Aircraft noise and metabolic outcomes

Abstract

Background: Long-term aircraft noise exposure may increase the risk of cardiovascular disease, but no study has investigated chronic effects on the metabolic system. Aims: The aim of this study was to assess the associations between long-term aircraft noise exposure and body mass index (BMI), waist circumference and Type 2 diabetes. Furthermore, we aimed to explore the modifying effects of sleep disturbance. Methods: In this prospective cohort study, we followed 5 411 Swedish men and women living in five municipalities in Stockholm County for up to ten years between 1992 and 2006. Time-weighted average aircraft noise exposure around Stockholm Arlanda airport was estimated during the follow-up period based on residential history. Baseline and follow-up surveys, including questionnaires and clinical examinations, provided information on outcomes and confounders. Subjects with prediabetes or Type 2 diabetes were identified by an oral glucose tolerance test. We used linear and logistic regression models to assess statistical associations and adjusted the results for individual as well as area-based confounders. Results: Mean increase in BMI between baseline and follow-up was 1.10 kg/m2 (SD 1.99) and for waist circumference 4.40 cm (SD 6.45). In total, we identified 434 cases of prediabetes and 172 cases of Type 2 diabetes, corresponding to cumulative incidences of 8 % and 3 %, respectively. In the fully adjusted model, we found a statistically significant association between aircraft noise and change in waist circumference, with a 1.24 cm (95 % CI 0.62 to 1.85) increase per 5 dB(A) rise. No clear associations were found for BMI or Type 2 diabetes, although the risk for diabetes tended to be elevated among women; OR=1.60 (95 % CI 0.94 to 2.70) per 5 dB(A) rise. Sleep disturbances did not appear to modify the association with aircraft noise. Conclusions: Long-term aircraft noise exposure may be linked to metabolic outcomes, in particular change in waist circumference.