DNA samples were collected in the Third National Health and Nutrition Examination Survey (NHANES III; 1988-1994) and in subsequent NHANES cycles (1999-2002, 2007-2008, 2009-2010, and 2011-2012). The program is a nationally representative collection of stored DNA samples and genetic data and will serve to add to the extensive amount of health, nutritional, and environmental information collected from NHANES. Resulting genetic variants are deposited into the NHANES Genetic Data Repository. These datasets are categorized as restricted data since they contain identifiable information.

For more information on the NHANES Genetic Data please visit: NHANES DNA Specimens and Genetic Data Program at: https://www.cdc.gov/nchs/nhanes/biospecimens/dnaspecimens.htm. For more information on NHANES, visit the NHANES - National Health and Nutrition Examination Survey Homepage at: https://www.cdc.gov/nchs/nhanes/index.htm.

The National Health and Nutrition Examination Surveys (NHANES) is a program of studies designed to assess the health and nutritional status of adults and children in the United States. The NHANES combines personal interviews and physical examinations, which focus on different population groups or health topics. These surveys have been conducted by the National Center for Health Statistics (NCHS) on a periodic basis from 1971 to 1994. In 1999 the NHANES became a continuous program with a changing focus on a variety of health and nutrition measurements which were designed to meet current and emerging concerns. The surveys examine a nationally representative sample of approximately 5,000 persons each year. These persons are located in counties across the United States, 15 of which are visited each year.

For NHANES 2003-2004, there were 12,761 persons selected for the sample, 10,122 of those were interviewed (79.3 percent) and 9,643 (75.6 percent) were examined in the mobile examination centers (MEC). Many of the NHANES 2003-2004 questions were also asked in NHANES II 1976-1980, Hispanic HANES 1982-1984, NHANES III 1988-1994, and NHANES 1999-2002. New questions were added to the survey based on recommendations from survey collaborators, NCHS staff, and other interagency work groups. As in past health examination surveys, data were collected on the prevalence of chronic conditions in the population. Estimates for previously undiagnosed conditions, as well as those known to and reported by survey respondents, are produced through the survey. Risk factors, those aspects of a person's lifestyle, constitution, heredity, or environment that may increase the chances of developing a certain disease or condition, were examined. Data on smoking, alcohol consumption, sexual practices, drug use, physical fitness and activity, weight, and dietary intake were collected. Information on certain aspects of reproductive health, such as use of oral contraceptives and breastfeeding practices, were also collected. The diseases, medical conditions, and health indicators that were studied include: anemia, cardiovascular disease, diabetes and lower extremity disease, environmental exposures, equilibrium, hearing loss, infectious diseases and immunization, kidney disease, mental health and cognitive functioning, nutrition, obesity, oral health, osteoporosis, physical fitness and physical functioning, reproductive history and sexual behavior, respiratory disease (asthma, chronic bronchitis, emphysema), sexually transmitted diseases, skin diseases, and vision. The sample for the survey was selected to represent the United States population of all ages. Special emphasis in the 2003-2004 NHANES was on adolescent health and the health of older Americans. To produce reliable statistics for these groups, adolescents aged 15-19 years and persons aged 60 years and older were over-sampled for the survey. African Americans and Mexican Americans were also over-sampled to enable accurate estimates for these groups. Several important areas in adolescent health, including nutrition and fitness and other aspects of growth and development, were addressed. Since the United States has experienced dramatic growth in the number of older people during the twentieth century, the aging population has major implications for health care needs, public policy, and research priorities. NCHS is working with public health agencies to increase the knowledge of the health status of older Americans. NHANES has a primary role in this endeavor. In the examination, all participants visit the physician who takes their pulse or blood pressure. Dietary interviews and body measurements are included for everyone. All but the very young have a blood sample taken and see the dentist. Depending upon the age of the participant, the rest of the examination includes tests and procedures to assess the various aspects of health listed above. Usually, the older the individual, the more extensive the examination. Some persons who are unable or unwilling to come to the examination center may be given a less extensive examination in their homes.

Demographic data file variables are grouped into three broad categories: (1) Status Variables: provide core information on the survey participant. Examples of the core variables include interview status, examination status, and sequence nu

The National Health and Nutrition Examination Surveys (NHANES) is a program of studies designed to assess the health and nutritional status of adults and children in the United States. The NHANES combines personal interviews and physical examinations, which focus on different population groups or health topics. These surveys have been conducted by the National Center for Health Statistics (NCHS) on a periodic basis from 1971 to 1994. In 1999, the NHANES became a continuous program with a changing focus on a variety of health and nutrition measurements which were designed to meet current and emerging concerns. The sample for the survey is selected to represent the U.S. population of all ages. Many of the NHANES 2007-2008 questions also were asked in NHANES II 1976-1980, Hispanic NHANES 1982-1984, NHANES III 1988-1994, and NHANES 1999-2006. New questions were added to the survey based on recommendations from survey collaborators, NCHS staff, and other interagency work groups. Estimates for previously undiagnosed conditions, as well as those known to and reported by survey respondents, are produced through the survey. In the 2003-2004 wave, the NHANES includes more than 100 datasets. Most have been combined into three datasets for convenience. Each starts with the Demographic dataset and includes datasets of a specific type. 1. National Health and Nutrition Examination Survey (NHANES), Demographic & Examination Data, 2003-2004 (The base of the Demographic dataset + all data from medical examinations). 2. National Health and Nutrition Examination Survey (NHANES), Demographic & Laboratory Data, 2003-2004 (The base of the Demographic dataset + all data from medical laboratories). 3. National Health and Nutrition Examination Survey (NHANES), Demographic & Questionnaire Data, 2003-2004 (The base of the Demographic dataset + all data from questionnaires) Variable SEQN is included for merging files within the waves. All data files should be sorted by SEQN. Additional details of the design and content of each survey are available at the NHANES website.

The National Health and Nutrition Examination Survey (NHANES) is designed to assess the health and nutritional status of adults and children in the United States. The survey is unique in that it combines interviews with standardized physical examinations and laboratory tests.
NHANES was conducted on a periodic basis from 1971 to 1994, including NHANES I (1971-1975), NHANES II (1976-1980), NHANES III (1988-1994), and a Hispanic Health and Nutrition Examination Survey (HHANES, 1982-1984). In 1999, NHANES became continuous and has been collecting data annually ever since.
All of the NHANES programs utilized a stratified, multistage probability cluster design to provide a nationally representative sample of the U.S. civilian, noninstitutionalized population. The NHANES interview includes demographic, socioeconomic, dietary, and health-related questions. The examination component conducted in a mobile examination center consists of medical, dental, and physiological measurements, as well as the collection of biospecimens, such as blood and urine for laboratory testing.

This set of restricted data contains indirect identifying and/or sensitive information collected in NHANES prior to 1999. Please refer to the links below for additional data available from NHANES:

• NHANES Public Use Data at: https://wwwn.cdc.gov/nchs/nhanes/Default.aspx
• NHANES Restricted Data: 1999 - present at: https://data.cdc.gov/dataset/National-Health-and-Nutrition-Examination-Survey-N/9ixb-fwvy
• NHANES Genetic Restricted Data at: https://data.cdc.gov/dataset/National-Health-and-Nutrition-Examination-Survey-N/hdx4-e4uu
• NHANES National Youth Fitness Survey (NNYFS) Restricted Data at: https://data.cdc.gov/dataset/3-NHANES-National-Youth-Fitness-Survey-NNYFS-Restr/5u84-m4rs

The third National Health and Nutrition Examination Survey (NHANES III, ICPSR 2231), conducted in 1988-1994, was designed to obtain nationally representative information on the health and nutritional status of the population of the United States through interviews and direct physical examinations. This release, Series II, No. 3A, contains data obtained from a second exam of selected survey participants who had had a primary exam. This release does not replace any previous NHANES III data releases. The second exam sample consists of seven separate data files. The Combination Foods file contains information on food weight, nutrient data, and descriptions about combination foods. The Total Nutrient Intake file records respondent intake of foods and beverages in a 24-hour time period. The Examination file consists of a comprehensive physical/dental examination. The Individual Foods file lists the food records and component food records for single and multi-component combination foods. The Laboratory file contains data collected through whole blood, serum, plasma, and urine specimens collected from respondents. The Second Laboratory file contains blood and urine assessments by specimen type and age group. The Variable Ingredient file reports data pertaining to the variable ingredients for many recipe foods in the Individual Foods file.

Description: The National Health and Nutrition Examination Survey (NHANES) provides data and have considerable potential to study the health and environmental exposure of the non-institutionalized US population. However, as NHANES data are plagued with multiple inconsistencies, processing these data is required before deriving new insights through large-scale analyses. Thus, we developed a set of curated and unified datasets by merging 614 separate files and harmonizing unrestricted data… See the full description on the dataset page: https://huggingface.co/datasets/nguyenvy/cleaned_nhanes_1988_2018.

Abbreviations: BP, blood pressure; SBP, systolic blood pressure; DBP, diastolic blood pressure; HTN, hypertension; HDL, high density lipoprotein; GFR, glomerular filtration rate; NA, not available.*Weighted number.†The unweighted number (for means) or numerator (for prevalences) corresponding with each variable category.‡In order to account for a change in NHANES race/ethnicity definitions in 2005–2010, we placed Hispanic in the “Other” to be consistent with NHANES 1988–2004.§Defined as >6.0 mg/dL (360 µmol/L) in women and >7.0 mg/dL (420 µmol/L) in men.∥Gout medications included allopurinol, probenecid, colchicine, sulfinpyrazone, alloxanthine.

Measurements of discrimination by sex and race/ethnicity, NHANES III linked mortality file 1988–2006.

ObjectiveHearing loss can cause speech and language delays, communication barriers, and learning problems. Such factors are associated with reduced academic achievement, social isolation, decreased quality of life, and poorer health outcomes. We use a national cohort of children to examine how subclinical hearing loss is associated with academic/educational performance. The goal of this study is to determine if different levels of subclinical hearing loss (pure tone average ≤ 25 dB HL) are associated with educational testing outcomes in children.DesignAnalysis of children 6–16 years old who participated in the National Health and Nutrition Examination Survey (NHANES-III, 1988–1994) was performed. Air-conduction thresholds were measured at 0.5, 1, 2, 4, 6, and 8 kHz. A four-frequency pure-tone average (PTA) was calculated from 0.5, 1, 2, and 4 kHz. Hearing thresholds were divided into categories ( ≤ 0, 1–10, and 11–25 dB) for analysis. The outcomes of interest were the Wide Range Achievement Test (WRAT-R) and Wechsler Intelligence Scale for Children (WISC-R). Analysis was conducted using ANOVA and logistic regression.ResultsWe analyzed 3,965 participants. In univariable analysis, the average scores in scaled math, reading, digit span (short-term memory), and block design (visual-motor skills) were significantly lower with worsening hearing categories (p < 0.01). In multivariable regression PTAs of 1–10 dB HL (OR 1.72, 95% CI 1.29–2.29, p < 0.01) and 11-25 dB HL (OR: 2.99, 95% CI 1.3–6.65, p < 0.01), compared to PTA of ≤0 dB HL, were associated with poor reading test performance (

Baseline characteristics according to presence of NAFLD (NHANES 1988–1994, n = 5,404).

Differences in CMV IgM Seroprevalence among Women Aged 12–49 Years by Selected Demographic Factors, NHANES III, 1988–1994.

Abbreviations: Neg, Negative; Pos, Positive.aPrevalence percentages are weighted to be representative of the US population. Row percentages add to 100 except for rounding error.bNumbers are unweighted numbers of participants.cP based on Pearson’s χ2test.dDefined as total family income divided by poverty threshold, as determined by the US Census Bureau for the year of the interviewWeighted Prevalence of Helicobacter pylori Across Demographic Characteristics in US 21 to 59 Year-Olds, NHANES III (1988–1994).

ImportanceReligiosity has been associated with positive health outcomes. Hypothesized pathways for this association include religious practices, such as church attendance, that result in reduced stress.ObjectiveThe objective of this study was to examine the relationship between religiosity (church attendance), allostatic load (AL) (a physiologic measure of stress) and all-cause mortality in middle-aged adults.Design, setting and participantsData for this study are from NHANES III (1988–1994). The analytic sample (n = 5449) was restricted to adult participants, who were between 40–65 years of age at the time of interview, had values for at least 9 out of 10 clinical/biologic markers used to derive AL, and had complete information on church attendance.Main outcomes and measuresThe primary outcomes were AL and mortality. AL was derived from values for metabolic, cardiovascular, and nutritional/inflammatory clinical/biologic markers. Mortality was derived from a probabilistic algorithm matching the NHANES III Linked Mortality File to the National Death Index through December 31, 2006, providing up to 18 years follow-up. The primary predictor variable was baseline report of church attendance over the past 12 months. Cox proportional hazard logistic regression models contained key covariates including socioeconomic status, self-rated health, co-morbid medical conditions, social support, healthy eating, physical activity, and alcohol intake.ResultsChurchgoers (at least once a year) comprised 64.0% of the study cohort (n = 3782). Non-churchgoers had significantly higher overall mean AL scores and higher prevalence of high-risk values for 3 of the 10 markers of AL than did churchgoers. In bivariate analyses non-churchgoers, compared to churchgoers, had higher odds of an AL score 2–3 (OR 1.24; 95% CI 1.01, 1.50) or ≥4 (OR 1.38; 95% CI 1.11, 1.71) compared to AL score of 0–1. More frequent churchgoers (more than once a week) had a 55% reduction of all-cause mortality risk compared with non-churchgoers. (HR 0.45, CI 0.24–0.85) in the fully adjusted model that included AL.Conclusions and relevanceWe found a significant association between church attendance and mortality among middle-aged adults after full adjustments. AL, a measure of stress, only partially explained differences in mortality between church and non-church attendees. These findings suggest a potential independent effect of church attendance on mortality.

BackgroundSarcopenia is prevalent in metabolic dysfunction-associated fatty liver diseases (MAFLD), and the primary treatment for both diseases is lifestyle modification. We studied how dietary components and physical activity affect individuals with sarcopenia and MAFLD.Materials and methodsWe conducted a study utilizing National Health and Nutrition Examination Survey (NHANES) III (1988–1994) data with Linked Mortality file (through 2019). The diagnosis of fatty liver disease (FLD) was based on ultrasound images revealing moderate and severe steatosis. Using bioelectrical measures, sarcopenia was assessed. Using self-report data, dietary intake and physical activity levels were evaluated.ResultsAmong 12,259 participants, 2,473 presented with MAFLD, and 290 of whom had sarcopenia. Higher levels of physical activity (odds ratio [OR] = 0.51 [0.36–0.95]) and calorie (OR = 0.58 [0.41–0.83]) intake reduced the likelihood of sarcopenia in MAFLD patients. During a median follow-up period of 15.3 years, 1,164 MAFLD and 181 MAFLD patients with sarcopenia perished. Increased activity levels improved the prognosis of patients with sarcopenia (Insufficiently active, HR = 0.75 [0.58–0.97]; Active, HR = 0.64 [0.48–0.86]), which was particularly pronounced in older patients.ConclusionIn the general population, hyperglycemia was highly related to MAFLD prognosis. Physical inactivity and a protein-restricted diet corresponded to sarcopenia, with physical inactivity being connected to poor outcomes. Adding protein supplements would be beneficial for older people with sarcopenia who are unable to exercise due to frailty, while the survival benefits were negligible.

Abbreviations: CI, Confidence intervals; Neg/Neg, H. pylori negative and CagA negative; Pos/Neg, H. pylori positive and CagA positive; Pos/Pos, H. pylori positive and CagA positive. Note: Covariates that did not have significant interactions with H. pylori and CagA were included in all models but not shown. N = 1,755.* P

Sample characteristics by race/ethnicity and Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) Status, United States adults, The National Health and Nutrition Examination Survey (NHANES III) 1988–1994 (n = 10,605).

Abbreviations: CI, Confidence intervals; Neg/Neg, H. pylori negative and CagA negative; Pos/Neg, H. pylori positive and CagA negative; Pos/Pos, H. pylori positive and CagA positive. Note: Covariates that did not have significant interactions with H. pylori and CagA were included in model but not shown. N = 1,755.* P

The distribution of blood heavy metals in the 1999–2020 NHANES data.

BackgroundExposure to heavy metals (cadmium, mercury, and lead) has been linked with adverse health outcomes, especially their nephrotoxic effects at high levels of exposure. We conducted a replication study to examine the association of low-level heavy metal exposure and chronic kidney disease (CKD) using a larger NHANES data set compared to previous studies.MethodsThe large cross-sectional study comprised 5,175 CKD cases out of 55677 participants aged 20–85 years from the 1999–2020 National Health and Nutrition Examination Survey [NHANES]. Logistic regression analysis was applied to estimate the associations between CKD and heavy metals [Cd, Pb, Hg] measured as categorical variables after adjusting with age, race, gender, socioeconomic status, hypertension, diabetes mellitus and blood cotinine level as smoking status.ResultsCompared to the lowest quartile of blood Cd, exposures to the 2nd, 3rd and 4th quartiles of blood Cd were statistically significantly associated with higher odds of CKD after adjustment for blood Pb and Hg, with OR = 1.79, [95% CI; 1.55–2.07, p

BackgroundAbnormalities in the electrocardiographic QT interval duration have been associated with an increased risk of ventricular arrhythmias and sudden cardiac death. However, there is substantial uncertainty about the effect of modifiable factors such as coffee intake, cigarette smoking, alcohol consumption, and physical activity on QT interval duration. MethodsWe studied 7795 men and women from the Third National Health and Nutrition Survey (NHANES III, 1988–1994). Baseline QT interval was measured from the standard 12-lead electrocardiogram. Coffee and tea intake, alcohol consumption, leisure-time physical activities over the past month, and lifetime smoking habits were determined using validated questionnaires during the home interview. ResultsIn the fully adjusted model, the average differences in QT interval comparing participants drinking ≥6 cups/day to those who did not drink any were −1.2 ms (95% CI −4.4 to 2.0) for coffee, and −2.0 ms (−11.2 to 7.3) for tea, respectively. The average differences in QT interval duration comparing current to never smokers was 1.2 ms (−0.6 to 2.9) while the average difference in QT interval duration comparing participants drinking ≥7 drinks/week to non-drinkers was 1.8 ms (−0.5 to 4.0). The age, race/ethnicity, and RR-interval adjusted differences in average QT interval duration comparing men with binge drinking episodes to non-drinkers or drinkers without binge drinking were 2.8 ms (0.4 to 5.3) and 4.0 ms (1.6 to 6.4), respectively. The corresponding differences in women were 1.1 (−2.9 to 5.2) and 1.7 ms (−2.3 to 5.7). Finally, the average differences in QT interval comparing the highest vs. the lowest categories of total physical activity was −0.8 ms (−3.0 to 1.4). ConclusionBinge drinking was associated with longer QT interval in men but not in women. QT interval duration was not associated with other modifiable factors including coffee and tea intake, smoking, and physical activity.