Dog Ownership Reduces Mortality Risk, Especially in Heart Attack Patients

A new study from the Leadership Sinai Center for Diabetes is suggesting owning a dog could help patients live longer through reductions in risk for all-cause and cardiovascular mortality.

Investigators performed a review of previously published data and found dog ownership was associated with a 24% reduced risk of all-cause mortality, 65% reduced risk of mortality after a heart attack, and a 31% reduction in risk of mortality due to cardiovascular-related issues—results the investigators suggest highlight the impact of social isolation and lack of physical activity.

“Our findings suggest that having a dog is associated with longer life. Our analyses did not account for confounders such as better fitness or an overall healthier lifestyle that could be associated with dog ownership. The results, however, were very positive,” said lead investigator Caroline Kramer, MD, PhD, endocrinologist and clinician scientist at Leadership Sinai Centre for Diabetes at Mount Sinai Hospital.

In an effort to expand on previous data suggesting dog ownership reduces cardiovascular risk, investigators performed a systematic review and meta-analysis of literature—literature was obtained through a search of articles published in Embase and PubMed between 1950 and May 2019. For inclusion in the current analysis, studies needed to be done in a population aged 18 or older, present original data of prospective observational studies, evaluate dog ownership at baseline, and report all-cause mortality or cardiovascular mortality.

From the review, a total of 1155 studies were identified, of which 10 met inclusion criteria. Of these 10, 9 studies included all-cause mortality outcomes and 4 included cardiovascular outcomes. From the 10 studies included, investigators obtained information on 3,837,005 and included 3,833,041 participants in their main analyses.

Upon analyses, investigators found dog ownership was associated with a 24% reduction in risk for all-cause mortality compared to those who did not own a dog(RR, 0.76; 95% CI, 0.67-0.86). Investigators noted this association was significant when examining population-based studies(RR, 0.78; 95% CI, 0.68—0.88) and among individuals with prior coronary events(RR, 0.35; 95% CI, 0.17–0.69).

Additionally, investigators observed a significant decrease in the risk of death associated with dog ownership in a cohort of 6 studies, but there was significant heterogeneity in the individual estimates of the magnitude of the association (I2=97.6%, P<0.001). When restricting the analyses to studies evaluating cardiovascular mortality, investigators noted dog ownership resulted in a 31% risk reduction for cardiovascular death with no significant heterogeneity(RR, 0.69; 95% CI, 0.67—0.71; I2 5.1%).

In a related editorial, Dhruv Kazi, MD, associate director of the Smith Center at Beth Israel Deaconess Medical Center, wrote the results of the study indicate dog ownership could be a relatively risk-free way to potentially improve health outcomes, but it is not an undertaking recommended for all patients.

“Given the magnitude of the potential benefit—and likely little or no harm&mdash;these findings should encourage clinicians to discuss pet adoption with their patients, particularly those with preexisting cardiovascular disease and those living by themselves,” Kazi wrote. “But before leaping to the conclusion that increasing rates of dog ownership in the population will unleash enormous cardiovascular benefits, we should acknowledge that adopting a dog is a much larger undertaking than embarking on a new medical therapy.”

This study, “Dog Ownership and Survival A Systematic Review and Meta-Analysis,” was published in Circulation.