Abstract
Despite the increasing knowledge on the association between neighborhood and health, few studies have investigated sleep disorders in Japan, particularly the impact of neighborhood noise on sleep. Thus, this study aimed to investigate the associations between insomnia symptoms and annoyance because of traffic and neighborhood noise in Japan, which has different neighborhood conditions compared with those of the western societies. Neighborhood built and socioeconomic environments roles were also examined. We used nationwide cross-sectional data collected through a 2015 online survey of Japanese adults aged 20-64 years (n = 4,243). Adjusted prevalence ratios for insomnia according to the exposures were estimated using the multilevel Poisson regression models. The results showed that having insomnia was significantly associated with experiencing neighborhood and traffic-noise annoyance. Neighborhood noise had a stronger and independent association with insomnia. However, the neighborhood environmental variables, including population density, deprivation index, and access to commercial areas, were not associated with insomnia. In conclusion, noise annoyance, particularly that sourced from neighbors, is an important factor in relation to sleep health. Health and urban-planning policymakers should consider neighborhood noise, in addition to traffic noise, as health-related issues in residential neighborhoods.