Two new studies have found that people with sleep apnea, a common disorder that causes snoring, fatigue and dangerous pauses in breathing at night, have a higher risk of cancer.
「睡眠呼吸暫停（或稱中止）」是常見的身體失調症狀，會引起打鼾、疲倦，以及夜間睡眠時危險的呼吸暫停現象。兩項最新公布的研究報告顯示，有這種狀況的人罹患癌症的機率也比較高。

The new research is the first to link sleep apnea to cancer in humans.
這是指出睡眠呼吸暫停症與癌症有關的第一批研究報告。

About 28 million Americans have some form of sleep apnea, though many cases go undiagnosed. The condition deprives the body of oxygen at night and often coincides with cardiovascular disease, obesity and diabetes.
大約2800萬名美國人有某種形式的睡眠呼吸暫停症狀，只是許多實例未經診斷。它會使身體在夜間睡眠時失去氧氣，經常與心血管疾病、肥胖、糖尿病同時發生。

Dr. Joseph Golish, a professor of sleep medicine with the Metro-Health System in Cleveland who was not involved in the research, called it “really big news.”
未參與這項研究的克里夫蘭大都會健康系統的睡眠醫學教授戈里希表示，這項研究結果「確實是大新聞」。

In one study, researchers in Spain found that patients with the severe sleep apnea had a 65 percent greater risk of developing cancer of any kind. The second study, in Wisconsin, showed that those with the most breathing abnormalities at night had five times the rate of dying from cancer as people without sleep apnea.
前述兩項研究由西班牙研究人員所做的一項發現，睡眠呼吸暫停程度嚴重的病人罹患某種癌症的機率比常人高出65%。另一項研究是在美國威斯康辛州做的，顯示夜間睡眠呼吸異常程度最嚴重者死於癌症的機率是無此症狀者的5倍之多。

Both studies ruled out the possibility that the usual risk factors for cancer, like age, smoking, alcohol use, physical activity and weight, could have played a role.
這兩項研究均排除常見的癌症風險因素，如年齡、吸菸、飲酒、身體的活動、體重，與此一結果有關的可能性。

Dr. Mitesh Borad, a cancer researcher at the Mayo Clinic who was not involved with the studies, said the studies were “provocative” but more research was needed.
同樣未參與這項研究的梅約診所癌症研究員波拉德表示，這個研究結果「極具挑戰性」，然而醫學界必須做更多後續研究。

In a recent animal study, when mice with tumors were placed in low-oxygen environments that simulate the effects of sleep apnea, their cancers progressed more rapidly. Scientists speculate that depriving mice of oxygen may cause their bodies to develop more blood vessels to compensate, an effect that could act as a kind of fertilizer for cancer tissue and cause tumors to grow and spread more quickly.
在最近的一項動物實驗中，研究人員把體內長有腫瘤的老鼠放在模擬睡眠呼吸暫停狀態的低氧濃度環境下，結果發現，牠們的腫瘤成長得更快速。科學家研判，如果使老鼠無法呼吸正常濃度的氧，牠們的身體可能為了彌補而生出更多血管。這可能為癌症組織提供養分，導致腫瘤更快速的成長、擴散。

The researchers wondered whether a similar relationship might exist in people with sleep apnea, in whom throat muscles collapse during sleep, choking off the airway and causing gasping and snoring as the body fights for air. Severe sleep apnea can produce hundreds of such episodes each night, depleting the body of oxygen.
研究人員好奇的是，類似的因果關係是否同樣會出現在睡眠呼吸暫停的人身上。熟睡時，他們的喉嚨肌肉會萎陷並阻斷氣管，最後因為身體要爭取空氣而引起喘息及打鼾。程度嚴重者，一個晚上可能出現數百次同樣的狀況，導致身體嚴重缺氧。

A study at the University of Wisconsin School of Medicine and Public Health examined data in the Wisconsin Sleep Cohort, a landmark project that was one of the first to reveal the widespread occurrence of sleep apnea.
具有分水嶺意義的威斯康辛睡眠研究計畫，是第一個把睡眠呼吸暫停狀況的普遍性呈現在世人眼前的計畫之一。威斯康辛大學醫學暨公共衛生學院檢視了該計畫彙整的數據。

Researchers found that the more severe a person’s breathing problems at night, the greater the likelihood of dying from cancer. People with moderate apnea died of cancer at a rate double that of people without sleep apnea, while those rated severe died at a rate 4.8 times that of those without it.
研究人員發現，一個人夜間睡眠呼吸問題越嚴重，死於癌症的機率就越高。與無呼吸暫停問題者相比，有呼吸暫停問題但情況不算嚴重者死於癌症的機率是2倍，情況嚴重者更高達4.8倍。

“That is really striking,” said Dr. F. Javier Nieto, a study author and chairman of the department of population health sciences at the University of Wisconsin.
這項研究報告的撰寫人之一、威斯康辛大學人口健康學系主任尼耶托說：「那真是驚人。」

In the second study, the Spanish Sleep Network looked not at cancer mortality among apnea patients, but at the incidence of cancer. They used a measure called the hypoxemia index, which looks at the amount of time oxygen level in the blood drops below 90 percent at night.
在另外一項研究中，「西班牙睡眠網絡」研究的不是呼吸暫停病人死於癌症的機率，而是罹患癌症的機率。他們採用所謂的血氧過少指數，以檢視血中的氧氣濃度在夜間降至90%以下所占的時間。

The researchers found that the greater the extent of hypoxemia, or oxygen depletion, during sleep, the more likely a person would receive a cancer diagnosis.
研究人員發現，如果一個人熟睡時，血氧過少的情況越嚴重，罹癌的可能性也越高。

People whose oxygen levels dropped below 90 percent for up to 12 percent of the total time they were asleep had a 68 percent greater likelihood of developing cancer. As time spent without oxygen increased, so, too, did cancer risk.
如果熟睡時，血中氧氣濃度降至90%以下的時間達到全部睡眠時間的12%，罹癌的機率比一般人高出68%。缺氧的時間越長，罹癌的機率也越高。

“This is one more instance that shows that sleep apnea can have profound impacts for people’s health,” said Dr. Nieto.
尼耶托說：「這個實例再度顯示，睡眠呼吸暫停會大大影響身體的健康。」

原文參照：
http://well.blogs.nytimes.com/2012/05/20/sleep-apnea-tied-to-increased-cancer-risk/

2012-06-05聯合報/G9版/UNITEDDAILYNEWS 陳世欽譯 原文參見紐時週報十一版左