NCHS Data Brief ■ No. 36 ■ April 2010

u.s. department of health and human services

Centers for Disease Control and Prevention

National Center for Health Statistics

Hypertension, High Serum Total Cholesterol, and Diabetes:

Racial and Ethnic Prevalence Differences in

U.S. Adults, 1999–2006

Cheryl D. Fryar, M.S.P.H.; Rosemarie Hirsch, M.D., M.P.H.; Mark S. Eberhardt, Ph.D.;

Sung Sug Yoon, Ph.D.; and Jacqueline D. Wright, Dr.P.H.

Eliminating health disparities among different segments of the population 

is one of two overarching goals of both Healthy People 2010 and 2020 (1). 

Race/ethnicity differences in health care and chronic diseases have been 

well documented (2,3). Hypertension, hypercholesterolemia, and diabetes 

are all chronic conditions associated with cardiovascular disease, the 

leading cause of death in the United States. The co-occurrence of these three 

chronic conditions by race/ethnicity has been less frequently documented. In 

addition, reliance on only self-reported diagnosis results in an underestimate 

of the prevalence of these conditions. The objective of this report is to 

compare the prevalence of diagnosed and undiagnosed hypertension, 

hypercholesterolemia, and diabetes among three racial/ethnic groups and the 

prevalence of co-morbidity of these conditions for U.S. adults. 

Keywords: chronic conditions • hypercholesterolemia • comorbidity

Does hypertension, hypercholesterolemia, or diabetes vary 

by race/ethnicity?

The prevalence of diagnosed or undiagnosed hypertension, 

hypercholesterolemia, and diabetes varies by racial/ethnic group (Figure 1).

Key findings

• Forty-five percent of adults 

had at least one of three 

diagnosed or undiagnosed 

chronic conditions—hypertension, hypercholesterolemia,

or diabetes; one in eight 

adults (13%) had two of these 

conditions; and 3% of adults had 

all three chronic conditions.

• Nearly one in seven U.S. 

adults (15%) had one or more of 

these conditions undiagnosed. 

• Non-Hispanic black persons 

were more likely than nonHispanic white and MexicanAmerican persons to have at 

least one of the three conditions 

(diagnosed or undiagnosed). 

• Non-Hispanic black and nonHispanic white persons were 

more likely than MexicanAmerican persons to have both 

diagnosed or undiagnosed 

hypertension and hypercholesterolemia. Non-Hispanic 

black and Mexican-American 

persons were more likely than 

non-Hispanic white persons 

to have both diagnosed or 

undiagnosed hypertension and 

diabetes.

0

10

20

30

40

50

Total Non-Hispanic white Non-Hispanic black Mexican American

Hypertension Hypercholesterolemia Diabetes

1 is the significant difference between non-Hispanic white and non-Hispanic black persons.

2 is the significant difference between non-Hispanic white and Mexican-American persons.

3 is the significant difference between non-Hispanic black and Mexican-American persons.

NOTE: Persons of other race/ethnicity included in total.

SOURCE: CDC/NCHS, National Health and Nutrition Examination Surveys, 1999–2006.

Figure 1. Age-adjusted prevalence of diagnosed or undiagnosed hypertension, hypercholesterolemia, and diabetes in adults, by race/ethnicity: United States, 1999–2006

30.5

26.0

9.9

29.1 1,226.9

8.3

1,342.5

21.5

1

14.6

26.1

21.8

2

15.3

Percent
NCHS Data Brief ■ No. 36 ■ April 2010

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Non-Hispanic black persons (42.5%) have a significantly higher prevalence of hypertension 

compared with non-Hispanic white (29.1%) and Mexican-American persons (26.1%). NonHispanic white persons (26.9%) have a significantly higher prevalence of hypercholesterolemia 

compared with non-Hispanic black (21.5%) and Mexican-American persons (21.8%). NonHispanic black (14.6%) and Mexican-American persons (15.3%) have a significantly higher 

prevalence of diabetes than do non-Hispanic white persons (9.9%).

What proportion of U.S. adults has comorbid hypertension, 

hypercholesterolemia, or diabetes? 

Overall, 45% of U.S. adults have at least one of three diagnosed or undiagnosed conditions 

(hypertension, hypercholesterolemia, or diabetes) (Figure 2). Approximately 3% of U.S. 

adults have all three conditions and 13% have two conditions. Both hypertension and 

hypercholesterolemia were present in 9% of adults; 3% of adults have both hypertension and 

diabetes; and 1.5% of adults have both diabetes and hypercholesterolemia (Figure 3).

0

10

20

30

40

50

1 is the significant difference between non-Hispanic white and Mexican-American persons.

2 is the significant difference between non-Hispanic white and non-Hispanic black persons.

3 is the significant difference between non-Hispanic black and Mexican-American persons.

NOTE: Persons of other race/ethnicity are included in the total. 

SOURCE: CDC/NCHS, National Health and Nutrition Examination Surveys, 1999–2006. 

Figure 2. Age-adjusted prevalence of diagnosed or undiagnosed hypertension, 

hypercholesterolemia, and diabetes in adults, by number of conditions and race/ethnicity:

United States, 1999–2006

Mexican

American

Non-Hispanic

black

Non-Hispanic

white

Total

Percent

28.6

2,316.4

2

4.6

2,349.6

28.9

13.4

2.8

45.1

1

29.8

12.8

2.5

45.1

26.1

12.7

3.8

42.6

All three

conditions

Two conditions

only

One condition

only
NCHS Data Brief ■ No. 36 ■ April 2010

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0

2

4

6

8

10

1 is the significant difference between non-Hispanic white and Mexican-American persons.

2 is the significant difference between non-Hispanic black and Mexican-American persons.

3 is the significant difference between non-Hispanic white and non-Hispanic black persons.

NOTE: Persons of other race/ethnicity included in total.

SOURCE: CDC/NCHS, National Health and Nutrition Examination Surveys, 1999–2006.

Figure 3. Age-adjusted prevalence of two specific diagnosed or undiagnosed comorbid 

conditions in adults, by race/ethnicity: United States, 1999–2006

8.9

3.1

1.5

1

9.3

2.4

1.2

2

8.9

3

6.1

1.4

5.5 1

4.9

2.4

Hypertension and

hypercholesterolemia

Hypertension and

diabetes

Diabetes and

hypercholesterolemia

Percent

Total Non-Hispanic white Non-Hispanic black Mexican American

Does the number of comorbid conditions vary by race/ethnicity?

Non-Hispanic black persons (49.6%) were more likely than non-Hispanic white (45.1%) and 

Mexican-American persons (42.6%) to have at least one of three diagnosed or undiagnosed 

conditions (hypertension, hypercholesterolemia, or diabetes) (Figure 2). 

Non-Hispanic white persons (29.8%) were more likely to have only one condition compared with 

Mexican-American persons (26.1%). Non-Hispanic black persons (16.4%) were more likely to 

have two comorbid conditions compared with non-Hispanic white persons (12.8%) and MexicanAmerican persons (12.7%). Non-Hispanic black persons (4.6%) were also more likely to have all 

three conditions compared with non-Hispanic white persons (2.5%). 

For adults with only two of the conditions (Figure 3), non-Hispanic black (8.9%) and 

non-Hispanic white persons (9.3 %) were more likely to have both hypertension and 

hypercholesterolemia than were Mexican-American persons (5.5%). Non-Hispanic black 

(6.1%) and Mexican-American persons (4.9%) were more likely to have both hypertension and 

diabetes than were non-Hispanic white persons (2.9%). There was no statistically significant 

race/ethnicity difference among those having both diagnosed and undiagnosed diabetes and 

hypercholesterolemia. 
NCHS Data Brief ■ No. 36 ■ April 2010

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What is the burden of undiagnosed hypertension, hypercholesterolemia, or 

diabetes in U.S. adults?

Approximately 8% of U.S. adults have undiagnosed hypertension, 8% have undiagnosed 

hypercholesterolemia, and 3% have undiagnosed diabetes. The proportion of U.S. adults who 

have undiagnosed hypertension, hypercholesterolemia, or diabetes was similar across racial/

ethnic groups. 

0

2

4

6

8

10

NOTE: Persons of other race/ethnicity included in total.

SOURCE: CDC/NCHS, National Health and Nutrition Examination Surveys, 1999–2006.

7.8 8.2

2.7

7.5

8.3

2.6

8.7

7.6

3.3

8.4

9.2

3.1

Hypertension Hypercholesterolemia Diabetes

Percent

Figure 4. Age-adjusted prevalence of undiagnosed hypertension, hypercholesterolemia, and 

diabetes in adults, by race/ethnicity: United States, 1999–2006

Total Non-Hispanic white Non-Hispanic black Mexican American

What proportions of U.S. adults have comorbid undiagnosed hypertension, 

hypercholesterolemia, or diabetes? 

In over 15% of U.S. adults one or more of the three conditions was undiagnosed. The proportion 

of adults having one or more of these undiagnosed conditions was similar across racial/ethnic 

groups.

0

4

8

12

16

20

NOTE: Persons of other race/ethnicity included in total.

SOURCE: CDC/NCHS, National Health and Nutrition Examination Surveys, 1999–2006.

Figure 5. Age-adjusted prevalence of undiagnosed hypertension, hypercholesterolemia, and 

diabetes in adults, by number of conditions and race/ethnicity: United States, 1999–2006

Mexican

American

Non-Hispanic

black

Non-Hispanic

white

Total

Percent

14.0 14.0 14.3 14.5

1.4 1.3 1.4 2.0

Two or more

conditions only

One condition

only
NCHS Data Brief ■ No. 36 ■ April 2010

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Summary

Overall, 45% of U.S. adults aged 20 and over have one of the three following diagnosed or 

undiagnosed chronic conditions—hypertension, hypercholesterolemia, or diabetes. Non-Hispanic 

black persons were more likely than non-Hispanic white and Mexican-American persons to 

have at least one of these three conditions. These findings indicate that a high percentage of the 

population have a condition associated with heart disease, the leading cause of death in the United 

States.

The prevalence of the comorbidity of diagnosed or undiagnosed hypertension, 

hypercholesterolemia, and diabetes varies by race/ethnicity. Non-Hispanic white persons were 

more likely to have only one of the three conditions compared with Mexican-American persons. 

Non-Hispanic black persons were more likely to have two comorbid conditions compared with 

non-Hispanic white and Mexican-American persons. Non-Hispanic black persons were also more 

likely to have all three chronic conditions compared with non-Hispanic white persons. These 

results emphasize the need for research to identify the reasons for the race/ethnicity differences 

and to identify factors that could be modified to mitigate the race/ethnicity differences.

Diagnosed or undiagnosed hypertension and hypercholesterolemia are more likely to coexist in 

non-Hispanic black and non-Hispanic white persons than Mexican-American persons. Diagnosed 

or undiagnosed hypertension and diabetes are more likely to coexist in non-Hispanic black and 

Mexican-American persons than non-Hispanic white persons. In 15% of U.S. adults, one or more 

of the three conditions is undiagnosed. 

Definitions

Consensus definitions for the diagnosis of the hypertension, hypercholesterolemia, and diabetes 

have been presented elsewhere and serve as the rationale for the analytic definitions used in 

this report as described in the following text (4–6). An overarching definition was used for each 

condition even though more rigorous criteria may exist for some groups in this analysis (e.g., 

hypertension for diabetic persons is usually defined as systolic BP ≥ 130 mm Hg or diastolic 

BP > 80 mm Hg). 

Hypertension: Systolic BP ≥ 140 mm Hg or diastolic BP ≥ 90 mm Hg or currently taking 

medication to lower high BP.

Undiagnosed hypertension: A finding of hypertension and never told by health care provider that 

blood pressure was high (based on a negative response to the question “Ever told by a doctor or 

other health care professional that you had hypertension, also called high blood pressure?”)

Hypercholesterolemia: Levels of serum total cholesterol ≥ 240 mg/dl or currently taking 

cholesterol lowering medication.

Undiagnosed hypercholesterolemia: A finding of hypercholesterolemia and never told by health 

care provider that cholesterol was high (based on a negative response to the question “Have you 

ever been told by a doctor or other health care professional that your blood cholesterol is high?”)
NCHS Data Brief ■ No. 36 ■ April 2010

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Diabetes: A self-report of a previous physician diagnosis of diabetes or having undiagnosed 

diabetes.

Undiagnosed diabetes: Fasting plasma glucose of at least 126 mg/dL and no reported physician 

diagnosis. 

Data source and methods

The National Health and Nutrition Examination Survey (NHANES) data were used for these 

analyses. NHANES is a cross-sectional survey designed to monitor the health and nutritional 

status of the civilian, noninstitutionalized U.S. population (7). The survey consists of interviews 

conducted in participants’ homes, standardized physical examinations conducted in mobile 

examination centers, and laboratory tests utilizing blood and urine specimens provided by 

participants during the physical examination. 

The NHANES sample is selected through a complex, multistage design that includes selection of 

primary sampling units (counties), household segments within the counties, and finally sample 

persons from selected households. The sample design includes oversampling in order to obtain 

reliable estimates of health and nutritional measures for population subgroups. In 1999–2006, 

African Americans, Mexican Americans, persons with low income, persons aged 12–19 years , 

and persons aged 60 and over were oversampled. In 1999, NHANES became a continuous survey, 

fielded on an ongoing basis. Each year of data collection is based on a representative sample 

covering all ages of the civilian, noninstitutionalized population. Public-use data files are released 

in 2-year cycles.

Sample weights, which account for the differential probabilities of selection, nonresponse, 

and noncoverage, were incorporated into the estimation process. The standard errors of the 

percentages were estimated using Taylor Series Linearization, a method that incorporates the 

sample weights and sample design (8).

Estimates for the total population were age adjusted to the 2000 U.S. standard population using 

three age groups, 20–39, 40–59, and aged 60 and over (9). Differences between groups were 

evaluated using a univariate t-statistic at the p < 0.05 significance level. For comparison of 

estimates by race/ethnicity, adjustments for multiple comparisons were made using the Bonferroni 

method (10). All differences reported are statistically significant unless otherwise indicated.

Statistical analyses were conducted using the SAS System for Windows (release 9.1; SAS 

Institute Inc, Cary, N.C.) and SUDAAN (release 9.0; Research Triangle Institute, Research 

Triangle Park, N.C.).

About the authors

Cheryl D. Fryar, Rosemarie Hirsch, Mark S. Eberhardt, Sung Sug Yoon, and Jacqueline D. Wright 

are with the Centers for Disease Control and Prevention’s National Center for Health Statistics, 

Division of Health and Nutrition Examination Surveys.
NCHS Data Brief ■ No. 36 ■ April 2010

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References

1. U.S. Department of Health and Human Services. Office of Disease Prevention and Health 

Promotion. Healthy People 2010. Available from: http://www.health.gov/healthypeople. 

[Accessed 11/25/09].

2. National Center for Health Statistics. Health, United States, 2008. Hyattsville, MD. Available 

from: http://www.cdc.gov/nchs/hus.htm. [Accessed 11/25/09].

3. Agency for Healthcare Research and Quality. 2008 National Healthcare Disparities 

Report (NHDR). Rockville, MD: U.S. Department of Health and Human Services, Agency for 

Healthcare Research and Quality. 2009.

4. Chobanian AV, Bakris GL, Black HR, et al. Seventh report of the Joint National Committee 

on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Hypertension 

42(6):1206–52. 2003.

5. Third Report of the Expert Panel on Detection, Evaluation, and Treatment of High Blood 

Cholesterol in Adults (Adult Treatment Panel III). Washington, DC: National Institutes of Health. 

2001. 

6. Diagnosis and classification of diabetes mellitus. Diabetes Care 32:S62–7. 2009. Available 

from: http://care.diabetesjournals.org/content/32/Supplement_1/S62.full.pdf+html [Accessed 

11/25/09].

7. Centers for Disease Control and Prevention. National Center for Health Statistics. National 

Health and Nutrition Examination Surveys 1999–2006. Available from: http://www.cdc.gov/nchs/

nhanes/nhanes_questionnaires.htm [Accessed 11/25/09].

8. Centers for Disease Control and Prevention. National Center for Health Statistics. National 

Health and Nutrition Examination Surveys Analytic Guidelines. Available from: http://www.cdc.

gov/nchs/nhanes/nhanes2003-2004/analytical_guidelines.htm [Accessed 11/25/09]. 

9. Klein RJ, Schoenborn CA. Age adjustment using the 2000 projected U.S. population. Healthy

People Statistical Notes, no 20. Hyattsville, MD: National Center for Health Statistics. 2001.

10. Miller RG. Developments in multiple comparisons, 1966–76. JASA 72:779–88. 1977.
NCHS Data Brief ■ No. 36 ■ April 2010

Suggested citation

Fryar CD, Hirsch R, Eberhardt MS, Yoon 

SS, Wright JD. Hypertension, high serum 

total cholesterol, and diabetes: Racial 

and ethnic prevalence differences in U.S. 

adults, 1999–2006. NCHS data brief, no 36. 

Hyattsville, MD: National Center for Health 

Statistics. 2010.

Copyright information

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the public domain and may be reproduced 

or copied without permission; citation as to 

source, however, is appreciated.

National Center for Health 

Statistics

Edward J. Sondik, Ph.D., Director

Jennifer H. Madans, Ph.D., Associate 

Director for Science

Division of Health and Nutrition 

Examination Surveys

Clifford L. Johnson, M.S.P.H., Director

U.S. Department of

Health & Human Services

Centers for Disease Control and Prevention

National Center for Health Statistics

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