作者：Caroline Cassels
出處：WebMD醫學新聞
April 13, 2010 (多倫多) — 新研究認為，如果有抽菸的話，那可能會抹殺了適度飲酒對於中風風險的任何可能好處。
這篇大型前瞻研究發表於美國神經醫學會第62屆年會，包括了10,171名男性和12,353名女性，研究者追蹤他們的偶發中風，結果顯示，抽菸者和沒有抽菸者之間，飲酒和中風的關聯有顯著的差異。
沒有抽菸者之中，適量飲酒者(定義為每天2-3杯一般玻璃杯的紅酒)發生中風的機率比沒有飲酒者低了37%。
根據研究作者、英國劍橋大學的Yangmei Li小姐表示，飲酒和中風風險之間的潛在關聯並不清楚。
雖然研究顯示，過量飲酒會增加中風風險，輕微到適量飲酒與中風的關聯較不清楚，各研究之間有一些值得考量的差異。
為了檢視飲酒和中風之間的前瞻關聯，研究者蒐集參與「European Prospective Investigation into Cancer–Norfolk study」這項研究之一般人口的資料。
研究對象年紀介於39-79歲，研究開始期間(1993-1997年)沒有已知的心肌梗塞、中風或癌症，研究者針對他們的偶發中風進行追蹤。
在12年追蹤期間，觀察到864例偶發中風，根據研究者表示，飲酒和中風風險的關係呈現U字型，確認了「適量飲酒減少中風風險、過量飲酒則是增加風險」的假設。
相較於未飲酒者，飲酒者的中風風險比(HRs)和95%信心區間(CIs)也是U字型，所以，輕微到適度飲酒減少中風風險，過量飲酒的風險隨著量增加。
表、根據每週飲酒量分類之相關中風風險
每週飲酒單位數 | 風險比 (95% 信心區間 ) |
0.1 – 3 | 0.72 (0.60 – 0.86) |
3.1 – 7 | 0.56 (0.45 – 0.70) |
7.1 – 14 | 0.55 (0.44 – 0.70) |
14.1 – 21 | 0.71 (0.53 – 0.95) |
21.1 – 28 | 0.82 (0.55 – 1.21) |
>28 | 0.96 (0.67 – 1.39) |
不過，根據研究發現，這個保護效果似乎會被抽菸抹殺。
相較於未曾飲酒且未曾抽菸者，目前有抽菸而未曾飲酒者、未曾飲酒而以前有抽菸者、目前有飲酒而以前有抽菸者、未曾飲酒而目前有抽菸者、目前有飲酒且有抽菸者的年紀校正HRs (95% CIs)分別是0.75 (0.52 – 1.09)、 0.62 (0.22 – 1.75)、0.88 (0.61 – 1.26)、0.73 (0.18 – 3.06)與1.75 (1.17 – 2.62)。
Li小姐向Medscape表示，輕微到適度飲酒可以減少中風風險，但是根據我們的研究結果，過量飲酒的中風風險不會減少，實際上還會增加。我們知道，抽菸對中風風險有負面效果，而抽菸也會抵消掉適量飲酒的可能好處。
美國心臟協會理事長候選人、佛羅里達邁阿密大學傑克森紀念醫院神經科主任Ralph L. Sacco醫師為Medscape發表評論時表示，如同之前的一些研究，包括其研究團隊的「Northern Manhattan Study (NOMAS)」，這些新發現確認了「適量飲酒對於中風有絕對的保護效果」。
Sacco醫師表示，我們在NOMAS研究中指出，適量飲酒在兩個不同情況下有保護效果，不過，我們並未發現和抽菸的任何相互影響，事實上，在NOMAS研究中，我們發現該保護效果與抽菸無關。
在這個大型歐洲世代中，適量飲酒對抽菸者沒有保護效果的研究發現是有趣的，不令人意外的，底線是，你絕對不要抽菸，這個研究似乎認為抽菸是一個強力風險因素，對血管內皮有直接的毒性效果，抵銷了飲酒的保護效果。
該研究接受英國醫學研究委員會癌症研究小組支持，Li小姐宣告沒有相關財務關係。
美國神經醫學會第62屆年會：摘要P01.297。發表於2010年4月13日。
Smoking Negates Positive Effect of Moderate Alcohol Use on Stroke Risk
By Caroline Cassels
Medscape Medical News
April 13, 2010 (Toronto, Ontario) — Any potential beneficial effect of moderate alcohol consumption on stroke risk appears to be negated if individuals also smoke, new research suggests.
Presented here at the American Academy of Neurology 62nd Annual Meeting, a large, prospective study of 10,171 men and 12,353 women who were followed up for incident stroke showed that the association between alcohol consumption and stroke was significantly different between smokers and nonsmokers.
In nonsmokers, those who consumed moderate amounts of alcohol, defined as 2 to 3 regular glasses of red wine per day, were 37% less likely to develop stroke than nondrinkers.
According to the study investigator Yangmei Li, MPhil, University of Cambridge in the United Kingdom, the potential link between alcohol consumption and stroke risk is unclear.
Although research shows heavy alcohol use increases stroke risk, the relationship between light to moderate drinking and stroke is less clear, with considerable variation among studies.
To examine the prospective association between alcohol consumption and stroke, investigators gathered data on individuals in the general population who were participating in the European Prospective Investigation into Cancer–Norfolk study.
Participants were aged 39 to 79 years without known myocardial infarction, stroke, or cancer at the baseline period in 1993-1997 and were followed up for incident stroke.
At 12-year follow-up, 864 incident strokes were observed. According to investigators, alcohol consumption and stroke risk appeared U-shaped, confirming the hypothesis that moderate alcohol use reduces stroke risk, whereas heavy use increases it.
Compared with nondrinkers, the hazard ratios (HRs) and 95% confidence intervals (CIs) for stroke for participants who consumed were U-shaped so that mild to moderate drinking decreased stroke risk, whereas heavy alcohol consumption increased risk by amount consumed.
Table. Associated Stroke Risk by Weekly Alcohol Consumption
| No. of Units per Week | Hazard Ratio (95% Confidence Interval) |
| 0.1 – 3 | 0.72 (0.60 – 0.86) |
| 3.1 – 7 | 0.56 (0.45 – 0.70) |
| 7.1 – 14 | 0.55 (0.44 – 0.70) |
| 14.1 – 21 | 0.71 (0.53 – 0.95) |
| 21.1 – 28 | 0.82 (0.55 – 1.21) |
| >28 | 0.96 (0.67 – 1.39) |
However, according to the study findings, this protective effect appears to be negated by smoking.
Compared with never-drinking never-smokers, the age-adjusted HRs (95% CIs) for current drinking never-smokers, never-drinking former smokers, current drinking former smokers, never-drinking current smokers, and current drinking current smokers were 0.75 (0.52 – 1.09), 0.62 (0.22 – 1.75), 0.88 (0.61 – 1.26), 0.73 (0.18 – 3.06), and 1.75 (1.17 – 2.62), respectively.
"Mild to moderate alcohol use may reduce risk of stroke, but according to our results heavy drinkers will not experience a reduced risk and in fact may increase their risk of stroke. We know that smoking has a negative effect on stroke risk, but smoking in combination of moderate drinking seems to counteract this potential benefit," Ms. Li told Medscape.
Commenting for Medscape, Ralph L. Sacco, MD, neurologist-in-chief at University of Miami Jackson Memorial Hospital in Florida and president-elect of the American Heart Association, said like a number of previous papers, including research by his team in the Northern Manhattan Study (NOMAS), these new findings confirm that "moderate alcohol use is absolutely protective against stroke."
"We have demonstrated in NOMAS on 2 different occasions that moderate alcohol use is protective. However, we did not find any interactions with smoking. In fact, [in NOMAS] we found [the protective effect] was independent of smoking," said Dr. Sacco.
It was interesting to see that in this large European cohort moderate alcohol use was not protective among smokers. The bottom line, which is no surprise to anyone, is that you absolutely shouldn't smoke, and this study seems to suggest that smoking is such a potent risk factor and has such a direct toxic effect on the blood vessel endothelium that it overwhelms the small protective effects of alcohol," he added.
The study was supported by the Medical Research Council Cancer Research UK. Ms. Li has disclosed no relevant financial relationships.
American Academy of Neurology (AAN) 62nd Annual Meeting: Abstract P01.297. Presented April 13, 2010.
