Personal-level exposure to environmental temperature is a superior predictor of endothelial-dependent vasodilatation than outdoor-ambient level

Abstract

Environmental temperatures influence cardiovascular physiology. However, the majority of time is spent indoors, making outdoor-ambient temperatures inaccurate estimates of true exposures encountered by most individuals. We evaluated in 50 healthy adults the associations between previous 7-day outdoor-ambient (4 occasions) and prior 24-hour personal-level (2 occasions) environmental temperature exposures with blood pressure, heart rate variability, sleep parameters, and endothelial-dependent vasodilatation (brachial flow-mediated dilatation [FMD]) using generalized estimating equations. Participants (34 females; age, 32.1±9.6 years) had normal blood pressures (107.8±13.3/70.2 ± 9.4 mm Hg), FMD (7.4±2.8%), as well as sleep and HRV parameters. Mean 7-day outdoor-ambient (4.6±9.7 °C) differed from personal-level temperature exposures (22.0±3.0 °C). Colder outdoo r-ambient temperatures (per -10°C) over the previous 1-6 days (rolling averages) were associated with decreases in FMD: -0.57% (95% confidence interval [CI] -1.14% to 0.01%, p=0.055) to -0.62% (95%CI -1.07% to -0.18%, p=0.006). However, a 10°C decrease in personal-leve l temperature during the prior 24-hours was associated with a greater decrement in FMD: -2.44% (95%CI -4.74% to -0.13%, p=0.038). Both were also linearly related to FMD during all seasons and without a threshold temperature. Other endpoints were not significantly related to either temperature level in this study. Short-term exposures to colder environmental temperatures reduced endothelial-dependent vasodilatation, supporting the epidemiological associations with heightened cardiovascular risk. We show here for the first time that temperature exposures characterized at the personal-level may be more robust predictors of endothelial function than outdoor-ambient levels.

Assessment of the Relationship Between Ambient Temperature and Home Blood Pressure in Patients From a Web-Based Synchronous Telehealth Care Program: Retrospective Study

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Effect of Ambient Fine Particulate Matter Air Pollution and Colder Outdoor Temperatures on High-Density Lipoprotein Function

“…In addition, the rolling average of exposures from 1 to 7 days in duration was calculated. Personal-level exposures and temperatures were recorded as averages for the 24-hour period before the blood draw visit in each study block 23 .…”

Should a fistula first policy be revisited in elderly haemodialysis patients?

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