Do the Benefits of Dog Ownership on Cardiovascular Disease and Diabetes Extend to US Military Veterans?

A study published in Scientific Reports finds that dog ownership reduces the risk of cardiometabolic disease among US military veterans.

Background

Post-traumatic stress disorder (PTSD) increases the risk of cardiovascular disease and type 2 diabetes. PTSD has been found to associate with reduced cardiac contractility, cardiac ischemia, inflammation, and insulin resistance. Some lifestyle factors, including smoking, alcohol consumption, poor diet, and lack of physical activity, are believed to increase cardiometabolic disease risk in individuals with PTSD.

Dog ownership is known to improve cardiac health in the general population. Evidence suggests that dog ownership might be considered as an alternative intervention for improving PTSD condition. A large-scale study on the Swedish population found an association between dog ownership and reduced cardiovascular mortality risk over a follow-up period of 12 years.

In the current study, scientists have explored the effect of dog or cat ownership on the risk of cardiometabolic disease among US military veterans.

Study design

The National Health and Resilience in Veterans Study (NHRVS), which includes multiple online surveys, was initiated in 2011 to evaluate the association between psychological health and successful aging among US military veterans. Data from the most recent cohort (2019 – 2020) of the NHRVS was used in the current study.

A total of 4,069 veterans participated in the first survey in November 2019. The second survey, which included questions about dog and cat ownership, was conducted on 3,078 veterans in November 2020. 

The presence of certain cardiometabolic diseases, including heart disease, heart attack, high cholesterol, hypertension, stroke, and diabetes, was assessed in the surveys. The presence of lifetime PTSD, major depressive disorder, alcohol use disorder, nicotine use disorder, and substance use disorder were also assessed. Regarding lifestyle factors, the weekly frequency of physical exercise was assessed.    

Important observations

About 99% of survey participants responded about dog or cat ownership. Specifically, about 39% and 24% of participants responded affirmatively about dog and cat ownership, respectively.

The analysis of non-adjusted self-reported data revealed significantly lower prevalence of heart disease, high blood pressure, diabetes, and high cholesterol among dog owners compared to that among non-dog owners. However, no significant effect of cat ownership was observed on the prevalence of any cardiometabolic conditions.

Dog owners were found to be younger than non-dog owners and were more likely to be female. A higher prevalence of tested psychological disorders and addictive behaviors was observed among dog owners compared to that among non-dog owners. In addition, dog owners were found to be more physically active than non-dog owners.

The analysis of self-reported data after adjustment for age, sex, trauma load, psychological disorders, addictive behaviors, and exercise revealed that dog ownership is significantly associated with a lower risk of high blood pressure and high cholesterol.    

Considering participants’ physical exercise levels, the analysis revealed a reduction in heart disease risk with the induction of habitual exercise among dog owners. Moreover, dog owners showed a significantly lower risk of high blood pressure than non-dog owners, even with more lifetime traumatic events.

Considering the age of participants, the analysis revealed a higher risk of diabetes among dog owners over 80 years compared to age-matched non-dog owners. Similarly, a comparative higher risk of stroke was observed among dog owners aged over 70 years.

Among participants without nicotine use disorder, having a dog was found to reduce the risk of stroke. In contrast, an increased risk of stroke was observed among dog owners who had nicotine use disorder.

Study significance

The study reveals that having a dog may reduce the risk of high blood pressure and high cholesterol among US military veterans. However, a negative impact of dog ownership on the risk of diabetes and stroke has been observed among older veterans and those with nicotine use disorder. Future studies are needed to establish these correlations more firmly.

Overall, the study highlights the benefits of having a dog in terms of reducing the risk of PTSD-related cardiometabolic disease.