Diabetes mellitus and pancreatitis--cause or effect?

L. J. Davison

doi:10.1111/jsap.12295

Abstract

Diabetes mellitus and pancreatitis are two distinct diseases encountered commonly in small animal practice. Whilst the clinical signs of diabetes mellitus are usually unmistakeable, a firm diagnosis of pancreatitis can prove more elusive, as clinical signs are often variable. Over the past 10 to 15 years, despite the fact that the clinical signs of diabetes mellitus are remarkably consistent, it has become more apparent that the underlying pathology of diabetes mellitus in dogs and cats is heterogeneous, with exocrine pancreatic inflammation accompanying diabetes mellitus in a number of cases. However, the question remains as to whether the diabetes mellitus causes the pancreatitis or whether, conversely, the pancreatitis leads to diabetes mellitus--as there is evidence to support both scenarios. The concurrence of diabetes mellitus and pancreatitis has clinical implications for case management as such cases may follow a more difficult clinical course, with their glycaemic control being "brittle" as a result of variation in the degree of pancreatic inflammation. Problems may also arise if abdominal pain or vomiting lead to anorexia. In addition, diabetic cases with pancreatitis are at risk of developing exocrine pancreatic insufficiency in the following months to years, which can complicate their management further.

Highlights

SUMMARYDiabetes mellitus (DM) and pancreatitis are two distinct diseases encountered commonly in small animal practice
Ranging from humans (Larsen 1993), to dogs and cats (Hess and others 2000, Rand and others 2004), to a cow (Doherty and others 1998), a horse (Jeffrey 1968) and a sea lion (Meegan and others 2008). It is more than 100 years since the relationship between diabetes mellitus (DM) and pancreatitis was first described in the scientific literature (Opie 1901), yet it is still not clear which disease occurs first i.e. whether the DM is a cause or a consequence of the pancreatic inflammation (Cook and others 1993, Zini and others 2010b)
As the pathology of DM in cats relates to insulin resistance, which can be caused by a focus of inflammation within the body, it is not difficult to propose a causal role for pancreatitis in feline DM

Summary

SUMMARY

Diabetes mellitus (DM) and pancreatitis are two distinct diseases encountered commonly in small animal practice. Over the past 10-15 years, despite the fact that the clinical signs of DM are remarkably consistent, it has become more apparent that the underlying pathology of DM in dogs and cats is heterogeneous, with exocrine pancreatic inflammation accompanying DM in a number of cases. The question remains as to whether the DM causes the pancreatitis or whether, the pancreatitis leads to DM - as there is evidence to support both scenarios. The concurrence of DM and pancreatitis has clinical implications for case management as such cases may follow a more difficult clinical course, with their glycaemic control being ‘brittle’ as a result of variation in the degree of pancreatic inflammation. Diabetic cases with pancreatitis are at risk of developing exocrine pancreatic insufficiency in the following months to years, which can complicate their management further

INTRODUCTION

Pathogenesis of Canine DM

Pathogenesis of Feline DM

Pathophysiology of acute and chronic pancreatitis in dogs

Pathophysiology of acute and chronic pancreatitis in cats

The relationship between pancreatitis and DM in dogs

The relationship between pancreatitis and DM in cats

Clinical implications of the relationship between pancreatitis and DM

Findings

CONCLUSIONS