Noise burden and the risk of myocardial infarction: false interpretation of results due to inadequate treatment of data.

AIMS Chronic noise exposure is associated with adverse pathophysiological effects and may contribute to the progression of cardiovascular disease. We, therefore, determined the risk of noise for the incidence of myocardial infarction. METHODS AND RESULTS In a case-control study, 4115 patients (3054 men, 56+/-9 years; 1061 women, 58+/-9 years) consecutively admitted to all 32 major hospitals in Berlin with confirmed diagnosis of acute myocardial infarction were enrolled from 1998 to 2001 in the Noise and Risk of Myocardial Infarction (NaRoMI) study. Controls were matched for gender, age, and hospital. In standardized interviews, information was obtained on environmental and work noise annoyance. The sound levels of environmental and work noise were assessed using traffic noise maps as proxy and international standards for workplaces, respectively. In multivariate logistic regression models, the adjusted odds ratios of noise variables were determined. There was a marginally increased risk of myocardial infarction associated with annoyance by environmental noise in women (adjusted odds ratio 1.47, 95% confidence interval 0.95-2.25, P=0.081) but not in men, and not associated with annoyance by work noise. Environmental sound levels were associated with increased risk in men and women (odds ratios 1.46, 1.02-2.09, P=0.040 and 3.36, 1.40-8.06, P=0.007) and work sound levels in men only (1.31, 1.01-1.70, P=0.045). CONCLUSION Chronic noise burden is associated with the risk of myocardial infarction. The risk increase appears more closely associated with sound levels than with subjective annoyance. Further investigation of the gender-related risk of noise exposure may aid in improving prevention.