Background: Extreme weather and air pollution are associated with increased cardiovascular risk in people with diabetes.
Objectives: In a population with diabetes, we conducted a novel assessment of vascular brachial artery responses both to ambient pollution and to weather (temperature and water vapor pressure, a measure of humidity).
Methods: Sixty-four 49- to 85-year-old Boston residents with type 2 diabetes completed up to five study visits (279 repeated measures). Brachial artery diameter (BAD) was measured by ultrasound before and after brachial artery occlusion [i.e., flow-mediated dilation (FMD)] and before and after nitroglycerin-mediated dilation (NMD). Ambient concentrations of fine particulate mass (PM2.5), black carbon (BC), organic carbon (OC), elemental carbon, particle number, and sulfate were measured at our monitoring site; ambient concentrations of carbon monoxide, nitrogen dioxide, and ozone were obtained from state monitors. Particle exposure in the home and during each trip to the clinic (home/trip exposure) was measured continuously and as a 5-day integrated sample. We used linear models with fixed effects for participants, adjusting for date, season, temperature, and water vapor pressure on the day of each visit, to estimate associations between our outcomes and interquartile range increases in exposure.
Results: Baseline BAD was negatively associated with particle pollution, including home/trip–integrated BC (–0.02 mm; 95% CI: –0.04, –0.003, for a 0.28 μg/m3 increase in BC), OC (–0.08 mm; 95% CI: –0.14, –0.03, for a 1.61 μg/m3 increase) as well as PM2.5, 5-day average ambient PM2.5, and BC. BAD was positively associated with ambient temperature and water vapor pressure. However, exposures were not consistently associated with FMD or NMD.
Conclusion: Brachial artery diameter, a predictor of cardiovascular risk, decreased in association with particle pollution and increased in association with ambient temperature in our study population of adults with type 2 diabetes.
1Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA; 2Joslin Diabetes Center, Boston, Massachusetts, USA; 3Department of Biostatistics, Harvard School of Public Health, Boston, Massachusetts, USA; 4IUF Leibniz Research Institute for Environmental Medicine and Medical School, University of Düsseldorf, Düsseldorf, Germany; 5Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA; 6Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA; 7Channing Laboratory, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA
Recommended Citation:
Antonella Zanobetti,1 Heike Luttmann-Gibson,1 Edward S. Horton,et al. Brachial Artery Responses to Ambient Pollution, Temperature, and Humidity in People with Type 2 Diabetes: A Repeated-Measures Study[J]. Environmental Health Perspectives,2014-01-01,Volume 122(Issue 3):242