Study Identifies Environmental Risk Factors for Feline Diabetes Mellitus

Swedish researchers confirmed known risk factors and identified new potential risk factors for feline diabetes mellitus (DM) in a study recently published in the Journal of Veterinary Internal Medicine. The authors noted that this was the largest case-control study on feline diabetes to date.

The proportion of cats with diabetes has risen in recent years. The pathophysiology of feline DM typically resembles that of human type 2 diabetes mellitus (T2DM), which is characterized by impaired insulin secretion and increased insulin resistance. In addition, previous studies have reported similar risk factors between T2DM and feline DM, including obesity and physical inactivity; these two factors are thought to play primary roles in diabetes-associated insulin resistance in humans and cats.

The authors used a Swedish pet insurance company database to conduct a case-control study with diabetic cats (cases; n = 396) and birth-year—matched non-diabetic cats (controls; n = 1,670). The cats’ owners completed a web-based questionnaire with questions on owner and cat demography as well as potential DM risk factors (diet type, physical activity, body condition, indoor confinement). Questions were answered based on the year before the DM diagnosis for cases and on the last year of the cat’s life for controls.

Demographic Results

Nearly 85% of owners were female. The majority of households (80%) did not have children.

The majority of cats were domestic (81%) and neutered (98%). Most cats ate either a mixed food or dry food diet. Approximately two-thirds of the cats nibbled throughout the day, and about 15% immediately finished their meals (“greedy eaters”).

Univariable Analysis

Using univariate logistic regression, the authors identified several factors that either increased or decreased DM risk.

Factors that increased risk:

• Male
• Vaccinated
• Overweight
• Indoor confinement
• Greedy eating behavior
• No other household pets
• Predominantly dry food diet
• Previous corticosteroid treatment

Factors that decreased risk:

• Female
• Underweight
• Outdoor access
• Ad libitum feeding
• Dog in the household
• Rural living environment

Compared with domestic cats, Burmese and Norwegian breeds had a higher DM risk and Maine Coons, Persians, and Birmans had a lower DM risk.

Multivariable Analysis

Using multivariate logistic regression, the authors observed notable associations with DM risk.

Body condition and diet type:

• Regardless of diet type, the risk was higher for overweight versus normal weight cats.
• Risk increased for normal weight cats eating dry food versus wet food.

Physical activity and indoor confinement or outdoor access:

• Risk increased for moderately active and inactive cats with strict indoor confinement versus outdoor access.
• Risk decreased for inactive cats with partial outdoor access versus strict indoor confinement.
• Indoor confinement versus outdoor access did not affect risk for active cats.

Taken together, study results indicated that a dry food diet for normal weight cats and greedy eating behavior were potentially new risk factors for feline DM. It is possible that the dry food diet in normal weight cats increased the demand for insulin secretion, thus predisposing them to DM. However, because the diets’ nutrient contents were not known for this study, the reported association between dry food and DM for normal weight cats should be interpreted cautiously, wrote the authors.

A previous study reported a possible association between greedy eating and DM in Burmese cats. The current study’s authors proposed further investigation of this eating behavior as a risk factor for feline DM. Interestingly, rapid eating has been associated with T2DM in people.

In summary, the authors believed that “better knowledge on predisposing factors for feline DM is important to identify individuals at risk at an earlier stage and subsequently have a better possibility to prevent development of disease.”

Dr. JoAnna Pendergrass received her doctorate in veterinary medicine from the Virginia-Maryland College of Veterinary Medicine. Following veterinary school, she completed a postdoctoral fellowship at Emory University’s Yerkes National Primate Research Center. Dr. Pendergrass is the founder and owner of JPen Communications, LLC, a medical communications company.