Living With In-Laws Linked to Heart Risks in Japanese Women
Reported December 15, 2008Japanese women are generally not at high risk for heart attacks — unless they live with in-laws, according to a new study.
Married Japanese women who live with both their husbands and a set of parents — in Japan, that almost always means the husband’s parents, according to the researchers — were three times more likely to suffer a heart attack than those living just with their husbands.
Having children at home also was associated with an increased risk of heart attacks among Japanese women, but not by as much, the study found. When women lived with both parents and children, the risk of heart attacks doubled rather than tripled.
The heart attack risk was slightly higher among women living with both spouses and children, the study found.
The study was conducted by researchers at the Harvard School of Public Health and was published in this week’s issue of the journal Heart.
“We tend, in the West, to view family relations and social support as being protective of health,” said Dr. Ichiro Kawachi, an epidemiologist at the school and one of the study’s authors. “This is the first epidemiological study to show that these traditional living arrangements in Japan are rather harmful for women.”
He added, “If you’re balancing a spouse and children, it’s also a problem.”
Remarkably, however, the living arrangements do not affect men’s health.
“One of the overwhelming things that stands out is that it doesn’t matter for Japanese men what the living arrangements are,” Dr. Kawachi said. “They’re immune from the stresses in the home.” Young Japanese women are “voting with their feet” by postponing marriage and having fewer children, he added.
The researchers followed 91,000 Japanese men and women living in different household arrangements for more than 10 years. The participants ranged in age from 40 to 69 and had not been diagnosed at the start of the study with any serious illnesses, including heart disease, stroke or cancer.
By the end of the study, 671 participants had been diagnosed with coronary artery disease, 339 had died of heart disease, and 6,255 had died of other causes.
Women who lived with their spouses and parents, usually in-laws, were less likely to smoke or drink heavily, but were three times more likely to have had a heart attack, the researchers found.
They were not more likely to die of a heart attack than the women who lived alone with their spouses. Dr. Kawachi speculated that once the women fall ill, they begin to receive the support they need, in which case “having parents around is probably helpful.”
The results were adjusted to control for age, smoking and other factors.
“This is yet another study that shows a link between stress and increased rates of cardiovascular disease, although we don’t have the definitive study that proves it,” said Dr. Nieca Goldberg, a cardiologist specializing in women and author of the book “The Women’s Healthy Heart Program.”
An earlier study from Sweden found that marital stress increased the risk of heart disease for women, she noted. But emotional stress may be a marker for other risk factors and not necessarily a risk in itself, Dr. Goldberg added.
Dr. Kawachi said that the risk for heart attacks may not be quite as high among Japanese women who live with both parents and children, compared to those living just with parents, because parents may be helping with child care and other responsibilities, offsetting other stresses.