The spectrum of pancreatic exocrine and endocrine (Beta-cell) function in tropical calcific pancreatitis

Abstract

Exocrine pancreatic marker (immunoreactive-trypsin) and endocrine Beta-cell function (plasma insulin and C-peptide during an oral glucose tolerance test) were studied in 40 subjects with tropical-calcific-pancreatitis [seven non-diabetic, seven with impaired-glucose-tolerance and 26 diabetic (fibro-calculous-pancreatic-diabetes)]. In non-diabetic and impaired-glucose-tolerance subjects there was evidence of active pancreatitis in some and exocrine function was partially preserved. Fibro-calculous-pancreatic-diabetic subjects showed severely diminished exocrine pancreatic function; none showed 'pancreatitic' elevation of immunoreactive-trypsin. Beta-cell function was preserved in non-diabetic and impaired-glucose-tolerance subjects; diabetic subjects showed variable Beta-cell function but it was severely diminished in more than 75%. Immunoreactive-trypsin and C-peptide were directly correlated (rs = 0.55, p less than 0.01). This cross sectional study demonstrates, for the first time, that the Beta-cell loss in tropical-calcific-pancreatitis is related to the exocrine loss. It suggests that diabetes in tropical-calcific-pancreatitis is either secondary to pancreatitis or that a common factor(s) acts simultaneously on both components.

Tropical Chronic Pancreatitis

“…Yajnik et al measured beta cell function in TCP patients with different degrees of glucose tolerance and found that plasma C-peptide concentrations were normal in those with normal or mildly impaired glucose tolerance. 108 In the diabetic group, the Cpeptide levels were scattered; they were severely diminished in some while in the rest some beta cell reserve was present.…”

Genetic aspects of tropical calcific pancreatitis

“…At presentation, almost all patients have markedly diminished exocrine function, though clinical steatorrhoea is uncommon [12,14,15]. Diabetes develops in >50% of patients with normal glucose tolerance over a 5-year period [16] and is associated with severe reductions in C-peptide [7,11,12,14].…”

Diabetes mellitus in tropical chronic pancreatitis is not just a secondary type of diabetes

“…Previous studies of endocrine pancreatic function in patients with chronic pancreatitis of the tropics have used a variety of non-specific endocrine function tests [3,4,[17][18][19][20][21], where certain results vaguely pointed towards a selective ß-cell dysfunction in the presence of preserved ·-cell function [2,3,4,22]. To elucidate this correlation, we chose to examine our study population with an arginine stimulation test, as this test is a powerful stimulus to pancreatic · and ß cells [23].…”

“…Pancreatic exocrine function was also examined in the population of interest using a variety of non-invasive function tests [4,17,18,26,27]. Although these tests are useful in a clinical setting, they are not suitable to precisely differentiate exocrine function, especially in early and moderate stages of chronic pancreatitis where their sensitivity and specificity are low.…”