生物谷報(bào)道：北卡羅來(lái)納州大學(xué)（University of North Carolina）的科學(xué)家表示：「道路施工揚(yáng)起的灰塵可能會(huì)造成氣喘病人心臟方面的問(wèn)題,。」研究人員發(fā)現(xiàn)患有氣喘的人，聞到室外含有粗糙微?；覊m等物質(zhì),，會(huì)使其壞的膽固醇量升高,，也會(huì)引起過(guò)量的發(fā)炎反應(yīng),，此研究發(fā)表于5月份的Environmental Health Perspectives期刊。提醒氣喘患者及易敏感的族群必需留意空氣污染對(duì)身體造成的影響,。
研究人員以12位患有氣喘的病人進(jìn)行測(cè)試,，由研究結(jié)果顯示：空氣中每立方公尺的范圍內(nèi)，只要增加一毫克的微?；覊m,，受試者體內(nèi)三甘油酯（triglyceride）含量就會(huì)增加5%，而三甘油酯數(shù)值過(guò)高,，正是造成冠狀動(dòng)脈心臟病的高風(fēng)險(xiǎn)因子,。而受試人員在曝露于高含量微粒灰塵時(shí),，其血液中的嗜伊紅白血球（eosinophils）也會(huì)增加0.16%,，這種白血球過(guò)度表現(xiàn)會(huì)造成過(guò)敏或氣喘等癥狀，研究人員也發(fā)現(xiàn)到這些微?；覊m會(huì)使受試者的心率變異（heart rate variability）降低3%,，此現(xiàn)象代表受試者壓力過(guò)大或者有心臟相關(guān)的疾病。
(資料來(lái)源 : Bio.com)
英文原文:
Coarse Particulate Matter in Air May Harm Hearts of Asthma Sufferers, UNC Study Finds
05/09/07 -- Breathing air containing coarse particulate matter such as road or construction dust may cause heart problems for asthma sufferers and other vulnerable populations, according to a new study led by the University of North Carolina at Chapel Hill School of Public Health.
The researchers found that in people with asthma, a small increase in coarse particulate matter in outdoor air raised bad cholesterol and increased the count of inflammation-linked white blood cells, among other changes.
"This research was all done with study participants just being outside and breathing outdoor air," said Dr. Karin Yeatts, research assistant professor of epidemiology at the UNC School of Public Health, a member of the UNC Center for Environmental Medicine, Asthma and Lung Biology, and the study's principal investigator. "Our results indicate that susceptible people really need to pay attention to air pollution warnings and stay inside when the air pollution is bad. This is particularly the case for people with asthma."
The study, published in the May 2007 issue of Environmental Health Perspectives, was a collaboration by researchers from the School of Public Health, the School of Medicine's Center for Environmental Medicine, Asthma and Lung Biology and the U.S. Environmental Protection Agency (EPA).
The team found that when adult asthma sufferers were exposed to a one microgram per cubic meter increase in coarse particulate matter in ambient air their triglyceride levels increased by nearly five percent. Elevated levels of triglycerides have been shown to increase one's risk of coronary heart disease. The amount of eosinophils in study participants' blood also increased by 0.16 percent after exposure to the higher levels of coarse particulate matter. Eosinophils are a type of white blood cell created by the human body to fight infections, allergies and diseases like asthma among other things. Finally, the same increase in coarse particulate matter resulted in a three percent decrease in a measure of heart rate variability, the variation of the beat-to-beat intervals of the heart. A healthy heart has wide heart rate variability, while decreased variability can indicate stress or cardiac disease.
Surprisingly, there was no relationship between coarse particulate matter and rescue medication use, asthma symptoms, lung function or airway inflammatory markers, Yeatts said. However, 10 of the 12 adult asthmatics in the study were taking anti-inflammatory controller medication for their disease, and nine of the 12 had mild disease. It is possible that anti-inflammatory treatment mitigated the effects in their airways, or that adults with asthma are less susceptible to the effects of coarse particulate matter.
Study participants consisted of 12 adults between the ages of 21 and 50 with persistent asthma. All lived within a 30-mile radius of the study's particulate matter monitor, located on the EPA Human Studies Facility at the Carolina campus. Each study participant took part in nine clinic visits: five the first week, and four spaced randomly over the subsequent six to 11 weeks. Data collection took place between September 2003 and July 2004. During the study, outdoor air levels of coarse particulate matter ranged between zero to 14.6 micrograms per cubic meter and did not exceed safety levels set by the EPA of 150 micrograms per cubic meter.
Other study authors include Lawrence Kupper, Alumni Distinguished Professor of biostatistics in the UNC School of Public Health; Dr. David Peden, director of the UNC Center for Environmental Medicine, Asthma and Lung Biology; Neil Alexis and Margaret Herbst, UNC Center for Environmental Medicine, Asthma and Lung Biology; Erik Svendsen, John Creason, James Scott, Lucas Neas, Robert Devlin and Ronald Williams of the EPA; and Dr. Wayne Cascio of Eastern Carolina University's Brody School of Medicine.
Source: University of North Carolina of Chapel Hill
