National Health And Nutrition Examination Survey Survey Research Articles

Consumer Usage and Reasons for Using Dietary Supplements: Report of a Series of Surveys

Objective: Consumer usage of dietary supplements is prevalent in the United States, and total usage is higher than reported in recent National Health and Nutrition Examination Surveys (NHANES), because these surveys capture usage only in the 30 days prior to the respondent's interview and do not capture occasional and seasonal use throughout the year. We report data from a series of consumer surveys on the full extent of dietary supplement use, on the reasons for supplement use, and on the products most commonly taken, as well as other health habits of supplement users. Methods: The Council for Responsible Nutrition (CRN), a trade association of the dietary supplement industry, has contracted with Ipsos Public Affairs to conduct consumer surveys annually since 2000. The surveys have been administered online since 2007 to about 2000 subjects each year. We report 5 years of data (2007 to 2011) on the prevalence of dietary supplement use, as well as more detailed data from the 2011 survey on the products used, the reasons for using supplements, and other health habits of supplement users. Results: The prevalence of supplement use fluctuated within the range of 64% to 69% from 2007 to 2011, and the prevalence of regular supplement use ranged from 48% to 53%, with no statistically significant differences from year to year. Over the 5-year period, the percentage of respondents who said that they regularly used a variety of supplements increased from 28% to 36%, and the increase from 2010 to 2011 was statistically significant. The percentage of respondents who said that they regularly used only a multivitamin, as opposed to a variety of supplements, declined from 24% to 17%, and the decrease from 2007 to 2008 was statistically significant. Detailed results from the 2011 survey confirm that supplement use increases with age and is higher in women than in men. Vitamin or mineral supplements were used by 67% of all respondents in 2011, specialty supplements by 35%, botanicals by 23%, and sports supplements by 17%. Among supplement users, multivitamins were the most commonly used supplement (71%), followed by omega-3 or fish oil (33%), calcium (32%), vitamin D (32%), and vitamin C (32%). The reasons most often cited for supplement use were for overall health and wellness (58%) and to fill nutrient gaps in the diet (42%). Supplement users were significantly more likely than nonusers to say that they try to eat a balanced diet, visit their doctor regularly, get a good night's sleep, exercise regularly, and maintain a healthy weight. Conclusions: Annual consumer surveys over a period of 5 years show that dietary supplement use is somewhat more prevalent in the United States than has been reported in the NHANES surveys, when occasional and seasonal use are taken into account, in addition to regular use. Most dietary supplement users take a multivitamin, and many take a variety of products. The primary reasons given for supplement use are for overall health and wellness or to fill nutrient gaps. Users of dietary supplements are more likely than nonusers to adopt a variety of healthy habits, indicating that supplement use is part of an overall approach to living healthy.

Analysis of NHANES measured blood PCBs in the general US population and application of SHEDS model to identify key exposure factors

Studies have shown that the US population continues to be exposed to polychlorinated biphenyls (PCBs), despite their ban more than three decades ago, but the reasons are not fully understood. The objectives of this paper are to characterize patterns of PCBs in blood by age, gender, and ethnicity, and identify major exposure factors. EPA's Stochastic Human Exposure and Dose Simulation (SHEDS)-dietary exposure model was applied, combining fish tissue PCB levels from a NYC Asian Market survey with National Health and Nutrition Examination Survey (NHANES) dietary consumption data, and then linked with blood biomarkers for the same NHANES study subjects. Results reveal that the mean concentration of total PCBs in blood was higher with increasing age; however, for the same age, gender, and ethnicity, the blood PCB concentrations measured in the later NHANES survey were significantly lower than those in the earlier one. The decrease within an age group between the two survey periods lessened with increasing age. Blood PCBs among different ethnicities ranked differently between the older and the younger age groups within each survey. Non-Hispanic Blacks had significantly higher blood PCBs for the >30 year age group. For the 12 to ≤30 year age group, the "Asian, Pacific Islander, Native American or multiracial" group had the highest values, with patterns fairly consistent with fish consumption and modeled PCB exposure patterns. We conclude that for younger people, patterns correspond to reduced environmental contamination over time, and are strongly associated with fish consumption and dietary exposures. Higher PCB concentrations in blood of the older population may partially reflect past exposures to higher environmental PCB concentrations, particularly before the ban.

Shiftwork and Prostate-Specific Antigen in the National Health and Nutrition Examination Survey

Shiftwork has been implicated as a risk factor for prostate cancer. Results from prior studies have been mixed but generally support an association between circadian disruption and prostate cancer. Our aim was to investigate the relationship between shiftwork and prostate-specific antigen (PSA) test obtained as part of the National Health and Nutrition Examination Survey (NHANES) study. We combined three NHANES surveys (2005-2010) to obtain current work schedule among employed men aged 40 to 65 years with no prior history of cancer (except nonmelanoma skin cancer). Men who reported working regular night shifts or rotating shifts were considered shiftworkers. We obtained the total and percentage free PSA test results for these men and dichotomized total PSA into less than 4.0 ng/mL or 4.0 ng/mL or greater and total PSA of 4.0 ng/mL or greater combined with percentage free PSA less than or equal to 25%. Using multivariable logistic regression models, we compared PSA level among current shiftworkers and nonshiftworkers. All statistical tests were two-sided. We found a statistically significant, age-adjusted association between current shiftwork and elevated PSA at the 4.0 ng/mL or greater level (odds ratio = 2.48, 95% confidence interval [CI] = 1.08 to 5.70; P = .03). The confounder-adjusted odds ratio was 2.62 (95% CI = 1.16 to 5.95; P = .02). The confounder-adjusted odds ratio for those with total PSA of 4.0 ng/mL or greater and free PSA less than or equal to 25% was 3.13 (95% CI = 1.38 to 7.09; P = .01). We observed a strong positive association with shiftwork and elevated PSA level. Our data support the notion that sleep or circadian disruption is associated with elevated PSA, indicating that shiftworking men likely have an increased risk of developing prostate cancer.

Comparison of the prevalence and treatment of hypertension in two populations in the United States: Masters swimmers versus the NHANES population

This research compares the prevalence of hypertension in a group of adult masters swimmers with an age and sex matched cohort from the 2008 NHANES (National Health and Nutrition Examination Survey), used to represent the general population in the United States. Masters swimmer data were obtained from a one-time survey of all United States Masters Swimming (USMS) members. Both datasets included demographics, drug therapy, diseases and health status. Characteristics of swimming sessions as well as perceptions of impact of medications on exercise were also collected from the USMS respondents. Of 1346 completed surveys from USMS respondents, 15.8% self-identified as having hypertension while 36.2% participants in the NHANES survey suffered from hypertension (P < 0.001). The two groups were well matched for age and gender but the USMS group was primarily Caucasian, higher income, higher education, and reported higher health status. In the USMS group, not only was hypertension less prevalent but those who suffered from hypertension took fewer medications (P = 0.04) to manage their hypertension than in the NHANES group. Additionally, The USMS group suffering from hypertension considered themselves healthier (P < 0.001) than the NHANES group.

Sufficient Iodine Intake During Pregnancy: Just Do It

Sufficient Iodine Intake During Pregnancy: Just Do It

Menopause and age-driven changes in blood level of fat- and water-soluble vitamins

Objective The purpose of this cross-sectional study was to assess the association of the menopausal transition with changes in vitamins.Methods The study group comprised women aged 17–85 years from the Third National Health and Nutrition Examination Survey (NHANES), which was conducted between 1988 and 1994, and from the NHANES surveys conducted between 1999 and 2006. Menopausal status was defined using the time since the last period, < 2, 2–12, and > 12 months, for the pre-, peri-, and postmenopause, respectively. The data-cleaning technique employing serum follicle stimulating hormone activity resulted in pre-, peri- and postmenopausal samples encompassing the following age brackets: 17–50, 42–51, and 46–85 years. Statistical inferences were analyzed using non-parametric techniques.Results Significant increases in vitamin A and vitamin E concentrations across all phases of the menopausal transition were observed. There was a gradual decrease in the vitamin C concentration across all stages of the menopause but a fairly stable concentration of vitamin B12. There was a statistically significant increase in vitamin D between the pre- and postmenopause. Body mass index correlated negatively with serum vitamin concentration in the pre- and postmenopause.Conclusions Vitamin A should be supplemented in postmenopausal women to decrease the risk of bone fracture. The daily diet should be supplemented with vitamin B12, to avoid possible neurological symptoms due to vitamin B12 deficiency, and with vitamin D to decrease the risk of developing secondary hyperparathyroidism. Due to an adverse influence on serum vitamin concentration, body mass index should be monitored in pre- and postmenopausal women.

Blood lead levels in the United States “Oldest-Old” population

Context. Previous studies have suggested significant endogenous lead release from bony stores in the elderly raising the concern for elevated blood lead levels in that population. Objective. We undertook to determine the range of blood lead levels in the “oldest-old” population, a demographic category that includes persons aged 80 years and older. Materials and methods. We analyzed blood lead level data from the National Health and Nutrition Examination Survey (NHANES) for the years 1999–2010 for persons aged 80 years and older. We also screened an inner-city population of patients aged 80 years of age and older presenting to an emergency department. Results. Among persons aged 80 years and older sampled in the NHANES surveys, the geometric mean blood lead level each year varied from 1.98 to 2.66 mcg/dL. Of the 2,168 measured blood lead levels, only 15 samples (0.69%) exceeded our a priori definition of an elevated blood lead level (greater than 10 mcg/dL). Of those 15 samples, the highest blood lead level was 15.3 mcg/dL. For our screening of an inner-city oldest-old population, we enrolled 76 subjects and found a geometric mean blood lead level of 1.72 mcg/dL. Discussion. Several considerations place elderly persons at a theoretically increased risk of elevated blood lead level, including previously documented birth cohort effect for blood lead levels with older cohorts having higher mean blood lead levels and concern for endogenous lead exposure due to release of lead from bony stores. However, our statistical analysis of NHANES data and screening of an inner-city oldest-old population suggests that elevated blood lead levels in this population are rare. Conclusion. Routine blood lead level screening in the elderly is not indicated.

Abstract LB-339: Cause of death in cancer survivors

Abstract Background: Cancer, in general, is regarded as one of the most life threatening diseases. In the past decade, with the application of advanced scientific and medical technologies for cancer early detection, prevention, and treatment, cancer survivors are now living much longer and do not died directly from cancer, but from other diseases and complications, therefore, becomes increasingly important to understand major causes of death among cancer survivors to improve the quality of life and prolong life expectancy of cancer survivors. We conducted a study to investigate the cause of death among cancer survivors using data from national surveys. Methods: The analytical population consist of 1807 cancer survivors identified from the National Health and Nutrition Examination Survey (NHANES) III 1988-1994 and NHANES 1999- 2004. We excluded participants with age less than 18 years old and those with skin cancer. Cancer survivors were identified if they self-reported having ever been told by a doctor or other health professional that he/she had cancer or a malignancy of any kind. The cause of death was ascertained through the National Death Index (NDI). All participants were followed from the date of survey to the date of the survey to December 31, 2006 by linking NDI death certificate records. Results: The Follow-up time ranged from 0 to 17.3 years. Total 776 participants died during the follow-up period. Underlying cause of death were recoded as 113 death causes in the National Death Index. We classified all death causes into 3 categories: related with cancer, indeterminate and not related with cancer. The causes of death were stratified by the duration since the diagnosis of cancer, which was calculated as follow-up time plus years between age at NHANES survey and age when being diagnosed with cancer. Commonly reported types of cancer were prostate (n=165), breast (n=141) and colorectal cancer (n=117) among 761 male and 1046 female participants. At time of the survey, there were 17.7% and 26.5% with diabetes, 63.2 and 66.9 with cardiovascular condition, and 58.7 and 62.9 had hypertension, and 61.3% and 70.5% with hypercholesterolemia in men and women, respectively. Among the deseeded cancer survivor, 41.8%, 9.3, and 48.9% were died from cancer, indeterminate, disease not related with cancer. The percentages were 43.4%, 6.2% and 50.4%, respectively in men and 40.4%, 12.1% and 47.6%, respectively in women. Noticeably, with the increase of the duration since diagnosis of cancer, higher percentage of cancer survivor died from disease not related to cancer, ranging from 23.3% within 5 years to 72.1% in more than 30 years (p value for trend &amp;lt;0.001). Conclusion: Although cancer is the major cause of death among cancer survivors, approximately half of participants died from other diseases and complications, such as cardiovascular and respiratory diseases. Clinicians and cancer survivors should pay attention to the prevention and treatment of other diseases and complications. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-339. doi:1538-7445.AM2012-LB-339

Hepatitis C virus infection in USA: an estimate of true prevalence

The recent National Health and Nutrition Examination Survey (NHANES) sampled only the civilian, non-institutionalized population of USA and may have underestimated the prevalence of hepatitis C virus (HCV) in this country. We searched the database MEDLINE, the Bureau of Justice Statistics, Center for Medicare and Medicaid and individual states Department of Corrections for all epidemiological studies regarding the prevalence of HCV in populations not sampled by the NHANES survey namely the incarcerated, homeless, nursing home residents, hospitalized and those on active military duty. Because of their relatively low frequency in the NHANES sample, we also expanded our search to include healthcare workers and long-term dialysis patients. Although included in the NHANES sample, we also performed searches on drug users (injection and non-injection) and veterans to confirm the findings of the NHANES study. Based on the prevalence of studies identified meeting our inclusion criteria, our most conservative estimates state that there at least 142,761 homeless persons, 372,754 incarcerated persons and 6805 persons on active military duty unaccounted for in the NHANES survey. While the NHANES estimates of drug users (both injection and non-injection) appear to be reasonable, the survey seems to have underestimated the number of HCV-positive veterans. Our most conservative estimates suggest that there are at least 5.2 million persons living with HCV in USA today, approximately 1.9 million of whom were unaccounted for in the NHANES survey.

Prevalence and Determinants of Constipation in the United States: Results from the 2005-2006 National Health and Nutrition Examination Survey (NHANES): 2010 ACG/Radhika Srinivasan Gender-Based Research Award, 2010 Presidential Poster

Purpose: Constipation exacts a heavy toll on the healthcare system owing to its cost of treatment, adverse impact on the quality of life and possibly even survival. As such, measuring accurately its burden at the population level is paramount and recent data is lacking. We determined the population-level prevalence of constipation in the United States and its associated factors. Methods: We conducted a cross-sectional study in adults 20 years and older who participated in the NHANES survey between 2005 and 2006 and completed the bowel health questionnaire (BHQ). The BHQ includes the Bristol stool form scale (BSFS) and the stool frequency questionnaire (SFQ). Constipation was defined as either a BSFS score <3 or <3 reported stools per week on the SFQ. Constipated subjects thus defined were compared to the non-constipated subjects. Statistical analysis was done taking into account the complex survey design and incorporating sampling weights. Multivariable adjusted odds of having constipation were derived using survey logistic regression, with age, gender, race/ethnicity, body mass index (BMI), education and income level as the explanatory variables. Results: The overall prevalence of constipation was 8.7% amongst the 4302 study subjects (weighted total N=16,769,379). It was more prevalent in women as compared to men (13% vs. 4%, p<0.0001) and non-Hispanic blacks compared to Non-Hispanic whites (14% vs. 8%, p=0.003). Mexican-Americans had a 10.7% prevalence of constipation. Those over age 60 had a 7.3% prevalence compared to 10.3% in the age group of 20-39 years. Multivariable analysis adjusting for other factors showed that women were 4.4 times more likely to have constipation than men, and non-Hispanic blacks were twice more likely than non-Hispanic whites to be constipated. There was a weak inverse association between age and constipation [OR 0.99 (95%CI 0.98-0.99)]. Subjects with an annual household income less than $20,000 were twice more likely to be constipated than those with an income of $75,000 and above. Education level was also associated with constipation with participants who had no high school education having a greater likelihood of constipation compared to those with some college education and above. A non-significant trend of decreasing association of constipation with increasing BMI was noted. Conclusion: In this population-based study, we report updated estimates of the prevalence of constipation in the United States and identify sub-groups associated with a potential increased risk. Despite medical advances, constipation remains a common cause of morbidity. Sub-groups with a high prevalence may potentially be targeted to reduce the burden of this disorder.

Methods to assess iron status in various NHANES surveys.

This paper summarizes iron status measurements included in the three cross-sectional National Health and Nutrition Examination Surveys (NHANES) completed to date, as well as a special study of Hispanics, known as the Hispanic Health and Nutrition Examination Survey (HHANES). Approaches for defining iron status in the population based on these measurements are also described as well as issues in comparing iron status data between surveys, using NHANES II and III data as an example.

U.S. Iodine Nutrition: Where Do We Stand?

Surveillance of urinary iodine values of the U.S. population has been carried out at intervals since 1971. In this issue, Caldwell et al. (1) report on the most recent U.S. National Health and Nutrition Examination Survey (NHANES) iodine data, for the 2003–2004 sample. Reassuringly, there has been no significant change since the last NHANES survey in 2001–2002. Following a precipitous drop in urinary iodine values between NHANES I (1971–1974) and NHANES III (1988–1994), U.S. dietary iodine intake appears to have stabilized. Importantly, the U.S. population overall remains iodine sufficient. Spot urinary iodine values are used most frequently to screen for iodine deficiency in general populations. A limitation of urinary iodine testing is that identifying individuals at risk for iodine deficiency is not possible, as there is substantial diurnal and day-to-day variation in urinary iodine excretion (2,3). Urinary iodine concentration thresholds have only been identified for populations. In NHANES 2003–2004, 2.4% of all adults and 4.0% of women of childbearing age had urinary iodine concentrations 100mg=L are consistent with adequate iodine intake in lactating women (4). These values are lower than for pregnant women because some iodine is excreted in breast milk rather than in urine. NHANES does not provide any information about the iodine

Shock Wave Lithotripsy Not Associated With Development of Diabetes Mellitus at 6 Years of Follow-up

To investigate the hypothesis that extracorporeal shock wave lithotripsy (ESWL) increases the incident risk of new-onset diabetes mellitus (DM). Studies have suggested that ESWL predisposes to DM. Using a mail survey, we collected data on the presence and onset of DM in 1947 patients treated with the Medstone-STS electrohydraulic lithotripter from 1999 to 2002. These patients were matched by age, sex, and body mass index to controls from the National Health and Nutrition Examination Survey (NHANES) database. Of the 1947 patients, 4% could not be matched and were excluded, leaving 1869 for analysis, of whom 60.0% were men. The mean age was 51.9 years at ESWL and the median follow-up was 6 years. The mean body mass index at the end of the study was 28.6 kg/m(2). At ESWL, 8.67% of matched patients had a diagnosis of DM. This had increased to 13.9% at the time of survey. In the NHANES group, 8.34% had DM at the time the ESWL group underwent treatment, and this had increased to 14.1% at the NHANES survey. Therefore, the rate of new DM cases in the ESWL group was similar to that in the NHANES group (5.2% vs 5.8%, respectively; P = .47). Multivariate analysis of the patient cohort confirmed that age, sex, body mass index, and family history correlated with development of DM and that the laterality of treatment and number of treatments or shocks given were not significant predictors of DM. The results of our study have shown that patients treated with ESWL do not develop DM at a greater rate than does the general population at 6 years of follow-up.

Calibration of Serum Creatinine in the National Health and Nutrition Examination Surveys (NHANES) 1988-1994, 1999-2004

The calibration of serum creatinine values to standardized creatinine and the commutability of serum creatinine across surveys are essential to the correct use of National Health and Nutrition Examination Survey (NHANES) data for kidney function and for generating estimates of the burden of kidney disease in the United States. Calibration study of serum creatinine in NHANES III (1988-1994) and NHANES 1999-2000, 2001-2002, and 2003-2004 to directly compare creatinine measurements from the original surveys with standard creatinine measured using an assay traceable to known gold-standard methods. We also assessed predictors of differences between methods (potential interferences) in this general population. The NHANES are ongoing cross-sectional surveys of the civilian noninstitutionalized population of the United States. We selected random samples of approximately 200 stored specimens from persons aged 60 years or older from each survey (NHANES III, 1999-2000, 2001-2002, and 2003-2004). Stored serum specimens from the 4 NHANES surveys were analyzed for serum creatinine by using a Roche enzymatic assay implemented at the Cleveland Clinic Research Laboratory (CCRL). The Roche assay is traceable to gold-standard reference methods. The original NHANES serum creatinine values were obtained using the Jaffé method (kinetic alkaline picrate) implemented in several different laboratories. Overall agreement between the original NHANES values (Jaffé method) and CCRL measurements (Roche enzymatic) was high, but substantial biases were observed in NHANES III and 1999-2000. No bias was observed in NHANES 2001-2002 and 2003-2004. Final calibration equations to correct serum creatinine values in the relevant surveys are provided. Assay differences were independent of sex, race/ethnicity, and bilirubin and triglyceride levels, but weakly related to age and glucose concentration. We were not able to examine drift in measurements over time within each survey or directly evaluate freeze-thaw effects. The magnitude of differences in serum creatinine measurements in NHANES III and 1999-2000 from standard creatinine would result in large differences in estimates of kidney function (10% to 20%). Thus, correction of original creatinine values in NHANES III and 1999-2000 is essential, but no correction is needed for NHANES 2001-2002 or 2003-2004.

Primary Prevention of Cardiovascular Disease in Nursing Practice: Focus on Children and Youth

Cardiovascular disease (CVD) is a leading cause of morbidity and premature mortality in women and men in the United States, most of the industrialized world, and many developing countries.1 Data accumulated over the past 3 decades indicate that atherosclerotic-CVD processes begin early in childhood and are influenced over the life course by genetic and potentially modifiable risk factors and environmental exposures. Taken together, these data provide compelling evidence for primary prevention of CVD beginning early in childhood. Within the pediatric healthcare community, this evidence has prompted and informed the development of science-based guidelines with recommendations for individual/high-risk and population-based approaches to primary prevention of CVD in children and youth. The purpose of this statement is to provide an overview of the evidence and current science-based recommendations and to emphasize the role of advanced practice nurses in the implementation of strategies consistent with population-based and individual/high-risk approaches to CVD prevention in children and youth. Evidence-based guidelines for primary and secondary prevention of CVD in adults are informed by the results of randomized controlled trials. The existing evidence (discussed below) argues convincingly for prevention of CVD beginning early in childhood. It is noteworthy that data from randomized controlled trials documenting the effect of risk reduction in childhood on the development of CVD in adulthood are nonexistent. Similarly, no long-term longitudinal studies have been conducted to determine the absolute levels of risk factors measured in childhood that predict CVD in adult life. However, evidence from laboratory, clinical, and epidemiological studies supports the need for primary prevention of CVD beginning early in life and has prompted and informed existing guidelines for children and adolescents. ### Laboratory/Pathology and In Vivo/Clinical Studies Autopsy studies conducted as part of the Bogalusa Heart Study2,3 and the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) Study4,5 demonstrate significant positive associations between potentially modifiable …

Nontuberculous Mycobacterial Sensitization in the United States

The prevalence of pulmonary nontuberculous mycobacterial (NTM) infections in the United States appears to be rising, but it is unclear if this is due to enhanced detection or actual increases in the burden of infection. Temporal changes in the epidemiology of Mycobacterium intracellulare sensitization may help explain recently observed trends in pulmonary NTM infections. Describe the epidemiology of M. intracellulare sensitization in the United States in 1971-1972 and 1999-2000. We studied nationally representative cohorts of the United States' noninstitutionalized civilian population participating in the 1971-1972 and 1999-2000 National Health and Nutrition Examination Surveys (NHANES). Participants were skin tested with M. intracellulare antigen and sensitization prevalence was compared across NHANES surveys and between participant subgroups. Logistic regression was used to identify associations between participant characteristics, environmental factors, and NTM sensitization. The 1971-1972 and 1999-2000 NHANES cohorts included 1,490 and 7,384 individuals, respectively. Between 1971-1972 and 1999-2000, the prevalence of M. intracellulare sensitization increased from 11.2% (95% confidence interval, 9.2-13.5%) to 16.6% (95% confidence interval, 13.2-20.6%). On multivariate analysis of the 1999-2000 cohort, age, sex, race, birthplace, education, and occupation were strongly associated with M. intracellulare sensitization. In 1999-2000, an estimated one in six persons in the United States demonstrated M. intracellulare sensitization, up from one in nine persons in 1971-1972. The observed rising prevalence of sensitization is consistent with observed increases in the rates of pulmonary NTM infections in the United States.

Body Weight Distributions for Risk Assessment

Precise age-specific average body weight estimates are necessary for deterministic risk assessments, and an accurate body weight distribution is equally important in probabilistic risk assessments. Age-specific body weight distributions for U.S. residents are estimated using NHANES (National Health and Nutrition Examination Survey) data collected in four surveys over the last 24 years. The weighted mean and standard deviation of natural log-transformed body weights are computed for single-year age groups and population age-specific weight patterns further described using piece-wise polynomial spline functions and nonparametric age-smoothed trend lines. These functions are used to compare distributional changes in age-specific body weight in the United States from the first NHANES survey in 1976-1980 to the most recent in 1999-2002. Analysis demonstrates that age- and sex-specific average body weight changes over this time period are not uniform. Use of these functions to compute body weight distributions for selected child-age categories is demonstrated.

Trends in prevalence, awareness, treatment and control of hypertension in the United States, 1988–2000

ContextPrior analyses of National Health and Nutrition Examination Survey (NHANES) data through 1991 have suggested that hypertension prevalence is declining, but more recent self-reported rates of hypertension suggest that the rate is increasing.ObjectiveTo describe trends in the prevalence, awareness, treatment, and control of hypertension in the United States using NHANES data.Design, Setting, and ParticipantsSurvey using a stratified multistage probability sample of the civilian noninstitutionalized population. The most recent NHANES survey, conducted in 1999-2000 (n = 5448), was compared with the 2 phases of NHANES III conducted in 1988-1991 (n = 9901) and 1991-1994 (n = 9717). Individuals aged 18 years or older were included in this analysis.Main Outcome MeasuresHypertension, defined as a measured blood pressure of 140/90 mm Hg or greater or reported use of antihypertensive medications. Hypertension awareness and treatment were assessed with standardized questions. Hypertension control was defined as treatment with antihypertensive medication and a measured blood pressure of less than 140/90 mm Hg.ResultsIn 1999-2000, 28.7% of NHANES participants had hypertension, an increase of 3.7% (95% confidence interval [CI], 0%-8.3%) from 1988-1991. Hypertension prevalence was highest in non-Hispanic blacks (33.5%), increased with age (65.4% among those aged ≥60 years), and tended to be higher in women (30.1%). In a multiple regression analysis, increasing age, increasing body mass index, and non-Hispanic black race/ethnicity were independently associated with increased rates of hypertension. Overall, in 1999-2000, 68.9% were aware of their hypertension (nonsignificant decline of −0.3%; 95% CI, −4.2% to 3.6%), 58.4% were treated (increase of 6.0%; 95% CI, 1.2%-10.8%), and hypertension was controlled in 31.0% (increase of 6.4%; 95% CI, 1.6%-11.2%). Women, Mexican Americans, and those aged 60 years or older had significantly lower rates of control compared with men, younger individuals, and non-Hispanic whites.ConclusionsContrary to earlier reports, hypertension prevalence is increasing in the United States. Hypertension control rates, although improving, continue to be low. Programs targeting hypertension prevention and treatment are of utmost importance.