Prevalence Rate and Predictive Factors of Pancreatic Diseases in Cases with Pancreatic Duct Dilatation: A Cross-sectional Study of a Large, Healthy Japanese Population.

Objectives To clarify the significance of ultrasonographically recorded pancreatic duct dilatation. Methods Various parameters predicting pancreatic disease were evaluated in relation to pancreatic duct dilatation using data from medical checkups of healthy examinees. Results Records of 281,384 subjects were analyzed. Pancreatic duct dilatation (≥3 mm) was determined ultrasonographically in 524 patients (0.19%). Subsequent detailed examinations revealed the presence of pancreatic disease in 24.8% of these patients, including pancreatic cysts (15.6%) and chronic pancreatitis (4.9%). Pancreatic cancer was found in 6 cases (1.3%). Predictive factors of pancreatic diseases in examinees with pancreatic duct dilatation were investigated, and the diameter of the pancreatic duct (p<0.001) and HbA1c (p=0.003) were identified by a multivariate analysis. The diameter of the pancreatic duct (p<0.013), HbA1c (p=0.009), and body mass index (p=0.032) were identified as predictive factors in pancreatic cancer. The diameter of the pancreatic duct (p<0.001), age (p=0.006), and bilirubin (p=0.020) in pancreatic cyst as well as the diameter of the pancreatic duct (p<0.001), white blood cells (p=0.022), HbA1c (p=0.033), and alkaline phosphatase (p=0.043) in chronic pancreatitis were also identified. In patients with pancreatic duct dilatation, the optimal cut-off values were 3.5 mm and 6.1% for the pancreatic duct diameter and age, respectively, based on a receiver operating characteristic analysis. Conclusion In cases with ultrasonography-determined pancreatic duct dilatation, subsequent detailed examinations of the pancreas were necessary because of the high-prevalence rate of 24.8%. In particular, marked pancreatic duct dilatation (≥3.5 mm) and elevated HbA1c (≥6.1%) strongly suggest the presence of pancreatic diseases.