 |
|
The Increasing Incidence of Coronary Artery Disease and Cardiovascular Risk Factors Among a Southwest Native American Tribe
The White Mountain Apache Heart Study
Justin L. Sewell, MPH;
Beth R. Malasky, MD;
Curtis L. Gedney, MD, PhD;
Trevor M. Gerber, BA;
Eric A. Brody, MD;
Edith A. Pacheco, RN;
David Yost, MD;
Betty R. Masden, PA-C;
James M. Galloway, MD
Arch Intern Med. 2002;162:1368-1372.
ABSTRACT
| |
Background Rates of cardiovascular disease and its risk factors seem to be increasing
in American Indian populations, yet these changes have received little documentation.
Objectives To evaluate incidence rates of coronary artery disease, acute myocardial
infarction, and cardiac events during a 10-year period (1987-1996); to assess
cardiac risk factors for an American Indian tribe in Arizona.
Methods A retrospective medical chart review was performed for tribal members
from January 1, 1987-December 31, 1996. Patient records with even minor indications
of coronary disease were reviewed independently by 2 cardiologists of the
Native American Cardiology Program. Multiple databases were reviewed in an
effort to find all diagnoses, and incidence rates were calculated and analyzed
for increasing trends. Cardiac risk factors were assessed in a population
convenience sample.
Results From 1987 through 1996, the number of incident cases increased from
3 to 18 for coronary artery disease, 1 to 10 for acute myocardial infarction,
and 3 to 26 for cardiac events. Statistically significant increasing trends
were calculated for each. Of our youthful convenience sample, 49% had 2 or
more cardiac risk factors.
Conclusions This study confirms increasing rates of coronary artery disease and
its comorbidities in this American Indian population and demonstrates high
prevalence of cardiovascular risk factors among tribal members without extant
coronary disease. This suggests that coronary disease will likely continue
to increase as this population ages. To prevent such increases, culturally
appropriate, aggressive preventive interventions are needed.
INTRODUCTION
DESPITE RECENT, large-scale efforts to eliminate health disparities
in minority populations,1-2 current
clinical impressions and studies suggest that the incidence of cardiovascular
disease (CVD) and its associated risk factors may be increasing among American
Indian populations.3 This is in distinct contrast
to the historically held belief that American Indian groups have low rates
of CVD.
Numerous studies dating from the early 20th century through the early
1990s have documented an exceedingly low incidence and prevalence of coronary
artery disease (CAD) and acute myocardial infarction (AMI) in American Indian
populations relative to the general US population.4-9
According to a 1963 study,6 the rate of death
from heart disease in the general US population was 2.5 times greater than
the rate for American Indians. A more recent study8
found that among Navajo patients, the rate of discharge for AMI from major
tertiary care medical facilities in and around the reservation between 1976
and 1983 was relatively low (0.6 and 1.8 cases per 1000 persons per year for
patients aged 45-64 years and  65 years, respectively) compared with the
general US population (4.3 and 9.4 cases per 1000 persons per year, for the
same age groups). As recently as 1993, research has continued to show lower
rates of AMI among American Indians and Alaskan natives relative to the general
US population (11.8 hospital discharges per 10 000 population for American
Indians and Alaskan natives vs 29.1 per 10 000 population for the general
US population).10 Of particular interest is
a publication6 demonstrating a previously low
rate of CAD among the White Mountain Apache Tribe (WMAT), the group under
consideration in the current research; between 1952 and 1960, not a single
case of CAD was identified at the Indian Hospital on the White Mountain Apache
Reservation.
Concordant with these previously low rates of CAD and AMI were low rates
of cardiovascular risk factors in American Indians when compared with the
general US population. However, many of the cardiovascular risk factors that
were infrequent in American Indian populations have recently increased to
levels equal to or greater than the general US population as shown by the
Strong Heart Study.11-12
In the past, hypertension was infrequent in American Indian populations.
In 1937, the incidence of hypertension among Navajo Indians was about one
tenth of a percent,13 and in 1963, the rate
was 4.7% in the same group.7 Recent studies,
however, have indicated much higher rates of hypertension among American Indian
populations. The Strong Heart Study12 found
a prevalence of hypertension ranging from 32% to 51% for men and women from
other tribes in Arizona, North and South Dakota, and Oklahoma. Strong Heart
Study research also found that hypertension conferred an increased likelihood
of coronary heart disease in this population.11
Hypercholesterolemia was also less common historically among American
Indians than in the general US population. In 1986, Coulehan et al8 suggested that cholesterol levels among American Indians
averaged 20% to 40% lower than comparable white groups. More recent studies,
however, have revealed that lipid levels among American Indians are increasing.
In 1992, 33.8% of Navajo men aged 25 to 74 years studied had significantly
elevated total cholesterol levels (>240 mg/dL [6.22 mmol/L]), whereas only
27.6% of the general population surveyed in the Second National Health and
Nutrition Examination Survey had levels this high.14
The most profound recent trend has been the increasing rates of diabetes
mellitus and obesity among many American Indian populations, often to epidemic
proportions. Although surveys of tribal members have supported low rates of
diabetes in prior generations, recent data from the Strong Heart Study identified
prevalence rates of diabetes ranging from 25% to 67% among participants aged
45 to 74 years.12 Among these Strong Heart
Study participants, diabetes conferred a 3.8-fold increased likelihood of
definite myocardial infarction and 4.6-fold increased likelihood of definite
CAD compared with nondiabetes.11 Furthermore,
in a 1993 study, Justice15 found evidence supporting
recent increases in diabetes rates among American Indians; a study of the
Tohono O'odham Tribe in Arizona found that most patients with diabetes (62.8%)
had a duration of disease of less than 10 years, and 42.4% of the patients
with diabetes had a duration of disease of less than 5 years. Finally, although
the age-adjusted diabetes-related death rates increased 5% (to a rate of approximately
40 per 100 000 population) for the general US population between 1988
and 1993, they increased by 15% (to a rate of approximately 60 per 100 000
population) for American Indians, the largest increase of any ethnic group.16
In accordance with increasing cardiovascular risk factors, increasing
rates of CAD and cardiac events among American Indians are beginning to be
documented. Data from the Indian Health Service (CAD death rate of 135.6 per
100 000 population from 1992-1994) and the American Heart Association
(CAD death rate of 102.2 per 100 000 population for 1998) identify CAD
as the leading cause of death among American Indians.17-18
In fact, age-adjusted death rates for CAD and all cardiovascular diseases
are now higher for the American Indian than for the general US population.
Death rates for American Indians in 1992 through 1994 were 157.6 per 100 000
population and 194.6 per 100 000 population for CAD and CVD, respectively.
Death rates for the general US population for these same diseases in 1993
were 145.3 per 100 000 population and 181.8 per 100 000 population.17 Furthermore, the Strong Heart Study found current
cardiovascular incidence rates for American Indians to be almost twice those
of the general US population. Incidence of CVD (fatal and nonfatal) was 7
and 16 per 1000 person-years for American Indian women and men, respectively,
whereas rates for the general US population were 3 and 9 per 1000 person-years.3
Data on the cardiovascular health status of American Indians necessary
to develop broad and effective preventive intervention strategies are limited.
Specifically, the recent and marked changes in CVD epidemiology have not been
well documented. The White Mountain Apache Heart Study was thus developed
to study the incidence of CAD, AMI, and cardiac events and the prevalence
of cardiovascular risk factors in the WMAT of Arizona.
METHODS
This study involved a determination of the incidence rates for CAD,
AMI, and cardiac events during a 10-year period and a determination of the
current cardiovascular risk factor prevalence in a convenience sample of WMAT
members.
INCIDENCE DETERMINATION
A retrospective medical chart review was performed of WMAT members aged
45 to 79 years who initially presented to the Whiteriver Public Health Service
Hospital (WPHSH) from January 1, 1987 through December 31, 1996, including
transfers and referred admissions to the cardiovascular referral hospital,
the University Medical Center (UMC) in Tucson, Ariz. Because almost every
cardiac referral from WPHSH is sent to UMC, referrals to any other hospitals
were determined to be too infrequent for the purposes of this study.
The following databases were reviewed for potential cases: the emergency
department log, inpatient admissions log, and transfer log from WPHSH; the
Indian Health Service Death Log for patients with nontraumatic fatality; and
the database of inpatients transferred from WPHSH to UMC. From these sources,
a list of patients with possible CAD was generated and available medical records
were reviewed; patients with even minor indications were reviewed as well.
The following indicators were used to select potential cases: chest pain,
shortness of breath, congestive heart failure, arm pain, jaw pain, indigestion,
and back pain, as well as diagnoses of AMI, angina, unstable angina, or CAD.
Trained field abstractors evaluated all records and identified probable cases.
Final diagnoses were subsequently made independently by 2 cardiologists of
the Native American Cardiology Program at the University of Arizona (E.A.B.
and J.M.G.).
A diagnosis of AMI required at least 2 of the following criteria: prolonged
cardiac pain, cardiac enzyme levels greater than twice the upper limit of
normal range, or evolving, diagnostic resting electrocardiograms. A diagnosis
of new CAD required a cardiac catheterization revealing at least 50% stenosis
in 1 or more coronary arteries or their major branches or, in the absence
of a cardiac catheterization, a classic AMI presentation with positive isoenzymes
and evolving, diagnostic electrocardiograms. It was also required that the
patient have no history of CAD before the presentation investigated. A diagnosis
of a cardiac event was a definite or possible AMI as commonly defined by other
researchers,11 a diagnosis of unstable angina
(a clinical syndrome of chest pain of increasing frequency, increasing severity,
or chest pain at rest confirmed by cardiac catheterization with at least 70%
stenosis in a major or branch epicardial vessel), or a non–Q-wave myocardial
infarction confirmed by cardiac catheterization.
Annual population estimates were provided by the WMAT Office of Vital
Records and serve as denominators for incidence calculations. Incidence was
calculated for CAD, AMI, and cardiac events per 100 000 population for
2-year intervals, and 95% confidence intervals were calculated using the Poisson
distribution.
RISK FACTOR PREVALENCE DETERMINATION
To provide a conservative estimate of risk factor prevalence, a convenience
sample of 70 WMAT members aged 18 to 46 years (mean age, 27.3 years) was selected
for persons applying for an occupation requiring sustained, vigorous physical
activity. A physician interviewed and examined each participant. Recorded
data included age, weight, body mass index (calculated as weight in kilograms
divided by the square of height in meters), sex, personal and family history
of CVD, smoking history, and presence of diabetes mellitus, hypertension,
and dyslipidemia. Laboratory analyses included lipid profiles, urinalysis,
and serum glucose, blood urea nitrogen, and creatinine measurement. Resting
electrocardiograms were also performed.
Six cardiovascular risk factors were evaluated to create cardiovascular
risk profiles. Obesity was defined as a body mass index of 30 or more. Hypertension
was defined as medical chart–documented diagnosis of hypertension with
3 consecutive blood pressure measurements of 140/90 mm Hg or higher or hypertensive
medication use. Dyslipidemia was defined as total cholesterol level of more
than 240 mg/dL (6.22 mmol/L), low-density lipoprotein cholesterol level of
more than 160 mg/dL (4.14 mmol/L), high-density lipoprotein cholesterol level
of less than 40 mg/dL (1.04 mmol/L), triglyceride levels of more than 250
mg/dL (2.83 mmol/L), and/or lipid medication use. Diabetes mellitus was defined
as medical chart–documented diagnosis of diabetes mellitus, use of medications
for diabetes, or fasting glucose levels of more than 126 mg/dL (6.99 mmol/L).
Personal history of smoking was defined as any reported long-term cigarette
use within the past year. Family history of CVD was defined as having any
blood family member with premature CAD or cardiac event history.
DATA ANALYSIS
To determine whether the changing incidence rates of CAD, AMI, and cardiac
events were statistically significant, we used the Mantel extension of the  2 test for trend using the Epi Info statistical program (version 6;
Centers for Disease Control and Prevention, Atlanta, Ga), which provides an
extended Mantel-Haenszel 2 figure and P value.19 Poisson confidence intervals
were calculated because of the relatively low ratio of cases to total population.
A variety of descriptive statistics are reported for the risk factor prevalence
determination, including percentages and means. Because a relatively young
and healthy participant sample was taken, we believe the calculated prevalence
rates most likely underestimate the true prevalence rates for the general
WMAT adult population.
RESULTS
The number of new CAD diagnoses increased from 3 in 1987-1988 to 18
in 1995-1996. The number of AMIs increased from 1 in 1987-1988 to 10 in 1995-1996.
The number of cardiac events increased from 3 in 1987-1988 to 26 in 1995-1996.
The WMAT population of persons aged 45 to 79 years increased from 2813 in
1987-1988 (average, 1406.5 per year) to 3522 persons in 1995-1996 (average,
1761 per year). Incidence rates for new CAD diagnosis increased from 106.65
per 100 000 population in 1987-1988 to 511.07 per 100 000 population
in 1995-1996. The incidence of AMI increased from 35.55 per 100 000 population
in 1987-1988 to 283.93 per 100 000 population in 1995-1996. The incidence
rates for cardiac events increased from 106.65 per 100 000 population
in 1987-1988 to 738.22 per 100 000 population in 1995-1996. All trends
produced statistically significant extended Mantel-Haenszel 2
values, despite overlap between some confidence intervals. These results provide
evidence for an increasing trend in incidence of CAD, AMI, and cardiac events.
Table 1 and
Figure 1, Figure 2, and Figure 3 provide further details and confidence
intervals.
|
|
|
|
Table 1. Incident Cases and Incidence Rates of CAD, AMI, and Cardiac
Events for Periods Investigated*
|
|
|
|
|
|
|
Figure 1. Coronary artery disease incidence
rates with time for tribal members aged 45 to 79 years with 95% Poisson confidence
intervals.
|
|
|
|
|
|
|
Figure 2. Acute myocardial infarction incidence
rates with time for tribal members aged 45 to 79 years with 95% Poisson confidence
intervals.
|
|
|
|
|
|
|
Figure 3. Cardiac event incidence rates
with time for tribal members aged 45 to 79 years with 95% Poisson confidence
intervals.
|
|
|
The convenience sample of 70 job applicants consisted of 41 men (59%)
and 29 women (41%), ranging in age from 18 to 46 years, with a mean age of
27.3 years; all but 3 subjects were 40 years or younger. The most prevalent
risk factors found were obesity (51%), tobacco use (44%), dyslipidemia (21%),
and hypertension (20%). Nearly one third of subjects had 2 risk factors, and
nearly 50% had 2 or more of the 6 risk factors under consideration. Table 2 gives a full description of results
obtained.
|
|
|
|
Table 2. Summary of Cardiovascular Risk Factors in a Group of White
Mountain Apache Tribal Members Applying for a Physically Intense Occupation*
|
|
|
COMMENT
We have demonstrated that there exists among the WMAT a statistically
and clinically significant, yet previously undocumented, increase in the incidence
of CAD, AMI, and cardiac events during the 10-year span of 1987 through 1996.
Although we did not analyze mortality from CVD in this study, these increasing
disease rates are in stark contrast to the declining mortality rates from
CVD seen in Arizona and the United States in general from 1989 through 1998
(150.8 and 125.8 deaths per 100 000 population in Arizona for 1989 and
1998; 155.9 and 126.0 deaths per 100 000 population in the United States
for 1989 and 1998).20
The high prevalence of cardiovascular risk factors and risk factor clustering
most likely accounts for the increases found, and, given the high risk factor
prevalence among our convenience sample, it is likely that CVD and mortality
rates will continue to increase as this generation ages. Likely contributors
are the significant dietary and lifestyle changes that seem to have occurred
among many Southwest American Indian tribes during the past several decades.21 The observed increasing adoption of a Western, more
sedentary lifestyle among some tribal groups contrasts sharply with traditional
occupations that require moderate-to-heavy daily physical activity, and this
is often accompanied by suboptimal access to healthful food options. This
combination is recognized as contributing to coronary risk factors in some
American Indian populations and has resulted in a significant increase in
obesity, diabetes, and the metabolic syndrome.21
Although it has been proposed that there may be a genetic predisposition toward
diabetes among some tribes, lifestyle factors seem to be a more significant
contributor.15
The marked increase in CAD and AMI and the high prevalence of cardiovascular
risk factors among the White Mountain Apache in recent years requires aggressive
intervention at a fundamental level. Primary prevention efforts should optimally
begin in grade school to prevent, or at least delay, the onset of obesity
and the subsequent development of diabetes, hypertension, and dyslipidemia.
Educational efforts should focus on disseminating information about cardiac
risk factors, their consequences, means of modifying risks, and current disease
trends. To be effective, these efforts must be developed in conjunction with
community health leaders and must integrate the cultural ideals and beliefs
of the White Mountain Apache. Lifestyle interventions must be adaptable and
relevant to the unique economic and geographic conditions found on the White
Mountain Apache Reservation, where electricity, running water, and reliable
transportation are far from universal, and residences are often located at
great distances from health care facilities and grocery stores. Additional
secondary prevention efforts are also needed among the White Mountain Apache
to decrease morbidity and mortality of extant coronary disease and to improve
daily quality of life.
There are several potential sources of error in our study, some of which
might serve to overestimate the trends determined for CAD, AMI, and cardiac
events. The Native American Cardiology Program was developed in 1993 as a
specific response to Indian Health Service clinicians' belief that the incidence
of CVD was increasing in American Indian populations and that more emphasis
needed to be placed on this area of American Indian health. The advent of
the program likely resulted in increased awareness of CVD among practitioners
in American Indian populations and may therefore have resulted in increased
referrals to UMC and hence increased catheterizations and diagnoses of CAD,
AMI, and cardiac events. The increased availability of cardiologists as a
result of the program might also have resulted in increased diagnoses. However,
such influences on actual incident numbers would likely be small; furthermore,
the bulk of our study covers periods before 1993, yet still demonstrates increasing
trends. Clearly, though, this may contribute to the sharp increase in events
during that period. Changes in diagnostic practices of physicians, cardiac
catheterization thresholds, and/or catheterization facilities at UMC could
also contribute to overestimation of trends. However, no significant changes
were made in any of these areas during this period, and such factors are not
thought to contribute significantly.
The use of facilities other than UMC for patients with cardiovascular
concerns would be extremely uncommon; however, if this occurred, it would
result in an underestimation of the rates of CAD, AMI, and cardiac events.
In the risk factor analysis, we recognize that our youthful convenience sample
assessed was not representative of the general WMAT population, but this would
likely result in an underestimation of true prevalence rates. In particular,
our convenience sample significantly underestimated the actual rates of diabetes
mellitus among the WMAT. Indian Health Service data from the diabetes educator
at WPHSH indicate that, as of February 2001, the prevalence of type 2 diabetes
mellitus among WMAT patients aged 45 to 79 years was 26.7% for men, 38.1%
for women, and 33.1% for both sexes combined (P. Lundgren, RN, EdD, written
communication, February 27, 2001). These rates are clearly higher than those
for the general US population of comparable age.
Finally, the large confidence intervals calculated for the incidence
trends are largely due to the fact that the analysis is based on a small tribal
population with small numbers of incident events. Although the analysis is
certainly driven to a degree by the large differences between the first and
last periods studied, all plots show evidence of increasing trends for the
incidences of CAD, AMI, and cardiac events in this population, and there is
no evidence that these rates will decrease on their own in the future.
In conclusion, this study demonstrates dramatically increasing incidence
rates of CAD, AMI, and cardiac events and high prevalence of cardiovascular
risk factors in the WMAT. These rates are evidence of a problem whose solution
requires appropriate prevention funding, policy formation, and intervention.
We also believe it is clearly indicative of a need for urgent action to promote
improved health of American Indian populations in the Southwest and throughout
the United States. Through appropriate intervention and further study, we
hope that future efforts will shift the trends in CAD and AMI among American
Indians in the opposite direction and foster improved outcomes in this population.
AUTHOR INFORMATION
Accepted for publication October 23, 2001.
This study was funded in part by a grant AZGS-41-97 from the American
Heart Association.
The opinions expressed in this document are those of the authors and
do not necessarily represent those of the Indian Health Service.
We thank the following organizations and persons for their invaluable
assistance in the completion of this project: White Mountain Apache Tribe,
Whiteriver Service Unit of the Indian Health Service, Phoenix Area Indian
Health Service Institutional Review Board, American Heart Association (Dallas,
Tex), and Robin Harris, PhD.
Corresponding author and reprints: James M. Galloway, MD, University
Medical Center, 1501 N Campbell Ave, PO Box 245037, Tucson, AZ 85724.
From the Native American Cardiology Program, University of Arizona,
Tucson (Messrs Sewell and Gerber, Drs Malasky, Gedney, Brody, and Galloway,
and Ms Pacheco); Department of Clinical Medicine, Sarver Heart Center (Drs
Malasky, Brody, and Galloway), University of Arizona College of Medicine,
Tucson; Indian Health Service, Tucson (Drs Brody, Yost, and Galloway and Mss
Pacheco and Masden); and Whiteriver Public Health Service Hospital, Whiteriver,
Ariz (Dr Yost and Ms Masden).
REFERENCES
| |
1. Eliminating racial and ethnic disparities in health. Public Health Rep. 1998;113:372-375.
ISI
| PUBMED
2. US Department of Health and Human Services. Healthy People 2010. Conference ed, in 2 vols. Washington, DC: US Dept of Health and Human
Services; 2000.
3. Howard BV, Lee ET, Cowan LD, et al. Rising tide of cardiovascular disease in American Indians: the Strong
Heart Study. Circulation. 1999;99:2389-2395.
FREE FULL TEXT
4. Sievers ML. Myocardial infarction among Southwest American Indians. Ann Intern Med. 1967;67:800-807.
5. Pinkerton RE, Badke FR. Coronary heart disease: an epidemiologic study of Crow and Northern
Cheyenne Indians. Rocky Mt Med J. 1974;71:577-583.
PUBMED
6. Clifford NJ, Kelly JJ, Leo TF, Eder HA. Coronary heart disease and hypertension in the White Mountain Apache
Tribe. Circulation. 1963;28:926-931.
FREE FULL TEXT
7. Fulmer HS, Roberts RW. Coronary heart disease among the Navajo Indians. Ann Intern Med. 1963;59:740-764.
8. Coulehan JL, Lerner G, Helzlsouer K, Welty TK, McLaughlin J. Acute myocardial infarction among Navajo Indians, 1976-83. Am J Public Health. 1986;76:412-414.
FREE FULL TEXT
9. Gilbert J. Absence of coronary thrombosis in Navajo Indians. Calif Med. 1955;82:114-115.
10. Welty TK, Coulehan JL. Cardiovascular disease among American Indians and Alaskan natives. Diabetes Care. 1993;16:277-283.
ABSTRACT
11. Howard BV, Lee ET, Cowan LD, et al. Coronary heart disease prevalence and its relation to risk factors
in American Indians. Am J Epidemiol. 1995;142:254-268.
FREE FULL TEXT
12. Howard BV, Welty TK, Fabsitz RR, et al. Risk factors for coronary heart disease in diabetic and nondiabetic
Native Americans: the Strong Heart Study. Diabetes. 1992;41:4-11.
13. Salsbury CG. Disease incidence among the Navajo Indians. Southwest Med. 1937;21:230-233.
14. Sugarman JR, Gilbert TJ, Percy CA, Peter DG. Serum cholesterol concentrations among Navajo Indians. Public Health Rep. 1992;107:92-99.
ISI
| PUBMED
15. Justice JW. The history of diabetes mellitus in the Desert People. In: Joe JR, Young RS, eds. Diabetes as a Disease
of Civilization. New York, NY: Mouton de Gruyter; 1993.
16. National Center for Health Statistics. Healthy People 2000 Review, 1995-96. Hyattsville, Md: Public Health Service; 1996.
17. Indian Health Service. Trends in Indian Health, 1997. Rockville, Md: US Dept of Health and Human Services; 1997.
18. American Heart Association. 2001 Heart and Stroke Statistical Update. Dallas, Tex: American Heart Association; 2001.
19. Schlesselman JJ. Case Control Studies: Design, Conduct, Analysis. New York, NY: Oxford University Press; 1982.
20. Office of Epidemiology and Statistics, Bureau of Public Health Statistics. Arizona Health Status and Vital Statistics 1999 Annual
Report. Phoenix: Arizona Dept of Health Services; 2000.
21. Ballew C, White LL, Strauss KF, Benson LJ, Mendlein JM, Mokdad AH. Intake of nutrients and food sources of nutrients among the Navajo:
findings from the Navajo Health and Nutrition Survey. J Nutr. 1997;127(suppl):2085S-2093S.
RELATED ARTICLE
Archives of Internal Medicine Reader's Choice: Continuing Medical Education
Arch Intern Med. 2002;162(12):1424.
FULL TEXT
THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES
Differences in Hospital Mortality Among Critically Ill Patients of Asian, Native Indian, and European Descent
Khan et al.
Chest 2008;134:1217-1222.
ABSTRACT
| FULL TEXT
The nutrition transition in american indians.
Compher
J Transcult Nurs 2006;17:217-223.
ABSTRACT
Cigarette smoking and cardiovascular risk factors among Aboriginal Canadian youths
Retnakaran et al.
CMAJ 2005;173:885-889.
ABSTRACT
| FULL TEXT
|
