One problem of interpreting population-based biomonitoring data is the reconstruction of corresponding external exposure in cases where no such data are available.
We demonstrate the use of a computational framework that integrates physiologically based pharmacokinetic (PBPK) modeling, Bayesian inference, and Markov chain Monte Carlo simulation to obtain a population estimate of environmental chloroform source concentrations consistent with human biomonitoring data. The biomonitoring data consist of chloroform blood concentrations measured as part of the Third National Health and Nutrition Examination Survey (NHANES III), and for which no corresponding exposure data were collected.
We used a combined PBPK and shower exposure model to consider several routes and sources of exposure: ingestion of tap water, inhalation of ambient household air, and inhalation and dermal absorption while showering. We determined posterior distributions for chloroform concentration in tap water and ambient household air using U.S. Environmental Protection Agency Total Exposure Assessment Methodology (TEAM) data as prior distributions for the Bayesian analysis.
Posterior distributions for exposure indicate that 95% of the population represented by the NHANES III data had likely chloroform exposures ≤ 67 μg/L in tap water and ≤ 0.02 μg/L in ambient household air.
Our results demonstrate the application of computer simulation to aid in the interpretation of human biomonitoring data in the context of the exposure–health evaluation–risk assessment continuum. These results should be considered as a demonstration of the method and can be improved with the addition of more detailed data.
Bayesian; biomonitoring; chloroform; Markov chain Monte Carlo; MC; MCMC; Monte Carlo; PBPK; reverse dosimetry
Vitamin D insufficiency is associated with suboptimal health. The prevalence of vitamin D insufficiency may be rising, but population-based trends are uncertain. We sought to evaluate US population trends in vitamin D insufficiency.
We compared serum 25-hydroxyvitamin D (25[OH]D) levels from the Third National Health and Nutrition Examination Survey (NHANES III), collected during 1988 through 1994, with NHANES data collected from 2001 through 2004 (NHANES 2001–2004). Complete data were available for 18 883 participants in NHANES III and 13 369 participants in NHANES 2001–2004.
The mean serum 25(OH)D level was 30 (95% confidence interval [CI], 29–30) ng/mL during NHANES III and decreased to 24 (23–25) ng/mL during NHANES 2001–2004. Accordingly, the prevalence of 25(OH)D levels of less than 10 ng/mL increased from 2% (95% CI, 2%–2%) to 6% (5%–8%), and 25(OH)D levels of 30 ng/mL or more decreased from 45% (43%–47%) to 23% (20%–26%). The prevalence of 25(OH)D levels of less than 10 ng/mL in non-Hispanic blacks rose from 9% during NHANES III to 29% during NHANES 2001–2004, with a corresponding decrease in the prevalence of levels of 30 ng/mL or more from 12% to 3%. Differences by age strata (mean serum 25[OH]D levels ranging from 28–32 ng/mL) and sex (28 ng/mL for women and 32 ng/mL for men) during NHANES III equalized during NHANES 2001–2004 (24 vs 24 ng/mL for age and 24 vs 24 ng/mL for sex).
National data demonstrate a marked decrease in serum 25(OH)D levels from the 1988–1994 to the 2001–2004 NHANES data collections. Racial/ethnic differences have persisted and may have important implications for known health disparities. Current recommendations for vitamin D supplementation are inadequate to address the growing epidemic of vitamin D insufficiency.
In order to identify novel genetic variants that influence plasma lipid concentrations, we performed a genome-wide association study (GWAS) comprised of 411 children under 18 years of age, ascertained at St. Jude Children’s Research Hospital, all of whom were of European, African, or Mexican-descent. Promising associations (p<10−5) were subsequently examined in 1,040 additional youths and 3,508 adults from the Third National Health and Nutrition Examination Survey (NHANES III), a diverse population-based study. Three genotype-phenotype associations replicated in NHANES III youths and three associated in NHANES III adults at p<0.05; however, no single association was significant in both youths and adults. The most significant association (p=0.009) in NHANES III youths was between low-density lipoprotein cholesterol (LDL-C) and intronic rs2429917 among participants of African-descent. Given the known age-dependency of lipid levels, we also tested for gene-age interactions in NHANES III participants across all ages. We identified a significant (p=0.024) age-dependent association between SGSM2 rs2429917 and LDL-C. This finding illustrates the utility of using children to discover novel variants associated with complex phenotypes and the importance of considering age-dependent genetic effects in association studies of lipid levels.
The aim of this study was to make projections of the future diabetes burden for the adult US population based in part on the prevalence of individuals at high risk of developing diabetes.
Materials and methods
Models were created from data in the nationally representative National Health and Nutrition Examination Survey (NHANES) II mortality survey (1976–1992), the NHANES III (1988–1994) and the NHANES 1999–2002. Population models for adults (>20 years of age) from NHANES III data were fitted to known diabetes prevalence in the NHANES 1999–2002 before making future projections. We used a multivariable diabetes risk score to estimate the likelihood of diabetes incidence in 10 years. Estimates of future diabetes (diagnosed and undiagnosed) prevalence in 2011, 2021, and 2031 were made under several assumptions.
Based on the multivariable diabetes risk score, the number of adults at high risk of diabetes was 38.4 million in 1991 and 49.9 million in 2001. The total diabetes burden is anticipated to be 11.5% (25.4 million) in 2011, 13.5% (32.6 million) in 2021, and 14.5% (37.7 million) in 2031. Among individuals aged 30 to 39 years old who are not currently targeted for screening according to age, the prevalence of diabetes is expected to rise from 3.7% in 2001 to 5.2% in 2031. By 2031, 20.2% of adult Hispanic individuals are expected to have diabetes.
The prevalence of diabetes is projected to rise to substantially greater levels than previously estimated. Diabetes prevalence within the Hispanic community is projected to be potentially overwhelming.
Electronic supplementary material
Supplementary material is available in the online version of this article at http://dx.doi.org/10.1007/s00125-006-0528-5 and is accessible to authorized users.
Diabetes; Epidemiology; Projection
The distribution of lipoprotein(a) [Lp(a)] levels can differ dramatically across diverse racial/ethnic populations. The extent to which genetic variation in LPA can explain these differences is not fully understood. To explore this, 19 LPA tagSNPs were genotyped in 7,159 participants from the Third National Health and Nutrition Examination Survey (NHANES III). NHANES III is a diverse population-based survey with DNA samples linked to hundreds of quantitative traits, including serum Lp(a). Tests of association between LPA variants and transformed Lp(a) levels were performed across the three different NHANES subpopulations (non-Hispanic whites, non-Hispanic blacks, and Mexican Americans). At a significance threshold of p<0.0001, 15 of the 19 SNPs tested were strongly associated with Lp(a) levels in at least one subpopulation, six in at least two subpopulations, and none in all three subpopulations. In non-Hispanic whites, three variants were associated with Lp(a) levels, including previously known rs6919246 (p = 1.18×10−30). Additionally, 12 and 6 variants had significant associations in non-Hispanic blacks and Mexican Americans, respectively. The additive effects of these associated alleles explained up to 11% of the variance observed for Lp(a) levels in the different racial/ethnic populations. The findings reported here replicate previous candidate gene and genome-wide association studies for Lp(a) levels in European-descent populations and extend these findings to other populations. While we demonstrate that LPA is an important contributor to Lp(a) levels regardless of race/ethnicity, the lack of generalization of associations across all subpopulations suggests that specific LPA variants may be contributing to the observed Lp(a) between-population variance.
Background: The Food Quality Protection Act (FQPA) was signed into law in 1996 to strengthen the regulation of pesticide tolerances in food. Organophosphorus (OP) insecticides were the first group of pesticides reviewed by the U.S. Environmental Protection Agency (EPA) under the new law.
Objective: Our goal was to determine whether urinary concentrations of dialkylphosphate (DAP) metabolites of OP pesticides declined between the National Health and Nutrition Examination Survey (NHANES) III and NHANES 1999–2004.
Methods: Using mass spectrometry–based methods, we analyzed urine samples from a nationally representative sample of 2,874 adults 20–59 years of age in NHANES 1999–2004 and samples from a non-nationally representative sample of 197 adult participants for NHANES III (1988–1994) for six common DAP metabolites of OP pesticides.
Results: Median urinary DAP concentrations decreased by more than half between NHANES III and NHANES 2003–2004. Reductions of about 50%–90% were also observed for 95th percentile concentrations of five of the six metabolites. Frequencies of detection (FODs) decreased in all six metabolites (< 50% reduction). On average, median and 95th percentile concentrations and FODs showed a larger decrease in diethylphosphate metabolites than dimethylphosphate metabolites.
Conclusions: Human exposure to OP insecticides as assessed by urinary DAP concentrations has decreased since the implementation of the FQPA, although we cannot be certain that U.S. EPA actions in response to the FQPA directly caused the decrease in DAP concentrations.
biomonitoring; dialkylphosphate metabolite; FQPA; NHANES; organophosphorus insecticide
Prevalence of childhood obesity and its complications have increased world-wide. Parental status may be associated with children’s health outcomes including their eating habits, body weight and blood cholesterol. The National Health and Nutrition Examination Survey (NHANES) for the years 1988–1994, provided a unique opportunity for matching parents to children enabling analyses of joint demographics, racial differences and health indicators. Specifically, the NHANES III data, 1988–1994, of 219 households with single-parents and 780 dual-parent households were analyzed as predictors for primary outcome variables of children’s Body Mass Index (BMI), dietary nutrient intakes and blood cholesterol. Children of single-parent households were significantly (p < 0.01) more overweight than children of dual-parent households. Total calorie and saturated fatty acid intakes were higher among children of single-parent households than dual-parent households (p < 0.05). On average, Black children were more overweight (p < 0.04) than children of other races. The study results implied a strong relationship between single-parent status and excess weight in children. Further studies are needed to explore the dynamics of single-parent households and its influence on childhood diet and obesity. Parental involvement in the development of school- and community-based obesity prevention programs are suggested for effective health initiatives. Economic constraints and cultural preferences may be communicated directly by family involvement in these much needed public health programs.
children’s diet; childhood obesity; NHANES; single-parent households; BMI; blood-cholesterol
OBJECTIVES: To establish rates of childhood asthma symptoms, diagnosis, and hospitalization by race, ethnicity, and income, and to ascertain if elevated reported prevalence of asthma diagnosis among African-American children could be explained by differences in clinical findings. METHODS: Estimates of each indicator were calculated based on data from the third National Health and Nutrition and Examination Survey (NHANES III). Bivariate and multivariate logistic regression models were estimated to predict parent or guardian report of current asthma diagnosis. RESULTS: African-American children aged 1 to 5 have a 2-fold higher probability of both asthma diagnosis and hospitalization during the previous year but no significant difference in wheeze prevalence compared to Mexican-American and European-American children. These differences are not explained by household income or clinical information. Children aged 6 to 16 had similar rates of diagnosis and hospitalization for all racial/ethnic groups, although African-American children reported wheeze symptoms one-third less often. CONCLUSIONS: Although younger African-American children have higher morbidity from asthma than their Mexican-American and European-American peers, clinical findings were similar and did not explain increased rates of diagnosis. Interpersonal dynamics within families and communication between families and clinicians are believed to influence both symptom reporting and diagnosis generation.
Congestive heart failure (CHF) has been associated with insulin resistance, but few studies have examined its relationship with metabolic syndrome (MetS). Little is known about whether insulin resistance explains the association between MetS and CHF.
Population‐based, cross‐sectional surveys.
Third National Health and Nutrition Examination Survey (NHANES III).
Data from 5549 men and non‐pregnant women aged ⩾40 years in NHANES III were analysed.
About 4% of men and 3% of women had CHF between 1988 and 1994 in the US. The age‐adjusted prevalence of CHF was significantly higher in African Americans (4.1%), in Mexican Americans (8.5%) and in those of other ethnic origin (6.7%) than in white people (2.5%). People with MetS had nearly twice the likelihood of self‐reported CHF (adjusted odds ratio 1.8; 95% confidence interval 1.1 to 3.0) after adjustment for demographic and conventional risk factors such as sex, ethnicity, age, smoking, total cholesterol, left ventricular hypertrophy, and probable or possible myocardial infarction determined by electrocardiography. However, this association was attenuated after further adjustment for insulin resistance as measured by the homoeostasis model assessment (HOMA). >90% of the association between MetS and CHF was explained by the HOMA.
MetS was associated with about a twofold increased likelihood of self‐reported CHF and it may serve as a surrogate indicator for the association between insulin resistance and CHF.
Diabetes is the leading cause of kidney disease in the developed world. Over time, the prevalence of diabetic kidney disease (DKD) may increase due to the expanding size of the diabetes population or decrease due to the implementation of diabetes therapies.
To define temporal changes in DKD prevalence in the United States.
Design, Setting, and Participants
Cross-sectional analyses of the Third National Health and Nutrition Examination Survey (NHANES III) from 1988–1994 (N = 15 073), NHANES 1999–2004 (N = 13 045), and NHANES 2005–2008 (N=9588). Participants with diabetes were defined by levels of hemoglobin A1c of 6.5% or greater, use of glucose-lowering medications, or both (n = 1431 in NHANES III; n = 1443 in NHANES 1999–2004; n = 1280 in NHANES 2005–2008).
Main Outcome Measures
Diabetic kidney disease was defined as diabetes with albuminuria (ratio of urine albumin to creatinine >30 mg/g), impaired glomerular filtration rate (<60 mL/min/1.73 m2 estimated using the Chronic Kidney Disease Epidemiology Collaboration formula), or both. Prevalence of albuminuria was adjusted to estimate persistent albuminuria.
The prevalence of DKD in the US population was 2.2% (95% confidence interval [CI], 1.8%–2.6%) in NHANES III, 2.8% (95% CI, 2.4%–3.1%) in NHANES 1999–2004, and 3.3% (95% CI, 2.8%–3.7%) in NHANES 2005–2008 (P<.001 for trend). The prevalence of DKD increased in direct proportion to the prevalence of diabetes, without a change in the prevalence of DKD among those with diabetes. Among persons with diabetes, use of glucose-lowering medications increased from 56.2% (95% CI, 52.1%–60.4%) in NHANES III to 74.2% (95% CI, 70.4%–78.0%) in NHANES 2005–2008 (P<.001); use of renin-angiotensin-aldosterone system inhibitors increased from 11.2% (95% CI, 9.0%–13.4%) to 40.6% (95% CI, 37.2%–43.9%), respectively (P<.001); the prevalence of impaired glomerular filtration rate increased from 14.9% (95% CI, 12.1%–17.8%) to 17.7% (95% CI, 15.2%–20.2%), respectively (P=.03); and the prevalence of albuminuria decreased from 27.3% (95% CI, 22.0%–32.7%) to 23.7% (95% CI, 19.3%–28.0%), respectively, but this was not statistically significant (P=.07).
Prevalence of DKD in the United States increased from 1988 to 2008 in proportion to the prevalence of diabetes. Among persons with diabetes, prevalence of DKD was stable despite increased use of glucose-lowering medications and renin-angiotensin-aldosterone system inhibitors.
Evidence of an association between cigarette smoking and latent tuberculosis infection (LTBI) is based on studies in special populations and/or from high prevalence settings. We sought to evaluate the association between LTBI and smoking in a low prevalence TB setting using population-based data from the National Health and Nutrition Examination Survey (NHANES).
In 1999–2000, NHANES assessed LTBI (defined as a tuberculin skin test measurement ≥10 mm) in participants, and those ≥20 years of age were queried regarding their tobacco use and serum cotinine was measured. We evaluated the association of LTBI with self-reported smoking history and smoking intensity in multivariable logistic regression models that adjusted for known confounders (gender, age, birthplace, race/ethnicity, poverty, education, history of BCG vaccination, and history of household exposure to tuberculosis disease).
Estimated LTBI prevalence was 5.3% among those ≥20 years of age. The LTBI prevalence among never smokers, current smokers, and former smokers was 4.1%, 6.6%, and 6.2%, respectively. In a multivariable model, current smoking was associated with LTBI (OR 1.8; 95% CI, 1.1–2.9). The association between smoking and LTBI was strongest for Mexican-American and black individuals. In multivariate analysis stratified by race/ethnicity, cigarette packs per day among Mexican-American smokers and cotinine levels among black smokers, were significantly associated with LTBI.
In the large, representative, population-based NHANES sample, smoking was independently associated with significantly increased risks of LTBI. In certain populations, a greater risk of LTBI corresponded with increased smoking exposure.
The US National Health and Nutrition Examination Survey (NHANES 2003–2004) evaluated oral health quality of life for the first time using a previously untested subset of seven Oral Health Impact Profile (OHIP) questions, i.e. the NHANES-OHIP.
(i) To describe the impact of dental conditions on quality of life in the US adult population; (ii) to evaluate construct validity and adequacy of the NHANES-OHIP in NHANES 2003–2004 and a comparable Australian survey.
In the cross-sectional NHANES 2003–2004 survey of a nationally representative sample of US adults (n = 4907), prevalence was quantified as the proportion of adults who reported experiencing one or more impacts fairly often or very often within the past year. Construct validity was tested by comparing prevalence estimates across categories of sociodemographic, dental health and utilization characteristics known to vary in oral health. In 2002, Australian cross-sectional survey of a nationally representative sample of adults (n = 2644), adequacy of the NHANES-OHIP questions were tested with reference to a slightly modified version of the OHIP-14 questions.
NHANES-OHIP prevalence estimates were markedly similar in the United States (15.3%) and Australia (15.7%). In the US construct, validity was evidenced by higher NHANES-OHIP scores among groups with greater levels of tooth loss, perceived treatment need and problem-oriented visiting and with lack of private dental insurance and low income. In Australia, prevalence for the NHANES-OHIP closely resembled prevalence estimates of the modified OHIP-14. Both varied to a similar degree across levels of tooth loss, perceived treatment need, problem-oriented visiting, and private dental insurance and income, demonstrating adequacy of the NHANES-OHIP as a brief independent instrument.
There was acceptable construct validity and adequacy of the NHANES-OHIP questionnaire. In the United States, the impact of oral disease disproportionately affected disadvantaged groups, a finding that supports application of the US Healthy People 2010 major goals of improved quality of life and reduced health disparities.
adults; health policy; health surveys; NHANES; population groups
Magnesium plays an essential role in the synthesis and metabolism of vitamin D and magnesium supplementation substantially reversed the resistance to vitamin D treatment in patients with magnesium-dependent vitamin-D-resistant rickets. We hypothesized that dietary magnesium alone, particularly its interaction with vitamin D intake, contributes to serum 25-hydroxyvitamin D (25(OH)D) levels, and the associations between serum 25(OH)D and risk of mortality may be modified by magnesium intake level.
We tested these novel hypotheses utilizing data from the National Health and Nutrition Examination Survey (NHANES) 2001 to 2006, a population-based cross-sectional study, and the NHANES III cohort, a population-based cohort study. Serum 25(OH)D was used to define vitamin D status. Mortality outcomes in the NHANES III cohort were determined by using probabilistic linkage with the National Death Index (NDI).
High intake of total, dietary or supplemental magnesium was independently associated with significantly reduced risks of vitamin D deficiency and insufficiency respectively. Intake of magnesium significantly interacted with intake of vitamin D in relation to risk of both vitamin D deficiency and insufficiency. Additionally, the inverse association between total magnesium intake and vitamin D insufficiency primarily appeared among populations at high risk of vitamin D insufficiency. Furthermore, the associations of serum 25(OH)D with mortality, particularly due to cardiovascular disease (CVD) and colorectal cancer, were modified by magnesium intake, and the inverse associations were primarily present among those with magnesium intake above the median.
Our preliminary findings indicate it is possible that magnesium intake alone or its interaction with vitamin D intake may contribute to vitamin D status. The associations between serum 25(OH)D and risk of mortality may be modified by the intake level of magnesium. Future studies, including cohort studies and clinical trials, are necessary to confirm the findings.
Magnesium intake; Serum 25-hydroxyvitamin D levels; Vitamin D insufficiency; Vitamin D deficiency; Parathyroid hormone; Mortality; Colorectal cancer; Cardiovascular diseases
Background and Objectives
Despite India's substantial economic growth in the past two decades, girls in India are discriminated against in access to preventive healthcare including immunizations. Surprisingly, no study has assessed the contribution of gender based within-household discrimination to the overall inequality in immunization status of Indian children. This study therefore has two objectives: to estimate the gender based within-household inequality (GWHI) in immunization status of Indian children and to examine the inter-regional and inter-temporal variations in the GWHI.
Data and Methods
The present study used households with a pair of male-female siblings (aged 1–5 years) from two rounds of National Family Health Survey (NFHS, 1992–93 and 2005–06). The overall inequality in the immunization status (after controlling for age and birth order) of children was decomposed into within-households and between-households components using Mean log deviation to obtain the GWHI component. The analysis was conducted at the all-India level as well as for six specified geographical regions and at two time points (1992–93 and 2005–06). Household fixed-effects models for immunization status of children were also estimated.
Results and Conclusions
Findings from household fixed effects analysis indicated that the immunization scores of girls were significantly lower than that of boys. The inequality decompositions revealed that, at the all-India level, the absolute level of GWHI in immunization status decreased from 0.035 in 1992–93 to 0.023 in 2005–06. However, as a percentage of total inequality, it increased marginally (15.5% to 16.5%). In absolute terms, GWHI decreased in all the regions except in the North-East. But, as a percentage of total inequality it increased in the North-Eastern, Western and Southern regions. The main conclusions are the following: GWHI contributes substantially to the overall inequality in immunization status of Indian children; and though the overall inequality in immunization status declined in all the regions, the changes in GWHI were mixed.
Although a number of studies have examined the respiratory impact of marijuana smoking, such studies have generally used convenience samples of marijuana and tobacco users. The current study examined respiratory effects of marijuana and tobacco use in a nationally representative sample while controlling for age, gender, and current asthma.
Analysis of the nationally representative third National Health and Nutrition Examination Survey (NHANES III).
A total of 6,728 adults age 20 to 59 who completed the drug, tobacco, and health sections of the NHANES III questionnaire in 1988 and 1994. Current marijuana use was defined as self-reported 100+ lifetime use and at least 1 day of use in the past month.
MEASUREMENTS AND MAIN RESULTS
Self-reported respiratory symptoms included chronic bronchitis, frequent phlegm, shortness of breath, frequent wheezing, chest sounds without a cold, and pneumonia. A medical exam also provided an overall chest finding and a measure of reduced pulmonary functioning. Marijuana use was associated with respiratory symptoms of chronic bronchitis (P =.02), coughing on most days (P =.001), phlegm production (P =.0005), wheezing (P <.0001), and chest sounds without a cold (P =.02).
The impact of marijuana smoking on respiratory health has some significant similarities to that of tobacco smoking. Efforts to prevent and reduce marijuana use, such as advising patients to quit and providing referrals for support and assistance, may have substantial public health benefits associated with decreased respiratory health problems.
marijuana; tobacco; smoking; respiratory symptoms; epidemiology
Epidemiologic studies suggest that several gene variants increase the risk of stroke, and population-based studies help provide further evidence. We identified polymorphisms associated with the prevalence of self-reported stroke in US populations using a representative sample.
Our sample comprised US adults in the Third National Health and Nutrition Examination (NHANES III) DNA bank. We examined nine candidate gene variants within ACE, F2, F5, ITGA2, MTHFR, and NOS3 for associations with self-reported stroke. We used multivariate regression and Cox proportional hazards models to test the association between these variants and history of stroke.
In regression models, the rs4646994 variant of ACE (I/I and I/D genotypes) was associated with higher prevalence adjusted prevalence odds ratio [APOR] = 2.66 [1.28, 5.55] and 2.23 [1.30, 3.85], respectively) compared with the D/D genotype. The heterozygous genotype of MTHFR rs1801131 (A/C) was associated with lower prevalence of stroke (APOR = 0.48 [0.25, 0.92]) compared with A/A and C/C genotypes. For rs2070744 of NOS3, both the C/T genotype (APOR = 1.91 [1.12, 3.27]) and C/C genotype (APOR = 3.31 [1.66, 6.60]) were associated with higher prevalence of stroke compared with the T/T genotype.
Our findings suggest an association between the prevalence of self-reported stroke and polymorphisms in ACE, MTHFR, and NOS3 in a population-based sample.
stroke; gene; polymorphisms; NHANES III; gene association analysis
The National Health and Nutrition Examination Survey (NHANES) 2005–2006 was the first population-based study to investigate levels of serum total and allergen-specific immunoglobulin E (IgE) in the general US population.
We estimated prevalence of allergy-related outcomes and examined relationships between serum IgE levels and these outcomes in a representative sample of the US population.
Data for this cross-sectional analysis were obtained from the NHANES 2005–2006. Study subjects aged 6 years and older (N=8086) had blood taken for measurement of total IgE and 19 specific IgEs against common aeroallergens, including Alternaria alternata, Aspergillus fumigatus, Bermuda grass, birch, oak, ragweed, Russian thistle, rye grass, cat dander, cockroach, dog dander, dust mite (Dermatophagoides farinae and D. pteronyssinus), mouse and rat urine proteins; and selected foods (egg white, cow’s milk, peanut, and shrimp). Serum samples were analyzed for total and allergen-specific IgEs using the Pharmacia CAP System. Information on allergy-related outcomes and demographics was collected by questionnaire.
In the NHANES 2005–2006, 6.6% reported current hay fever and 23.5% suffered from current allergies. Allergy-related outcomes increased with increasing total IgE (adjusted ORs for a 10-fold increase in total IgE =1.86, 95% CI:1.44–2.41 for hay fever and 1.64, 95% CI: 1.41–1.91 for allergies). Elevated levels of plant-, pet-, and mold-specific IgEs contributed independently to allergy-related symptoms. The greatest increase in odds was observed for hay fever and plant-specific IgEs (adjusted OR=4.75, 95% CI:3.83–5.88).
In the US population, self-reported allergy symptoms are most consistently associated with elevated levels of plant-, pet-, and mold-specific IgEs.
allergen; allergy; allergic sensitization; serum IgE
Season of birth has been reported as a risk factor for food allergy, but the mechanisms by which it acts are unknown.
Two populations were studied; 5862 children from the National Health and Nutrition Examination Survey (NHANES) III, 1514 well-characterized food allergic children from the Johns Hopkins Pediatric Allergy Clinic (JHPAC). Food allergy was defined as self report of an acute reaction to a food (NHANES), or as milk, egg and peanut allergy. Logistic regression compared fall or non-fall birth between (1) food allergic and non-allergic subjects in NHANES, adjusted for ethnicity, age, income and sex, and (2) JHPAC subjects and the general Maryland population. For NHANES, stratification by ethnicity and for JHPAC, eczema, was examined.
Fall birth was more common among food allergic subjects in both NHANES (OR: 1.91, 95%CI: 1.31–2.77) and JHPAC/Maryland (OR: 1.31, 95%CI: 1.18–1.47). Ethnicity interacted with season (OR 2.34, 95%CI 1.43–3.82 for Caucasians, OR 1.19, 95%CI 0.77–1.86 for non-Caucasians, p=0.04 for interaction), as did eczema (OR 1.47, 95%CI 1.29–1.67 with eczema, OR 1.00, 95%CI 0.80–1.23 without eczema, p=0.002 for interaction).
Fall birth is associated with increased risk of food allergy, and this risk is greatest among those most likely to have seasonal variation in vitamin D during infancy (Caucasians) and those at risk for skin barrier dysfunction (subjects with a history of eczema), suggesting that vitamin D and the skin barrier may be implicated in seasonal associations with food allergy.
food allergy; season of birth; eczema; vitamin D
The genetic relatedness of Vibrio cholerae O1/O139 isolates obtained from 100 patients and 146 of their household contacts in Dhaka, Bangladesh, between 2002 and 2005 was assessed by multilocus variable-number tandem-repeat analysis. Isolate genotypes were analyzed at five loci containing tandem repeats. Across the population, as well as within households, isolates with identical genotypes were clustered in time. Isolates from individuals within the same household were more likely to have similar or identical genotypes than were isolates from different households, but even within a household, isolates from different individuals often had different genotypes. When household contacts were sampled regularly for 3 weeks after the illness of the household index patient, isolates with genotypes related to the index patient appeared in contacts, on average, ∼3 days after the index patient, while isolates with unrelated genotypes appeared in contacts ∼6 days after. Limited data revealed that multiple isolates from the same individual collected within days of each other or even from a single stool sample may have identical, similar, or unrelated genotypes as well. Our results demonstrate that genetically related V. cholerae strains cluster in local outbreaks but also suggest that multiple distinct strains of V. cholerae O1 may circulate simultaneously within a household.
Much forensic inference based upon DNA evidence is made assuming Hardy-Weinberg Equilibrium (HWE) for the genetic loci being used. Several statistical tests to detect and measure deviation from HWE have been devised, and their limitations become more obvious when testing for deviation within multiallelic DNA loci. The most popular methods-Chi-square and Likelihood-ratio tests-are based on asymptotic results and cannot guarantee a good performance in the presence of low frequency genotypes. Since the parameter space dimension increases at a quadratic rate on the number of alleles, some authors suggest applying sequential methods, where the multiallelic case is reformulated as a sequence of “biallelic” tests. However, in this approach it is not obvious how to assess the general evidence of the original hypothesis; nor is it clear how to establish the significance level for its acceptance/rejection. In this work, we introduce a straightforward method for the multiallelic HWE test, which overcomes the aforementioned issues of sequential methods. The core theory for the proposed method is given by the Full Bayesian Significance Test (FBST), an intuitive Bayesian approach which does not assign positive probabilities to zero measure sets when testing sharp hypotheses. We compare FBST performance to Chi-square, Likelihood-ratio and Markov chain tests, in three numerical experiments. The results suggest that FBST is a robust and high performance method for the HWE test, even in the presence of several alleles and small sample sizes.
Hardy-Weinberg equilibrium; significance tests; FBST
This study examined prospective data from the Third National Health and Nutrition Examination Survey (NHANES III) cohort to investigate the relationship between cadmium exposure and cancer mortality, and the specific cancers associated with cadmium exposure, in the general population.
Vital status and cause of death through December 31, 2006 were obtained by the National Center for Health Statistics for NHANES III participants. Cadmium concentration of spot urine samples was measured, and corrected for urine creatinine. Weighted Cox proportional hazards regression with age as the time metric was applied to estimate sex-specific adjusted hazard ratios (aHRs) of mortality associated with uCd for all cancers and the cancers responsible for the most deaths in the US. Estimates were stratified by smoking history and adjusted education, body mass index, and race.
uCd was associated with cancer mortality (aHR per 2-fold higher uCd (95%CI), men: 1.26 (1.07–1.48)); women: 1.21 (1.04–1.42)). In men, mortality from lung, pancreatic cancer and non-Hodgkin lymphoma was associated with uCd; an association with leukemia mortality was suggested. In women, associations were suggested with mortality due to lung cancer, leukemia, ovarian, and uterine cancer, but evidence was weaker than in men.
Cadmium appears to be associated with overall cancer mortality in men and women, but the specific cancers associated differ between men and women, suggesting avenues for future research. Limitations of the study include the possibility of uncontrolled confounding by cigarette smoking or other factors, and the limited number of deaths due to some cancers.
cadmium; cancer mortality; National Health and Nutrition Examination Survey
Leptin has been suspected to contribute to the development of osteoarthritis (OA). However, this hypothesis has not been tested in large-scale hand OA cohorts. Our study aimed to determine whether there is a cross-sectional relationship between serum leptin levels and hand OA in a population-based sample of US adults.
We used the Third National Health and Nutrition Examination Survey (NHANES III), a national cross-sectional population-based survey, to study the relationship between hand OA and serum leptin concentration. We applied previously established classification criteria for hand OA. Patients with rheumatoid arthritis were excluded. Potential confounders included sex, body mass index, the presence of polyarticular OA, diabetes, and total cholesterol. We estimated unadjusted mean leptin concentration by hand OA status and by all confounders. We further developed a linear regression model to assess mean leptin levels, adjusted for appropriate confounders.
Of 2,477 subjects in the NHANES III sample that had a hand examination and did not have rheumatoid arthritis, 1,056 (42.6%) had a leptin measurement and were included in the analysis. Subjects with and without leptin measurement had similar demographic characteristics. We did not find any significant differences in mean serum leptin levels in subjects with symptomatic hand OA (7.38 ng/ml in males (95% confidence interval (CI) = 5.31, 9.46) and 21.55 ng/ml in females (95% CI = 17.08, 26.02)), asymptomatic hand OA (6.69 ng/ml in males (95% CI = 5.19, 8.18) and 17.09 ng/ml in females (95% CI = 15.00, 19.18)), and no hand OA (8.22 ng/ml in males (95% CI = 7.47, 8.97) and 20.77 ng/ml in females (95% CI = 18.01, 23.53)) in the unadjusted analysis. In a multivariable linear regression model that included variables of hand OA status, age, race/ethnicity, and obesity status, we found no statistically significant association between serum leptin and hand OA status.
In this cross-sectional study of a large representative US cohort, we did not find any evidence to support the hypothesis that serum leptin is associated with hand OA.
To examine the impact of family structure on pharmacologic stimulant use among children with attention-deficit/hyperactivity disorder (ADHD).
Nationally representative, population-based sample of the National Health Interview Survey from 1997 to 2003 linked with drug event files from the Medical Expenditure Panel Survey from 1998 to 2005.
Stepwise multivariate logistic regression was used to examine the likelihood of stimulant use for each individual during 2 years of observation after adjustment for sociodemographic, health, and family characteristics. Stratified analyses were also conducted to examine whether family characteristics had different impacts within single-mother and dual-parent households.
Stimulant use varied based on children's sociodemographic and health characteristics. In multivariate analyses, associations between children's household structure, parental education, and stimulant use appeared to be mediated by children's access to care and health status. However, in full multivariate models, there remained a robust positive association between family size and stimulant use.
These findings highlight the influence that nonclinical factors such as family size may have in mediating the use of pharmacologic therapies for children.
Attention-deficit/hyperactivity disorder (ADHD); prescription drug use; access to care
OBJECTIVE: Investigation into the relationship between lifestyle factors (particularly cigarette smoking) and perceived oral health has been limited. Data from the third National Health and Nutrition Examination Survey (NHANES II), 1988-1994, were used to explore this relationship in a large sample of U.S. adults. METHODS: This study used data on 13,357 dentate participants in NHANES III aged 20-79 years. In NHANES III, information on perceived dental health, sociodemographic attributes, smoking status, frequency of dental visits, dental insurance, and general health perception were collected during a home interview, and oral health status was assessed at a mobile examination center. RESULTS: Overall, 34.4% of individuals in the study sample reported having an unfavorable perception of their dental health by qualifying it as "fair" or "poor." Furthermore, 46.6% of smokers had an unfavorable dental health perception, compared to 28.3% of non-smokers. An interaction between smoking and race/ethnicity was found in logistic regression modeling. Stratified results show that cigarette smoking was not a significant predictor for an unfavorable dental health perception among individuals who self-identified as Mexican American, but smoking was a significant predictor for an unfavorable dental health perception among those who identified as non-Hispanic black or non-Hispanic white. CONCLUSIONS: This is the first study to describe the effects of smoking on dental health perception while controlling for examined oral health status. Because perceived dental health is a potential indicator for dental care utilization, a better knowledge of the factors that influence dental health perception is not only important for dental services planning, but also for understanding oral health-related quality of life issues. Additionally, given that smoking may negatively affect dental health perception, these findings have potential implications for smoking cessation activities conducted by dental care providers.
The objectives of this study were to explore the relation between body mass index (BMI) and prevalence of diabetes mellitus, hypertension and dyslipidaemia; examine BMI distributions among patients with these conditions; and compare results from two national surveys. The Study to Help Improve Early evaluation and management of risk factors Leading to Diabetes (SHIELD) 2004 screening questionnaire (mailed survey) and the National Health and Nutrition Examination Surveys (NHANES) 1999–2002 (interview, clinical and laboratory data) were conducted in nationally representative samples ≥ 18 years old. Responses were received from 127,420 of 200,000 households (64%, representing 211,097 adults) for SHIELD, and 4257 participants for NHANES. Prevalence of diabetes mellitus, hypertension and dyslipidaemia was estimated within BMI categories, as was distribution of BMI levels among individuals with these diseases. Mean BMI was 27.8 kg/m2 for SHIELD and 27.9 kg/m2 for NHANES. Increased BMI was associated with increased prevalence of diabetes mellitus, hypertension and dyslipidaemia in both studies (p < 0.001). For each condition, more than 75% of patients had BMI ≥ 25 kg/m2. Estimated prevalence of diabetes mellitus and hypertension was similar in both studies, while dyslipidaemia was substantially higher in NHANES than SHIELD. In both studies, prevalence of diabetes mellitus, hypertension and dyslipidaemia occurred across all ranges of BMI, but increased with higher BMI. However, not all overweight or obese patients had these metabolic diseases and not all with these conditions were overweight or obese. Except for dyslipidaemia prevalence, SHIELD was comparable with NHANES. Consumer panel surveys may be an alternative method to collect data on the relationship of BMI and metabolic diseases.