Road traffic noise and risk for cardiovascular disease and diabetes

1. Road traffic noise and risk for cardiovascular disease and diabetes Mette Sørensen, Senior Researcher Danish Cancer Society Research Centre

2. Road traffic noise and MI • Wolfgang Babisch, Noise and Health, 2008 • Meta-analyses of 7 case-control and cohort studies on road traffic noise and myocardial infarction (MI) • Dose-response relationship No adjustment for air pollution Babisch W, Noise and Health 2008; 10:27-33

3. Road traffic noise and MI Two studies after 2008 included both road traffic noise and air pollution: Selander, Epidemiology, 2009 Road traffic noise increase risk for incident MI after adjustment for air pollution (modeled NO2) Beelen, Occup Environ Med, 2009 Before air pollution adjustment weak tendency to higher risk for mortality from IHD at road traffic noise > 65 dB After adjustment (BS, traffic intensity) no association Lund, April 2013

4. Stroke and diabetes • DIABETES • Stress and sleep disturbances has been associated with • Insulin resistance • High morning glucose • Appetite regulation • Type 2 diabetes • WHO: at least 171 million people worldwide have diabetes • STROKE • Many risk factors in common with MI • Major risk factor is hypertension • WHO: 15 million people suffer stroke each year Lund, April 2013

5. Hypotheses • Exposure to road traffic noise increase the risk for: • Incident myocardial infarction • Incident stroke • Diabetes • -> also after adjusting for air pollution Lund, April 2013

6. The cohort • Diet, Cancer and Health cohort • Enrolment in 1993-1997 • 160 725 persons aged 50-64 years invited • Copenhagen and Aarhus • 57 053 participated • Questionnaire (diet, smoking, alcohol, education etc.) • Weight, height and waist circumference measured Lund, April 2013

7. Noiseexposure • Addresses • Central Population Registry • Since 1971 all residents addresses (incl. change of address) recorded • All residential addresses between 1987 and 2006 using the PIN • Complete address history for ≈ 54 000 participants • All in all ≈ 62 000 addresses • Geocoded Lund, April 2013

8. Noise exposure • SoundPLAN – the Nordic Prediction Method • Geographical coordinates for each address (≈ 62 000 addresses) • Height (floor) for each address • Building polygons • All road lines with > 1000 vehicles • Traffic composition (heavy/light) • Yearly average daily traffic • Traffic speed Lund, April 2013

9. Road noise at enrolment Lund, April 2013

10. Air pollution • Danish AirGIS modeling system • Dispersion model • At each address from 1987 until 2006 • Calculates the sum of: local, urban background and regional background contributions • NOx: indicator of air pollution; correlates with traffic such as ultrafine particles (r = 0.93) and PM10 (r = 0.70) Lund, April 2013

11. Identification of cases • Myocardial infarction (MI) and stroke • Danish National Hospital Registry (1977): • registers ALL discharges from Danish hospitals • follow-up cohort using PIN (censoring in 2006) • MI: also validation using medical records • Primary event - exclude participants with stroke/MI before enrolment • In total 1881 stroke cases and 1600 MI cases Lund, April 2013

12. Identification of cases • Diabetes • The National Diabetes Registry (1995) • Registers all diabetes based on information from other registers: • Hospital admission (National Hospital Registry) • Medication (National Prescription Registry) • Reimbursement for chiropody due to diabetes (National Health Service Registry) • Blood glucose tests (National Health Service Registry) • In total 3869 cases • Exclude participants with diabetes before enrolment (questionnaire) Lund, April 2013

13. Design • Cox proportional hazard model • Follow-up until: stroke/MI/diabetes (event), death, emigration or censoring (June 2006) • Age underlying time • Road traffic noise: time-varying - annual mean of Lden at the address at time of diagnosis (5-y preceding diagnosis) • Adjustment: • sex, calendar-year, socioeconomic factors, railways and airport noise, air pollution (NOx) • Lifestyle confounders, e.g. smoking status, BMI and intake of fruit, vegetables and alcohol Lund, April 2013

14. Results, stroke/MI * P interaction (< 0.001) Adjusted for age, sex, BMI, lifestyle habits, socioeconomic factors, railway and airport noise, air pollution Lund, April 2013

15. Results, rcs Stroke Myocardialinfarction Lund, April 2013

16. Results, stroke age Lund, April 2013

17. Results, diabetes * Exclusion of cases only included in the National Diabetes Registry based on blood glucose tests. Adjusted for age, sex, BMI, waist circumference, lifestyle habits, socioeconomic factors, railway and airport noise, air pollution Lund, April 2013

18. Results, diabetes Lund, April 2013

19. Conclusions • Exposure to residential road traffic noise was associated with a higher risk for stroke, MI and diabetes • For stroke the association was strongest among the oldest • For stroke indications of threshold limit around 60 dB • For MI no threshold limit • For diabetes indications of level off around 65 dB Lund, April 2013

20. Strenghts • Large study with good power • Prospective design • Follow-up in nationwide registers • For MI – validation by medical records • Historical address information • Adjustment for air pollution Lund, April 2013

21. Weaknesses • No information on noise barriers • No information on the bedroom location • Stroke – no information on subtype (hemorrhagic/ischemic) • Diabetes – unknown whether type I or II (though exclusion of all diabetes before age 50) Lund, April 2013

22. Co-authors • Danish Cancer Society: • Ole Raaschou-Nielsen, Zorana Andersen, Rikke Baastrup, Anne Tjønneland • Danish EPA: Jørgen Jakobsen • Aarhus University, Denmark: Kim Overvad, Martin Hvidberg, Steen Jensen • Rambøll, Denmark: Kenneth Lillelund • Utrecht University, The Netherlands: Rob Beelen • FUNDING: • Danish EPA • Research Centre for Environmental Health, Danish Ministry of the Interior and Health • European Research Council, EU 7th Research Framework Programme (grant 281760) Lund, April 2013

23. Thank you for your attention