Among 88 unselected patients with
chronic pancreatitis 35% (95% confidence limits 25 to 46) had
insulin-dependent diabetes, 31% (21% to 41%) had non-
insulin-dependent diabetes or
impaired glucose tolerance (by intravenous
glucose tolerance test), and 34% (24% to 45%) had normal
glucose tolerance. B cell function measured by
C-peptide concentration after 1 mg
glucagon IV correlated with the pancreatic
enzyme secretion (meal stimulated duodenal
lipase content). B cell function was preserved to a greater extent (P less than .01), and
glycosylated hemoglobin and fasting level of
glucose were lower (P less than .01 to .05) in the 31 patients with pancreatogenic diabetes than than in 35 otherwise comparable patients with type I (
insulin-dependent) diabetes, yet daily
insulin dose was similar in the two groups.
Glucagon stimulated
C-peptide was inversely correlated to
glycosylated hemoglobin in
insulin-dependent patients with pancreatogenic diabetes and in type I diabetes. Since body mass indices were identical in the two groups, better glucoregulation was not due to reduced food intake or malabsorption in pancreatogenic diabetes. Rather residual B cell function and/or different secretion of other
pancreatic hormones in pancreatogenic diabetes may account for different metabolic control in type I
IDDM compared with
insulin-dependent pancreatogenic diabetes.