Ketosis resistant diabetes of the young: a profile of its exocrine and endocrine pancreatic dysfunction.

A subset of insulin requiring diabetes in the young (IRDY) is ketosis resistant. Its pathogenesis and pathophysiology remain ill defined. The current study was done to evaluate the exocrine and endocrine dysfunction in ketosis resistant young diabetics. Fecal chymotrypsin (unit/G), basal & stimulated c-peptide levels (pmol/ml) and sonographic evaluation of the pancreas were done in 59 IRDY patients: 34 ketosis resistant (KR) and 24 ketosis prone (KP). Fecal chymotrypsin levels in KR (11.1 +/- 3.4) and KP (10.3 +/- 5.1) were lower than in controls (22.4 +/- 7.3) (P < 0.01). KR subjects had better endogenous insulin reserves than KP subjects: the basal and stimulated c-peptide levels in KR patients (0.12 & 0.17) were higher than in KP subjects (0.06 and 0.07) (P < 0.05). A strong correlation was noted between the exocrine and beta cell dysfunction in KR subjects (r = 0.7, P < 0.05). Pancreas was smaller in KR and KP patients than in controls (P < 0.05) on sonography. Thus the resistance to ketosis is a reflection of the better preserved beta cell reserves in the KR patients. Loss of the trophic effect of insulin and associated malnutrition is responsible for their exocrine dysfunction.