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

Abstract

Background and aimsGlucagon levels and glucagon suppression in response to oral glucose load has not been elucidated at different stages of glucose intolerance in India. MethodsA 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. ResultsPlasma 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 < 0.0001). The groups did not differ in terms of early glucagon suppression(p = 0.094). NDM group suppressed glucagon more than NGT from 30 to 120 min after glucose intake. ConclusionThis 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.