Most veterinarians and cat owners are well aware of the risk of diabetes in overweight or obese cats as they age. New research suggests that the overweight or obese condition in cats less than a year of age also experience insulin resistance that may pose a predisposition to the development of diabetes later in life.
Insulin resistance and the association of future risk of developing diabetes have been heavily researched in obese children. The link to diabetes and cardiovascular disease in this same group has also been heavily researched. Those findings have sparked the present campaigns to influence nutrition and activity behaviors in children to prevent these outcomes in later life.
As with children, perhaps obesity prevention and weight management early in life should have an equal or greater focus for veterinarians and cat owners than simply dealing with the 10-year-old fat cat.
New Research in Feline Diabetes
Researchers at the University of Zurich in Switzerland analyzed insulin sensitivity and body condition score (BCS) on the 9-point scale in a population of sexually intact cats from 3 to 8 months of age. Insulin sensitivity in animals is tested the same way it is in humans: by means of a glucose tolerance test. By challenging a subject with a glucose load, periodic glucose blood levels measure the amount of glucose moving from the bloodstream into the body cells. Since glucose can only penetrate the cell wall with the aid of insulin, changes in blood glucose levels reflects the activity of cell membrane receptors to recognize and respond to insulin. In other words, it demonstrates cellular insulin sensitivity. In diabetics, insulin sensitivity is significantly decreased and circulating glucose levels remain high.
In addition to assigning a weight phenotype (overweight vs. lean) to BCS scores, dual energy X-ray absorptiometry of DEXA (considered the gold standard) documented the percentage of body fat for each subject.
Not surprisingly, the researchers found that overweight cats of both sexes, defined by BCS or DEXA, had decreased insulin sensitivity by eight months of age as compared to lean cats of both sexes. As in children, the body of overweight or obese cats establishes early "programing" toward the development of diabetes. Notice that these were sexually intact cats that are not typically thought of as prone to diabetes. Most pets are sexually altered, which we know is a predisposing factor to obesity, making them more prone to these early changes.
Prevention Trumps Intervention for Feline Diabetes
Those of you who follow my posts know why successful dieting in cats is very difficult, especially in multi-cat households. Prevention is better than intervention after the fact.
Owners need to work with their veterinarians on nutritional strategies much earlier than is presently common — the initial kitten exam would be ideal. Cat owners need to re-think feeding behavior and institute multiple feedings, with hard-to-get-to stations and limited amounts of calories at much younger ages. Play behavior with laser lights and feather toys should become standard daily activities starting during "kittenhood" and continued throughout life.
Remember that preventing obesity not only reduces the risk of diabetes but also reduces the risks for cancer, osteoarthritis, kidney disease, cardiac and lung disease, chronic pancreatitis, and other inflammatory diseases.
Dr. Ken Tudor