Diagnostic Value of the PEI-Q and Pancreatic Ultrasound for Identifying Reduced Pancreatic Exocrine Function in Early Type 2 Diabetes

Background/Objectives: Pancreatic symptoms and structural abnormalities do not necessarily correspond to reduced exocrine function in type 2 diabetes mellitus (T2DM). We aimed to estimate the frequency of reduced fecal elastase-1 (FE-1) and examine its associations with gastrointestinal symptom burden and pancreatic ultrasound findings. Methods: This cross-sectional study included 251 Kazakh adults with T2DM of ≤5 years’ duration not receiving insulin therapy. FE-1 < 200 μg/g was classified as reduced. Symptoms were assessed using the Pancreatic Exocrine Insufficiency Questionnaire (PEI-Q). Model 1 included pancreatic dimensions, splenic vein diameter, and Wirsung duct dilatation; Model 2 included splenic vein diameter, duct dilatation, and PEI-Q score; Model 3 additionally adjusted for age, sex, BMI, and current smoking. Discrimination was assessed using ROC analysis, with paired DeLong comparisons and Holm adjustment. Results: Reduced FE-1 was identified in 59 participants (23.5%) and was associated with higher PEI-Q scores, smaller pancreatic dimensions, and more frequent Wirsung duct dilatation. In Model 3, duct dilatation (adjusted OR 5.388, 95% CI 2.346–12.376) and PEI-Q score (adjusted OR 2.089, 95% CI 1.043–4.187) were independently associated with reduced FE-1. PEI-Q alone showed limited discrimination (AUC 0.583); AUCs for Models 1, 2, and 3 were 0.771, 0.697, and 0.726, respectively. Model 2 did not significantly outperform Model 1, and Model 3 did not significantly outperform Model 2. Conclusions: Reduced FE-1 was identified in 23.5% of participants and was associated with symptom burden and selected ultrasound findings. PEI-Q alone showed limited discrimination, whereas models incorporating ultrasound variables showed higher AUCs. Neither PEI-Q nor pancreatic ultrasound can replace FE-1 measurement; external validation is required before clinical application.