Use of low carbohydrate, high protein diets in cats with diabetes mellitus

The goal of this randomized, double‐blind study was to compare the effects of feeding a low carbohydrate, high protein diet versus a maintenance diet in a group of cats with diabetes mellitus treated with insulin glargine twice daily. All cats with naturally occurring diabetes mellitus not currently treated with insulin glargine or diabetogenic drugs or being fed a low carbohydrate, high protein diet were eligible for inclusion. Baseline testing included a physical examination, complete blood count, serum biochemistry profile, urinalysis and urine culture, serum thyroxine concentration, and serum fructosamine concentration. All cats were treated with insulin glargine (starting dose of 0.25 U/kg) twice daily. Insulin was adjusted as needed for glucose regulation. Cats were randomized to receive either a low carbohydrate, high protein diet or a feline maintenance diet. Re‐evaluations were performed on all cats at weeks 1, 2, 4, 6 and 10, and included an assessment of clinical signs, physical examination, 12‐h blood glucose curve, and serum fructosamine concentrations. Changes in continuous variables over the course of the study were analyzed using analysis of variance with repeated measures. p < 0.05 was considered statistically significant. Ten cats have completed the study. There were no significant differences between diet groups at baseline for age, gender, weight, body condition score, serum glucose or fructosamine concentrations. Although there was not a significant difference over time in clinical signs, insulin doses, or peak or nadir glucose concentrations between diet groups, diet did have a significant effect on serum fructosamine concentrations (p = 0.01). Six of the 10 cats that have completed the study achieved complete remission by the end of the study period, with no statistical difference between diets. The study's results indicate that diet can have significant effects on glucose regulation in cats receiving insulin glargine for treatment of feline diabetes mellitus.