Noise annoyance--a modifier of the association between noise level and cardiovascular health?

OBJECTIVES The effect modifying impact of annoyance due to aircraft noise and road traffic noise on the relationships between the aircraft noise level and road traffic noise level on the prevalence of hypertension was investigated in 4861 subjects of the HYENA study (HYpertension and Exposure to Noise near Airports). METHODS Different models were investigated either including the noise level and noise annoyance variables separately, or simultaneously, or together with an interaction term referring to the same noise source for the noise level and the noise annoyance. RESULTS Significant effect modification was found with respect to the association between aircraft noise and hypertension. The association was stronger in more annoyed subjects. No clear interaction was found with respect to road traffic noise. The comparison of the magnitude of the main effects (per standard deviation or inter-quartile range) of noise level and noise annoyance variables revealed stronger associations with hypertension for the noise levels. CONCLUSION There is some indication that the noise level has a stronger predictive meaning for the relationship between noise exposure and hypertension than the reported noise annoyance (main effects). The results from the Hyena study support the hypothesis that noise annoyance acts as an effect modifier of the relationship between the noise level and hypertension.