The Relation between CA 19-9 level and Early-Phase Insulin Secretion in Normoglycemic and Prediabetic Subjects

Background Carbohydrate antigen (CA) 19-9 is used as a clinical tumor marker of pancreatic cancer; recent studies report that CA 19-9 is also associated with changes in blood glucose levels. The aim of the present study was to investigate the relationship between serum CA 19-9 levels and early-phase insulin secretion in nondiabetic individuals. Methods We enrolled 269 normoglycemic participants and 172 prediabetic participants who had undergone the 75-g oral glucose tolerance test during their annual health examination. Insulin secretion was estimated using the disposition index (DI) [(Δinsulin(0-30 min)/Δglucose(0-30 min) × (1/HOMA-IR)], which is an adjusted measure of relationship between β-cell sensitivity and insulin sensitivity. Results Serum CA 19-9 level was significantly higher in the prediabetic participants than in the normoglycemic participants. Simple linear regression analysis showed a negative correlation between CA 19-9 levels and DI for all participants and prediabetic participants (r = -0.126, p = 0.009, and r = -0.189, p = 0.002, respectively). However, in the normoglycemic participants, CA 19-9 levels did not correlate with DI. For all participants, and prediabetic subjects, multivariate linear regression analysis revealed that serum CA 19-9 levels were one of the independent predictors of DI (adjusted β = -0.098, p = 0.025, and adjusted β = -0.177, p = 0.004, respectively). Conclusions Serum CA 19-9 levels significantly correlate with early-phase insulin secretion in the prediabetic individuals. Our results indicate that CA 19-9 may be involved in the endocrine function of pancreas.