Pancreatic insulin‐secreting carcinoma in a dog: Fructosamine for determining persistent hypoglycaemia

Abstract

A five-year-old intact male rottweiler was presented with a history of episodic weakness and mild-generalised seizures. A tentative diagnosis of an insulin-secreting tumour in the pancreas was made based on fasting hypoglycaemia with concomitant hyperinsulinaemia and a subnormal fructosamine value. The diagnosis was confirmed by exploratory coeliotomy, intravenous infusion of methylene blue, histopathology and immuno-histochemical analysis of suspected neoplastic tissue. Fructosamine assays are traditionally used for monitoring the metabolic status of diabetics where a single elevated measurement reflects persistent hyperglycaemia. This report suggests that a single low measurement of fructosamine may indicate persistent hypoglycaemia and may be helpful, in conjunction with an insulin measurement, in the diagnosis of insulin-secreting tumours.

Insulinoma in Dogs: A Review

“…30,31 Fructosamine concentration can be used as an indicator of chronic hypoglycemia as this parameter reflects the blood glucose concentrations over the previous 1-2 wk. [30][31][32] Initially used to evaluate chronic hyperglycemia in dogs with diabetes mellitus, several studies have reported that dogs with insulinomas do have significantly lower fructosamine concentrations than normal. [30][31][32] The turnaround time of this test varies between laboratories, but may take up to several days.…”

Reference Point: Exploring fructosamine beyond diabetes mellitus

“…107 This may be due to intermittent cortisol-induced peripheral insulin resistance while at the veterinary clinic; blood glucose concentration is in the normoglycemic range during these visits, yet is usually in the hypoglycemic range otherwise, resulting in decreased formation of fructosamine. 107 This may be due to intermittent cortisol-induced peripheral insulin resistance while at the veterinary clinic; blood glucose concentration is in the normoglycemic range during these visits, yet is usually in the hypoglycemic range otherwise, resulting in decreased formation of fructosamine.…”

The Endocrine and Metabolic Systems

“…Serum fructosamine concentrations may be below normal limits in a dog that has had frequent periods of hypoglycemia in the prior 2 weeks. 36 Normal fasting serum IRI levels in dogs are less than 30 μU/ml. The glucose/insulin ratio is generally sufficient for a diagnosis.…”