Exocrine Pancreatic and β-cell Function in Malnutrition-Related Diabetes Among North Indians

OBJECTIVE To compare the pancreatic exocrine and β-cell function in the two variants of malnutrition-related diabetes mellitus (MRDM): fibrocalculous pancreatic diabetes (FCPD) and protein-deficient pancreatic diabetes (PDPD).

RESEARCH DESIGN AND METHODS Fecal chymotrypsin (FCT) and fasting C-peptide levels were measured in 20 consecutive patients with FCPD and 19 with PDPD. FCPD was diagnosed by pancreatic calcification on ultrasonography, while the diagnosis of PDPD was made on the basis of low body mass index, severe diabetes requiring insulin therapy, and ketosis resistance on interruption of insulin. Twenty patients with type I diabetes and 32 healthy subjects served as control subjects.

RESULTS Both FCPD and PDPD patients had diminished levels of FCT when compared with those of control subjects and patients with type I diabetes. However, FCT levels were significantly lower in subjects with FCPD (median 0.4 U/g, range 0–8.9 U/g), in comparison with those with PDPD (4.7 U/g, 0.6–40.5 U/g; P < 0.001). Of the FCPD patients, 13 of 20 (65%) had severe exocrine pancreatic deficiency (FCT < 1 U/g) vs. 3 of 19 (15.8%) PDPD subjects (P < 0.01). In comparison with control subjects, fasting serum C-peptide levels were significantly diminished in both MRDM groups. However, C-peptide levels in subjects with FCPD (mean ± SE, 0.22 ± 0.04 nmol/l) and PDPD (0.26 ± 0.04 nmol/l) were comparable.

CONCLUSIONS Among the two variants of MRDM, subjects with FCPD have severe pancreatic exocrine deficiency in comparison with those with PDPD, even though their C-peptide levels are comparably diminished. This suggests that the pathogenesis of these two entities may differ or that the genetic and/or environmental factors leading to exocrine damage are different.