二. 美國流行病學對心血管疾病預防和治療的幫助（相對有效治療疾病範例）

　　美國從1950年代開始宣傳教育控制高血壓和改變飲食和生活習慣。同一個時
期，中國忙着搞革命，到了1990年代中國才開始這方面工作。比美國晚了40年。
下面這個列表總結了60年代到90年代的這30年間對於美國心血管和腦血管疾病的
明確致病因素（也叫危險因素risk factors）的控制和治療的結果。這個結果導
致了美國心血管和腦血管疾病發病率的減少。

　　TABLE 1. Estimated change in risk factors and correlates for heart
disease and stroke, by selected characteristics

　　1．20 歲到74歲診斷有高血壓的人：1960-1962年是37%，而1988-1994年是
23%。
　　Adults aged 20-74 years with hypertension*+
　　2．高血壓病人中接受治療和改變生活習慣的：1985年是79%，而1990年是
90%。
　　Persons with hypertension who are taking action to control their
blood pressure (e.g., medication, diet, reducing salt intake, and
exercise)
　　3．高血壓被有效控制的人：1976-1980年是11%，而1988-1991年是29%。
　　Persons with hypertension whose blood pressure is controlled
　　4．20 歲到74歲膽固醇升高的人：1960-1962年是32%，而1988-1994年是19%。
　　Adults aged 20-74 years with high blood cholesterol+&
　　5．成人平均膽固醇水平：1960-1962年是220 mg/dL，而1988-1994年是
203mg/dL。
　　Mean serum cholesterol levels mg/dL of adults aged >=18 years+

　　6．18歲以上抽煙的人：1965年是42%，而1995年是25%。
　　Adults aged >=18 years who are current smokers+
　　7．肥胖：1960-1962年是24%，而1988-1994年是35%。
　　Persons who are overweight+@
　　8．從脂肪懾入的卡路里比例：1976-1980年是36%，而1988-1994年是34%。
　　Percentage of calories in the diet from fat**
　　9．從飽和脂肪懾入的卡路里比例：1976-1980年是13%，而1988-1994年是
12%。
　　Percentage of calories in the diet from saturated fat**
　　10．對全民的心血管病的宣傳教育，指導，治療作為主業的醫生人數：1975
年是5046人，而1996年是14304人。
　　Number of physicians indicating cardiovascular diseases as their
primary area of practice
　　
----------------------------------------------------------------------
--------------------------------------
　　* Systolic pressure >=140 mm Hg, diastolic pressure >=90 mm Hg, or
taking antihypertensive medication.
　　+ Estimate is age-adjusted to the 1940 U.S. population.
　　& Serum cholesterol level >=240 mg/dL (6.2 mmol/L).
　　@ Defined as a body mass index >=27.8 kg/m2 among men and 27.2
kg/m2 among women.
　　** Based on 1-day dietary recall.
　　Source: References 11-14.

　　（王澄註：這篇美國的文章引用的最新文獻是1998年的。對於醫生來說，這
篇文章有些舊了。我看好的是這篇文章中對流行病學的簡要和準確地闡述，與中
醫的治未病形成鮮明的對照。另一方面，有心的人可以從最新的2007年報告中比
較這個6-7年以前的文章中的計劃和今天的實施有哪些出入。可以看出科學是怎
樣實事求是地，一步一步走過來的。下面有很多英文原文，不讀英文的讀者可以
跳過英文部分。）

　　自從1921年，心臟病成為美國人死亡的第一大原因。自從1938年，腦血管疾
病成為美國人死亡的第三大原因。兩個病死的人數占總死亡人數的40%。 從1950
年代到20世紀末的40 多年裡，美國人死於心血管病的減少了60%。它代表了20世
紀美國公共健康最重要的成就之一，這是因為對致病因素採取了積極干預的結果。
相反，中國從來不把注意力放在醫療正事上，政府整天跟着中醫瞎吆喝。到了美
國心血管病明顯減少的時代，中國迎來了心腦血管病對公共衛生的重大衝擊。

　　Achievements in Public Health, 1900-1999: Decline in Deaths from
Heart Disease and Stroke -- United States, 1900-1999
　　Heart disease has been the leading cause of death in the United
States since 1921, and stroke has been the third leading cause since
1938 (1); together they account for approximately 40% of all deaths.
Since 1950, age-adjusted death rates from cardiovascular disease (CVD)
have declined 60%, representing one of the most important public
health achievements of the 20th century. This report summarizes the
temporal trends in CVD, advances in the understanding of risk factors
for CVD, development of prevention interventions to reduce these risks,
and improvements in therapy for persons who develop CVD.

　　心血管疾病死亡率從1950年的每10萬人有307.4人下降到1996年的每10萬人
有134.6人。降幅56%。各種心血管病中，冠心病是主要死因，直到1960年以後才
開始下降。和1963年比，直到1996年冠心病比預估值總共少死了621,000人。

　　Decline in CVD Death Rates
　　Age-adjusted death rates per 100,000 persons (standardized to the
1940 U.S. population) for diseases of the heart (i.e., coronary heart
disease, hypertensive heart disease, and rheumatic heart disease) have
decreased from a peak of 307.4 in 1950 to 134.6 in 1996, an overall
decline of 56% (1) (Figure 1). Age-adjusted death rates for coronary
heart disease (the major xxxx of CVD contributing to mortality)
continued to increase into the 1960s, then declined. In 1996, 621,000
fewer deaths occurred from coronary heart disease than would have been
expected had the rate remained at its 1963 peak (1).

　　和1950年代比，中風（腦血管病）死亡已經下降了70%。從1950年的每10萬
人有88.8人降到1996年的每10萬人有26.5人。

　　Age-adjusted death rates for stroke have declined steadily since
the beginning of the century. Since 1950, stroke rates have declined
70%, from 88.8 in 1950 to 26.5 in 1996. Total age-adjusted CVD death
rates have declined 60% since 1950 and accounted for approximately 73%
of the decline in all causes of deaths during the same period (1).

　　美國流行病學的歷程（也就是中醫說的治未病）
　　Disease Epidemiology

　　二戰後，美國在1940年代大大加強了心血管病的流行病學研究。最著名的有
兩個研究，Ancel Keys 和Frammingham Heart Study。通過這些研究，發現了心
血管病的主要致病因素 the major risk factors：1。高膽固醇，2。高血壓，3。
抽煙，4。飲食中膽固醇，脂肪，和鈉鹽含量高。也發現了其它重要致病因素
other important factors：1。貧富，2。肥胖，3。少運動。這些因素涉及到生
物生態，生活方式，文化，社會狀況（條件），環境等等多方面內容。

　　Intensive investigation into the CVD epidemic largely began in the
1940s following World War II, although causal hypotheses about CVD and
recognition of geographic differences in disease rates occurred
earlier (2-4). Landmark epidemiologic investigations, including the
cross-country comparisons of Ancel Keys (5) (see box) and the
Framingham Heart Study (6), established the major risk factors of high
blood cholesterol, high blood pressure, and smoking and dietary
factors (particularly dietary cholesterol, fat, and sodium). The risk
factor concept--that particular biologic, lifestyle, and social
conditions were associated with increased risk for disease--developed
out of CVD epidemiology (3,4). In addition to the major risk factors
(i.e., high blood pressure, high blood cholesterol, and smoking),
other important factors include socioeconomic status, obesity, and
physical inactivity (7). Striking regional differences were noted
particularly for stroke mortality, with the highest rates observed in
the southeastern United States (1). Cross-national and cross-cultural
studies highlighted the importance of social, cultural, and
environmental factors in the development of CVD.

　　預防
　　Advances in Prevention

　　40年代調查，50年代確認，（大眾教育已經開始了），60年代開始實驗性干
擾心血管病的各種致病因素，看看能不能把心血管病的發病率和死亡率減低下來。
70年代和80年代，無數臨床實驗確定了抗高血壓藥和降血脂藥的預防心血管疾病
的作用。其它公共健康事業的努力不僅減少了個人患心血管疾病的危險，同時也
減少了群體患心血管疾病的危險，比如禁止抽煙，大幅度提高煙稅和煙價，減少
抽煙人數。減少精神壓力。國家加強對醫務人員，病人和普通民眾的教育。

　　Early intervention studies in the 1960s sought to establish
whether lowering risk factor levels would reduce risk for CVD (2-4).
During the 1970s and 1980s, along with numerous clinical trials
demonstrating the efficacy of antihypertensive and lipid-lowering drugs,
community trials sought to reduce risk at the community level (9).
Public health interventions to reduce CVD have benefited from a
combination of the "high risk" approach--aimed at persons with
increased risk for CVD--and the population-wide approach--aimed at
lowering risk for the entire community (10). National programs that
combine these complementary approaches and that are aimed at
health-care providers, patients, and the general public include the
National High Blood Pressure
　　Education Program (11), initiated in 1972, and the National
Cholesterol Education Program, initiated in 1985 (12).

　　以前國家的目標集中在心血管腦血管疾病，1989年開始展開慢性疾病的預防
和教育。
　　Although earlier CDC community demonstration projects focused on
cardiovascular health (9), CDC established its National Center for
Chronic Disease Prevention and Health Promotion in 1989, with a high
priority of promoting cardiovascular health.

　　哪些工作對心血管病死亡率下降起到作用？
　　Factors Contributing to the Decline in CVD Deaths

　　（見前表）減少抽煙人數。減少抽煙也同時減少癌症的發生率。降低血壓。
更多的高血壓得到控制。降低血中膽固醇。改變飲食成分。
　　Reasons for the declines in heart disease and stroke may vary by
period and across region or socioeconomic groups (e.g., age, sex, and
racial/ethnic groups). Prevention efforts and improvements in early
detection, treatment, and care have resulted in a number of beneficial
trends (Table 1), which may have contributed to declines in heart
disease and stroke. These trends include

　　a decline in cigarette smoking among adults aged greater than or
equal to 18 years from approximately 42% in 1965 to 25% in 1995 (13).
Substantial public health efforts to reduce tobacco use began soon
after recognition of the association between smoking and CVD and
between smoking and cancer and the first Surgeon General's report on
smoking and health published in 1964.
　　a decrease in mean blood pressure levels in the U.S. population
(11,13,14).
　　an increase in the percentage of persons with hypertension who
have the condition treated and controlled (11,13,14).
　　a decrease in mean blood cholesterol levels (12-14).
　　changes in the U.S. diet. Data based on surveys of food supply
suggest that consumption of saturated fat and cholesterol has
decreased since 1909 (15). Data from the National Health and Nutrition
Examination surveys suggest that decreases in the percentage of
calories from dietary fat and the levels of dietary cholesterol
coincide with decreases in blood cholesterol levels (16).

　　改進診斷和治療心血管病和腦血管病的技術。開發更好的更有效的藥物。培
養更多這方面的醫務人員。加強心肌梗死和中風的急症治療。增加急症治療（醫
院）單位。
　　improvements in medical care, including advances in diagnosing and
treating heart disease and stroke, development of effective
medications for treatment of hypertension and hypercholesterolemia,
greater numbers of specialists and health-care providers focusing on
CVD, an increase in emergency medical services for heart attack and
stroke, and an increase in coronary-care units (13,17). These
developments have contributed to lower case-fatality rates, lengthened
survival times, and shorter hospital stays for persons with CVD (1,17).

　　21世紀美國面臨的心血管疾病問題
　　Challenges for the 21st Century

　　發現了心血管和腦血管病有種族，性別，貧富，地區之間的差異。（後略）
　　70%的高血壓病人的血壓沒有降到標準值，140/90。中風病人的死亡率不再
下降了（1998年報告）。老人多了，心肌梗死後人死的少了，造成心衰病人多了。
美國肥胖的人數在增加。

　　Although many trends have been positive, trends for some important
indicators have not improved substantially, have leveled off, or are
reversing. For example, approximately 70% of persons with hypertension
do not have the condition controlled at levels below 140/90 mm Hg, and
death rates for stroke have not declined in recent years (1,11,13).
Heart failure has emerged as a health concern for older adults (20),
and adults who survive a myocardial infarction or other
hypertension-related diseases remain at increased risk for heart
failure. In addition, the pr????ence of obesity has increased among
both children and adults in the United States (13).

　　面向21世紀
　　Major public health challenges for the 21st century include

　　美國需要：繼續減少和預防致病因素。進一步研究和發現心血管病的社會，
精神病學，環境，生理學，和遺傳學因素。（王澄註：這就是中醫說的天人合
一。）重視發病率高的種族群體。減少中風死亡率。對相對缺醫少藥的地區和人
群要加強指導和教育。促進對人民健康（行為）有利的政策和環境法規出台。確
定遺傳和心血管疾病的關係，特別是遺傳和環境之間的相互作用。今後遺傳（和
環境）的因素的研究會越來越重要。因為癌症和心血管疾病都有兩大原因，環境
和遺傳。當一個有錢且負責的政府盡力把環境因素減到最小的時候，比如飲食飲
水衛生，飲食結構合理，減少環境污染等等，人類的遺傳因素就越來越凸現了。

　　發現和確定新的因素，比如homocyst(e)ine, fibrinogen, and C-reactive
protein, and infectious agents such as Helicobacter pylori and
Chlamydia pneumoniae. 面對人口老化和心血管病存活的人增加，功能障礙和生
活品質問題越來越突出。防止已有心血管病的病人病情惡化。國際合作，心血管
病在發達國家人口中比例高，但是在發展中國家病人人數多。和發達國家比，發
展中國家還多了一個困難，就是感染性疾病。比如，中國2006年報告了174506例
梅毒病例。

　　reducing risk factor levels and preventing the development of
adverse risk factors. Continued research is needed to understand the
determinants (social, psychological, environmental, physiologic, and
genetic) of CVD risk factors.
　　reducing the racial/ethnic disparities in heart disease and stroke
mortality.
　　increasing the ability to reach underserved groups with
appropriate and effective public health messages.
　　promoting policy and environmental strategies that enhance healthy
behavior.
　　determining the relation between genetics and disease. The
associations of genetic variants with CVD, and especially the
interplay between genetic and environmental factors, may play
increasingly important roles in the nation's efforts to prevent CVD.
　　identifying new or emerging risk factors and determining their
potential for public health intervention. New or emerging risk factors
that have been associated with CVD include elevated levels of total
homocyst(e)ine, fibrinogen, and C-reactive protein, and infectious
agents such as Helicobacter pylori and Chlamydia pneumoniae.
　　focusing on secondary prevention and disability. An aging U.S.
population and an increasing number of persons surviving
life-threatening cardiovascular conditions requires public health
programs to focus on issues such as disability and quality of life.
Persons with existing cardiovascular conditions are at increased risk
for future life-threatening events related to those conditions.
　　addressing the needs of the global community. Although CVD death
rates are higher in developed nations, most cases occur in developing
nations (8). Developing countries may face a double burden of
infectious and chronic diseases. International collaboration to
improve cardiovascular health (9) will need to continue to reduce the
burden of CVD worldwide.
　　Reported by: Cardiovascular Health Br, Div of Adult and Community
Health, National Center for Chronic Disease Prevention and Health
Promotion, CDC.

　　參考文獻（略）