Glucagon Test Is a Useful Predictor of Withdrawal From Insulin Therapy in Subjects With Type 2 Diabetes Mellitus

Abstract

There are many tests for evaluating endogenous insulin secretory capacity. However, there are only a limited number of studies that have examined in detail in clinical practice which method most accurately reflects the ability to secrete endogenous insulin especially in hyperglycemic state. The purpose of this study was to find the endogenous insulin secretory capacity and a possible predictor of insulin withdrawal in subjects with type 2 diabetes requiring hospitalization due to hyperglycemia. In the endogenous insulin secretory test during hospitalization, CPR, CPR index, and ΔCPR after glucagon loading were all significantly higher in the insulin withdrawal group. On the other hand, there were no difference in fasting CPR index, HOMA-β, SUIT, and 24-hour urinary CPR excretion between the two groups. In the glucagon test of the insulin withdrawal group, the cutoff value of ΔCPR was 1.0 ng/mL, the withdrawal rate of ΔCPR of 1.0 ng/mL or more was 69.2%, and the withdrawal rate of less than 1.0 ng/mL was 25.0%. In conclusion, it is likely that glucagon test is the most powerful tool for predicting the possibility of insulin withdrawal as well as for evaluating endogenous insulin secretory capacity in subjects with type 2 diabetes requiring hospitalization due to hyperglycemia.

Recovery from insulin dependence in immune checkpoint inhibitor‐associated diabetes mellitus: A case report

“…The present patient did not have a history of diabetes, but developed hyperglycemia with ketosis at acute onset. We confirmed his insulin dependence using a 24‐h urine collection and ΔCPR in the glucagon challenge test at onset 5,6 . He was diagnosed with ICI‐DM and insulin therapy was initiated.…”

C‐peptide index at 2 h post‐meal is a useful predictor of endogenous insulin secretory capacity and withdrawal from insulin therapy in subjects with type 2 diabetes

“…Fasting CPR, fasting CPI, HOMA‐β and SUIT were calculated from early morning fasting blood sampling on the day following admission. Based on previously published methods, 6 HOMA‐β was calculated as (fasting insulin level [μIU/mL] × 360)/(fasting blood glucose [mg/dL] − 63), and SUIT was calculated as 1500 × fasting serum CPR (ng/mL)/(fasting blood glucose [mg/dL] − 61.7). Glucagon testing was also performed using previously described methods 6 7.3 ± 3.0 days after admission.…”

“…Based on previously published methods, 6 HOMA‐β was calculated as (fasting insulin level [μIU/mL] × 360)/(fasting blood glucose [mg/dL] − 63), and SUIT was calculated as 1500 × fasting serum CPR (ng/mL)/(fasting blood glucose [mg/dL] − 61.7). Glucagon testing was also performed using previously described methods 6 7.3 ± 3.0 days after admission. Urine samples were collected 2–3 times for 24 h after admission, and the average 24‐h urinary CPR excretion was used for the present analysis.…”

“…Assessment of endogenous insulin secretory capacity helps to determine the treatment strategy for patients with type 2 diabetes. Methods used to assess endogenous insulin secretory capacity include homeostatic model assessment of β‐cell function (HOMA‐β), 1 secretory unit of insulin in transplantation (SUIT), 2 24‐h urinary C‐peptide immunoreactivity (CPR) excretion, 3 fasting CPR, fasting C‐peptide index (CPI), 4,5 glucagon test 6 and arginine tolerance test. If pancreatic β‐cell function is reduced and endogenous insulin secretory capacity is depleted, a patient is in an insulin‐dependent state and requires insulin therapy 7 …”