OBJECTIVE: Recent studies have drawn attention to the adverse effects of ambient air pollutants such as particulate matter 2.5 (PM2.5) on human health. We evaluated the association between PM2.5 exposure and diabetes prevalence in the U.S. and explored factors that may influence this relationship.

RESEARCH DESIGN AND METHODS: The relationship between PM2.5 levels and diagnosed diabetes prevalence in the U.S. was assessed by multivariate regression models at the county level using data obtained from both the Centers for Disease Control and Prevention (CDC) and U.S. Environmental Protection Agency (EPA) for years 2004 and 2005. Covariates including obesity rates, population density, ethnicity, income, education, and health insurance were collected from the U.S. Census Bureau and the CDC.

RESULTS: Diabetes prevalence increases with increasing PM2.5 concentrations, with a 1% increase in diabetes prevalence seen with a 10 ?g/m(3) increase in PM2.5 exposure (2004: ? = 0.77 [95% CI 0.39-1.25], P < 0.001; 2005: ? = 0.81 [0.48-1.07], P < 0.001). This finding was confirmed for each study year in both univariate and multivariate models. The relationship remained consistent and significant when different estimates of PM2.5 exposure were used. Even for counties within guidelines for EPA PM2.5 exposure limits, those with the highest exposure showed a >20% increase in diabetes prevalence compared with that for those with the lowest levels of PM2.5, an association that persisted after controlling for diabetes risk factors.

CONCLUSIONS: Our results suggest PM2.5 may contribute to increased diabetes prevalence in the adult U.S. population. These findings add to the growing evidence that air pollution is a risk factor for diabetes.

Diabetes Care. 2010 Oct;33(10):2196-201. Epub 2010 Jul 13.

Pearson JF, Bachireddy C, Shyamprasad S, Goldfine AB, Brownstein JS.
Children’s Hospital Informatics Program at the Harvard-MIT Division of Health Sciences and Technology, Boston, Massachusetts, USA.

We examined the relationship between use of progestagen-only before menopause (except for mini-pills) after the age of 40 and invasive breast cancer risk in 73 664 women from the French E3N cohort study (mean age at start of follow-up, 51.8 years; mean duration of follow-up, 9.1 years). A total of 2390 cases of invasive breast cancer were diagnosed during follow-up. Risk estimates were calculated using the Cox proportional hazard model. Overall, ever use of progestagen before menopause was not significantly associated with risk (relative risk (RR): 1.01, 95% confidence interval: 0.93-1.11). However, we observed a significant increase in risk associated with the duration of use (P-value for trend: 0.012), current use of progestagens for longer than 4.5 years being significantly associated with risk (RR: 1.44, 95% confidence interval: 1.03-2.00). Prolonged use of progestagens after the age of 40 may be associated with an increased risk of breast cancer and the subject needs to be investigated further.

Fabre A, Fournier A, Mesrine S, Desreux J, Gompel A, Boutron-Ruault MC, Clavel-Chapelon F.

Institut National de la Santé et de la Recherche Médicale, ERI 20, Institut Gustave Roussy, 39, rue Camille Desmoulins, F-94805 Villejuif, Cedex, France.

Br J Cancer. 2007 Mar 12;96(5):841-4. Epub 2007 Feb 13.

Links

Particulate matter (PM) air pollution is associated with an increased risk of cardiovascular morbidity and mortality. The focus of this review will be on the role that both acute and chronic exposure to PM plays in causing cardiovascular disease and on the latest major new findings and controversies in this field of research. Even short-term exposure to PM2.5 over a few hours can trigger myocardial infarctions, cardiac ischemia, arrhythmias, heart failure, stroke, exacerbation of peripheral arterial disease, and sudden death. Chronic exposure to moderately elevated levels also enhances the risk for developing a variety of cardiovascular diseases, possibly including hypertension and systemic atherosclerosis. Recent epidemiologic studies have furthered our understanding of the linkage between air pollutants and human health, with a multitude of plausible mechanistic explanations having been demonstrated experimentally during the past few years. Although a number of finer details relating to both the epidemiology and the mechanisms involved require more investigation, the overall weight of evidence is now sufficient to implicate PM exposure as a cause of cardiovascular disease. Without doubt, exposure to particulate matter can play a causal role in triggering a host of acute cardiovascular events via many mechanisms. Although long-term air pollution exposure has been shown to promote the development of atherosclerosis, the clinical significance of this relation requires more investigation.

1: Rev Environ Health. 2007 Apr-Jun;22(2):115-37.Links

Brook RD.

Division of Cardiovascular Medicine, University of Michigan, USA. robdbrok@umich.edu