A national case-crossover analysis of the short-term effect of PM2.5 on hospitalizations and mortality in subjects with diabetes and neurological disorders

Abstract

BackgroundDiabetes and neurological disorders are a growing burden among the elderly, and may also make them more susceptible to particulate air matter with aerodynamic diameter less than 2.5 μg (PM2.5). The same biological responses thought to effect cardiovascular disease through air pollution-mediated systemic oxidative stress, inflammation and cerebrovascular dysfunction could also be relevant for diabetes and neurodegenerative diseases.MethodsWe conducted multi-site case-crossover analyses of all-cause deaths and of hospitalizations for diabetes or neurological disorders among Medicare enrollees (>65 years) during the period 1999 to 2010 in 121 US communities. We examined whether 1) short-term exposure to PM2.5 increases the risk of hospitalization for diabetes or neurological disorders, and 2) the association between short-term exposure to PM2.5 and all-cause mortality is modified by having a previous hospitalization of diabetes or neurological disorders.ResultsWe found that short term exposure to PM2.5 is significantly associated with an increase in hospitalization risks for diabetes (1.14% increase, 95% CI: 0.56, 1.73 for a 10 μg/m3 increase in the 2 days average), and for Parkinson’s disease (3.23%, 1.08, 5.43); we also found an increase in all-cause mortality risks (0.64%, 95% CI: 0.42, 0.85), but we didn’t find that hospitalization for diabetes and neurodegenerative diseases modifies the association between short term exposure to PM2.5 and all-cause mortality.ConclusionWe found that short-term exposure to fine particles increased the risk of hospitalizations for Parkinson’s disease and diabetes, and of all-cause mortality. While the association between short term exposure to PM2.5 and mortality was higher among Medicare enrollees that had a previous admission for diabetes and neurological disorders than among Medicare enrollees that did not had a prior admission for these diseases, the effect modification was not statistically significant. We believe that these results provide useful insights regarding the mechanisms by which particles may affect the brain. A better understanding of the mechanisms will enable the development of new strategies to protect individuals at risk and to reduce detrimental effects of air pollution on the nervous system.

Estimation of future PM2.5- and ozone-related mortality over the continental United States in a changing climate: An application of high-resolution dynamical downscaling technique

“…The PM 2.5 -related mortality metrics are provided based on the acute effect to the short-term exposure. These short-term metrics, including all-cause mortality, ischemic heart disease, and lung cancer, are also utilized in the recent published work about PM 2.5 -related mortality Smith and Gans, 2014;Zanobetti et al, 2014). For ozone, the annual ozone-related mortality is analyzed here instead of seasonal results, which is also adopted in the other climate study (West et al, 2007;Tagaris et al, 2009).…”

MECHANISMS IN ENDOCRINOLOGY: Main air pollutants and diabetes-associated mortality: a systematic review and meta-analysis

“…Those 12 studies involved a total of 582 197 events of diabetes-associated mortality (12,13,14,15,16,17,18,19,20,25,26,27). Of those 12 studies, there were five timeseries studies (12,14,19,25,26,27), five case-crossover studies (13,15,16,17,28) and two cohort studies (18,20). Four of these studies were from Canada (12,14,18,19,25), four from USA (13,16,27,28), two from Italy (15,17), one from Denmark (20) and one from China (26) ( Table 1).…”

“…Of those 12 studies, there were five timeseries studies (12,14,19,25,26,27), five case-crossover studies (13,15,16,17,28) and two cohort studies (18,20). Four of these studies were from Canada (12,14,18,19,25), four from USA (13,16,27,28), two from Italy (15,17), one from Denmark (20) and one from China (26) ( Table 1). All studies reported adjusted estimates, but the adjusted factors were of various types and different from each other ( Table 1).…”

“…All studies reported adjusted estimates, but the adjusted factors were of various types and different from each other ( Table 1). There were five studies evaluating PM2.5 (18,19,25,27,28), four studies evaluating PM10 (13,15,25,26), five studies evaluating NO 2 (14,17,19,20,26), three studies evaluating SO 2 (14,19,26), two studies evaluating O 3 (12,16) and two studies evaluating CO (14,19) respectively (Table 1). According to the quality of criteria, there were two studies with an excellent quality (18,20) and the other ten studies were of good quality (12,13,14,15,16,17,19,25,26,27,28) (Table 1).…”

Comment on Schwartz, J.; Dockery, D.W.; Neas, M.L. 1996. Is daily mortality associated specifically with fine particles?; J. Air Waste Manage. Assoc. 46: 927–939

“…They even made dose response their second key word in the abstract. In the abstract of a 2014 paper, they still called an ambient PM 2.5 concentration an ambient PM 2.5 exposure six times (Zanobetti et al, 2014). Correcting such misnomers could make their work more understandable to the informed reader.…”