Glycemic Status and Predictors of Relapse for Diabetic Cats in Remission

Background: It is unknown if diabetic cats in remission have persistent abnormalities of glucose metabolism and should be considered prediabetic, or have normal glucose tolerance. Objective: To characterize glycemic status of diabetic cats in remission and to determine predictors of relapse. Animals: A total of 21 cats in diabetic remission and 28 healthy control cats. Methods: At a median of 107 days after remission, screening blood glucose concentration was measured on entry to the clinic. After a 24- hour fast in hospital, fasting blood glucose, fructosamine and feline pancreatic lipase concentrations were measured, and 3 hours later, a simplified IV glucose tolerance test ( 1 g glucose/ kg) performed. Twenty cats were monitored for relapse for at least 9 months. Results: Of the 21 cats in remission, 19% ( 4/ 21) had impaired fasting glucose concentration and 76% ( 16/ 21) had impaired glucose tolerance. Of cats followed up for 9 months after testing, 30% ( 6/ 20) had relapsed and required insulin treatment. Fasting blood glucose concentration = 7.5 mmol/ L (= 135 mg/ dL) ( odds ratio [ OR] = 12.8) and severely impaired glucose tolerance (= 5 hours to return to < 6.5 mmol/ L or < 117 mg/ dL; OR = 15.2) were significantly associated with relapse. Blood glucose concentration > 14 mmol/ L; 252 mg/ dL at 3 hours was significantly associated with relapse ( OR = 10.1). Conclusion and Clinical Importance: Most cats in diabetic remission have impaired glucose tolerance and a minority have impaired fasting glucose concentration and should be considered prediabetic. More severe glucose intolerance and impaired fasting glucose concentration are predictors of relapse. Ongoing glucose monitoring of diabetic cats in remission is recommended.