Hyperglucagonemia and impaired insulin sensitivity are associated with development of prediabetes and type 2 diabetes - A study from South India

Abstract Background and aims Glucagon levels and glucagon suppression in response to oral glucose load has not been elucidated at different stages of glucose intolerance in India. Methods A total of 81 subjects underwent OGTT and were classified into three groups as having normal glucose tolerance (NGT) (n = 23), prediabetes (PreDM) (n = 33), newly diagnosed diabetes (NDM) (n = 25). Insulin and glucagon at fasting, 30 and 120 min was measured by ELISA. HOMA-IR, measures of insulin sensitivity, early, late and overall glucagon suppression during OGTT was calculated. Results Plasma glucagon levels were higher at all-time points in the PreDM and NDM groups. Fasting glucagon levels were higher than post glucose load glucagon in all groups. There was a significant difference in the fasting(p = 0.001), 30 min(p = 0.004) and 120 min(p = 0.032) glucagon between the groups. HOMA-IR increased and insulin sensitivity decreased with worsening of glucose intolerance(p  Conclusion This study demonstrated higher fasting glucagon levels. Prediabetes and newly diagnosed diabetes individuals had higher glucagon levels, high insulin resistance and lower insulin sensitivity. Hyperglucagonemia may contribute to type 2 diabetes.