Noise levels related to heart attack risk

Living or working in noisy surroundings might increase a person's risk of suffering a heart attack. Researchers from the University Medical Centre in Berlin found that urban middle-aged adults who lived near high-traffic roads were 46 percent more likely to suffer a heart attack as compared to those who lived in more peaceful neighbourhoods. Similarly, men whose jobs exposed them to high levels of noise were about one-third more likely to have a heart attack than their peers who worked in quieter workplaces. The reason for these associations is not completely clear, but the stress of dealing with chronic noise might be involved. Previous studies have suggested that long-term exposure to traffic noise or loud workplaces such as factory floors might contribute to high blood pressure and heart attack risk. Loud noises act as a warning to the body and the normal stress response involves hormonal changes and a spike in blood pressure and heart rate. Researchers suspect that over time, chronic noise exposure might damage the cardiovascular system. The researchers analysed both the actual sound levels of neighbourhoods and workplaces and study participants' perceptions of the noise. The study included 4,115 men and women, mostly in their 50s, who had been treated for a heart attack in a Berlin hospital. They were compared with a control group of adults, of the same age without a heart attack history. It was found that women who said they were annoyed by traffic noise around their homes were at greater risk of having a heart attack than those who stayed in quieter areas. But men's annoyance levels, at home or work, were unrelated to the heart attack risk. By objective measures - based on official traffic-noise data for Berlin, men and women who lived close to noisy roadways had an elevated heart attack risk. Objective measures of workplace noise were related to heart attack risk only among men. The gender differences may reflect the fact that men are more likely to work in particularly noisy industries, while women may be more likely to be home during the day and be annoyed by surrounding traffic. Even with a number of heart risk factors considered such as smoking, obesity and family history of heart attack, people with greater noise exposure had a higher risk of heart attack.