SERUM FRUCTOSAMINE CONCENTRATION AS AN INDEX OF GLYCEMIA IN CATS WITHDIABETES-MELLITUS AND STRESS HYPERGLYCEMIA

The purpose of this study was to evaluate fructosamine concentrations in clinically healthy cats, sick cats with stress hyperglycemia, and u ntreated diabetic cats to determine the usefulness of this test in dia gnosing diabetes mellitus in cats, and in differentiating the disease from stress-induced hyperglycemia. In addition, we evaluated if the de gree of glycemic control in cats treated for diabetes influenced their serum fructosamine concentrations. In the 14 sick cats with stress hy perglycemia, the median serum fructosamine concentration (269 mu mol/L ) was not significantly different from the median value in the 26 clin ically normal cats (252 mu mol/L). Two of the 14 cats with stress hype rglycemia (14.3%) had serum fructosamine concentrations above the uppe r limit of the reference range (175 to 400 mu mol/L); on the basis of these results, the test specificity was calculated as 0.86. In 30 cats with untreated diabetes mellitus, the median serum fructosamine conce ntration was 624 mu mol/L, markedly higher than the value in either th e normal cats or the cats with stress hyperglycemia. All but 2 of the 30 untreated diabetic cats (6.7%) had serum fructosamine concentration above the upper limit of the reference range; on the basis of these r esults, the sensitivity of serum fructosamine con centration as a diag nostic test for diabetes mellitus was 0.93. When 30 diabetic cats rece iving treatment were divided into 3 groups according to their response to treatment tie, poor, fair, and good), the 16 cats that had a good response to treatment had significantly lower serum concentrations of both glucose and fructosamine compared with cats that had either a fai r or poor response to treatment. A significant correlation (r(s) = .70 , n = 100, P < .001) was found between serum concentrations of glucose and fructosamine. Results of this study indicate that quantification of serum fructosamine concentration is a meaningful test for the diagn osis of diabetes, for differentiating diabetes from stress hyperglycem ia; and for monitoring the metabolic control in treated diabetic cats. Copyright (C) 1996 by the American College of Veterinary Internal Med icine.