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Can Personal Exposures to Higher Nighttime and Early Morning Temperatures Increase Blood Pressure?
Citation:
Brook, R. D., H. H. Shin, R. L. Bard, R. T. Burnett, A. F. VETTE, C. W. CROGHAN, AND R. W. WILLIAMS. Can Personal Exposures to Higher Nighttime and Early Morning Temperatures Increase Blood Pressure? JOURNAL OF CLINICAL HYPERTENSION. John Wiley & Sons Incorporated, New York, NY, 13(12):881-888, (2011).
Impact/Purpose:
The National Exposure Research Laboratory′s (NERL) Human Exposure and Atmospheric Sciences Division (HEASD) conducts research in support of EPA′s mission to protect human health and the environment. HEASD′s research program supports Goal 1 (Clean Air) and Goal 4 (Healthy People) of EPA′s strategic plan. More specifically, our division conducts research to characterize the movement of pollutants from the source to contact with humans. Our multidisciplinary research program produces Methods, Measurements, and Models to identify relationships between and characterize processes that link source emissions, environmental concentrations, human exposures, and target-tissue dose. The impact of these tools is improved regulatory programs and policies for EPA.
Description:
Environmental temperatures are inversely related to BP; however, the effects of short-term temperature changes within a 24-hour period and measured with high accuracy at the personal level have not been described. Fifty-one nonsmoking patients living in the Detroit area had up to 5 consecutive days of 24-hour personal-level environmental temperature (PET) monitoring along with daily cardiovascular measurements, including BP, performed mostly between 5 PM and 7 PM during summer and ⁄ or winter periods. The associations between hour-long mean PET levels during the previous 24 hours with the outcomes were assessed by linear mixed models. Accounting for demographics, environmental factors, and monitoring compliance, systolic and diastolic BP were positively associated with several hour–long PET measurements ending from 10 to 15 hours beforehand. During this time, corresponding mostly to a period starting from between 1AM and 3 AM to ending between 7 AM and 9 AM, an increase of 1_C was associated with a 0.81 mm Hg to 1.44 mm Hg and 0.59 mm Hg to 0.83 mm Hg elevation in systolic and diastolic BP, respectively. Modestly warmer, commonly encountered PET levels posed a clinically meaningful effect (eg, a 6.95 mm Hg systolic pressure increase per interquartile range (4.8_C) elevation at lag hour 10). Community-level outdoor ambient temperatures were not related to BP. The authors provide the first evidence that personal exposure to warmer nighttime and early-morning environmental temperatures might lead to an increase in BP during the ensuing day.
URLs/Downloads:
Can Personal Exposures to Higher Nighttime and Early Morning Temperatures Increase Blood Pressure? (PDF, NA pp, 118 KB, about PDF)The Journal of Clinical Hypertension
