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Volume
2:
No. 1, January 2005
ORIGINAL RESEARCH
Prevalence of Overweight, Obesity, and Comorbid Conditions
Among U.S. and Kentucky Adults, 2000–2002
Todd M. Jenkins, MPH
Suggested citation for this article: Jenkins TM. Prevalence of
overweight, obesity, and comorbid conditions among U.S. and Kentucky adults,
2000–2002. Prev Chronic Dis [serial online] 2005 Jan [date cited].
Available from: URL:
http://www.cdc.gov/pcd/issues/2005/
jan/04_0087.htm.
PEER REVIEWED
Abstract
Introduction
Obesity rates for adults in Kentucky are regularly among the
highest in the nation. Since 1991, adult obesity in Kentucky and
the United States has nearly doubled. This trend is of great
concern because excess weight has been associated with several
chronic diseases and conditions. This paper reports on the
prevalence of overweight and obesity among adults in Kentucky
between 2000 and 2002. The estimates produced by this study will
provide baseline figures for developing Kentucky’s
statewide obesity action plan.
Methods
A secondary data analysis was performed using the Centers for
Disease Control and Prevention’s Behavioral Risk Factor
Surveillance System. Prevalence estimates and odds ratios were
calculated for the United States and Kentucky.
Results
In Kentucky, 24.2% of adults were obese, compared with 21.9%
nationally (P < .001). There were also significantly more
overweight adults in Kentucky than there were nationwide (P < .001).
Logistic regression showed that overweight and obese adults were
more likely to report various comorbid conditions.
Conclusion
Overweight and obesity estimates in Kentucky were
significantly higher than nationwide figures. However,
overweight/obese adults in Kentucky were no more likely than
their U.S. counterparts to report selected comorbid
conditions.
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Introduction
The obesity epidemic in the United States worsens with each
passing year. From 1991 to 2002, the prevalence of obesity has
increased more than 80%, representing an estimated 43 million adults
in 2002 (1). In 1991, no
state in the nation had an obesity prevalence at or above 20%,
but by 2002 there were 39 states with this characteristic (2). The severity of this epidemic
has been highlighted in Healthy People 2010, where overweight and
obesity have been grouped as leading health indicators
for the United States (3). In terms of mortality, an estimated 280,000 to 325,000 adults in the United States die
each year from causes related to obesity (4). More importantly, excess weight
has been positively correlated with years of life lost (5).
In addition to mortality, substantial morbidity
is associated with obesity. For example, in 2000, the total
cost of obesity in the United States was estimated to be $117 billion ($61
billion in direct medical costs, $56 billion in indirect costs)
(3,6). An estimated 9.1% of
annual medical spending in the United States is attributed to overweight and
obesity — a figure that rivals medical costs attributable to cigarette smoking
(7). Overweight and obesity have been associated with several chronic diseases
and conditions, including cardiovascular disease, type 2 diabetes, hypertension,
stroke, arthritis, high serum cholesterol, and some cancers (8-10). This is
of great concern in Kentucky because the prevalence rates for overweight and
obesity continue to increase and are regularly among the highest
in the nation. All told, obesity substantially increases
morbidity and impairs quality of life (11). Kentucky is developing a statewide
action plan to address this public health issue. Estimates
produced from this analysis will serve as baseline figures for
the action plan.
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Methods
A secondary data analysis was performed using data from the
Behavioral Risk Factor Surveillance System (BRFSS), 2000–2002 (12,13).
Conducted by the Centers for Disease Control and Prevention
(CDC), the BRFSS is an annual population-based, random-digit-dialed
telephone survey of the noninstitutionalized U.S. civilian
population aged 18 or older. This ongoing surveillance system
measures health behaviors and preventive practices related to
several leading causes of death (12,13). Kentucky data were obtained from
the Kentucky BRFSS Program (KY BRFSS) (14). Data from 21,016 adults in Kentucky
were collected during this period. U.S. data were retrieved
from the CDC’s public-use BRFSS datasets (15). Data from 642,924
adults across the nation were collected during 2000–2002. The
national dataset included data from Guam, Puerto Rico, and the
Virgin Islands, but these areas were excluded from this
analysis.
Overweight and obesity classifications used in the analysis
were derived from Body Mass Index (BMI) and were consistent with
the definitions set forth by the World Health Organization (WHO)
and the National Heart, Lung, and Blood Institute (underweight:
BMI <18.5; normal weight: BMI = 18.5–24.9; overweight: BMI
= 25.0–29.9; obesity-class 1: BMI = 30.0–34.9; obesity-class 2: BMI
= 35.0–39.9; obesity-class 3: BMI ≥40.0) (9,16). BMI (calculated
as weight in kilograms divided by the square of height in meters)
was calculated using the following questions: 1) “About how much do
you weigh without shoes?” and 2) “About how tall are you without
shoes?” (17). Respondents with
missing or unknown height or weight data were excluded from the
analysis. Women who reported they were pregnant at the time of
the interview were also excluded from the analysis. After all
exclusions, a total of 590,120 respondents for the United States and
19,722 respondents from Kentucky were included in the
analysis.
Comorbid conditions were measured using the following
questions (17):
Diabetes. Have you ever been told by a doctor that you have diabetes?
(2000–2002)
Asthma. Did a doctor ever tell you that you have asthma? (2000) Have you ever been told by a doctor, nurse, or other health
professional that you have asthma? (2001–2002)
Arthritis. Have you ever been told by a doctor that you have arthritis?
(2000–2001) Have you ever been told by a doctor or other health
professional that you have some form of arthritis, rheumatoid
arthritis, gout, lupus, or fibromyalgia? (2002)
High blood pressure. Have you ever been told by a doctor, nurse, or other health professional that
you have high blood pressure? (2001)
High cholesterol. Have you ever been told by a doctor, nurse, or other health professional that
your blood cholesterol is high? (2001)
Health status. Would you say that in general your health is:
Excellent, Very Good, Good, Fair, or Poor? (2000–2002).
Women reporting gestational diabetes were coded as having
diabetes. Questions assessing blood pressure and cholesterol are
asked in alternating years (rotating core questions) and were not
selected as modules in most states (including Kentucky) in 2000
or 2002; thus, data from these questions were analyzed for 2001
only.
SAS version 8.2 (SAS Institute Inc, Cary, NC) and SAS-Callable SUDAAN version 8.0.1
(Research Triangle Institute, Research Triangle Park, NC) were
used to perform the data analysis and to account for the complex
sampling design (18,19). PROC
DESCRIPT was used to calculate age-adjusted prevalence estimates
and their corresponding standard errors. Prevalence estimates of
obesity, overweight, and comorbid conditions were age-adjusted
to the 2002 BRFSS. However, figures representing total number of
adults were derived from crude estimates. Multivariate logistic
regression was performed using PROC RLOGIST to assess
associations between BMI and comorbid conditions while controlling for age,
race, sex, education, and smoking status. All reported
data are weighted, correcting for variation in selection
probability and demographic imbalances (20).
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Results
During the years 2000–2002, 24.2% of adults (683,000) in Kentucky were obese (BMI ≥30.0),
compared with 21.9% (42 million) in the United States (P < .001) (Table 1).
Both men (24.6%) and women (23.8%) in Kentucky had significantly higher levels
of obesity compared with men and women nationally (21.9% [P < .001] for men
and 21.7% [P < .001]
for women). Among race/ethnicity groups, only non-Hispanic whites in Kentucky
had a significantly higher obesity estimate compared with the United States (P < .001).
There were also more overweight (BMI = 25.0–29.9) adults in
Kentucky than nationwide. During 2000–2002, 62.8% of adults in
Kentucky (1.76 million adults) were overweight, compared with 59.7%
(115 million adults) nationally (P < .001) (Table
2). As seen with obesity, the prevalence of overweight
among men (70.7%) and women (54.8%) in Kentucky was also
significantly higher than among their counterparts nationally
(67.9% [P < .001] of men and 51.3% [P < .001] of women).
Estimates for overweight were also higher among non-Hispanic
whites in Kentucky (62.3%) compared with the United States (57.8% [P < .001]). Rates for non-Hispanic blacks in Kentucky and in the
United States were not significantly different, but they were
significantly higher than for non-Hispanic whites within both
regions. By age group, estimates peaked at ages 50–59 for both
Kentucky (70.0%) and the United States (67.6%).
Table 3 lists the prevalence of comorbid conditions
by BMI category among
Kentucky and U.S. adults. As expected, the
prevalence of each condition increased with BMI. The largest
increases in prevalence were observed with diabetes and fair or
poor health status. For comparisons between Kentucky and the
United States, differences were most pronounced for arthritis and fair or
poor health status. For every BMI category, the prevalence of
adults in Kentucky with arthritis was greater than adults
nationally. The prevalence of adults in Kentucky reporting fair
or poor health status was higher in the United States for all but the
highest BMI category, obesity-class 3.
Multivariate logistic regression analysis indicated
significant associations for overweight and obesity with each
comorbid condition (Table 4).
Overweight and obese adults in
Kentucky were more likely than those of normal weight to have
diabetes, asthma, arthritis, high blood pressure, high
cholesterol, and fair or poor health status. As expected, results
were strongest for those with obesity-class 3. Using a normal BMI
as the reference, the odds of Kentucky respondents with
obesity-class 3 were nine times higher (Prevalence Odds Ratio [POR] 9.10) to
report diabetes, four times higher (POR 4.26)
to report arthritis, more than six times higher (POR 6.83) to report
high blood pressure, and more than four times higher (POR 4.59) to report a
fair or poor health status. However, none of the results listed
in Table 4 for Kentucky was significantly different from U.S.
estimates.
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Discussion
Since 1991, the prevalence of obesity among adults in the United States
and Kentucky has doubled (1,21). When combined with overweight,
more than 60% of adults throughout the United States and Kentucky are
classified as overweight/obese (BMI ≥25). Among the
fifty states and the District of Columbia in 2002, the obesity rate in Kentucky was
the 13th highest (24.4%; 95% confidence interval [CI], 22.8–26.1), 8.5%
higher than the U.S. rate (22.5%; 95% CI, 22.2–22.8). For overweight, Kentucky
had the sixth highest estimate (63.6%; 95% CI, 61.8–65.4), 5.3% greater than the
U.S. rate (60.4%; 95% CI, 60.0–60.7).
Results by age indicate that younger adults in Kentucky (aged
18–29, 30–39, 40–49) had significantly higher obesity estimates
than younger adults in the United States. Data for overweight were similar, with estimates
for adults up to the age of 60 significantly higher in Kentucky.
Comparisons between the United States and Kentucky for youth (<18
years) were also similar. According to the 2001 Youth Risk
Behavioral Surveillance System (YRBSS), 12.3% of high school
students in Kentucky were overweight, and another 15.2% were at
risk for becoming overweight, compared with 10.5% overweight and
13.6% at risk nationally (22).
These data suggest that the prevalence of overweight and obesity
is unlikely to change in Kentucky in the foreseeable future.
Results from this analysis revealed that overweight and obesity
are more prevalent in Kentucky, but those with excess weight were
no more likely to have other comorbid conditions (e.g., diabetes,
arthritis) in Kentucky than observed nationally. However,
with its disproportionate share of overweight and obesity,
Kentucky will face the costly task of treating and caring for a
disproportionately greater number of its population beset with
comorbid conditions related to excess weight for many years to
come.
The results reported here are subject to several limitations.
First, the survey design includes only those
noninstitutionalized civilian adults who have a telephone.
Therefore, results are generalizable only to this population.
According to Census 2000, 2.4% of occupied housing units across
the nation and 4.7% in Kentucky do not have telephone service
(23). Individuals without
telephones are more likely to have a low socioeconomic status,
which is associated with obesity (24,25). Therefore, results in this
analysis are likely to be underestimated. The use of
self-reported height and weight represents another limitation.
Respondents in self-reported surveys tend to overestimate their
height, while overweight respondents tend to underestimate their
weight (1). Compared with
studies based on directly measured height and weight, such as the
National Health and Nutrition Examination Survey (NHANES),
obesity estimates from self-report tend to be lower (26). The prevalence of obesity from
NHANES 1999–2000 was 30.5%, compared with 19.8% from the 2000 BRFSS
(10,26). There are also
drawbacks to using BMI as an indicator for overweight and
obesity. BMI can overestimate body fat in persons who are very
muscular and underestimate body fat in persons who have lost
muscle mass, such as many elderly (10). However, estimates from these
potentially misclassified groups likely had little overall impact on the
analysis.
The impact of excess weight extends beyond the monetary costs
and physical ailments associated with it. Other issues
such as social stigma, discrimination, and poor body
image all contribute to a lower quality of life for the
overweight and obese compared with individuals of normal weight
(3,27). If current trends
continue, obesity will soon overtake smoking as the primary
preventable cause of death (28). These results, in part, serve as
baseline figures for Kentucky’s initial obesity action
plan. Future initiatives addressing diet and physical activity
are anticipated to be derived from this plan.
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Acknowledgments
Thanks go to Mark Dignan, Carol White, and Crystal Jenkins of
the University of Kentucky Prevention Research Center for their assistance with
editing the manuscript.
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Author Information
Corresponding Author: Todd M. Jenkins, MPH, University of
Kentucky Prevention Research Center, Lexington, Ky.
Current author address: Department of Biostatistics, University of Alabama
at Birmingham, Room 327, Ryals Bldg, 1665 University Blvd, Birmingham, AL
35294. Telephone: 205-934-5989.
E-mail: jenkitm@uab.edu.
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Tables
 Table 1. Prevalence of Obesity
(Body Mass Index ≥30) by
Demographic Characteristic, Adults Aged ≥18, United States and
Kentucky, 2000–2002 Behavioral Risk Factor Surveillance Systema
| Characteristic |
Kentucky |
United States
|
| Total |
24.2 (23.4-25.1) |
21.9 (21.7-22.1) |
| Sex |
| Male |
24.6 (23.2-25.9) |
21.9 (21.7-22.2) |
| Female |
23.8 (22.6-24.9) |
21.7 (21.5-22.0) |
| Race/ethnicity |
| Non-Hispanic white |
23.7 (22.8-24.6) |
20.3 (20.1-20.5) |
| Non-Hispanic black |
33.7 (29.2-38.2) |
32.9 (32.2-33.6) |
| Non-Hispanic other |
24.4 (17.2-31.5) |
16.5 (15.7-17.4) |
| Hispanic |
21.0 (14.2-27.7) |
26.2 (25.1-27.2) |
| Age
(years) |
| 18-29 |
18.4 (16.0-20.9) |
14.3 (13.9-14.7) |
| 30-39 |
26.9 (24.7-29.2) |
21.4 (21.0-21.8) |
| 40-49 |
28.2 (26.1-30.2) |
24.6 (24.1-25.1) |
| 50-59 |
27.0 (24.9-29.1) |
26.9 (26.4-27.4) |
| 60-69 |
25.2 (22.9-27.4) |
25.2 (24.6-25.7) |
| 70+ |
17.0 (15.2-18.9) |
17.4 (16.9-17.8) |
| Education |
| <High school |
28.2 (26.1-30.3) |
29.4 (28.6-30.1) |
| High school grad |
25.1 (23.6-26.5) |
24.3 (23.9-24.6) |
| Some college |
25.4 (23.4-27.3) |
22.3 (21.9-22.6) |
| College+ |
18.0 (16.1-19.8) |
16.2 (15.9-16.5) |
| Smoking status |
| Current |
19.6 (18.2-21.1) |
17.5 (17.1-17.8) |
| Former |
28.6 (26.0-31.3) |
24.0 (23.6-24.4) |
| Never |
25.2 (23.9-26.5) |
22.5 (22.2-22.7) |
|
aAll values represent percentages (95% confidence intervals). Age-adjusted to the 2002 Behavioral Risk Factor Surveillance System.
Table 2.
Prevalence of Overweight
(Body Mass Index = 25.0–29.9) by Demographic Characteristic,
Adults Aged ≥18, United States and Kentucky, 2000–2002 Behavioral Risk Factor Surveillance Systema
| Characteristic |
Kentucky |
United States |
| Total |
62.8 (61.8-63.8) |
59.7 (59.5-59.9) |
| Sex |
| Male |
70.7 (69.3-72.1) |
67.9 (67.6-68.2) |
| Female |
54.8 (53.5-56.1) |
51.3 (51.0-51.6) |
| Race/ethnicity |
| Non-Hispanic white |
62.3 (61.3-63.3) |
57.8 (57.5-58.0) |
| Non-Hispanic black |
71.0 (66.6-75.5) |
70.7 (70.0-71.4) |
| Non-Hispanic other |
62.3 (53.4-71.2) |
51.3 (50.0-52.6) |
| Hispanic |
58.2 (49.7-66.8) |
67.3 (66.3-68.3) |
| Age
(years) |
| 18-29 |
50.7 (47.9-53.5) |
43.4 (42.8-44.0) |
| 30-39 |
62.0 (59.6-64.4) |
58.7 (58.2-59.2) |
| 40-49 |
66.6 (64.5-68.8) |
62.9 (62.4-63.4) |
| 50-59 |
70.0 (67.9-72.1) |
67.6 (67.1-68.1) |
| 60-69 |
68.2 (65.7-70.7) |
67.0 (66.4-67.6) |
| 70+ |
57.1 (54.6-59.5) |
57.1 (56.5-57.7) |
| Education |
| <High school |
63.8 (61.5-66.1) |
66.3 (65.6-67.0) |
| High school grad |
64.1 (62.5-65.6) |
62.4 (62.0-62.7) |
| Some college |
64.0 (62.0-66.1) |
59.8 (59.3-60.2) |
| College+ |
57.1 (54.7-59.6) |
54.4 (54.0-54.8) |
| Smoking status |
| Current |
55.4 (53.4-57.3) |
52.7 (52.2-53.2) |
| Former |
68.7 (66.4-71.0) |
64.2 (63.8-64.7) |
| Never |
64.0 (62.6-65.5) |
59.7 (59.4-60.0) |
|
aAll values represent percentages (95%
confidence intervals). Age-adjusted to the 2002 Behavioral Risk Factor
Surveillance System.
|
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