Objective: To characterize glycosylated hemoglobin (GHb) concentrations in the blood of dogs with disorders that may affect serum glucose or blood GHb concentrations, and to determine whether changes in GHb concentration correlate with changes in control of diabetes in dogs.
Design: Prospective study.
Animals: 63 healthy dogs, 9 dogs with anemia, 24 dogs with untreated hyperadrenocorticism, 12 dogs with pancreatic beta-cell neoplasia, 23 dogs with newly diagnosed diabetes mellitus, and 77 diabetic dogs treated with insulin.
Procedure: Control of diabetes in dogs treated with insulin was classified as good or poor on the basis of history, physical examination findings, changes in body weight, and measurement of serum glucose concentrations Sequential evaluations of control were performed and GHb concentration in blood was measured, by means of affinity chromatography, for 5 untreated diabetic dogs before and after initiating insulin treatment, for 10 poorly controlled diabetic dogs before and after increasing insulin dosage, and for 5 diabetic dogs before and after pancreatic islet cell transplantation.
Results: Mean (+/-SD) GHb concentration was 3.3 +/- 0.8% in the blood of healthy dogs. Compared with results from healthy dogs, mean GHb concentration was significantly lower in the blood of dogs with anemia and pancreatic beta-cell neoplasia and significantly higher in the blood of untreated diabetic dogs. Mean GHb concentration was significantly higher in the blood of 46 poorly controlled diabetic dogs, compared with 31 well-controlled diabetic dogs (7.3 +/- 1.8 vs 5.7 +/- 1.7%, respectively). Mean GHb concentration in blood decreased significantly in 5 untreated diabetic dogs after treatment (8.7 +/- 1.9 vs 5.3 +/- 1.9%). Mean GHb concentration in blood also decreased significantly in 10 poorly controlled diabetic dogs after control was improved and in 5 diabetic dogs after they had received a pancreatic islet cell transplant.
Clinical implications: Measurement of GHb concentration in blood may assist in monitoring control of diabetes in dogs.