JAMA. 2005;294 (23)

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Hi All,

There are five items from this week for the journal JAMA that may interest some

of

us.

(1) is a commentary on the importance of maintaining our health.

(2) is an introduction to (3), in which heart fitness is reported to be a risk

for

having heart disease risk factors.

(4) is an article describing how erection difficulties correlate with later

heart

disease.

(5) is a paper relating our exposure to air pollution with heart disease ill

health

indicators.

1. Commentaries

On the Preservation of Health

A. Barondess

JAMA. 2005;294:3024-3026.

Health is intrinsically unstable and is subject to erosive forces across the

life

trajectory, from intrauterine life to old age. As a result, few individuals

achieve

idealized versions of the lifespan (ie, good health and functional status into

very

advanced years, with compression of morbidity toward the end of life).1

Each person may be thought of as having, at birth, a certain quantum of health

expectancy, determined by the characteristics of the individual genome and the

biological quality of the intrauterine environment in which the fetus has

developed.

The quantum is affected over time as the biological, psychosocial, and

behavioral

characteristics of the individual interact with environmental, socioeconomic,

and

educational factors, and with the amount and quality of the health care received

over the life course.

Programs aimed at reduction of risk through health promotion at the individual

or

population level have been effective to some degree, but such efforts are

frequently

post hoc in nature, addressing secondary or tertiary prevention needs. In

addition,

these efforts are disarticulated across the lifespan, with childhood and

adolescent

clinical and public health interventions discontinuous from those in the adult

years. Furthermore, the latter often focus on behavioral and environmental

health

risks only after they have been unaddressed for long periods, with incipient,

clinically silent disease already established. In fact, risk exposures tend to

increase in number, chronicity, and cumulative importance over the life

trajectory,

resulting in gradual erosion of health status and of future health prospects.

A more consistent effort organized around health preservation as a framing

paradigm,

instituted early in life, and addressed to mitigating risk factors through a

more

syncytial and coherent life course approach is suggested by a number of factors.

First, health risks are present throughout the life course and vary in nature

over

time, from intrauterine life to old age. Second, many clinical disorders that

manifest in adult life represent late stages of long-standing occult disease,

suggesting that earlier, even lifelong, application of preventive or moderating

efforts might be more effective. Third, increasing evidence suggests that

important

causes of morbidity in adult life have their origins very early and, in some

instances, may be to a significant degree determined before birth or

neonatally.2

Fourth, health-related behaviors are acquired in more or less staccato fashion

over

the lifespan, and once-acquired, health-adverse behaviors are often difficult to

disestablish, such as eating and physical activity patterns acquired in

childhood,

initiation of tobacco use, or exposure to illicit drugs in adolescence.

Despite an increase in life expectancy at birth of approximately 30 years during

the

past century in the United States,3 most individuals are subject to gradual

impairment of health. These impairments often become overt in the middle years

of

life; chronic diseases are the most common proximate causes. With advancing age,

the

occurrence and continuation of chronic disease is common; 80% of

community-dwelling

US individuals older than 65 years have at least 1 identified chronic disease

and

48% have 3 or more chronic diseases.4 The disorders that represent the chief

causes

of death largely reflect longstanding risk factors and many are characterized by

long clinical latency and progress silently often for years before becoming

clinically apparent. To a considerable extent, these disorders reflect the

effect of

health-adverse personal behaviors that are responsible for an estimated 40% of

deaths in the United States.5-6

The health effects of many of the major risk factors are avoidable or reversible

to

substantial degrees. Realization of the targets established in the most recent

Healthy People 2010 report7 is estimated to potentially increase healthy life

expectancy by 5.8 to 8.1 years.8 Studies among the Seventh Day Adventist

population

have suggested that optimal health-related personal behaviors could add 10 years

to

average life expectancy.9 Other studies indicate sharp reductions in health risk

with cessation of smoking and with the adoption of regular exercise patterns,

even

in old age.10 Appropriate clinical interventions in disease management have also

been associated with improved health outcomes, such as myocardial infarction,

depression, low birth weight, cataracts, and breast cancer.11 Mitigation of

social

and economic factors that adversely impact health presents a more complex set of

issues. Many of these factors are related to public policy, such as the

availability

of adequate housing, the nature and comprehensiveness of health insurance

programs,

remediation of toxic environments, and efforts to reduce poverty and thereby its

health impacts.

Patterns of health erosion are not evenly distributed in the US population.

Sharp

disparities in life expectancy and in health across the life trajectory

characterize

racial and ethnic minorities in the United States, as well as those who are

socioeconomically disadvantaged, groups that overlap substantially. For example,

black individuals in the United States have higher rates of obesity, diabetes

mellitus, and hypertension,3, 12-13 higher death rates from cancer,14 and

shorter

life expectancy than white individuals (72.3 vs 77.7 years in 2000).3

Furthermore, a

number of important behavioral and environmental risk factors disproportionately

affect disadvantaged subsets of the population, such as unhealthy diets,

substance

abuse, and health-adverse environments.15-16

The potential utility of a life course approach to protection of the health

quantum

is suggested by overall risk tending to build by accretion rather than

substitution.

Risks incurred even very early may have serious health effects that appear only

much

later. For example, small body size at birth, a marker of an adverse

intrauterine

environment, has emerged as a putative risk factor for death from cardiovascular

disease in adult life in men and for all-cause mortality in women.17 Infant

growth

rates substantially below normal and small body size at age 1 year may predict

coronary heart disease in adult life even more strongly than low birth weight.18

The

development of the metabolic syndrome in late life has been associated with low

rates of fetal and infant growth.19 Other studies have suggested that early

postnatal growth acceleration, particularly in the first 2 weeks of life, may

program later cardiovascular risk, insulin resistance, and obesity.2

The emergence of indicators of important chronic disease in childhood is

indicated

by a number of studies. Fatty streaks and fibrous plaques have been identified

in

the aortas and coronary arteries of children and young adults.20 Coronary artery

disease has been documented in young US combat fatalities in Korea and

Vietnam.21-22

In the Bogalusa Heart Study,23 such lesions not only appeared early but

increased

significantly as children aged and were related to the number of risk factors

present, including obesity, high systolic blood pressure, serum triglyceride

concentration, and low-density lipoprotein levels. These risk factors tended to

cluster in individuals and, importantly, to persist into adulthood. Such studies

suggest that heart disease prevention should begin in childhood24 and should

include

efforts in health education, with special attention to diet and exercise

patterns.

Additional risk factors and clinically apparent morbidities emerge in

adolescence

and youth, including initiation of tobacco use, exposure to sexually transmitted

diseases including human immunodeficiency virus (HIV), and initiation of

substance

abuse with associated risks of transmission of HIV and hepatitis C. These risks

are

added to patterns of poor nutrition and inadequate exercise that often persist

from

childhood, with resultant obesity and associated type 2 diabetes mellitus.

Violence

is an additional risk at this time of life, especially for disadvantaged youth,

as

is suicide, linked largely to situational pressures and depression.25

In adult life, the primary health erosive forces are often superimposed on

preexisting and ongoing risk factors and include the emergence of important

silent

or symptomatic disease, particularly cancer, ischemic heart disease,

hypertension,

diabetes mellitus, and glaucoma. In older age groups, erosion of health

accelerates

as multiple diseases reach clinical expression, as exposures to adverse social

circumstances are added, including narrowing of social networks, and as chronic

feelings of stress, depression, and loss of autonomy further compromise

well-being

and functionality.26 In addition, opportunities and capacity for physical

activity

decrease due to social isolation, physical limitations, and inadequate

opportunities

in the environment for walking or other forms of exercise.

The health preservation perspective implies the application of risk mitigation,

screening, and remediation over the life course in a manner that engages the

individual and his or her clinical caregivers, as well as the public health and

policy enterprises. Attention to environmental risks, prevention programs

related to

drug use, needle exchange programs, and extensive efforts in health education in

schools are examples of public health elements that should be to a greater

extent

interlaced with those of the clinical community. Substantial federal investment

in

the electronic medical record would help with the important business of linking

the

efforts of clinical and public health communities. Socioeconomically linked

differentials in health and life expectancy indicate the need for public

policies

that more effectively address problems in access to health care, especially for

the

uninsured, as well as programs designed specifically to clarify and address the

causes and consequences of health disparities affecting racial and ethnic

minorities. For example, reducing the risk of low birth weight requires maternal

awareness of health needs in pregnancy and enhanced access to adequate prenatal

care, including for disadvantaged women overcoming barriers posed by the

Medicaid

enrollment process or eligibility issues.

The health preservation paradigm emphasizes the chronicity of risks to health,

the

importance of ongoing interventions attuned to varying health pressures as they

emerge over the life trajectory, and the need for more closely articulated

preventive, clinical, public health, and policy programs. Through development of

a

more coherent view of health under chronic pressure, it may be possible to

construct

a sense of increasing alliance among the various elements of the health

equation,

and also to form a sense of partnership between the individual and his or her

health.

2. This Week in JAMA

JAMA. 2005;294:2943.

Cardiovascular Disease and Cardiorespiratory Fitness

Low cardiorespiratory fitness associated with physical inactivity is a risk

factor

for cardiovascular disease (CVD). To describe the prevalence of low fitness in

the

US population aged 12 through 49 years and to relate low fitness to CVD risk

factors, Carnethon and colleagues reviewed results of submaximal graded exercise

testing and maximal oxygen consumption from a nationally representative survey.

They

found low fitness in 33.6% of adolescents and 13.9% of adults. Among their

findings

were that body mass index and waist circumference were inversely associated with

fitness and that persons with low fitness had higher total cholesterol levels

and

systolic blood pressure and lower high-density lipoprotein cholesterol levels

compared with persons with high fitness.

3. Prevalence and Cardiovascular Disease Correlates of Low Cardiorespiratory

Fitness

in Adolescents and Adults

Mercedes R. Carnethon; Martha Gulati; Philip Greenland

JAMA. 2005;294:2981-2988.

ABSTRACT

Context Population surveys indicate that physical activity levels are low in

the

United States. One consequence of inactivity, low cardiorespiratory fitness, is

an

established risk factor for cardiovascular disease (CVD) morbidity and

mortality,

but the prevalence of cardiorespiratory fitness has not been quantified in

representative US population samples.

Objectives To describe the prevalence of low fitness in the US population aged

12

through 49 years and to relate low fitness to CVD risk factors in this

population.

Design, Setting, and Participants Inception cohort study using data from the

cross-sectional nationally representative National Health and Nutrition

Examination

Survey 1999-2002. Participants were adolescents (aged 12-19 years; n = 3110) and

adults (aged 20-49 years; n = 2205) free from previously diagnosed CVD who

underwent

submaximal graded exercise treadmill testing to achieve at least 75% to 90% of

their

age-predicted maximum heart rate. Maximal oxygen consumption (O2max) was

estimated

by measuring the heart rate response to reference levels of submaximal work.

Main Outcome Measures Low fitness defined using percentile cut points of

estimated

O2max from existing external referent populations; anthropometric and other CVD

risk

factors measured according to standard methods.

Results Low fitness was identified in 33.6% of adolescents (approximately 7.5

million US adolescents) and 13.9% of adults (approximately 8.5 million US

adults);

the prevalence was similar in adolescent females (34.4%) and males (32.9%) (P =

..40)

but was higher in adult females (16.2%) than in males (11.8%) (P = .03).

Non-Hispanic blacks and Mexican Americans were less fit than non-Hispanic

whites. In

all age-sex groups, body mass index and waist circumference were inversely

associated with fitness; age- and race-adjusted odds ratios of overweight or

obesity

(body mass index 25) ranged from 2.1 to 3.7 (P<.01 for all), comparing persons

with

low fitness with those with moderate or high fitness. Total cholesterol levels

and

systolic blood pressure were higher and levels of high-density lipoprotein

cholesterol were lower among participants with low vs high fitness.

Conclusion Low fitness in adolescents and adults is common in the US population

and

is associated with an increased prevalence of CVD risk factors.

4. Erectile Dysfunction and Subsequent Cardiovascular Disease

Ian M. ; M. Tangen; Phyllis J. Goodman; L.

Probstfield;

Carol M. Moinpour; A. Coltman

JAMA. 2005;294:2996-3002.

5. Long-term Air Pollution Exposure and Acceleration of Atherosclerosis and

Vascular

Inflammation in an Animal Model

Qinghua Sun; Aixia Wang; Ximei Jin; Natanzon; Damon Duquaine; D.

Brook;

-Gilberto S. Aguinaldo; Zahi A. Fayad; Valentin Fuster; Morton Lippmann;

Lung

Chi Chen; Sanjay Rajagopalan

JAMA. 2005;294:3003-3010.

Al Pater, PhD; email: old542000@...

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