Can Personal Exposures to Higher Nighttime and Early-Morning Temperatures Increase Blood Pressure?
Article first published online: 7 NOV 2011
© 2011 Wiley Periodicals, Inc.
The Journal of Clinical Hypertension
Volume 13, Issue 12, pages 881–888, December 2011
How to Cite
Brook, R. D., Shin, H. H., Bard, R. L., Burnett, R. T., Vette, A., Croghan, C. and Williams, R. (2011), Can Personal Exposures to Higher Nighttime and Early-Morning Temperatures Increase Blood Pressure?. The Journal of Clinical Hypertension, 13: 881–888. doi: 10.1111/j.1751-7176.2011.00545.x
- Issue published online: 5 DEC 2011
- Article first published online: 7 NOV 2011
- Manuscript received: November 1, 2010; Revised: February 14, 2011; Accepted: March 3, 2011
J Clin Hypertens (Greenwich). 2011;13:881–888. ©2011 Wiley Periodicals, Inc.
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.