Reduced Pancreatic Volume and β-Cell Area in Patients With Chronic Pancreatitis

Background & AimsChronic pancreatitis (CP) often leads to the development of diabetes. To understand better this pathogenic mechanism, we investigated whether islet cell area and pancreatic volume are reduced in CP patients, islet cell turnover increases in CP patients, and islet cells are less vulnerable to apoptosis than acinar cells.MethodsPancreatic tissues from 43 patients with CP and 27 controls were examined by immunohistochemistry and quantitative morphometry. Pancreas volume was determined using abdominal computed tomography data.ResultsThe pancreatic volumes were 64.9 ± 4.3 cm3 in CP patients and 82.3 ± 6.7 cm3 in controls (P = .035). β-cell areas were 0.69% ± 0.08% in CP patients and 0.97% ± 0.08% in controls (P = .017), whereas α-cell areas did not differ between the groups (P = .47). There were no differences in the frequencies of replication among groups of α-cells, β-cells, duct cells, or acinar cells nor were there differences in numbers of apoptotic α-cells or β-cells between CP patients and controls. However, CP patients had an ∼10-fold increase in numbers of apoptotic acinar cells compared with controls (P < .0001).ConclusionsPancreatic volume was reduced by 21%, and the area comprising β-cells was reduced by 29% in patients with CP. The lack of increased β-cells turnover in CP patients, despite an ∼10-fold increase in the number of apoptotic acinar cells, suggests that the damage to the pancreas is highly specific for the exocrine compartment and affects the endocrine islets to a lesser extent.