No heart health benefit seen for pet ownership

NEW YORK (Reuters Health) - A new study questions the idea that older people who own pets have healthier hearts than their pet-less peers.

Dr. Joel David Wright of the University of California, San Diego and colleagues found no difference in blood pressure or risk of high blood pressure (hypertension) between pet owners and non-pet owners, after they adjusted their analysis for the fact that pet owners were nine years younger, on average, than men and women who didn't currently own animals.

"The overall results of this study suggest that there is no beneficial effect of pet ownership on blood pressure in old age," Wright and his team conclude in the September issue of the journal Epidemiology.

Past studies on pets and heart health have yielded mixed results, they note. Some studies have found owning or being with a pet reduces blood pressure and helps people do a better job of coping with stress, while others have found no benefit.

To investigate, the researchers looked at 1,179 men and women between the ages of 50 and 95 years. All were surveyed in 1991-1992 about pet ownership, and had their blood pressures and other heart health indicators checked between 1992 and 1996.

Thirty percent of the study participants owned pets, while 55.6 percent had high blood pressure. On the first analysis, the researchers found that the pet owners indeed had lower blood pressures than the non-pet owners, and were 38 percent less likely to have hypertension.

But when the investigators adjusted for the relative youth of pet owners (they were 64, on average, while non-pet owners' average age was 73) the advantage of pet owning disappeared.

Some past studies that found owning an animal improved heart health didn't adjust for potentially confounding factors like age, Wright and colleagues point out.

"These results show the importance of adjustment for confounders, especially age, when examining blood pressure and related outcomes," they write.

SOURCE: Epidemiology, September 2007.