Triglyceride-glucose index and glycemic dynamics in pancreatic ductal adenocarcinoma: implications for disease progression and prognosis

Abstract Background To elucidate the relationship between the triglyceride-glycemic index (TyG) and clinical characteristics of pancreatic ductal adenocarcinoma (PDAC). Methods A total of 1,594 individuals diagnosed with pancreatic and periampullary neoplasms were categorized into four groups: PDAC-early ( n = 403), locally advanced PDAC (LAPC, n = 315), PDAC-late with distant metastasis ( n = 371), and other tumor types ( n = 505). TyG-high was defined as a TyG index greater than 8.81 in males and 8.73 in females. Results The prevalence of TyG-high status was highest in PDAC-early (68.48%), followed by LAPC (53.33%), and lowest in PDAC-late (44.47%). TyG-high status significantly predicted worse PDAC prognosis ( P = 0.0166), particularly in PDAC-late ( P = 0.0420). Despite similar blood glucose levels across PDAC groups ( P = 0.897), PDAC-early patients showed significantly higher rates of glycemic disturbances (56.33% vs. 32.28%) and TyG-high status (68.48% vs. 47.13%) compared to those with other tumors. Progressive increases in glycemic disturbances and TyG-high status were observed from benign to pre-malignant lesions and PDAC-early. PDAC-early patients at the pancreatic head exhibited higher rates of glycemic disturbances (58.12% vs. 33.33%, P < 0.0001), larger pancreatic duct diameters (0.4056 cm vs. 0.3398 cm, P = 0.0043), and poorer prognosis compared to periampullary cancers, although the TyG-high rate and body mass index were similar. Conclusion The TyG index exhibits a complex association with PDAC stages, profoundly shaping glycemic profiles. At the initial stages of PDAC, a notable elevation in TyG-high status and glycemic disturbances is observed. However, in advanced PDAC, while the TyG-high rate diminishes, abnormal glucose levels persist.