross sectional study

Abstract Background Type 2 diabetes mellitus is a complex metabolic disorder and over the last decade, scientific attention has been drawn to the potential role of Growth hormone (GH) and Insulin like Growth Factor-1 (IGF-1) in the pathogenesis and progression of T2DM. Both hormones are interrelated but exert variable effect on glucose homeostasis and while GH increases blood glucose level, IGF-1 maintain insulin secretion and enhance insulin sensitivity. Aim of study: To examine the effect of Insulin resistance and glycaemic control on IGF-1levels and asses other risk factors that affect IGF-1in type 2 diabetes mellitus. Methods A cross sectional study conducted in the National Diabetes Centre, Baghdad, Iraq, from May 2020 to May 2021. Sixty patients with types 2 diabetes were investigated for fasting plasma glucose (FPG), GH, lGF-1 HbA1c, HOMA-IR, HOMA-B and anthropometric measures after full history and physical examination focusing on any variable that could affect their metabolic profile. Patients with Type 1 diabetes mellitus, thyroid disease, pituitary disease, chronic kidney disease, hepatic disease and Pregnancy were excluded from our study. Results Patients with poorly controlled Diabetes and HbA1c > 8 had a significantly higher IGF-1 compared to those with HbA1c < 8 (166 vs 134, P = 0.016). The Mean of IGF-1 was significantly lower in patients with insulin resistance IR compared to those without IR 143 vs 192 P = 0.001, with a significant negative correlation with BMI and a significant positive correlation with HbA1c and with QUICKI. A high IGF-1 is seen with increasing age, duration of type 2 diabetes, higher HbA1c, higher quantitative insulin sensitivity index (QUICKI) and lower body mass index (BMI). No significant difference found in IGF-1 values with regards to HOMA-B, fasting insulin, and waist hip ratio. Conclusion patients with poorly controlled type 2 diabetes have higher levels of IGF-1 while those with Obesity and high insulin resistance have a lower IGF-1. Further prospective studies are needed to evaluate the role of using IGF-1 to lower insulin resistance and improve metabolic and glycemic measures in people with type 2 diabetes and obesity or insulin resistance.