Diabetes Mellitus – The Final Chapter
Well, this week we will finally wrap up diabetes mellitus. I hope this has been a helpful series of blogs for you. Diabetes is certainly one of my favorite diseases to manage, and I have enjoyed talking about it.
Our final chapter will be on the role of nutrition in the management of feline diabetes mellitus. For those who don't know, my clinic cat, Truman, is also diabetic. He can be seen in the picture above.
Ultimately, the goal of dietary management is to control hyperglycemia, achieve or maintain an ideal body weight, and manage any concurrent illness. There are two basic types of diets that have been used to manage diabetic cats – high fiber and low carbohydrate. There are only a handful of studies that have been published to evaluate the diets, and most of those studies have actually evaluated the low carbohydrate diets. Nonetheless, we will talk about both types of diets today.
In some of the initial studies evaluating diet, Dr. Richard Nelson (one of the gurus of diabetes mellitus and other endocrine diseases in veterinary medicine) found that cats fed a high fiber diet had lower glucose concentrations before meals and 12 hours after meals when compared to cats fed a low fiber food. Another study evaluating a high fiber moist diet found that 41% of the cats experienced clinical remission of their DM (diabetes mellitus).
Soon afterwards, these findings were challenged by others when low carbohydrate/high protein diets were fed. The rationale behind this type of diets is that cats have evolved to eat a diet high in protein, high in moisture, and low in carbohydrates. Because of the changes in their metabolism to accommodate this type of diet, cats do not process carbohydrates very efficiently. In fact, humans and dogs will have elevations of glucose and insulin after a mo
derate carbohydrate meal for 2 – 5 hours, and cats can have elevations for 12 hours or more. The proponents for this type of diet usually recommend feeding a canned form of a low carbohydrate/high protein diet, and when evaluating the clinical trials in these studies, clinical remission of diabetes has ranged from 17 – 68%.
At the end of the day, the choice of diet composition (high fiber versus low carbohydrate) is not resolved. In cats that are overweight or obese, the high fiber diet may be more appropriate to aid in weight loss, and cats that are normal or underweight may benefit from the low carbohydrate diet.
Another dilemma in feeding diabetic cats is the form of diet. Canned foods can be lower in carbohydrates than dry foods, and they also contain more water, which makes the cats feel full. They are less energy dense because of the higher water content, reducing the overall calories of the diet, and feeding canned food only can result in improved weight control, probably the result of better calorie control with meal feeding. Some cats will not eat canned foods exclusively, and transitioning from a more typical dry diet to a canned diet can be difficult. In a multi-cat household, feeding canned food only may prove even more difficult.
Concurrent health problems must be taken into consideration when choosing a diet. Since most diabetic cats are older, they may have other illnesses. Low carbohydrate diets are higher in protein. For cats with kidney disease, these diets can speed progression of their disease and decrease their survival. High protein diets are also contraindicated in cats with liver disease. Since low carbohydrate diets are higher in fat and more calorie dense, they can worsen obesity, making diabetes more difficult to manage.
Last week we talked a little about changing diets for variety, and again, I want to stress that dietary consistency is most important. Eliminating variability is more likely to result in stable blood glucose concentrations.
To summarize, the goal of dietary management in feline diabetes is achieving and maintaining ideal body weight and improving blood glucose control. If we accomplish these goals, we may be able to discontinue insulin therapy. For diabetic cats that are normal in weight or underweight, a low carbohydrate/high protein diet will likely be the mainstay, but in overweight diabetics, a high fiber diet may be more helpful. Concurrent illnesses will factor into the dietary recommendation that is formulated by you veterinarian for your individual cat. If cats go into diabetic remission, we are likely to continue the diet that helped get there for the remainder of the cat’s life to prevent relapse of disease.