 |
|
An Evidence-Based Assessment of Federal Guidelines for Overweight and Obesity as They Apply to Elderly Persons
Asefeh Heiat, MD;
Viola Vaccarino, MD, PhD;
Harlan M. Krumholz, MD
Arch Intern Med. 2001;161:1194-1203.
ABSTRACT
| |
Background The US Clinical Guidelines on the Identification, Evaluation, and Treatment
of Overweight and Obesity in Adults set the body mass index (BMI; weight in
kilograms divided by the square of height in meters) of 25 as the upper limit
of ideal weight for all adults regardless of age. However, the prognostic
importance of overweight and obesity in elderly persons ( 65 years) is
controversial. We sought to analyze the guidelines in the context of currently
available evidence that is relevant to older adults.
Methods We searched MEDLINE for all English-language studies of the association
between BMI and all-cause or cardiovascular mortality or coronary heart disease
events from January 1966 through October 1999. Additional pertinent articles
were identified through bibliographies of the MEDLINE articles. We selected
studies for detailed review if they reported on the association between BMI
and mortality for nonhospitalized subjects who were 65 years or older and
had been followed up for at least 3 years. We controlled for age, smoking,
and baseline health status. Of the 444 screened articles, 13 were selected
to assess the guidelines. We extracted information regarding publication year,
study design, population, recruitment period, follow-up duration, number of
subjects, sex, age range, inclusion and exclusion criteria, and statistical
models, including variables and end points.
Results These data do not support the BMI range of 25 to 27 as a risk factor
for all-cause and cardiovascular mortality among elderly persons. The results
were not substantially different for men and women. Most studies showed a
negative or no association between BMI and all-cause mortality. Three studies
indicated overweight (BMI 27) as a significant prognostic factor for all-cause
and cardiovascular mortality among 65- to 74-year-olds, and one study showed
a significant positive association between overweight (BMI 28) and all-cause
mortality among those 75 years or older. Higher BMI values were consistent
with a smaller relative mortality risk in elderly persons compared with young
and middle-aged populations.
Conclusions Federal guideline standards for ideal weight (BMI 18.7 to <25) may
be overly restrictive as they apply to the elderly. Studies do not support
overweight, as opposed to obesity, as conferring an excess mortality risk.
Future guidelines should consider the evidence for specific age groups when
establishing standards for healthy weight.
INTRODUCTION
THE FIRST US Clinical Guidelines on the Identification, Evaluation,
and Treatment of Overweight and Obesity in Adults,1
released by the National Institutes of Health, National Heart, Lung, and Blood
Institute, in June 1998, identified overweight and obesity as major risk factors
for increased morbidity and mortality. In earlier official documents (the
National Institutes of Health Consensus Conference on Health Implications
of Obesity in 1985 and the 1990 Dietary Guidelines for Americans from the
Department of Agriculture), overweight was defined as a body mass index (BMI;
defined as weight in kilograms divided by the square of height in meters)
of 27.8 or greater and 27.3 for men and women 35 years or older, respectively.
Those documents recommended age-specific ranges of weight for height, with
heavier weight standards indicated with increased age, and adapted the obesity and overweight terms interchangeably
without clear distinction.2-3
In contrast, the recent national guidelines, in agreement with the 1995 Dietary
Guidelines for Americans, defined overweight as a BMI of 25 to 29.9 and obesity
as a BMI of 30 or more for adults 18 years or older, without recommending
age-specific cut points.1, 4 According
to the current definitions, the percentage of overweight and obese adults
20 years or older in the United States is estimated to be 54.9%.5
Although the recent recommendations consider younger and older adults
as one group, they are almost exclusively based on studies that predominantly
included young and middle-aged populations. Overall, there is a paucity of
data relative to the association between overweight and all-cause and coronary
heart disease (CHD) mortality among elderly persons and more specifically
among very old individuals (75 years). This issue is important because
the prevalence of overweight among persons who are 70 years or older is estimated
to be more than 37%, and at least another 15% are estimated to be obese by
the published standards.5
To determine the strength of evidence regarding the prognostic importance
of increased weight and the appropriateness of the existing recommendations
for healthy weight for older people, we performed a systematic review of the
literature. We specifically focused on evidence that was relevant to people
who were aged at least 65 years, with special emphasis on those who were at
least 75 years old.
METHODS
SOURCES OF DATA
The sources of data for this review were published articles that examined
the relation between body weight adjusted for height (BMI) and all-cause mortality,
cardiovascular mortality, and CHD in individuals 65 years or older. We performed
a computerized search of MEDLINE from January 1966 through October 1999 with
the following search terms: body mass index/BMI/body weight/obesity, aged/elderly, and either mortality or cardiovascular disease
or coronary disease/coronary artery
disease/coronary heart disease. We limited
our search to English-language articles.
The search resulted in 444 articles. We examined the titles and abstracts
of these articles and selected those that corresponded to the inclusion criteria
of our systematic review as described herein. Subsequently, we performed a
detailed examination of the articles. Finally, we completed our review by
examining the relevant references from the articles that had been detected
by the MEDLINE search.
Our search did not identify any interventional trials regarding the
topic. Observational studies were selected if they included only, or presented
separate data analysis for, subjects 65 years or older; performed age adjustment;
included at least 100 subjects; had at least 3 years of follow-up; had all-cause
and/or cardiovascular mortality and/or CHD events as end points; restricted,
stratified, or adjusted for smoking and health status at baseline; and selected
nonhospitalized subjects at the time of enrollment.
We excluded studies that used weight and did not adjust for height (BMI).
Studies were also excluded if they were based on specific populations of diseased
individuals, eg, case-control studies of patients who presented to the hospital
with acute myocardial infarction.
END POINT DEFINITION
The end points in these studies were all-cause mortality, cardiovascular
mortality, stroke mortality, cancer mortality, noncardiovascular mortality,
CHD mortality, or CHD incidence. For the purpose of our systematic review,
we evaluated 4 end points: all-cause mortality, cardiovascular mortality,
CHD mortality, and CHD incidence.
DATA EXTRACTION
For each article, we determined the study design, population, recruitment
period, follow-up duration, number of subjects 65 years or older, age range,
and sex. We recorded the methods used to assess standardized weight and the
way BMI was used as a variable in the statistical models. Exclusion and inclusion
criteria were evaluated for each study. We compared the methods used in the
studies to control for smoking and baseline health status by exclusion, restriction,
or adjustment. We also examined the factors that were controlled for in the
different statistical models in addition to age, smoking, and health status.
Controversy exists with respect to the statistical adjustment for potential
weight-related cardiovascular risk factors, such as high blood pressure, diabetes
mellitus, and hypercholesterolemia, since those risk factors might be a consequence
of excess weight and mediators of adverse outcomes rather than confounders.6 Consequently, we present both adjusted and unadjusted
analyses for those risk factors whenever they were available. Results presented
as "adjusted for potential weight-related cardiovascular risk factors" have
been controlled for at least 1 of the following: serum cholesterol level;
serum glucose level; systolic, diastolic, or mean arterial blood pressure;
and history of diabetes, dyslipidemia, or high blood pressure.
In addition, we evaluated whether early mortality was excluded and whether
adjustment was made for history of weight loss. When possible, we present
the magnitude of the association between BMI and mortality and CHD and the
statistical significance as relative risks (RRs) with confidence intervals
(CIs) or P values for trend.
RESULTS
Characteristics and findings of the studies with respect to older subjects
are presented in Table 1,
Table 2,
Table 3, and
Table 4. For studies that also included participants younger than 65 years, only the
information and results concerning those 65 years or older are included.
|
|
|
|
Table 2. Study Characteristics
|
|
|
|
|
|
|
Table 3. Association Between Body Mass Index (BMI) and All-Cause Mortality
|
|
|
|
|
|
|
Table 4. Association Between Body Mass Index (BMI) and Cardiovascular
Mortality and Coronary Heart Disease Incidence
|
|
|
Thirteen articles met the inclusion criteria for this systematic review.
The selected studies were all observational, prospective cohort studies and
were population based except for one, which was based on male health professionals.
Except for the Honolulu Heart Program study, which also included nursing home
residents, they all included noninstitutionalized, nonhospitalized individuals.
Of note, some of these investigations7-10
consisted of different analyses performed on data from the same observational
study but with different cohorts or different recruitment periods or follow-up
duration. The studies, their characteristics, and the potential weight-related
covariables introduced in their statistical models are listed in Table 1 and Table 2. The studies included 1437 to 46 954 individuals, with
follow-up between 3 and 23 years. Eight of these studies included both sexes,
4 included only men, and 1 included only women. Ten studies were from the
United States and 3 from Europe, and except for the Honolulu Heart Program
study on Japanese American men, they all included predominantly white subjects
from industrialized countries. In the 3 European studies,11-13
the subjects' race was not reported, but it is likely that the participants
from those countries (Finland, the Netherlands, and Italy) were mostly white.
Only one study,10 by Cornoni-Huntley and colleagues,
reported results separately for black subjects.
Weight was measured in 8 studies and self-reported in 5 (Table 2). Body mass index was used as a categorical variable in
all but 1 study,11 and 2 studies14-15
reevaluated BMI as a continuous variable. The classification of BMI varied
among studies, with a range of groupings from 3 to 10 levels. Four studies8, 14-16 controlled
for history of weight loss. Four studies7-8,15, 17
controlled for early mortality by excluding participants who died during the
early years of follow-up.
ALL-CAUSE MORTALITY
Unadjusted for Potential Weight-Related Cardiovascular Risk Factors
Seven studies reported results on the association between BMI and all-cause
mortality without adjusting for potential weight-related cardiovascular risk
factors. When available, the magnitude of the association, the CIs, and the
referent groups are displayed in Table 2 and Table 3.
A positive association between BMI and all-cause mortality was shown
in only 2 investigations. Even though the first study, published by Harris
et al18 in 1988 based on the Framingham Heart
Study data, revealed a positive association between BMI and mortality for
both men and women, this positive association was detected only for a BMI
of 28.5 or more, and there was no significant or substantial increased risk
detected for the group with a BMI between 25 and 28.5. Furthermore, Harris
et al based their study on subjects who were all 65 years old at baseline;
consequently, no conclusion can be made, based on this study, regarding the
presence of the increased mortality risk associated with high BMI among very
elderly persons (75 years).
The second study, by Stevens et al15
based on the American Cancer Society's Cancer Prevention data, also found
that higher BMI was significantly associated with increased mortality in men
and women, though exclusively for the participants aged 65 to 74 years. There
was no significant association in this study between BMI and mortality for
those 75 years or older. Again, for those aged 65 to 74 years, the RR was
statistically significant for the BMI category of 27.0 or higher. The magnitude
of the association and the CIs are not given in the article. However, the
most important finding of this study was that the increased risk associated
with high BMI declined with age for both men and women (P for trend <.01 and <.05, respectively). Using a BMI of 21.0
as the reference value, the BMI associated with a 20% increase in the risk
of all-cause mortality was 24.7 among men aged 55 to 64 years but 28.2 and
30.5 among men aged 65 to 74 years and 75 to 84 years, respectively. Correspondingly,
among women, the BMI associated with a 20% increase in the risk of all-cause
mortality was 25.9 for those aged 55 to 64 years but increased to 29.9 for
the 65- to 74-year-old age group.
Cornoni-Huntley et al10 found a U-shaped
relation between BMI and mortality among white women aged 65 to 74 years with
increased risks in the lowest ( 21.4) and highest (31.3) ranges of
BMI. No significant association was found between BMI and mortality among
white men in the same age group in this study.
All other studies showed either no association13-14
or negative significant associations8, 10
between BMI and all-cause mortality.
Most studies showed either a negative or a nonsignificant association
between BMI and all-cause mortality. When a positive relation was found, it
was for a BMI of 27 or more. Furthermore, this relation was attenuated with
age and usually disappeared after the age of 75 years. Consequently, the overall
trends for the relation between BMI and mortality in older adults can be represented
as a U-shaped curve, with a large flat bottom and a right curve that starts
to rise for BMIs of more than 31 to 32.
Adjusted for Potential Weight-Related Cardiovascular Risk Factors
Despite the controversy regarding the statistical adjustment for weight-related
risk factors, for completeness we included investigations that performed this
adjustment. Ten studies presented results on the association between BMI and
all-cause mortality after including some cardiovascular risk factors that
could be weight related in their statistical models (Table 1). In general, control for weight-related cardiovascular
risk factors attenuated the strength of the association between high BMI and
all-cause mortality.8, 10, 18
Only 2 studies demonstrated that high BMI was associated with increased
all-cause mortality. Based on the Framingham Heart Study data, Harris et al18 reported a significant positive linear association
between BMI and all-cause mortality. Nevertheless, this positive association
was exclusively found among women who were 65 years old at entry and for a
BMI of 28.7 or more. In this study, BMI was not significantly associated with
all-cause mortality among men. The second study, based on the Cancer Prevention
Study, found that a BMI of 28 or more was significantly related to increased
mortality in the 65- to 74-year-old age group. In this study,16
the relation between BMI and mortality was found to be U-shaped, with BMIs
of less than 20.5 and 28 or more associated with increased mortality, among
individuals 75 years or older. Two studies11-12
showed a U-shaped association between BMI and mortality exclusively for people
aged 65 to 74 years and no association among people 75 years or older. In
one of these studies, only the extreme values of BMI (<19.0 and 34.0)
were associated with increased mortality,12
and the other revealed a weakly significant U-shaped relation between BMI
and mortality (ß coefficient, 0.0064).11
Three studies7-8,14
showed no significant association between BMI and all-cause mortality among
the elderly (65 years) after including some potential weight-related cardiovascular
risk factors in the model. Two studies,10, 17
one published recently from the Honolulu Heart Program and the other based
on the First National Health and Nutrition Examination Survey, Epidemiologic
Follow-up Study, showed that only low BMI was significantly associated with
increased mortality among elderly Japanese American men and among elderly
men and women in both black and white populations.
With inclusion of more variables in the model, especially the potential
weight-related cardiovascular risk factors, either BMI was not related to
increased all-cause mortality or low BMI was associated with greater risk
of mortality. When a positive association was found, it was for high values
of BMI (28), and except in one study,16
the significant association disappeared after the age of 75 years.
CARDIOVASCULAR MORTALITY
Results of the association between BMI and cardiovascular mortality
are less conclusive compared with those for all-cause mortality (Table 4). This association was found to
be none, negative, or positive in different studies. However, when positive,
the association was not strong in magnitude, started for high values of BMI
(27-29), and did not persist after the age of 75 years.
Unadjusted for Potential Weight-Related Cardiovascular Risk Factors
Two investigations reported results on the association between BMI and
cardiovascular mortality without adjusting for potential weight-related cardiovascular
risk factors. The study by Stevens et al15
found this association to be significant for a BMI of 27 or more and exclusively
in the 65- to 74-year-old age group. Again, BMI was not associated with increased
mortality among persons 75 years or older. Also, the investigation13 among Finnish women aged 65 to 79 years did not reveal
high BMI as a risk factor for cardiovascular mortality.
Adjusted for Potential Weight-Related Cardiovascular Risk Factors
Three studies reported results on the association between BMI and cardiovascular
mortality after adjusting for potential weight-related cardiovascular risk
factors. The investigation based on the Framingham Heart Study showed a significant
positive association between BMI and cardiovascular mortality among women
who were 65 years old at baseline and a negative association among men in
the same age group. The magnitude of the association and CIs are not reported
in the article.18 Although the study by Rissanen
et al12 revealed a positive association between
BMI and cardiovascular mortality among Finnish men, this association was significant
for a BMI of 34 or more and exclusively among persons aged 65 to 74 years.
High BMI was again not shown to be a risk factor for the very elderly (75
years). Finally, Seeman et al9 reported that
BMI was not significantly related to CHD mortality.
CHD INCIDENCE
Only 2 investigations studied the association between BMI and CHD incidence
among elderly persons (Table 3).
Unadjusted for Potential Weight-Related Cardiovascular Risk Factors
The Health Professionals Follow-up Study19
failed to demonstrate a significant association between high BMI and CHD incidence
among men 65 years or older. No association was found between weight gain
in adult life and coronary risk in this group. Nevertheless, waist-to-hip
ratio was a significant risk factor for CHD among men 65 years or older (RR,
2.76; 95% CI, 1.22-6.23).
Adjusted for Potential Weight-Related Cardiovascular Risk Factors
A study by Seeman et al,9 based on Established
Populations for Epidemiologic Studies of the Elderly data, showed that high
BMI was significantly related to increased myocardial infarction incidence
among men but not among women.
OPTIMUM BMI
Optimum BMIs with respect to all-cause and cardiovascular mortality
and CHD incidence are displayed in Table
2. In general, the nadirs for risk increased with age and, for the
most part, were at high levels of BMI ranging from 27 to 30.7, 9-15,19
Only the investigation by Cornoni-Huntley et al10
among black men and the recent study published by Calle et al16
showed an optimum BMI that was consistent with the recent guidelines (22.9-25.6
and 20.5-24.9, respectively).
COMMENT
Although there are not many studies on the association between BMI and
mortality in elderly persons, our systematic review revealed several important
findings. Most studies failed to show a significant association between high
BMI and increased mortality, despite the large number of participants. In
addition, while few studies found a significant U-shaped or positive linear
association between BMI and mortality, only values of BMI that are higher
than recent guideline cut points for overweight were associated with increased
mortality.10-12,15-16,18
Even so, this association was not large, ranging from an RR of 1.15 to 1.34
for a BMI of 28.0 to 29.9 to an RR of 1.31 to 2.0 for a BMI of 31 to 35.10, 12, 16 We found that only
one study16 demonstrated a nadir of mortality
risk among elderly subjects that was consistent with the ranges of BMI (19
to 25) defined as ideal weight by the new guidelines. Except for that
study, this relation, when it existed, attenuated with age and seemed to disappear
for persons 75 years or older.7, 11-15,18
Finally, when the association was U-shaped, it was generally asymmetric, with
a less steep curve on the right and a wide, flat bottom, which demonstrates
that a broad range of increasing BMI is compatible with minimum excess mortality
in elderly persons. As a consequence, the optimum BMI commonly tended to be
higher for the elderly compared with young and middle-aged populations.7, 10-15,17
In summary, the overall trends for the relation between BMI and mortality
in older adults can be represented as a U-shaped curve, with a large, flat
bottom and a right curve that starts to rise significantly for BMIs greater
than 31 to 32.
There are even fewer studies on the association between BMI and cardiovascular
mortality. However, in general, a pattern similar to the latter was found.9, 12-13,15, 18
Results from the only 2 studies9, 19
on the association between BMI and CHD incidence are contradictory.
Authors of the recent guidelines base their recommendations on the observational
and randomized clinical trial evidence. However, by necessity the expert panel
used evidence from studies that mainly included young and middle-aged populations.
For example, to evaluate the effects of weight loss on blood pressure, they
considered 45 articles from a pool of 76 randomized clinical trials. The mean
age in almost all of those studies was between 35 and 55 years, and only one
study included individuals with a mean age of 61 years. Again, to evaluate
the effects of weight loss on dyslipidemia, 65 articles reporting randomized
clinical trials were considered for review, and 22 were accepted. The mean
age in almost all of those studies was also between 35 and 55 years, and only
2 studies included individuals with a mean age of 61 years.20
Even though the guidelines recommend the treatment of overweight "only when
patients have 2 or more risk factors," the age itself (45 years for men
and 55 years or postmenopausal for women) is considered a risk factor
in this document. Therefore, based on the guidelines, a 70-year-old patient
with a weight of 64 kg and a height of 160 cm and one of the following risk
factors is a candidate for weight reduction treatment and interventions1:
. . . established coronary heart disease, other atherosclerotic
diseases . . . gynecological abnormalities, osteoarthritis, gallstones . .
. stress incontinence . . . cigarette smoking, hypertension . . . high risk
LDL-C [low-density lipoprotein cholesterol] . . . low HDL-C [high-density
lipoprotein cholesterol], impaired fasting glucose level . . . family history
of premature coronary heart disease . . . physical inactivity, and high serum
triglyceride levels.
The methodologic challenges of isolating the impact of weight on prognosis
are considerable. The issues in these studies include lack of control for
smoking status; preponderant effects of poor baseline health status and underlying
diseases of underweight participants, hampering the negative effects of higher
BMI on mortality (hence, impeding high BMI to emerge as a risk factor for
excess mortality); inappropriate control for some potential weight-related
conditions (high blood pressure, diabetes, and dyslipidemia) that would weaken
the association between high BMI and mortality; and lack of power to detect
a significant association even if one existed. We considered these methodologic
problems in our selection of studies. All the studies that we reviewed were
controlled for smoking status. Although we recognize that underweight could
be a consequence rather than a cause of poor health that might result in excess
mortality, all selected studies in our systematic review were controlled in
some way for baseline health status. All the study populations, except for
that in the study by Kalmijn et al,17 consisted
of noninstitutionalized, relatively healthy elderly individuals. In addition,
the inclusion criteria in most of those studies were directed to minimize
the effects of preexisting diseases on the outcomes. Studies that excluded
participants with important weight loss before the study baseline8, 14-15 and/or early mortality7-8,15 found a decline in
association between low BMI and mortality but did not show increased risk
of mortality associated with overweight. This was also true for investigations10, 13 that performed separate analyses
for early and later duration of follow-up. Therefore, the absence of prognostic
significance of increased weight observed in those investigations is unlikely
to be a consequence of the excess mortality in low-weight participants.
Body mass index was used as a categorical variable in most of these
studies, and the RR was calculated compared with the reference group with
the middle or healthy range of BMI and not with the lowest BMI category or
nonobese persons in general.7-8,10, 12-13,15, 18
We also looked at the issues concerning the importance of unadjusted association
between BMI and mortality rather than the independent association and presented
both results from unadjusted and adjusted analyses for weight-related cardiovascular
risk factors whenever they were available. In general, control for these risk
factors attenuated the RR of mortality associated with high BMI.8, 10, 18
Also, inclusion of chronic conditions and history of weight loss in the model
weakened the strength of association between low BMI and mortality.8, 14-15 Finally, all the studies
that we reviewed were observational studies that included a large number of
participants.
How is it possible that mild-to-moderate excess weight is not an important
risk factor for cardiovascular disease and all-cause mortality in elderly
persons in contrast with young and middle-aged individuals? It is conceivable
that overweight individuals who survive to old age have characteristics that
protect them from adverse effects of overweight. Also, underweight-related
risk factors might prevail over the risks related to overweight in old age.
It is possible that the significance and prognostic effects of traditional
cardiovascular risk factors may change with increased age. For example, several
studies found that elevated total serum cholesterol and LDL-C levels or low
HDL-C levels are not associated with increased overall and cardiovascular
mortality or first myocardial infarction in elderly patients21-23
and more specifically in very elderly patients.24
Data from the Framingham Heart Study revealed that the positive relation between
high cholesterol level and all-cause and cardiovascular mortality declined
with age to become negative after the age of 80 years.25-26
The interaction of age on the relation between weight and health outcomes
is not a recent finding. Various studies that included subjects from different
age groups reported that the association between BMI and mortality and CHD
(all-cause and cardiovascular) declines with age.27-39
A recent study40 among obese patients in Germany
(age, 18-74 years; BMI, 25 to 40) with a median follow-up of 14.8 years
also showed that the excess mortality associated with obesity declined with
age and that the lowest mortality risk was observed in patients aged 50 to
74 years with BMIs of 25 to less than 32.
Interestingly, we found that low BMI was more consistently associated
with greater mortality risk compared with high BMI in elderly persons. Different
factors appear to prevail for longevity in older people. The protective effects
of overweight, such as nutritional reserve, may prevail over its negative
effects in this population. Malnutrition, osteoporosis, and traumatic events
secondary to fall (specifically hip fracture and mortality allied with those
conditions) could be an explanation for the increased mortality associated
with weight loss and underweight.41-43
The absolute gain from modifying risk factors and the risk-benefit balance
with respect to interventions are complicated to evaluate in elderly persons.
In contrast with younger persons, elderly persons are usually faced with multiple
health hazards and shorter life expectancy. Even if the mechanisms of disease
are the same for young and older people, the multiplicity of risk factors
accompanied by increased morbidity modify the prognostic significance of each
individual factor; hence, the concept of competing risks becomes more relevant
with age.44 Consequently, a single cause-specific
mortality affects the survival less as the patient becomes older. Also, the
absolute benefit of reducing a specific risk depends on the magnitude of the
baseline RR attributed to this hazard. That is, since an elderly person has
several risk factors for so many adverse outcomes, the relative gain in survival
with changes in 1 risk factor is often small unless this risk factor has a
large impact on all-cause mortality.
STRENGTHS AND LIMITATIONS
We performed a comprehensive search of all the studies on the association
between BMI and mortality and CHD. We also conducted an extensive analysis
of the literature with respect to this issue, including other review articles.
To our knowledge, almost all the reviews published to date are narrative.
Our goal was to achieve a systematic review with predesigned methods and predefined
selection criteria. We performed a systematic review and not a meta-analysis
because of the heterogeneity of the observational studies. We examined the
articles objectively and completed a general synthesis of the existing evidence
with regard to the issue. We also considered the methodologic problems concerning
the impact of smoking status, underlying disease, and baseline health status
in our selection of studies.
We were restrained by the limitations of the quality of the observational
studies, which do not provide definitive evidence about causality. Data in
most of these studies were collected based on self-coded interviews, and weight,
height, and comorbidity are usually self-reported. The end points in these
investigations were limited to mortality (all-cause and cardiovascular) and
CHD incidence. However, mortality is not the sole indicator of good health.
Quality of life and functional and psychosocial status are also important
outcomes that should be taken into consideration. In addition, little is known
about the influence of sex, race, and weight history on the association between
BMI and mortality.
CONCLUSIONS
Evidence does not support mild-to-moderate overweight, defined by the
new guidelines, as a risk factor for all-cause and cardiovascular mortality
among elderly persons. We agree that marked overweight (obesity) might be
a risk factor for this population. However, adverse effects of energy (calorie)
restriction in elderly persons and the potential harms of diet-induced weight
reduction, as well as the paucity of information about effectiveness of weight
loss programs, would not support weight reduction interventions among mildly
to moderately overweight elderly individuals. Further studies that focus on
elderly and very elderly individuals are required, and future guidelines should
consider age-specific recommendations that reflect existent evidence when
establishing standards for ideal weight.
AUTHOR INFORMATION
Accepted for publication September 21, 2000.
We thank Maria Johnson for her outstanding editorial assistance.
Corresponding author and reprints: Harlan M. Krumholz, MD, Yale University
School of Medicine, 333 Cedar St, PO Box 208025, New Haven, CT 06520-8025
(e-mail: harlan.krumholz{at}yale.edu).
From the Department of Internal Medicine/Preventive Medicine, Griffin
Hospital, Derby, Conn (Dr Heiat); Department of Epidemiology and Public Health
(Drs Heiat, Vaccarino, and Krumholz) and Section of Cardiovascular Medicine,
Department of Medicine (Dr Krumholz), Yale University School of Medicine,
and Yale–New Haven Hospital Center for Outcomes Research and Evaluation
(Dr Krumholz), New Haven, Conn; and Qualidigm, Middletown, Conn (Dr Krumholz).
Dr Vaccarino is now with the Division of Cardiology, Department of Medicine,
Emory University School of Medicine, Atlanta, Ga.
REFERENCES
| |
1. National Institutes of Health, National Heart, Lung, and Blood Institute. Executive Summary of the Clinical Guidelines on the Identification,
Evaluation, and Treatment of Overweight and Obesity in Adults. Arch Intern Med. 1998;158:1855-1867.
FREE FULL TEXT
2. Health Implications of Obesity: National Institutes of Health Consensus
Development Conference Statement. Ann Intern Med. 1985;103:1073-1077.
3. US Department of Agriculture and US Department of Health and Human
Services. Nutrition and Your Health: Dietary Guidelines for
Americans. 3rd ed. Washington, DC: US Dept of Agriculture and US Dept of Health
and Human Services; 1990.
4. US Department of Agriculture and US Department of Health and Human
Services. Nutrition and Your Health: Dietary Guidelines for
Americans. 4th ed. Washington, DC: US Dept of Agriculture and US Dept of Health
and Human Services; 1995.
5. Flegal KM, Carroll MD, Kuczmarski RJ, Johnson CL. Overweight and obesity in the United States: prevalence and trends,
1960-1994. Int J Obes Relat Metab Disord. 1998;22:39-47.
FULL TEXT
|
ISI
| PUBMED
6. Willett WC, Dietz WH, Colditz GA. Guidelines for healthy weight. N Engl J Med. 1999;341:427-434.
FREE FULL TEXT
7. Tayback M, Kumanyika S, Chee E. Body weight as a risk factor in the elderly. Arch Intern Med. 1990;150:1065-1072.
FREE FULL TEXT
8. Losonczy KG, Harris TB, Cornoni-Huntley J, et al. Does weight loss from middle age to old age explain the inverse weight
mortality relation in old age? Am J Epidemiol. 1995;141:312-321.
FREE FULL TEXT
9. Seeman TE, Mendes de Leon CF, Berkman LF, Ostfeld A. Risk factors for coronary heart disease among older men and women:
a prospective study of community-dwelling elderly. Am J Epidemiol. 1993;138:1037-1049.
FREE FULL TEXT
10. Cornoni-Huntley JC, Harris TB, Everett DF, et al. An overview of body weight of older persons, including the impact on
mortality: the National Health and Nutrition Examination Survey I, Epidemiologic
Follow-up Study. J Clin Epidemiol. 1991;44:743-753.
FULL TEXT
|
ISI
| PUBMED
11. Menotti A, Kromhout D, Nissinen A, et al. Short-term all-cause mortality and its determinants in elderly male
populations in Finland, the Netherlands, and Italy: the FINE Study (Finland,
Italy, Netherlands Elderly Study). Prev Med. 1996;25:319-326.
FULL TEXT
|
ISI
| PUBMED
12. Rissanen A, Heliovaara M, Knekt P, Aromaa A, Reunanen A, Maatela J. Weight and mortality in Finnish men. J Clin Epidemiol. 1989;42:781-789.
FULL TEXT
|
ISI
| PUBMED
13. Rissanen A, Knekt P, Heliovaara M, Aromaa A, Reunanen A, Maatela J. Weight and mortality in Finnish women. J Clin Epidemiol. 1991;44:787-795.
FULL TEXT
|
ISI
| PUBMED
14. Diehr P, Bild DE, Harris TB, Duxbury A, Siscovick D, Rossi M. Body mass index and mortality in nonsmoking older adults: the Cardiovascular
Health Study. Am J Public Health. 1998;88:623-629.
FREE FULL TEXT
15. Stevens J, Cai J, Pamuk ER, Williamson DF, Thun MJ, Wood JL. The effect of age on the association between body-mass index and mortality. N Engl J Med. 1998;338:1-7.
FREE FULL TEXT
16. Calle EE, Thun MJ, Petrelli JM, Rodriguez C, Heath CW Jr. Body-mass index and mortality in a prospective cohort of U.S. adults. N Engl J Med. 1999;341:1097-1105.
FREE FULL TEXT
17. Kalmijn S, Curb JD, Rodriguez BL, Yano K, Abbott RD. The association of body weight and anthropometry with mortality in
elderly men: the Honolulu Heart Program. Int J Obes Relat Metab Disord. 1999;23:395-402.
FULL TEXT
|
ISI
| PUBMED
18. Harris T, Cook EF, Garrison R, Higgins M, Kannel W, Goldman L. Body mass index and mortality among nonsmoking older persons: the Framingham
Heart Study. JAMA. 1988;259:1520-1524.
FREE FULL TEXT
19. Rimm EB, Stampfer MJ, Giovannucci E, et al. Body size and fat distribution as predictors of coronary heart disease
among middle-aged and older US men. Am J Epidemiol. 1995;141:1117-1127.
FREE FULL TEXT
20. National Institutes of Health, National Heart, Lung, and Blood Institute. First federal obesity clinical guideline released. Available at:
http://www.nhlbi.nih.gov/guidelines/obesity/ob_home.htm.
Accessed June 17, 1998.
21. Fried LP, Kronmal RA, Newman AB, et al. Risk factors for 5-year mortality in older adults: the Cardiovascular
Health Study. JAMA. 1998;279:585-592.
FREE FULL TEXT
22. Krumholz HM, Seeman TE, Merrill SS, et al. Lack of association between cholesterol and coronary heart disease
mortality and morbidity and all-cause mortality in persons older than 70 years. JAMA. 1994;272:1335-1340.
FREE FULL TEXT
23. Psaty BM, Furberg CD, Kuller LH, et al. Traditional risk factors and subclinical disease measures as predictors
of first myocardial infarction in older adults: the Cardiovascular Health
Study. Arch Intern Med. 1999;159:1339-1347.
FREE FULL TEXT
24. Weverling-Rijnsburger AW, Blauw GJ, Lagaay AM, Knook DL, Meinders AE, Westendorp RG. Total cholesterol and risk of mortality in the oldest old. Lancet. 1997;350:1119-1123.
FULL TEXT
|
ISI
| PUBMED
25. Kronmal RA, Cain KC, Ye Z, Omenn GS. Total serum cholesterol levels and mortality risk as a function of
age: a report based on the Framingham data. Arch Intern Med. 1993;153:1065-1073.
FREE FULL TEXT
26. Anderson KM, Castelli WP, Levy D. Cholesterol and mortality: 30 years of follow-up from the Framingham
study. JAMA. 1987;257:2176-2180.
FREE FULL TEXT
27. Cox BD, Whichelow MJ, Prevost AT. The development of cardiovascular disease in relation to anthropometric
indices and hypertension in British adults. Int J Obes Relat Metab Disord. 1998;22:966-973.
FULL TEXT
|
ISI
| PUBMED
28. Society of Actuaries and Association of Life Insurance Medical Directors
of America. Build Study 1979. Chicago, Ill: Society of Actuaries and Association of Life Insurance
Medical Directors of America; 1980.
29. Jarrett RJ, Shipley MJ, Rose G. Weight and mortality in the Whitehall Study. Br Med J (Clin Res Ed). 1982;285:535-537.
30. Lew EA, Garfinkel L. Variations in mortality by weight among 750,000 men and women. J Chronic Dis. 1979;32:563-576.
FULL TEXT
|
ISI
| PUBMED
31. Takala JK, Mattila KJ, Ryynanen OP. Overweight, underweight and mortality among the aged. Scand J Prim Health Care. 1994;12:244-248.
PUBMED
32. Campbell AJ, Spears GF, Brown JS, Busby WJ, Borrie MJ. Anthropometric measurements as predictors of mortality in a community
population aged 70 years and over. Age Ageing. 1990;19:131-135.
FREE FULL TEXT
33. Hubert HB, Feinleib M, McNamara PM, Castelli WP. Obesity as an independent risk factor for cardiovascular disease: a
26-year follow-up of participants in the Framingham Heart Study. Circulation. 1983;67:968-977.
FREE FULL TEXT
34. Negri E, Santoro L, D'Avanzo B, Nobili A, La Vecchia C. Body mass and acute myocardial infarction: GISSI-EFRIM Investigators. Prev Med. 1992;21:292-301.
FULL TEXT
|
ISI
| PUBMED
35. Rajala SA, Kanto AJ, Haavisto MV, Kaarela RH, Koivunen MJ, Heikinheimo RJ. Body weight and the three-year prognosis in very old people. Int J Obes. 1990;14:997-1003.
ISI
| PUBMED
36. Allison DB, Gallagher D, Heo M, Pi-Sunyer FX, Heymsfield SB. Body mass index and all-cause mortality among people age 70 and over:
the Longitudinal Study of Aging. Int J Obes Relat Metab Disord. 1997;21:424-431.
FULL TEXT
|
ISI
| PUBMED
37. Brill PA, Giles WH, Keenan NL, et al. Effect of body mass index on activity limitation and mortality among
older women: the National Health Interview Survey, 1986-1990. J Womens Health. 1997;6:435-440.
ISI
| PUBMED
38. Kinney EL, Caldwell JW. Relationship between body weight and mortality in men aged 75 years
and older. South Med J. 1990;83:1256-1258.
ISI
| PUBMED
39. Mattila K, Haavisto M, Rajala S. Body mass index and mortality in the elderly. Br Med J (Clin Res Ed). 1986;292:867-868.
40. Bender R, Jockel KH, Trautner C, Spraul M, Berger M. Effect of age on excess mortality in obesity. JAMA. 1999;281:1498-1504.
FREE FULL TEXT
41. Langlois JA, Harris T, Looker AC, Madans J. Weight change between age 50 years and old age is associated with risk
of hip fracture in white women aged 67 years and older. Arch Intern Med. 1996;156:989-994.
FREE FULL TEXT
42. French SA, Folsom AR, Jeffery RW, Williamson DF. Prospective study of intentionality of weight loss and mortality in
older women: the Iowa Women's Health Study. Am J Epidemiol. 1999;149:504-514.
FREE FULL TEXT
43. Ensrud KE, Cauley J, Lipschutz R, Cummings SR. Weight change and fractures in older women: Study of Osteoporotic Fractures
Research Group. Arch Intern Med. 1997;157:857-863.
FREE FULL TEXT
44. Welch HG, Albertsen PC, Nease RF, Bubolz TA, Wasson JH. Estimating treatment benefits for the elderly: the effect of competing
risks. Ann Intern Med. 1996;124:577-584.
FREE FULL TEXT
 CiteULike  Connotea  Del.icio.us  Digg  Reddit  Technorati  Twitter
What's this?
RELATED ARTICLE
Archives of Internal Medicine Reader's Choice: Continuing Medical Education
Arch Intern Med. 2001;161(9):1240.
FULL TEXT
THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES
|
Low Serum Testosterone and Estradiol Predict Mortality in Elderly Men
Tivesten et al.
J. Clin. Endocrinol. Metab. 2009;94:2482-2488.
ABSTRACT
| FULL TEXT
Fitness and Fatness as Mortality Predictors in Healthy Older Men: The Veterans Exercise Testing Study
McAuley et al.
J Gerontol A Biol Sci Med Sci 2009;64A:695-699.
ABSTRACT
| FULL TEXT
Smoking and Weight Change After New Health Diagnoses in Older Adults
Keenan
Arch Intern Med 2009;169:237-242.
ABSTRACT
| FULL TEXT
Body mass index, muscle and fat in chronic kidney disease: questions about survival
Mafra et al.
Nephrol Dial Transplant 2008;23:2461-2466.
ABSTRACT
| FULL TEXT
Chronic Conditions and Mortality Among the Oldest Old
Lee et al.
AJPH 2008;98:1209-1214.
ABSTRACT
| FULL TEXT
Suppressive effects of nobiletin on hyperleptinemia and colitis-related colon carcinogenesis in male ICR mice
Miyamoto et al.
Carcinogenesis 2008;29:1057-1063.
ABSTRACT
| FULL TEXT
Underweight, overweight and obesity as risk factors for mortality and hospitalization
Ringback Weitoft et al.
Scand J Public Health 2008;36:169-176.
ABSTRACT
Sleep duration, general and abdominal obesity, and weight change among the older adult population of Spain
Lopez-Garcia et al.
Am. J. Clin. Nutr. 2008;87:310-316.
ABSTRACT
| FULL TEXT
Nutrition Recommendations and Interventions for Diabetes: A position statement of the American Diabetes Association
American Diabetes Association
Diabetes Care 2008;31:S61-S78.
FULL TEXT
Dietary patterns and risk of dementia: The Three-City cohort study
Barberger-Gateau et al.
Neurology 2007;69:1921-1930.
ABSTRACT
| FULL TEXT
Decreased muscle mass and increased central adiposity are independently related to mortality in older men
Wannamethee et al.
Am. J. Clin. Nutr. 2007;86:1339-1346.
ABSTRACT
| FULL TEXT
Body Mass Index and Mortality among Older Breast Cancer Survivors in the Study of Osteoporotic Fractures
Reeves et al.
Cancer Epidemiol. Biomarkers Prev. 2007;16:1468-1473.
ABSTRACT
| FULL TEXT
Associations Between Body Composition, Anthropometry, and Mortality in Women Aged 65 Years and Older
Dolan et al.
AJPH 2007;97:913-918.
ABSTRACT
| FULL TEXT
The Effect of Obesity on Disability vs Mortality in Older Americans
Al Snih et al.
Arch Intern Med 2007;167:774-780.
ABSTRACT
| FULL TEXT
Participation in Food Assistance Programs Modifies the Relation of Food Insecurity with Weight and Depression in Elders
Kim and Frongillo
J. Nutr. 2007;137:1005-1010.
ABSTRACT
| FULL TEXT
Prospective Effect of Job Strain on General and Central Obesity in the Whitehall II Study
Brunner et al.
Am J Epidemiol 2007;165:828-837.
ABSTRACT
| FULL TEXT
Measures of Adiposity and Dementia Risk in Elderly Persons
Luchsinger et al.
Arch Neurol 2007;64:392-398.
ABSTRACT
| FULL TEXT
Grip strength, body composition, and mortality
Gale et al.
Int J Epidemiol 2007;36:228-235.
ABSTRACT
| FULL TEXT
Nutrition Recommendations and Interventions for Diabetes: A position statement of the American Diabetes Association
American Diabetes Association
Diabetes Care 2007;30:S48-S65.
FULL TEXT
Nutritional risk and low weight in community-living older adults: a review of the literature (1995-2005).
Thompson Martin et al.
Journals of Gerontology Series A: Biological Sciences and Medical Sciences 2006;61:927-934.
ABSTRACT
| FULL TEXT
Nutrition Recommendations and Interventions for Diabetes-2006: A position statement of the American Diabetes Association.
American Diabetes Association
Diabetes Care 2006;29:2140-2157.
FULL TEXT
Weight, shape, and mortality risk in older persons: elevated waist-hip ratio, not high body mass index, is associated with a greater risk of death.
Price et al.
Am. J. Clin. Nutr. 2006;84:449-460.
ABSTRACT
| FULL TEXT
Association of Body Mass Index and Weight Change with All-Cause Mortality in the Elderly
Corrada et al.
Am J Epidemiol 2006;163:938-949.
ABSTRACT
| FULL TEXT
Cause-specific mortality in old age in relation to body mass index in middle age and in old age: follow-up of the Whitehall cohort of male civil servants
Breeze et al.
Int J Epidemiol 2006;35:169-178.
ABSTRACT
| FULL TEXT
Overweight and all-cause mortality in a Swedish rural population: Skaraborg Hypertension and Diabetes Project
Nyholm et al.
Scand J Public Health 2005;33:478-486.
ABSTRACT
Obesity in older adults: technical review and position statement of the American Society for Nutrition and NAASO, The Obesity Society
Villareal et al.
Am. J. Clin. Nutr. 2005;82:923-934.
ABSTRACT
| FULL TEXT
Prognosis in obesity: Older people should not be misinformed about being overweight
Visvanathan and Chapman
BMJ 2005;331:452-452.
FULL TEXT
Weight Change, Weight Change Intention, and the Incidence of Mobility Limitation in Well-Functioning Community-Dwelling Older Adults
Lee et al.
Journals of Gerontology Series A: Biological Sciences and Medical Sciences 2005;60:1007-1012.
ABSTRACT
| FULL TEXT
Excess Deaths Associated With Underweight, Overweight, and Obesity
Flegal et al.
JAMA 2005;293:1861-1867.
ABSTRACT
| FULL TEXT
Voluntary Weight Reduction in Older Men Increases Hip Bone Loss: The Osteoporotic Fractures in Men Study
Ensrud et al.
J. Clin. Endocrinol. Metab. 2005;90:1998-2004.
ABSTRACT
| FULL TEXT
Systolic Hypertension in Elderly Persons--Reply
Foody et al.
JAMA 2004;292:2466-2466.
FULL TEXT
Estimating Deaths Attributable to Obesity in the United States
Flegal et al.
AJPH 2004;94:1486-1489.
ABSTRACT
| FULL TEXT
Methods of Calculating Deaths Attributable to Obesity
Flegal et al.
Am J Epidemiol 2004;160:331-338.
ABSTRACT
| FULL TEXT
Weight-loss intention in the well-functioning, community-dwelling elderly: associations with diet quality, physical activity, and weight change
Lee et al.
Am. J. Clin. Nutr. 2004;80:466-474.
ABSTRACT
| FULL TEXT
Body Mass, Smoking, and Overall and Cause-Specific Mortality Among Older U.S. Adults
Krueger et al.
Research on Aging 2004;26:82-107.
ABSTRACT
Screening and Interventions for Obesity in Adults: Summary of the Evidence for the U.S. Preventive Services Task Force
McTigue et al.
ANN INTERN MED 2003;139:933-949.
ABSTRACT
| FULL TEXT
Prevalence and Correlates of Overweight and Obesity Among Older Adults: Findings From the Canadian National Population Health Survey
Kaplan et al.
Journals of Gerontology Series A: Biological Sciences and Medical Sciences 2003;58:M1018-1030.
ABSTRACT
| FULL TEXT
Obesity: Overview of Prevalence, Etiology, and Treatment
Racette et al.
ptjournal 2003;83:276-288.
FULL TEXT
|
