People in poor neighborhoods are more likely than those in well-to-do areas to have heart attacks, even when individual differences in income, education and occupation are taken into account, researchers say.
Dr. Ana V. Diez Roux of Columbia University looked at census blocks of 1,000 people in Jackson, Miss., Forsyth County, N.C., Washington County, Md., and suburban Minneapolis.
Whites in the poorest neighborhoods were 70 percent more likely to have heart attacks than whites in the best neighborhoods. Blacks in the poorest neighborhoods were 40 percent more likely to have heart attacks than those in the best.
The researchers offered a number of possible explanations.
"Neighborhoods may differ in the amount of tobacco advertising and in the availability and cost of healthful foods," they said. Parks and recreation areas may encourage people to get exercise, while a dangerous neighborhood makes them less likely to go outside. Noise, violence and poverty in bad neighborhoods create chronic stress, which can increase the likelihood of heart attacks.
Taking cholesterol levels, exercise and other medical and behavioral risk factors into account did not change the numbers much, Diez Roux said.
"We were surprised that the neighborhood effect was not reduced substantially when we controlled for risk factors," she said.
The percentages were taken from small numbers. For instance, there were 9.5 heart attacks per 1,000 people in a year among white men in the worst neighborhoods, versus 4.9 in the best. For black men, the figures were 9.8 and 6.4 among 1,000 people in a year.
Diez Roux reported her findings in today's New England Journal of Medicine.