肺炎和疱疹會增加中風風險

作者：Allison Gandey  
出處：WebMD醫學新聞

　　November 11, 2009 — 研究者認為，有一些感染症會因為血管發炎造成的凝集作用而增加中風風險。這項結果登載於11月9日的神經醫學誌，提出了有關中風的新的可調控風險因素。
　　
　　第一作者、紐約市哥倫比亞大學的Mitchell Elkind醫師向Medscape Neurology表示，如果我們的結果獲得確認，將開啟預防中風的新路徑，可能據以研發疫苗、甚至是抗生素。許多研究提供了各種感染與中風及心臟病發作風險的相關證據，所以我們對此研究發現並不感驚訝，但是，看到假設獲得確認總是令人高興的。
　　
　　研究者從「Northern Manhattan Study」這個研究中獲得超過1,600名研究對象的資料，這個進行中的世代研究，目標是探討中風發生率、風險因素、嚴重度與結果的預測因子，這些研究對象的追蹤中位數為8年。
　　
　　在這個新分析中，研究者希望確認用於一般感染的血清檢測結果的複合方法，所謂的感染負擔指數和中風風險之間的關聯，他們評估了肺炎披衣菌、幽門螺旋桿菌、巨細胞病毒和單純疱疹病毒第1型和第2型。
　　
　　Elkind醫師等人發現，校正其他風險因素之後，每個感染陽性者都與中風風險有關，不過未達顯著。
　　
　　感染負擔指數與所有中風風險增加有關。校正人口統計學因素與其他風險因素之後，每個標準差的風險比(HR)為1.39 (95%信心區間[CI]為1.02- 1.90)。排除有冠狀疾病患者之後，結果也類似(校正HR，1.50；95% CI，1.05- 2.13)。
　　
　　【與血清檢測陽性有關的中風風險】 血清學檢測
校正風險比 (95% 信心區間 )

肺炎披衣菌
1.30 (0.75 - 2.25)

幽門螺旋桿菌
1.13 (0.68 - 1.89)

巨細胞病毒
2.19 (0.84 - 5.70)

單純疱疹病毒第 1 型
1.35 (0.59 - 3.07)

單純疱疹病毒第 2 型
1.59 (0.91 - 2.76)


　　Elkind醫師指出，他的團隊並未納入所有的感染症，例如，並未分析牙周感染問題。
　　
　　他表示，雖然一般感染顯示與中風有關，但不太可能是「中風病毒」，而是有某種關聯，或許是因為感染的累積負擔造成，需要以其他族群進行這些結果的驗證，之後才可能轉為臨床實務。
　　
　　發表於11月版Stroke (2009;40:3443)的另一篇研究，指出帶狀疱疹和中風的關聯。這篇流行病學研究認為，感染增加了缺血性和出血性事件的風險。
　　
　　研究者表示，感染帶狀疱疹之後，中風風險增加了30%，如果感染部位包括眼睛(帶狀疱疹病毒眼症)，則此一風險會更高，達4倍之多。
　　
　　第一作者、台灣台北醫學大學附設醫院Jiunn-Horng Kang醫師在上個月的線上版中風(Stroke)發表此研究時向Medscape Neurology表示，目前對於預防帶狀疱疹(或稱之為shingles)感染，還沒有確立的治療，他指出，及早使用抗病毒藥物治療可能扮演重要角色，但還需要研究確認此功能。
　　
　　Kang醫師表示，就實務觀點，醫師們在照護急性帶狀疱疹病患時，對中風風險可能增加要有所警覺，再者，仔細監控與處置原本存在的中風風險因素，如高血壓、高血脂與糖尿病，將有助於減少中風風險。
　　
　　國家健康研究中心支持本研究。Elkind醫師與Kang醫師都宣告沒有相關財務關係。
　　
　　Arch Neurol. 線上發表於2009年11月9日。


Infections Such as Pneumonia and Herpes May Heighten Stroke Risk
By Allison Gandey
Medscape Medical News
November 11, 2009 — Investigators suggest that infections increase the risk for stroke through an aggregate effect on vascular inflammation. The results, published online November?9 in the Archives of Neurology, suggest a new modifiable risk factor for stroke.
"If our results are confirmed, it opens the path to new ways to prevent strokes, including vaccinations or even antibiotics," lead investigator Mitchell Elkind, MD, from Columbia University in New York City, told Medscape Neurology. "A great deal of research has provided evidence of an association between various infections and risk of stroke and heart attacks, so we were not surprised by the findings," he added, "but one is always happy to see a hypothesis confirmed."
Researchers studied more than 1600 participants from the Northern Manhattan Study. This ongoing cohort study is designed to investigate stroke incidence, risk factors, and predictors of severity and outcome. Participants have been followed for a median of 8 years.
In this new analysis, investigators wanted to determine the association between a composite measure of serologic test results for common infections, called the infectious burden index, and risk for stroke. They assessed Chlamydia pneumonia, Helicobacter pylori, cytomegalovirus, and herpes simplex virus?1 and 2.
Dr. Elkind and his team found that each individual infection was positively — although not significantly — associated with stroke risk after adjustment for other risk factors.
The infectious burden index was associated with an increased risk for all strokes. The hazard ratio (HR) per SD was 1.39 (95% confidence interval [CI], 1.02?- 1.90) after adjustment for demographics and risk factors. Results were similar after excluding patients with coronary disease (adjusted HR, 1.50; 95% CI, 1.05?- 2.13).
Stroke Risk Associated With Positive Serologic Test Results Serologic Test  Adjusted Hazard Ratio(95% Confidence Interval)  
Chlamydia pneumonia  1.30 (0.75 - 2.25)
Helicobacter pylori  1.13 (0.68 - 1.89)
Cytomegalovirus 2.19 (0.84 - 5.70)
Herpes simplex virus?1 1.35 (0.59 - 3.07)
Herpes simplex virus?2 1.59 (0.91 - 2.76)

Dr. Elkind pointed out that his group did not include all infections and did not assess periodontal problems, for example.
He said that although common infections appear to be linked to stroke, there is not likely a single "stroke bug" but rather an association, perhaps through a cumulative burden of infection. "These results need to be validated in other populations before they can be translated into clinical practice," he said.
Another study, published in the November issue of Stroke (2009;40:3443), linked herpes zoster to stroke. The epidemiologic study suggested that infection increases the risk for ischemic and hemorrhagic events.
Investigators showed that the risk for stroke increased by 30% after a herpes zoster attack. The risk is even higher, approximately 4-fold, if the attack involves the eye (herpes zoster ophthalmicus).
There is still no established therapy to prevent herpes zoster infection, also known as shingles, lead investigator Jiunn-Horng Kang, MD, from the Taipei Medical University Hospital in Taiwan, told Medscape Neurology last month, when the Stroke study was released online. Early antiviral therapy could play an important role, he noted, but this role still needs to be studied.
"From the practical view, physicians should be aware of the potential elevated risk of stroke when they care for patients with acute herpes zoster attack," Dr. Kang said. "Furthermore, careful monitoring and management of the pre-existing risk factors for stroke, such as hypertension, hyperlipidemia, and diabetes mellitus, could be helpful in reducing the risk for stroke."
This study was funded by the National Institutes of Health. Dr. Elkind and Dr. Kang have disclosed no relevant financial relationships.
Arch Neurol. Published online November 9, 2009.