Environmental exposure may increase heart disease risk as much as smoking, poor diet or obesity, the study suggests.
“It’s important for healthcare providers to recognise that environmental exposures may be under-appreciated risk factors for diseases such as sudden cardiac death and fatal coronary heart disease,” said Jaime E Hart, study lead author and an instructor in medicine at Brigham and Women’s Hospital and Harvard Medical School in Boston, Massachusetts.
“On a population level, living near a major roadway was as important a risk factor as smoking, diet or obesity,” Hart said.
While researchers previously found a modest increase in coronary heart disease risk among people who live near major roadways, the new study may be the first to examine the impact of roadway proximity to the risk of sudden cardiac death.
Researchers noted that roadway proximity could be a marker for exposure to air pollution.
They studied data from 107,130 women (predominately white, average age 60) who were part of the Nurses’ Health Study from 1986-2012.
The researchers calculated residential distance to roadways and adjusted for a large number of other factors including age, race, calendar time, cigarette smoking, physical activity and diet.
They found that in 523 cases of sudden cardiac death, living within 50 metres of a major road increased the risk of sudden cardiac death by 38 per cent, compared to living at least 500 metres away.
Each 100 metres closer to roadways was associated with a 6 per cent increased risk for sudden cardiac death.
In the 1,159 cases of fatal coronary heart disease, risk increased 24 per cent.
The public’s exposure to major roadways is comparable to major sudden cardiac death risk factors, researchers said.
“Our next step is to try to determine what specific exposures, such as air pollution, are driving the association between heart disease and major roadway proximity,” said Hart.