HIV、HIV/HCV合併感染加倍中風風險
作者：Barbara Boughton
出處：WebMD醫學新聞
February 26, 2010（加州舊金山）－根據發表在第17屆反轉錄病毒與伺機性感染會議的研究結果，合併感染HIV與C型肝炎病毒（HCV）會顯著地增加中風風險，這項發現代表感染這些病毒的病患們應該控制血管危險因子。
主要研究者與神經學家康乃狄克州紐哈芬市耶魯大學醫學院的Jason Sico醫師表示，一項收納超過8,000位退伍軍人的大型研究發現，相較於未感染HIV，感染HIV與中風風險增加有關。
Sico醫師在與Medscape HIV/AIDS的訪談中表示，那些感染HIV的病患罹患心臟疾病的可能性較高是可以理解的，但是中風風險可能鮮為人知。我們的研究顯示，HIV感染患者、以及那些合併感染HIV及HCV的病患，需要多加留意中風健康危險因子，例如高膽固醇與代謝症候群。
在這項研究中，研究者們分析8,579位退伍軍人老化世代研究實體世代男性受試者的資料，並比較HIV或是共同感染HIV及HCV以及那些沒有這些感染受試者的中風發生率。
在後續追蹤中位數7.3年間，退伍軍人們發生了160次中風與1,181件死亡事件。當那些罹患HIV或是HCV/HIV與未受感染個體比較時，研究者們發現那些有HIV/HCV的中風風險高出2倍。
Sico醫師解釋，在死亡被用為競爭風險的模式中，那些感染HIV的受試者們發生中風風險高出2倍。相較於未受感染者，罹患HIV病患比較早死亡，校正死亡為一個影響變項，是他們評估中一個重要的部分。當研究者們未校正死亡時，危險比值下降到1.34。
當他們以病毒感染狀況特徵化中風風險時，研究者們也校正年齡、種族、教育程度、身體質量指數、糖尿病、吸菸、高膽固醇血症以及濫用酒精及依賴性。
他表示，同時感染HIV與HCV造成增加中風風險的感染，且抗反轉錄病毒藥物有許多副作用，例如血脂異常，也可能增加風險。然而，那些感染HIV與HCV患者中風風險增加的生物機轉仍然需要在未來的研究中探索。
美國中風醫學會發言人、來自查爾斯頓南卡羅來納州醫學院的Daniel Lackland醫師在與Medscape HIV/AIDS的訪談中表示，過去，同時感染HIV與HCV患者可能沒有辦法活到發生中風。但是現在，接受了抗反轉錄病毒藥物治療，他們可以存活更久至發生中風。他附帶表示，我們現在知道發炎反應在中風上扮演一個很大的角色，同時也是HIV與HCV疾病進程的一部份，但是，對於相關機轉我們需要更多的資訊。
耶魯大學醫學院神經與檢驗醫學部門的榮譽教授John Booss醫師表示，這些發現被確認了，將會需要大家的合作，以確認是否調控血管危險因子會被HIV感染狀態負向影響，而治療HIV感染可以改善臨床預後。
Booss醫師向Medscape HIV/AIDS表示，Sico醫師的研究為我們打開了老化與HIV感染的交點。但是仍然有對HIV感染病患認知功能下降的擔憂。如果加上中風風險，老化對於HIV感染病患腦部常見的併發症會被放大且加快。
Sico醫師與Booss醫師、Lackland醫師表示已無相關資金上的往來。
HIV, HIV/HCV Coinfection Double the Risk for Stroke
By Barbara Boughton
Medscape Medical News
February 26, 2010 (San Francisco, California) — Patients who are coinfected with HIV and hepatitis?C virus (HCV) have a markedly increased risk for stroke — a finding that indicates that vascular risk factors need to be controlled in those with these infections, according to research presented here at the 17th Conference on Retroviruses and Opportunistic Infections.
In a large study of more than 8000 veterans, HIV-positive status was found to be associated with an increased risk for stroke, compared with those without the infection, said lead researcher and neurologist Jason Sico, MD, from the Yale University School of Medicine in New Haven, Connecticut.
"It's understood that those with HIV are more at risk for heart disease, but the risk for stroke may be underappreciated," Dr. Sico said in an interview with Medscape HIV/AIDS. "Our research shows that health risks for stroke, such as high cholesterol and metabolic syndrome, need to be addressed in those with HIV, as well as in those coinfected with HIV and HCV," he said.
In the study, researchers analyzed data on 8579 male participants in the Veterans Aging Cohort Study Virtual Cohort, and compared the incidence of stroke among those with HIV or HIV/HCV coinfection and those without these infections.
During the median follow-up of 7.3 years, the veterans experienced 160 strokes and 1181 deaths. When those with HIV or HCV/HIV were compared with uninfected individuals, the researchers found that those with HIV/HCV were at a 2-fold increased risk for stroke.
In a model in which death was used as a competing risk, those with HIV were also at a 2-fold increased risk for stroke. Because patients with HIV die sooner than those who are uninfected, adjustment for death as a confounding variable was an important part of their assessment, Dr. Sico explained. The hazard ratio dropped to 1.34 when the researchers did not adjust for mortality.
The researchers also adjusted for age, race, education, body mass index, hypertension, diabetes, smoking, hypercholesterolemia, and alcohol abuse and dependence when they characterized risk for stroke by viral status.
He noted that both HIV and HCV infection create inflammation that can increase the risk for stroke, and antiretroviral medications have adverse effects such as dyslipidemia that contribute to the enhanced risk. However, the exact biologic mechanisms for the increased risk for stroke in those with HIV and HCV need to be explored in further studies, Dr. Sico said.
"Historically, people with HIV/AIDS have not lived long enough to experience stroke. But now, in the age of antiretroviral therapy, they are surviving long enough to experience stroke," said Dr. Daniel Lackland, MD, from the Medical University of South Carolina in Charleston and a spokesperson for the American Stroke Association, in an interview with Medscape HIV/AIDS. "We do know that inflammation plays a large role in stroke, and is also part of the HIV and HCV disease process. But we need more information about the mechanisms involved," he added.
"If these findings are confirmed, a concerted effort will need to be undertaken to determine if modification of vascular risk factors adversely affected by HIV and its treatment can improve clinical outcomes," said John Booss, MD, professor emeritus in the Departments of Neurology and Laboratory Medicine at Yale University School of Medicine.
"Dr. Sico's study sheds light on the intersection of aging and chronic treated HIV infection," Dr. Booss told Medscape HIV/AIDS. "There is concern about cognitive decline in HIV infection. If one adds an increased risk of stroke, the usual complications of aging on the brain are amplified and accelerated in those with HIV infection," he added.
Dr. Sico, Dr. Booss, and Dr. Lackland have disclosed no relevant financial relationships.
17th Conference on Retroviruses and Opportunistic Infections (CROI): Abstract?668. Presented February?18, 2010.
