Incidence of Diabetes Mellitus in Insured Swedish Cats in Relation to Age, Breed and Sex

Abstract

Background: Diabetes mellitus (DM) is a common endocrinopathy in cats. Most affected cats suffer from a type of diabetes similar to type 2 diabetes in humans. An increasing prevalence has been described in cats, as in humans, related to obesity and other lifestyle factors. Objectives: To describe the incidence of DM in insured Swedish cats and the association of DM with demographic risk factors, such as age, breed and sex. Animals: A cohort of 504,688 individual cats accounting for 1,229,699 cat-years at risk (CYAR) insured by a Swedish insurance company from 2009 to 2013. Methods: We used reimbursed insurance claims for the diagnosis of DM. Overall incidence rates and incidence rates stratified on year, age, breed, and sex were estimated. Results: The overall incidence rate of DM in the cohort was 11.6 cases (95% confidence interval [CI], 11.0-12.2) per 10,000 CYAR. Male cats had twice as high incidence rate (15.4; 95% CI, 14.4-16.4) as females (7.6; 95% CI, 6.9-8.3). Domestic cats were at higher risk compared to purebred cats. A significant association with breed was seen, with the Burmese, Russian Blue, Norwegian Forest cat, and Abyssinian breeds at a higher risk compared to other cats. No sex predisposition was found among Burmese cats. Several breeds with a lower risk of DM were identified. Conclusions and clinical importance: Our results verify that the Burmese breed is at increased risk of developing DM. We also identified several previously unreported breeds with increased or decreased risk of DM.