1224-P: Glucagon Secretion Increases with Age in People with Type 2 Diabetes

It has been shown that the decline in the number of pancreatic beta cells and the insulin-secreting capacity of individual pancreatic beta cells progressively decreases with age, and this functional decline is accelerated by the addition of hyperglycemia. While, glucagon (GCG) is elevated in diabetes, and elevated GCG not only increases blood glucose levels (GLUs), but also decreases muscle mass due to protein metabolism leading to decrease in muscle glucose uptake, making blood glucose control more difficult. However, there are no reports yet regarding to age-related changes in GCG secretion. In this study, we analyze the age-related changes in GCG secretion in people with type 2 diabetes (T2D) after insulin treatment to remove glucose toxicity. A retrospective analysis was performed on people with T2D hospitalized for a period of 5 years from December 2017 in whom a test meal load (carbohydrate 75.5-70g, protein 8.5g, fat 28.5g) was performed before and after insulin treatment, and GLUs and GCG were measured. Insulin (IRI) and/or C-peptide (CPR) were also measured. A total of 121 patients (70 males, age 64.2 ± 11.6 years) were included in the analysis. After insulin treatment, GCG secretion was almost all lower than before treatment. GCG secretion increased with age (P=0.014). Insulinogenic Index decreased with age (R=-0.286 P=0.004), and IRI/GLU and CPR/GLU at 120 minutes after the test meal load also decreased with age (R=-0.314 P=0.001, R=-0.324 P=0.001). We confirmed that there is an increase in GCG secretion with aging in people with T2D. This might be one of the reasons for the decrease in muscle mass and physical activity in elderly people with T2D. Further studies are needed to expand the number including people with normal glucose and impaired glucose tolerance. Acknowledgments:The Cookie Testing Study Group provided support.