ABSTRACT
Objectives To investigate the value of oral glucose tolerance (OGTT)-insulin/C peptide release test in early diagnosis of chronic pancreatitis (CP)-associated abnormal glucose tolerance.Methods Sixty patients with CP who were admitted to the Department of Gastroenterology,Changhai Hospital from June 2017 to February 2018 were divided into CP with normal glucose tolerance (CP-NGT),CP with impaired glucose tolerance (CP-IGT),CP with newly diagnosed diabetes(CP-new-DM) and CP with the previous history of diabetes (CP-history-DM) according to previous medical records and data from OGTT-insulin/C peptide release test.The characteristics of glucose metabolism,the changes of blood glucose,insulin and C peptide released among the four groups were compared.Results In 43 cases of patients with CP without diabetes,the abnormal glucose metabolism was detected in 6 cases (14.0％) by fasting blood glucose or glycosylated hemoglobin,and in 30 cases (69.8％) by OGTT-insulin/C-peptide release test.The detection rate of abnormal glucose metabolism was increased by 55.8％.In the group of CP-history-DM,the peak secretion of blood glucose,insulin,C peptide was all at 120 min,and the multiplication of increased release of C peptide (peak/baseline) [4.1 (3.4,4.4) vs (6.1 ± 2.2) 、(6.4 ± 2.5)、(6.8 ± 3.8)],the C peptide area under curve (C-PAUC) [(3.6 ± 1.4)]μg · h-1 · L-1 vs 8.6(7.1,9.7),(8.1 ±3.1),(6.9 ±2.7) μg · h-1 L-1] and the homeostasis model of assessment for β cell (HOMA-β) [24.4 (11.4,37.4) vs 52.4 (44.6,92.1),(89.8 ± 57.2),(72.4 ± 57.0)] were all significantly lower,and the difference was statistically significant(all P＜0.05).In the group of CP-new-DM,the peak of blood glucose was at 60 min,while the peak of insulin,C peptide was at 1 20 min,the early insulin secretion index (/ I30/A G30) [2.2 (0.8,4.2)vs (11.4 ± 9.4)] and insulin secretion sensitivity index-2 (ISSI-2) [256.1 (160.1,340.7) vs (548.5 ± 173.2)] in group of CP-new-DM were significantly lower than those in the group of CP-NGT,and the difference was statistically significant (all P ＜0.05).Conclusions The insulin /C peptide secretion was insufficient in the early stage of CP-related diabetes mellitus.Routine OGTT-insulin / C peptide release test for patients with CP can increase the detection rate of abnormal glucose metabolism.