VOA慢速英語:Rethinking 'Good' Cholesterol; PSA Test Debate

有益膽固醇和PSA測試受到質疑

This is the VOA Special English Health Report.
這里是美國之音慢速英語健康報道。

A study has raised questions about a widely held belief involving cholesterol. The belief is that high levels of so-called good cholesterol in the blood can reduce the risk of a heart attack.
一項研究對一種涉及膽固醇的普遍觀點提出了質疑。這種觀點認為，血液中的有益膽固醇水平高能夠降低心臟病發(fā)作的風險。

The medical name for "good" cholesterol is high-density lipoprotein, or HDL. Doctors commonly believe it reduces the risk of heart attack by removing fatty deposits that can block the flow of blood in the arteries of the heart.
這種有益膽固醇的醫(yī)學名稱是高密度脂蛋白（以下簡稱HDL）。醫(yī)生們普遍認為，它能通過帶走阻塞心臟動脈血液流動的脂肪沉積，降低心臟病發(fā)作的風險。
 
But Dr. Sekar Kathiresan at Massachusetts General Hospital in Boston says the effects of high HDL have never been proven. He says the new study that he and other researchers did suggests that HDL cholesterol does not affect the risk of heart attack.
但波士頓市馬薩諸塞總醫(yī)院的謝卡爾·凱瑟雷森（Sekar Kathiresan）表示，HDL含量高的影響從未被證實。他表示，自己和其他研究人員進行的這項新研究證實，HDL膽固醇對心臟病發(fā)作的風險沒有影響。

SEKAR KATHIRESAN: "This has been the major assumption over the last thirty years, that if you raise HDL cholesterol, the risk for heart disease will be lowered. And I think we have now broken that assumption, broken that link using this gene variant."
凱瑟雷森：“這是過去30年的一種主流假設，如果提高HDL膽固醇含量，心臟病風險將會降低。而我認為，我們現(xiàn)在已經通過分析基因變異打破了這種假設，打破了這兩者的聯(lián)系。”

The researchers say about four percent of people have a genetic change that gives them a naturally high level of HDL. The study found that those who were genetically "programmed" to have higher HDL levels were just as likely to suffer heart attacks as those who were not.
研究人員稱，約4%的人擁有一種遺傳變異，使得他們生來HDL水平就高。研究發(fā)現(xiàn)，這種天生就HDL水平更高的人和普通人同樣會患心臟病。

A second analysis looked at fourteen gene variants that increase good cholesterol. Dr. Kathiresan says people with the most variants had no more protection against heart attacks than anyone else.
第二項分析著眼于能夠提升有益膽固醇含量的14種基因變異。凱瑟雷森表示，擁有基因變異最多的人群與其他人相比，并未能更好地預防心臟病發(fā)作。

But he says there is no dispute about low-density lipoprotein, or LDL. LDL, the so-called bad cholesterol, causes a buildup of fatty substances inside arteries and increases the risk of heart attack.
但他表示，有一點沒有爭議，低密度脂蛋白，也就是所謂的有害膽固醇（以下簡稱LDL），會導致動脈內的脂肪物質堆積，提高心臟病發(fā)作的風險。

Dr. Kathiresan and his colleagues published their findings in the Lancet medical journal.
凱瑟雷森醫(yī)生及其同事將他們的這一研究結果發(fā)表在《柳葉刀》醫(yī)學雜志上。

Another widely held medical belief has also come into question recently. For years, men over the age of forty have been told to get a simple blood test to see if they have prostate cancer. Now, experts on a government committee are advising them not to. Dr. Virginia Moyer heads the United States Preventive Services Task Force.
另一種普遍醫(yī)學觀點最近也受到了質疑。多年來，40歲以上男子一直被告知進行一種簡單的血液測試，看他們是否患有前列腺癌。目前，某政府委員會的專家建議他們不要這么做。弗吉尼亞·莫耶醫(yī)生（Virginia Moyer）負責美國預防醫(yī)學特別委員會。

VIRGINIA MOYER: "Close to two-thirds of older men have prostate cancer and yet the huge majority of them never have a problem from it in their lifetime."
莫耶：“將近2/3的老年男子患有前列腺癌，但他們中的絕大多數(shù)人終其一生都未因為前列腺癌產生什么問題。”

The task force examined two large studies before deciding that treating the cancer found by the PSA test can do more harm than good. Effects of the treatment can include a loss of sexual ability and bladder control, as well as other problems including heart attacks.
在斷定對經由PSA測試發(fā)現(xiàn)的前列腺癌患者的治療弊大于利前，該委員會審查了兩項大型研究。這種治療的后果包括喪失性能力和膀胱控制，以及包括心臟病發(fā)作在內的其它問題。

Some experts support the findings of the task force, but others disagree. Urologist Deepak Kapoor says in about twenty years of PSA testing, death rates for prostate cancer have dropped by thirty-eight percent.
一些專家支持該委員會的結論，但其他人并不同意。泌尿科醫(yī)生迪帕克·卡普爾（Deepak Kapoor）表示，在20多年的PSA測試中，前列腺癌的死亡率下降了38%。