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.