Abstract
AIMS: Hypersecretion of glucagon and reduced insulin secretion both contribute to hyperglycemia in type 2 diabetes (T2DM). However, the relative contributions of impaired glucagon and insulin secretions in glucose excursions at the various stages of T2DM development remain to be determined.
METHODS: The responses of glucagon and insulin as well as those of glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) were examined before and after ingestion of glucose or mixed meal in Japanese subjects with normal or impaired glucose tolerance (NGT and IGT) and in non-obese, untreated T2DM of short duration.
RESULTS: In OGTT, T2DM showed a rise in glucagon at 0-30min, unlike NGT and IGT, along with reduced insulin. In MTT, all three groups showed a rise in glucagon at 0-30min, with that in T2DM being highest, while T2DM showed a significant reduction in insulin. Linear regression analyses revealed that glucose area under the curve (AUC)0-120 min was associated with glucagon-AUC0-30 min and insulin-AUC0-30 min in both OGTT and MTT. Total and biologically intact GIP and GLP-1 levels were similar among the three groups.
CONCLUSIONS: Disordered early phase insulin and glucagon secretions but not incretin secretion are involved in hyperglycemia after ingestion of nutrients in T2DM of even a short duration.
Original language | English |
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Journal | Journal of Diabetes and its Complications |
Volume | 29 |
Pages (from-to) | 413-421 |
Number of pages | 9 |
ISSN | 1056-8727 |
DOIs | |
Publication status | Published - 2015 |