Air pollution and diabetes: it's time to get active!
Authors: Gary O'Donovan, Carlos Cadena-Gaitán
Journal: The Lancet Planetary Health (2018)

Cardiovascular disease, diabetes, chronic obstructive pulmonary disease, cancers, and other non-communicable diseases are among the leading causes of morbidity and mortality in low-income, middle-income, and high-income countries, and The Lancet Taskforce1Nugent R Bertram MY Jan S et al.Investing in non-communicable disease prevention and management to advance the Sustainable Development Goals.Lancet. 2018; 391: 2029-2035Summary Full Text Full Text PDF PubMed Scopus (183) Google Scholar recently made the case for investing in non-communicable disease prevention. Now, in The Lancet Planetary Health, Benjamin Bowe and colleagues2Bowe B Xie Y Li T Yan Y Xian H Al-Aly Z The 2016 global and national burden of diabetes mellitus attributable to PM2·5 air pollution: a longitudinal cohort study using the Global Burden of Disease 2016 data and methodologies.Lancet Planet Health. 2018; 7: e301-e312Google Scholar report that exposure to PM2·5 air pollution is indeed a risk factor for diabetes. In their adjusted models, a 10 μg/m3 increase in PM2·5 was associated with increased risk of diabetes (HR 1·15, 95% CI 1·08–1·22). There is the possibility of spurious associations in observational studies, but one of the strengths of Bowe and colleagues' study is the use of negative controls. Physical activity is a risk factor for diabetes, and one of the limitations of Bowe and colleagues' study is the absence of adjustment for physical activity. Whatever the strengths and limitations, Bowe and colleagues' study is another call for action. Liveable cities have been identified as a means of increasing physical activity and decreasing air pollution to help meet the Sustainable Development Goal of reducing premature mortality from non-communicable diseases by a third by 2030.1Nugent R Bertram MY Jan S et al.Investing in non-communicable disease prevention and management to advance the Sustainable Development Goals.Lancet. 2018; 391: 2029-2035Summary Full Text Full Text PDF PubMed Scopus (183) Google Scholar Hereafter, we describe some of the policies and interventions that might actually increase physical activity and decrease air pollution. The prevailing wisdom in high-income countries is that there are no successful community-wide physical activity interventions.3Baker PR Francis DP Soares J Weightman AL Foster C Community wide interventions for increasing physical activity.Cochrane Database Syst Rev. 2015; 1: CD008366PubMed Google Scholar, 4Bennie J Crane O Cullum A et al.Physical activity and the environment update. Effectiveness and cost-effectiveness evidence review 2: 'Ciclovia' and street closures, trails and safe routes to schools.https://www.nice.org.uk/guidance/gid-phg97/documents/evidence-review-2Date: 2017Date accessed: February 7, 2018Google Scholar However, one need only look to Latin America to know that this belief is mistaken.5Sarmiento OL Diaz Del Castillo A Triana CA Acevedo MJ Gonzalez SA Pratt M Reclaiming the streets for people: insights from Ciclovias Recreativas in Latin America.Prev Med. 2017; 103S: S34-S40Crossref PubMed Scopus (50) Google Scholar In Colombia, for example, the right to sport and exercise is enshrined in the constitution. The Ciclovía is the flagship programme, where roads are closed to motor vehicles on Sunday mornings and public holidays and are open to individuals for physical activities (figure). The Ciclovía in the city of Bogotá, Colombia, started in 1974 and progressively grew to a weekly programme. An average of more than 1 million people from all walks of life participate in each Ciclovía in Bogotá and the reasons given for taking part include for health, for fun, and to protect the environment.5Sarmiento OL Diaz Del Castillo A Triana CA Acevedo MJ Gonzalez SA Pratt M Reclaiming the streets for people: insights from Ciclovias Recreativas in Latin America.Prev Med. 2017; 103S: S34-S40Crossref PubMed Scopus (50) Google Scholar More than 40% of adult participants report more than 3 h of moderate to vigorous physical activity during a Ciclovía and most participants say they would not exercise if it were not for the Ciclovía.6Montes F Sarmiento OL Zarama R et al.Do health benefits outweigh the costs of mass recreational programs? An economic analysis of four Ciclovia programs.J Urban Health. 2012; 89: 153-170Crossref PubMed Scopus (66) Google Scholar The cost of the Ciclovía in Bogotá is mainly covered by the municipality5Sarmiento OL Diaz Del Castillo A Triana CA Acevedo MJ Gonzalez SA Pratt M Reclaiming the streets for people: insights from Ciclovias Recreativas in Latin America.Prev Med. 2017; 103S: S34-S40Crossref PubMed Scopus (50) Google Scholar and the benefits to these "weekend warriors" include a 30% reduction in all-cause mortality risk.7O'Donovan G Lee IM Hamer M Stamatakis E Association of "weekend warrior" and other leisure time physical activity patterns with risks for all-cause, cardiovascular disease, and cancer mortality.JAMA Intern Med. 2017; 177: 335-342Crossref PubMed Scopus (220) Google Scholar Medellín, Bogotá, São Paulo, and many other cities in Latin America have bicycle sharing schemes and the potential benefits of cycling to and from work include a 40% reduction in all-cause mortality risk;8Celis-Morales CA Lyall DM Welsh P et al.Association between active commuting and incident cardiovascular disease, cancer, and mortality: prospective cohort study.BMJ. 2017; 357: j1456Crossref PubMed Scopus (313) Google Scholar however, more needs to be done to separate cyclists from other road users and to reduce road traffic deaths in the region.9WHOGlobal status report on road safety 2015. Geneva: World Health Organization.http://www.who.int/violence_injury_prevention/road_safety_status/2015/en/Date: 2015Date accessed: June 5, 2018Google Scholar It is alarming that Bowe and colleagues2Bowe B Xie Y Li T Yan Y Xian H Al-Aly Z The 2016 global and national burden of diabetes mellitus attributable to PM2·5 air pollution: a longitudinal cohort study using the Global Burden of Disease 2016 data and methodologies.Lancet Planet Health. 2018; 7: e301-e312Google Scholar found that diabetes risk increased with PM2·5 concentrations much lower than those recommended by the WHO air quality guideline value of 10 μg/m3. Motor vehicles are one of the principal sources of PM2·5 air pollution and the transition to electric vehicles is urgently needed. This transition is challenging and the improvement of fuel quality is important in the short term. There is some evidence that the greatest reduction in emissions is achieved by reducing sulphur content in fuels.10Cooper E Arioli M Carrigan A Jain U Meta-analysis of transit bus exhaust emissions.Transp Res Rec. 2013; 2340: 20-28Crossref Scopus (4) Google Scholar The introduction of policies that guarantee the supply of ultra-low sulphur fuels would also complement the implementation of exhaust particle filters across heavy vehicle fleets because the effectiveness of filters is a function of the average sulphur concentration.11Partnership for Clean Fuels and Vehicles. Opening the door to cleaner vehicles in developing and transition countries: the role of lower sulphur fuels. http://wedocs.unep.org/bitstream/handle/20.500.11822/21551/opening_door_cleaner_vehicles_Summary.pdf?sequence=1&isAllowed=y (accessed June 5, 2018).Google Scholar Polices directed at limiting the use of vehicles must also be considered. Pico y placa (ie, rush hour and number plate) in Latin America, the ultra-low emission zone in London, UK, and other rotating driving prohibition schemes could contribute towards the reduction in air pollution, if only in the short term.12Cantillo V Ortúzar J Restricting the use of cars by license plate numbers: a misguided urban transport policy.DYNA. 2014; 81: 75-82Crossref Scopus (30) Google Scholar More research is required to determine the independent associations of physical activity and air pollution with diabetes and other non-communicable diseases;2Bowe B Xie Y Li T Yan Y Xian H Al-Aly Z The 2016 global and national burden of diabetes mellitus attributable to PM2·5 air pollution: a longitudinal cohort study using the Global Burden of Disease 2016 data and methodologies.Lancet Planet Health. 2018; 7: e301-e312Google Scholar, 13Cepeda M Schoufour J Freak-Poli R et al.Levels of ambient air pollution according to mode of transport: a systematic review.Lancet Public Health. 2017; 2: e23-e34Summary Full Text Full Text PDF PubMed Scopus (202) Google Scholar nonetheless, there is more than enough evidence to justify the implementation of policies and interventions that might actually increase physical activity and decrease air pollution, such as Ciclovías, free sport and exercise facilities, bicycle sharing schemes, electric vehicles, low sulphur fuels, exhaust filters, and driving prohibition schemes. We declare no competing interests. The 2016 global and national burden of diabetes mellitus attributable to PM2·5 air pollutionThe global toll of diabetes attributable to PM2·5 air pollution is significant. Reduction in exposure will yield substantial health benefits. Full-Text PDF Open Access