Brief Exposure to Secondhand Smoke Reversibly Impairs Endothelial Vasodilatory Function.
ABSTRACT We sought to determine the effects of brief exposures to low concentrations of tobacco secondhand smoke (SHS) on arterial flow-mediated dilation (FMD, a nitric oxide-dependent measure of vascular endothelial function), in a controlled animal model never before exposed to smoke. In humans, SHS exposure for 30min impairs FMD. It is important to gain a better understanding of the acute effects of exposure to SHS at low concentrations and for brief periods of time.
We measured changes in FMD in rats exposed to a range of real-world levels of SHS for durations of 30min, 10min, 1min, and 4 breaths (roughly 15 s).
We observed a dose response relationship between SHS particle concentration over 30min and post-exposure impairment of FMD, which was linear through the range typically encountered in smoky restaurants and then saturated at higher concentrations. One minute of exposure to SHS at moderate concentrations was sufficient to impair FMD.
Brief SHS exposure at real-world levels reversibly impairs FMD. Even 1min of SHS exposure can cause reduction of endothelial function.
SourceAvailable from: Michael E Widlansky[Show abstract] [Hide abstract]
ABSTRACT: Defining new approaches for the prevention and treatment of atherosclerosis is an important priority. Recently, measurement of endothelial function in patients has emerged as a useful tool for atherosclerosis research. Risk factors are associated with impaired endothelial function, and clinical syndromes relate, in part, to a loss of endothelial control of vascular homeostasis. Recent studies have shown that the severity of endothelial dysfunction relates to cardiovascular risk. A growing number of interventions known to reduce cardiovascular risk have been shown to improve endothelial function. This work suggests that studies of endothelial function could be used in the care of patients and as a surrogate marker for the evaluation of new therapeutic strategies. This article will review this growing literature in an effort to evaluate the current clinical utility of endothelial dysfunction.Journal of the American College of Cardiology 11/2003; 42(7):1149-60. DOI:10.1016/S0735-1097(03)00994-X · 15.34 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: To determine whether there was a change in hospital admissions for acute myocardial infarction while a local law banning smoking in public and in workplaces was in effect. Analysis of admissions from December 1997 through November 2003 using Poisson analysis. Helena, Montana, a geographically isolated community with one hospital serving a population of 68 140. All patients admitted for acute myocardial infarction. Number of monthly admissions for acute myocardial infarction for people living in and outside Helena. During the six months the law was enforced the number of admissions fell significantly (- 16 admissions, 95% confidence interval - 31.7 to - 0.3), from an average of 40 admissions during the same months in the years before and after the law to a total of 24 admissions during the six months the law was effect. There was a non-significant increase of 5.6 (- 5.2 to 16.4) in the number of admissions from outside Helena during the same period, from 12.4 in the years before and after the law to 18 while the law was in effect. Laws to enforce smoke-free workplaces and public places may be associated with an effect on morbidity from heart disease.BMJ (online) 05/2004; 328(7446):977-80. DOI:10.1136/bmj.38055.715683.55 · 16.38 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Secondhand smoke increases the risk of coronary heart disease by approximately 30%. This effect is larger than one would expect on the basis of the risks associated with active smoking and the relative doses of tobacco smoke delivered to smokers and nonsmokers. We conducted a literature review of the research describing the mechanistic effects of secondhand smoke on the cardiovascular system, emphasizing research published since 1995, and compared the effects of secondhand smoke with the effects of active smoking. Evidence is rapidly accumulating that the cardiovascular system--platelet and endothelial function, arterial stiffness, atherosclerosis, oxidative stress, inflammation, heart rate variability, energy metabolism, and increased infarct size--is exquisitely sensitive to the toxins in secondhand smoke. The effects of even brief (minutes to hours) passive smoking are often nearly as large (averaging 80% to 90%) as chronic active smoking. The effects of secondhand smoke are substantial and rapid, explaining the relatively large risks that have been reported in epidemiological studies.Circulation 06/2005; 111(20):2684-98. DOI:10.1161/CIRCULATIONAHA.104.492215 · 14.95 Impact Factor