Environmental Risk Factors for Diabetes Mellitus in Cats

Abstract

Background: Diabetes in cats resembles type 2 diabetes in people. The etiology is not fully understood, but both genetic and environmental factors are believed to contribute.

Objectives: To assess the associations of environmental risk factors with diabetes in cats.

Animals: Cats with a diagnosis of diabetes (n = 396) insured by a Swedish insurance company during years 2009-2013, and a control group (n = 1,670) matched on birth year.

Methods: A web-based questionnaire was used in a case-control study. An invitation to participate was sent to owners of 1,369 diabetic cats and 5,363 control cats. The survey contained questions related to the cat's breed, age, sex, neutering status, body condition, housing, access to the outdoors, activity level, diet, eating behavior, feeding routine, general health, stressful events, other pets in the household, medications, and vaccination status. Data were analyzed by multiple logistic regression.

Results: Response rate was 35% for the diabetic group and 32% for the control group. Indoor confinement, being a greedy eater, and being overweight were associated with an increased risk of diabetes. In cats assessed by owners as being normal weight, there was an association between eating predominantly dry food and an increased risk of diabetes (Odds ratio 3.8; 95% confidence intervals 1.3-11.2).

Conclusions and clinical importance: Dry food is commonly fed to cats worldwide. The association found between dry food and an increased risk of diabetes in cats assessed as normal weight by owners warrants further attention.

Keywords: Case-control study; Dry food; Logistic regression; Type 2 diabetes.

Figure 1

Odds ratios for diabetes mellitus (cases n = 396, controls n = 1,670) from the multiple logistic regression analysis depending on breed, sex, vaccination status, corticosteroid injections, eating behavior, and only cats as pets in a household. Error bars represent 95% confidence intervals (CI).

Figure 2

Odds ratios for diabetes mellitus (cases n = 396, controls n = 1,670) from the multiple logistic regression analysis for the interaction between diet and body condition. Comparisons within each body condition group. Error bars represent 95% confidence intervals (CI).

Figure 3

Odds ratios for diabetes mellitus (cases n = 396, controls n = 1,670) from the multiple logistic regression analysis for the interaction between diet and body condition. Comparisons within each diet group. Error bars represent 95% confidence intervals (CI).

Figure 4

Odds ratios for diabetes mellitus (cases n = 396, controls n = 1,670) from the multiple logistic regression analysis for the interaction between activity level and indoor confinement or access to the outdoors. Error bars represent 95% confidence intervals (CI).