Evaluation of Intensive Blood Glucose Control Using Glargine in Diabetic Cats
There are no reported studies of the outcome of long-term intensive blood glucose control in diabetic cats. The aim of this study was to determine the feasibility of such an approach, and if rigorous control of hyperglycemia soon after diagnosis was associated with higher remission rates.
Fifty-five cats diagnosed with diabetes mellitus were included in the study. Cats diagnosed with acromegaly were excluded. Fifty cats in the cohort were initially treated with other insulins (47 with procine lente insulin) for a median of 15 weeks, but failed to achieve remission prior to switching to glargine, and 43 of these cats were exclusively fed a low carbohydrate wet food diet.
Data were obtained from owners who joined the online German Diabetes-Katzen Forum and followed an intensive blood glucose regulation protocol using glargine. The aim was to achieve euglycemia (50-100 mg/dL as measured using a portable blood glucose monitor) using twice daily insulin dosing and a low carbohydrate wet food diet. Owners performed an average of 5 ± 2 blood glucose measurements per day, and supplied spreadsheets recording daily insulin dosages, blood glucose concentration and clinical information.
Thirty-five cats (64%) in the cohort achieved remission. The median time to remission was 59 days (1.9 months) after beginning the intensive protocol (range = 6 days to 10.2 months). Twenty-six cats (74% of remission cats) remained off insulin and the median duration of remission was 10.8 months (range = 2.8 months to 3.0 years). Nine (26% of remission cats) relapsed and required insulin again. Two of these relapsed cats achieved a second remission.
Twenty cats (36%) of the cohort required insulin throughout the study to control blood glucose concentrations and did not achieve remission. The median length of time on the protocol was 12.7 months (range = 2.6 months-2.1 years). The majority (70%; 14/20) of long-term diabetics were considered well regulated with a median blood glucose concentration of <150 mg/dL, 15% (3/20) were moderately well regulated (blood glucose <200 mg/dL) and 15% (3/20) remained difficult to regulate, which represented 6% of all cats in the study.
Asymptomatic hypoglycemia (blood glucose concentration <50 mg/dL) was measured in most (93%) cats at least once. However symptomatic hypoglycemia was rare, with only a single event in one cat which had mild signs (restlessness). Maximum insulin doses administered to cats in the study ranged from 1.00 to 9.00 IU twice daily.
Significantly higher remission rates occurred if the protocol for intensive glycemic control was initiated soon after diagnosis. The remission rate was 84% for cats started on the protocol within 6 months of diagnosis, and 35% for cats that began more than 6 months after diagnosis (P<0.001).
We conclude that intensive blood glucose control is a feasible and safe approach in cats, and that high remission rates are possible in previously treated cats if hyperglycemia is intensively managed using glargine within 6 months of diagnosis.