本帖最後由 lsc0019 於 2009-3-12 16:39 編輯
作者：Laurie Barclay, MD
出處：WebMD醫學新聞
February 24, 2009 — 一項發表於2月20日線上英國醫學期刊的以群體為基礎的前瞻性研究發現，合併四種健康行為模式可預測發生中風達兩倍以上的差異。
英國諾威治東英格蘭大學衛生政策與管理學院的Phyo K. Myint與同事寫到，生活型態的行為好比抽菸、運動與飲食，會影響心血管疾病的發生率，也包括中風。之前我們觀察四種健康行為對於社區中男性與女性死亡率的影響，包括抽菸、運動、喝酒與蔬果的攝取，我們發現這些健康行為對於40到79歲的男性與女性預防中風具有正面效益。
歐洲癌症前瞻性調查諾福克研究追蹤2007年居住在英國諾福克社區的成人，研究由20,040位經調查在1993年至1997年間沒有已知的中風、或心肌梗塞的40至79歲男性與女性組成。受試者被標記為零至四分，如果有以下健康行為任一項即得一分：目前沒有抽菸；有在運動；適當酒精攝取（每週1-14單位）；以及每天攝取五份或以上蔬果，維他命C反映在血中濃度要大於50 μmol/L。
平均追蹤期間為11.5年，在追蹤的229,993人次/年中，發生599次中風；在校正年紀、性別、身體質量指數、收縮壓、膽固醇濃度、是否有糖尿病或投予Aspirin，及社經地位後，擁有三項健康行為相較於四項健康行為的相對危險風險為1.15（95%信賴區間為0.89至1.49），兩項健康行為是1.58（95% 信賴區間為1.22至2.05），一項健康行為是2.18（95% 信賴區間為1.63至2.92），無任何健康行為則是2.31（P<.001）。
次組分析性別、年齡、身體質量指數及社經地位，皆有相似的結果；排除兩年內死亡的案例也不影響觀察到的結果。
研究作者寫到，合併四項健康行為能預測男性與女性發生中風達兩倍以上的差異；對於關注生活型態的些微改變就能減低風險，這些結果提供更多鼓勵與支持。
本研究的限制包括可能相反的因果關係或是殘餘的干擾因素、在評估暴露於風險的潛在衡量誤差、絕大部分人具有某些、或是全部正面健康的行為、排除了將近9,000個已填寫同意書，但無法參與健康檢查的受試者、以及潛在將中風或非中風做錯誤分類的可能。
在一篇隨後的主編評論中，英國牛津約翰拉德克利夫醫院生物醫學研究中心中風防治單位的Matthew F. Giles博士表示，本研究還有其他限制，包括錯誤區分缺血性或出血性中風，以及將維他命C濃度當作代替蔬果攝取的指標。
Giles博士寫到，不論是在觀察性或隨機的控制研究，對於不同族群發生中風以及合併健康行為的關係是值得鼓勵的。結論是，生活型態可以預測中風發生與否，能幫助個人做選擇以及政策的決定。為了達到目標必須改變行為，但即使生活型態的介入有最大的好處，也有一些是不被鼓勵用於少數族群的中風預防。
歐洲癌症前瞻性調查諾福克研究由英國癌症研究與醫學研究會贊助，其他贊助單位包括中風學會、英國心臟基金會、老化研究、醫學科學學會與衛爾康信託，作者與Giles博士表示無相關資金上的往來。
Four Health Behaviors Combined Help Predict Stroke Incidence
By Laurie Barclay, MD
Medscape Medical News
February 24, 2009 — Four health behaviors combined predict more than a 2-fold difference in stroke incidence in men and women, according to the results of a population-based prospective study reported in the February 20 Online First issue of the BMJ.
"Lifestyle behaviours such as smoking, physical activity, and diet influence the risk of cardiovascular disease, including stroke," write Phyo K. Myint, from School of Medicine, Health Policy and Practice, University of East Anglia, Norwich, United Kingdom, and colleagues. "Previously we looked at the combined impact of four health behaviours — smoking, physical activity, alcohol intake, and fruit and vegetable intake — on total and cause specific mortality in men and women living in the general community. As these health behaviours could beneficially affect the incidence of stroke we examined the potential magnitude of their combined impact on incidence of stroke in men and women aged 40-79."
In the European Prospective Investigation of Cancer–Norfolk study, adults living in the general community in Norfolk, United Kingdom, were followed up to 2007. The study cohort consisted of 20,040 men and women aged 40 to 79?years with no known stroke or myocardial infarction when surveyed at baseline from 1993 to 1997. Participants were scored from 0 to 4, receiving 1 point for each of the following health behaviors: current nonsmoking; physically not inactive; moderate alcohol intake (1 - 14 units a week); and fruit and vegetable intake of 5 or more servings daily, as reflected by plasma concentration of vitamin C of 50 μmol/L or more.
Average follow-up was 11.5 years. During 229,993 person-years of follow-up, there were 599?incident strokes. Compared with people with all 4 health behaviors, the relative risks for stroke for men and women were 1.15 (95% confidence interval [CI], 0.89 - 1.49) for 3 health behaviors, 1.58 (95% CI, 1.22 - 2.05) for 2 health behaviors, 2.18 (95% CI, 1.63 - 2.92) for 1?health behavior, and 2.31 (95% CI, 1.33 - 4.02) for no health behaviors (P?
Subgroups based on sex, age, BMI, and social class all had similar findings. Exclusion of deaths within 2 years also did not affect the observed pattern of results.
"Four health behaviours combined predict more than a twofold difference in incidence of stroke in men and women," the study authors write. "These results provide further incentive and support for the notion that small differences in lifestyle can have a substantial potential impact on risk."
Limitations of this study includepossible reverse causality or residual confounding, potential measurement errors in the assessment of exposures, relatively high proportions of the population with some or all positive health behaviors, exclusion of approximately 9000 participants who consented to the study but were unable to attend the health check, and possible misclassification of stroke vs nonstroke.
In an accompanying editorial, Dr. Matthew F. Giles, from the Stroke Prevention Research Unit, Biomedical Research Centre, John Radcliffe Hospital, Oxford, United Kingdom, notes additional limitations of the study, including failure to differentiate ischemic and hemorrhagic strokes, and use of vitamin C concentration only as a surrogate marker for fruit and vegetable intake.
"It is encouraging that the association between the risk of stroke and combined health behaviour is consistent across different populations, and between observational and randomised controlled trials," Dr. Giles writes. "The conclusion that lifestyle predicts the risk of stroke should help to inform individuals' choices and policy makers' decisions. However, what is also consistent but less encouraging is the small proportion of participants with a lifestyle that protects against stroke — although lifestyle interventions could be of great benefit, a huge shift in behaviour will be needed to achieve this."
European Prospective Investigation of Cancer–Norfolk is supported by research program grant funding from Cancer Research United Kingdom and the Medical Research Council, with additional support from the Stroke Association, British Heart Foundation, Research Into Ageing, Academy of Medical Sciences, and Wellcome Trust. The study authors and Dr. Giles have disclosed no relevant financial relationships.
BMJ. Published online February 20, 2009. |
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