Abstract P206: Dog Ownership and the Risk of Cardiovascular Disease: A Nation-wide Cohort Study
Introduction: Conflicting results surround the relationship between dog ownership and the risk of developing cardiovascular disease. Registration of dog ownership has been mandatory in Sweden since 2001 and it is estimated that 83% of dogs are registered. The aim of this study was to use the Swedish national dog registers to assess the association of dog ownership and incident cardiovascular disease.
Methods: The study cohort was defined from the Register of the Total Population including all Swedish residents aged 40-75 years in 2001. The personal identity number was used to link records to the Longitudinal Integration Database for Health Insurance and Labor Market Studies, the National Patient Register and the Cause of Death Register for socioeconomic variables and health outcomes. Dog exposure was defined as being registered or having a partner registered as a dog owner in either the Swedish Board of Agriculture and/or the Swedish Kennel Club dog registers. Study participants with cardiovascular events before baseline or immigrating to Sweden after 1987 were excluded. Outcomes were examined independently and included coronary heart disease, heart failure, ischemic stroke and hemorrhagic stroke. Cox proportional hazards regression using age as time-scale was used to calculate hazard ratios (HR) with 95% confidence intervals (CI). Study subjects were censored at death, emigration or 31st December 2012. Models were adjusted for sex, marital status, presence of children <18 years in the household, country of birth, province of residence, education level and income.
Results: The study population included 3 113 864 individuals, of whom 169 395 (5.4%) were dog owners. At baseline, the median age was 55 years in non-owners (interquartile range, IQR, 48 -62) and 52 years in dog owners (IQR 46-58). Dog ownership was inversely associated with hemorrhagic stroke (30 513 events, HR 0.93 [95% CI 0.88-0.98]), ischemic stroke (91 160 events, HR 0.94 [0.91-0.98]) and heart failure (67 740 events, HR 0.95 [0.91-0.99]). There was no association with coronary heart disease (165 275 events, HR 0.99 [0.97-1.01]).
Conclusion: Our study provides evidence that dog owners are at a lower risk for ischemic stroke, hemorrhagic stroke and heart failure. This relationship could be explained by a positive effect of dog ownership on daily exercise and psychosocial health or be due to unmeasured confounding. Although the cohort was free from cardiovascular disease at baseline, we cannot exclude the possibility that those individuals that buy a dog have better overall health than those that do not.
Author Disclosures: M. Mubanga: None. L. Byberg: None. E. Ingelsson: None. T. Fall: None.
- © 2016 by American Heart Association, Inc.