Metformin reduces insulin resistance and the tendency toward hyperglycaemia and dyslipidaemia in dogs with hyperadrenocorticism

Abstract

Hypercortisolism induces a state of insulin resistance that can occur concurrently with fasting hyperglycaemia,dyslipidaemia and diabetes mellitus. Metformin reduces hepatic glucose production and insulin resistance of theskeletal muscle and adipose tissue. The aim of this study was to evaluate the effects of metformin on the control ofmetabolic disorders of dogs with hyperadrenocorticism (HAC). Twenty-three dogs with HAC were randomly dividedinto two groups, consisting of a control group and a metformin group (10 mg metformin/kg/12 h). Both groupsreceived the same treatment for HAC. At baseline and 3 months, blood glucose, total cholesterol, triglycerides andinsulin concentrations, in addition to urinary cortisol:creatinine ratio, Homeostatic Model Assessment (HOMA) forinsulin sensitivity and β-cell function were measured. Dogs treated with metformin showed significantly reducedglycaemia, cholesterolaemia and triglyceridaemia. They also presented reduced hyperinsulinism and insulinresistance, as well as improved pancreatic β-cell function. The implementation of metformin as an adjuvant therapyis effective for the normalisation of metabolic disorders of dogs with HAC.