作者：Allison Gandey
出處：WebMD醫學新聞
November 24, 2009 — 研究者們表示，規律運動可以對抗缺血性中風。他們認為運動強度很重要，且效果與是否有高血壓、糖尿病或血脂異常無關。
紐約哥倫比亞大學的Joshua Willey博士表示，我們相信維持、甚至開始中度至重度強度的運動，像是網球或游泳，是降低缺血性中風風險的重要因素。
他向Medscape神經學表示，我們發現研究對象中有高達40.5%是不運動的。
研究團隊觀察Northern Manhattan Study超過3000位研究對象，只有20%規律地參與中重度運動。
研究對象的平均年齡為69歲，且追蹤長達9年的時間，這段期間有238個中風案例。
研究結果發表在11月24日神經學期刊，指出高效運動帶來的好處。
Willey博士表示，我們訝異的是，總能量的消耗與降低缺血性中風風險無關，反而是與運動本身的強度有關；這可能代表很難在老年人身上衡量能量的消耗，或是能從事中到重度強度的運動代表整體健康情況不錯。
[表格]缺血性中風與運動的關係
運動強度 | 校正後 危險比率 （ 95% 信賴區間 ） |
任一 比上 沒有 | 0.86 (0.66 – 1.13) |
輕度 比上 沒有 | 0.94 (0.71 – 1.25) |
中度至重度 比上 沒有 | 0.65 (0.43 – 0.98) |
中度至重度 比上 輕度至沒有 | 0.68 (0.46 – 0.99) |
這與其他研究「輕度運動也能降低中風風險」的發現相反；護理健康研究與婦女健康關懷研究指出，即使是輕度運動，像是散步，也是有好處的。
Willey博士解釋，由於一些事件的發生，我們無法偵測到輕度運動帶來的保護作用。
令人意外的是，保護作用只出現在男性。他表示，這可能不是一個實際的生物現象，可能有一些因素在我們的研究未被考量進去，例如荷爾蒙替代療法；有些人認為荷爾蒙替代療法可能增加中風的風險以及影響體能。
Willey博士也指出世代研究包括較年老的族群本身較不活動且有較高中風風險。他強調，規律運動的好處大於降低缺血性中風，他們的研究結果不該是女性不運動的理由。
本研究由國家衛生研究院贊助。Willey博士表示已無相關財務關係。
High-Impact Exercise Reduces Stroke Risk
By Allison Gandey
Medscape Medical News
November 24, 2009 — Regular workouts are protective against ischemic stroke, say researchers. They suggest that the intensity of the activity is important and the effect is independent of the improvement exercise has on hypertension, diabetes, or dyslipidemia.
"We believe that maintaining, and even initiating, moderate- to heavy-intensity activity, such as racket sports or swimming, is an important component of risk reduction strategies against ischemic stroke," said Joshua Willey, MD, from Columbia University in New York.
"We are alarmed by the high percentage — 40.5% — of our sample that was physically inactive," he told Medscape Neurology.
The research team looked at more than 3000 people from the Northern Manhattan Study. Only 20% reported that they regularly participated in moderate- to heavy-intensity activities.
The average age of the study sample was 69 years, and participants were followed up for approximately 9 years. During that time, there were 238 strokes.
The results appear in the November 24 issue of Neurology and point to the benefits of high-impact workouts.
"We were somewhat surprised that the total energy expended was not associated with risk of ischemic stroke, but the intensity itself was," Dr. Willey said. "This could represent difficulties with measuring total energy expended in the elderly, or it may be that the ability to perform more moderate- to heavy-intensity activity is indicative of overall good health."
Table. Risk of Ischemic Stroke Associated With Physical Activity
| Intensity of Activity | Adjusted Hazard Ratio (95% Confidence Interval) |
| Any vs none | 0.86 (0.66 – 1.13) |
| Light vs none | 0.94 (0.71 – 1.25) |
| Moderate to heavy vs none | 0.65 (0.43 – 0.98) |
| Moderate to heavy vs light to none | 0.68 (0.46 – 0.99) |
These results are contrary to other studies that found that even light exercise reduced the risk of stroke. In the Nurses' Health Study and the Women's Health Initiative Observational Study, even mild-intensity activity, such as walking, was beneficial.
"Due to the number of events, we may not have been able to detect more subtle protective effects from light-intensity activity that others have found," Dr. Willey explained.
Surprisingly, the protective effect investigators observed occurred only in men and not in women. "This may not be an actual biological phenomenon," he said. "There may be factors that we had not measured in our study, such as hormone replacement therapy." Some have suggested that hormone replacement increases the risk for stroke and influences physical activity.
Dr. Willey also points out that the cohort included older people with a high prevalence of physical inactivity and other stroke risk factors. He emphasized that there are many benefits of regular workouts beyond reduction of ischemic stroke. "Our findings should not discourage women from exercising," he said.
This study was funded by the National Institutes of Health. Dr. Willey has disclosed no relevant financial relationships.
Neurology. 2009;73:1774-1779.
