Pet Ownership, But Not ACE Inhibitor Therapy Blunts Home Blood Pressure Response to Mental Stress. Allen, K., B. E. Shykoff, and J. L. Izzo, Jr. Hypertension, 38, 815-820, 2001

Research has documented that, although ACE Inhibitors lower resting blood pressure, they do not diminish reactivity to mental stress. This study explored the degree to which a social support intervention (pet dogs and cats) can lessen cardiovascular reactivity to psychological stress among hypertensive patients treated with a daily dose of Lisinopril. Participants were divided into two equal groups: one group received only Lisinopril and the other received Lisinopril and also acquired a pet cat or dog. Before and during Lisinopril therapy, in-home reactivity tests measured each participant’s reactions to stressors such as mental arithmetic and speech tasks.

Six months after Lisinopril and pets were introduced, significant differences were found between the groups in their physiological reactions to stressors. For example, heart rate and blood pressure of individuals in both groups increased when the individuals were speaking, but for the individuals with pets present, the increase was much smaller than for the individuals without pets. The individuals with pets were about half as reactive to stressors as they were before they had pets, while the people with only Lisinopril had about the same level of reactivity. Mental arithmetic performance improved significantly among people with pets, and did not change among those without pets.

Self-reported social support was a significant predictor of reactivity to stress, both before and with Lisinopril. Those with high social support and pets had the lowest reactivity and those with low social support and no pets had the highest reactivity. This study documents the importance of social support in stress reactivity and supports previous research suggesting that pets can provide a type of social support.