You care about your heart, so you don't smoke, you eat a healthful diet and you exercise regularly. Maybe you should also lay off the negativity and controlling comments when you talk to your spouse.

A three-year study of older married couples conducted by psychologists from the University of Utah has found a link between the quality of relationships and atherosclerosis, or the narrowing of the arteries that carry blood to the heart.

In the study, reported at a psychology meeting last week, researchers evaluated videotapes of dialogue between 150 married couples. (At least one member of each couple was 60 to 70 years old.) Sitting across a table from each other, the couples were asked to talk about a subject of disagreement in their marriage, be it money, in-laws, children or household duties.

Two days later, husband and wife underwent a chest scan to determine their levels of coronary artery blockage.

The findings differed according to gender. For a woman, hostility in the marital relationship — whether on her part or her husband's — was associated with a buildup of plaque in the coronary arteries. For a man, the important factor was not hostility but control. Men who were controlling toward their wives, or had a controlling spouse, were more likely to have atherosclerosis.

"A low-quality relationship is a risk factor for cardiovascular disease," concludes study co-author Tim Smith of the University of Utah. However, it appears that men and women focus on different factors in gauging a relationship's "quality."