Association between Urinary Phytoestrogens and C-reactive Protein in the Continuous National Health and Nutrition Examination Survey

Objective: A reduced risk of some cancers and cardiovascular disease associated with phytoestrogen intake may be mediated through its effect on serum C-reactive protein (CRP; an inflammation biomarker). Therefore, this study examined the associations between urinary phytoestrogens and serum CRP.

Methods: Urinary phytoestrogen and serum CRP data obtained from 6009 participants aged ≥ 40 years in the continuous National Health and Nutrition Examination Survey during 1999–2010 were analyzed.

Results: After adjustment for confounders, urinary concentrations of total and all individual phytoestrogens were inversely associated with serum concentrations of CRP (all p < 0.004). The largest reductions in serum CRP (mg/L) per interquartile range increase in urinary phytoestrogens (ng/mL) were observed for total phytoestrogens (β = ?0.18; 95% confidence interval [CI], ?0.22, ?0.15), total lignan (β = ?0.15; 95% CI, ?0.18, ?0.12), and enterolactone (β = ?0.15; 95% CI, ?0.19, ?0.12). A decreased risk of having high CRP concentrations (≥3.0 mg/L) for quartile 4 vs quartile 1 was also found for total phytoestrogens (OR = 0.63; 95% CI, 0.53, 0.73), total lignan (OR = 0.64; 95% CI, 0.54, 0.75), and enterolactone (OR = 0.59; 95% CI, 0.51, 0.69).

Conclusion: Urinary total and individual phytoestrogens were significantly inversely associated with serum CRP in a nationally representative sample of the U.S. population.     

Urinary Phthalate Metabolite Concentrations and Diabetes among Women in the National Health and Nutrition Examination Survey (NHANES) 2001-2008

Background: Previous studies have shown that women have higher urinary concentrations of several phthalate metabolites than do men, possibly because of a higher use of personal care products. Few studies have evaluated the association between phthalate metabolites, diabetes, and diabetes-related risk factors among women.Objective: We explored the association between urinary phthalate metabolite concentrations and diabetes among women who participated in a cross-sectional study.Methods: We used urinary concentrations of phthalate metabolites, analyzed by the Centers for Disease Control and Prevention, and self-reported diabetes of 2,350 women between 20 and 79 years of age who participated in the NHANES (2001-2008). We used multiple logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) and adjusted for urinary creatinine, sociodemographic characteristics, dietary factors, and body size. A secondary analysis was conducted for women who did not have diabetes to evaluate the association between phthalate metabolite concentrations and fasting blood glucose (FBG), homeostasis model assessment-estimated insulin resistance, and glycosylated hemoglobin A1c.Results: After adjusting for potential confounders, women with higher levels of mono-n-butyl phthalate (MnBP), mono-isobutyl phthalate (MiBP), monobenzyl phthalate (MBzP), mono-(3-carboxypropyl) phthalate (MCPP), and three di-(2-ethylhexyl) phthalate metabolites (ΣDEHP) had an increased odds of diabetes compared with women with the lowest levels of these phthalates. Women in the highest quartile for MBzP and MiBP had almost twice the odds of diabetes [OR = 1.96 (95% CI: 1.11, 3.47) and OR = 1.95 (95% CI: 0.99, 3.85), respectively] compared with women in the lowest quartile. Nonmonotonic, positive associations were found for MnBP and ΣDEHP, whereas MCPP appeared to have a threshold effect. Certain phthalate metabolites were positively associated with FBG and insulin resistance.Discussion: Urinary levels of several phthalates were associated with prevalent diabetes. Future prospective studies are needed to further explore these associations to determine whether phthalate exposure can alter glucose metabolism and increase the risk of insulin resistance and diabetes.     

Association of polychlorinated biphenyls with hypertension in the 1999-2002 National Health and Nutrition Examination Survey

The association of 11 polychlorinated biphenyls (PCBs) with hypertension was investigated using the National Health and Nutrition Examination Survey (NHANES), 1999-2002. The unweighted number of participants assessed for hypertension ranged from 2074 to 2556 depending on the chemical(s) being analyzed. In unadjusted logistic regressions all 11 PCBs were associated with hypertension. After adjustment for age, gender, race, smoking status, body mass index, exercise, total cholesterol, and family history of coronary heart disease, seven of the 11 PCBs (PCBs 126, 74, 118, 99, 138/158, 170, and 187) were significantly associated with hypertension. The strongest adjusted associations with hypertension were found for dioxin-like PCBs 126 and 118. PCB 126>59.1 pg/g lipid adjusted had an odds ratio of 2.45 (95% CI 1.48-4.04) compared to PCB 12627.5 ng/g lipid adjusted had an odds ratio of 2.30 (95% CI 1.29-4.08) compared to PCB 118or=20 years old in the non-institutionalized US population. We hypothesize that association of seven PCBs with hypertension indicates elevated PCBs are a risk factor for hypertension. What clinicians can do, given the results of this study, is limited unless the appropriate laboratory methods can be made more widely available for testing patients.     

Association between Serum Klotho and Physical Frailty in Middle-Aged and Older Adults: Finding From the National Health and Nutrition Examination Survey

ObjectivesTo date, no consensus has been reached regarding the role of klotho in the development of frailty. This study aimed to examine the relationship between serum klotho and physical frailty and to explore potential age, sex, and racial/ethnic differences, using a large, nationally representative sample of middle-aged and older adults in the United States.DesignCross-sectional study.Setting and ParticipantsParticipants were 7107 adults aged 45 years or older from the 2007–2008, 2009–2010, 2011–2012, 2013–2014, and 2015–2016 cycles of the National Health and Nutrition Examination Survey (NHANES), a large data set including a series of cross-sectional nationally representative samples in the United States.MethodsWe assessed the frailty status using the Physical Frailty Phenotype (PFP) and the Frailty Index (FI). Five criteria were used in the PFP, and 34 health items were included to construct the FI as a proportion of accumulated deficits. We used multinomial and binary logistic regression models to examine the association between serum klotho and frailty, adjusted for several covariates.ResultsParticipants with a higher serum klotho level (>785.5 pg/mL) had a lower prevalence of frailty, defined by either the PFP or the FI, than those with a lower level (≤785.5 pg/mL). After adjustment for all covariates, the higher serum klotho level was associated with a 26% (95% CI 2%–45%) and 17% (95% CI 1%–30%) lower odds of frailty vs robustness when using the PFP and FI, respectively. In the PFP, the association was significantly stronger among participants aged <60 years than those aged ≥60 years (odds ratio: 0.60 vs 0.85; P_interaction = .03). No effect modification by race/ethnicity on the association was found.Conclusions and ImplicationsHigher serum klotho level relates to lower odds of physical frailty among middle-aged and older adults. Our findings suggest that klotho might be a potential biomarker of frailty, specifically in the middle-aged population. Future research should further investigate the mechanisms underlying this association to determine if lower levels of klotho may serve as a novel risk factor for physical frailty.     

Nutrition assessment in the National Health And Nutrition Examination Survey 1999-2002

The objective of this study is to describe the components of nutrition assessment in the National Health and Nutrition Examination Survey (NHANES) 1999-2002. The study design was a cross-sectional survey with a nationally representative sample of the US population. The survey participants were interviewed and completed a physical examination. From 1999 to 2002, a total of 25,316 people were included in the eligible sample, 21,004 people (83%) were interviewed, and 19,759 people (78% of the eligible sample) were examined. Dietary assessment consisted of a 24-hour dietary recall interview and questions on supplement use, food security, food-program participation, and other behaviors. Nutrition assessment included anthropometric measurements and body-composition assessment. A number of nutrition biochemistries were measured in blood and urine specimens. In addition, an assessment of cardiovascular fitness and questions on physical activity were included. Data are used to estimate population reference distributions and to monitor trends over time. Data have been used to evaluate the adequacy of nutrient intake using the Dietary Reference Intakes, to assist in development of nutrition policies related to obesity, and to evaluate policies such as folic acid fortification. The NHANES contributes to the knowledge and understanding of nutrition and health status in the US population through public-use microdata files for use by researchers in academia, in the private sector, and in government agencies. Continuous data collection will allow the NHANES to provide more timely information for policy development and evaluation.     

Hyperhomocysteinemia associated with poor recall in the third National Health and Nutrition Examination Survey

BACKGROUND: High circulating total homocysteine (tHcy) concentrations are associated with stroke, which is a major cause of cognitive dysfunction. Blood homocysteine concentrations are inversely correlated with performance on some cognitive-function tests and a relation was recently shown between hyperhomocysteinemia and Alzheimer disease. OBJECTIVE: The objective was to evaluate the relation between serum tHcy concentrations and performance on short delayed-recall tests of elderly men and women participating in the third National Health and Nutrition Examination Survey, phase 2 (1991--1994). DESIGN: Subjects were aged > or =60 y. Subjects reported no previous stroke, completed > or =8 y of education, and took a test of delayed recall of story ideas (n = 1200) or words (n = 1270). RESULTS: After adjustment for sex, age, race-ethnicity, income, years of education, and serum creatinine concentration, subjects in the upper half of the folate distribution recalled, on average, >4 of 6 story ideas; subjects with lower folate status recalled significantly fewer ideas (P < 0.001). Of the subjects with low folate status, story recall was significantly poorer in those with serum tHcy concentrations above the 80th percentile of the distribution (13.7 micromol/L) than in those with lower tHcy concentrations (P < 0.03). The odds ratio relating hyperhomocysteinemia to recall of > or =1 of 3 previously learned words was 0.3 (95% CI: 0.2, 0.7) after adjustment for the 5 demographic factors alone and was 0.4 (0.2, 0.9) after further adjustment for serum folate concentration. CONCLUSION: Hyperhomocysteinemia is related to poor recall and this association was partially independent of folate status.     

Association of antioxidants with memory in a multiethnic elderly sample using the Third National Health and Nutrition Examination Survey.

Oxidative stress has been implicated both in the aging process and in the pathological changes associated with Alzheimer's disease. Antioxidants, which have been shown to reduce oxidative stress in vitro, may represent a set of potentially modifiable protective factors for poor memory, which is a major component of the dementing disorders. The authors investigated the association between serum antioxidant (vitamins E, C, A, carotenoids, selenium) levels and poor memory performance in an elderly, multiethnic sample of the United States. The sample consisted of 4,809 non-Hispanic White, non-Hispanic Black, and Mexican-American elderly who visited the Mobile Examination Center during the Third National Health and Nutrition Examination Survey, a national cross-sectional survey conducted from 1988 to 1994. Memory is assessed using delayed recall (six points from a story and three words) with poor memory being defined as a combined score less than 4. Decreasing serum levels of vitamin E per unit of cholesterol were consistently associated with increasing levels of poor memory after adjustment for age, education, income, vascular risk factors, and other trace elements and minerals. Serum levels of vitamins A and C, beta-carotene, and selenium were not associated with poor memory performance in this study.     

Lipids and pulmonary function in the Third National Health and Nutrition Examination Survey

Studies considering the association between total cholesterol and noncardiovascular mortality, particularly from respiratory disease, yield inconclusive findings. To explore this question, the relation of lipids to pulmonary function, specifically forced expiratory volume in 1 second (FEV(1)), was investigated in the Third National Health and Nutrition Examination Survey. Conducted in the United States in 1988-1994 among adults aged > or =17 years, this survey measured serum lipids, FEV(1), and confounding factors including smoking and antioxidants. Multiple linear regression analysis explored the relation of FEV(1)/height(2) to low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol, and their respective apolipoproteins (apo) B and A-I. A standard deviation increase in HDL cholesterol or apo A-I was associated with an FEV(1) increase of 43 ml (95% confidence interval (CI): 30, 56) or 29 ml (95% CI: 11, 47), respectively, for an average-height adult. A standard deviation increase in LDL cholesterol or apo B was associated with an FEV(1) decrease of -24 ml (95% CI: -43, -5) or -53 ml (95% CI: -74, -32), respectively, adjusted for serum antioxidant status. The lipid subfractions were differentially associated with FEV(1) consistent with the possibility that LDL cholesterol contributes to endogenous oxidative burden while HDL cholesterol attenuates inflammatory tissue damage. Whether these associations are causal remains to be determined.     

Urinary concentrations of dialkylphosphate metabolites of organophosphorus pesticides: National Health and Nutrition Examination Survey 1999-2004

Organophosphorus (OP) insecticides were among the first pesticides that EPA reevaluated as part of the Food Quality Protection Act of 1996. Our goal was to assess exposure to OP insecticides in the U.S. general population over a six-year period. We analyzed 7,456 urine samples collected as part of three two-year cycles of the National Health and Nutrition Examination Survey (NHANES) from 1999-2004. We measured six dialkylphosphate metabolites of OP pesticides to assess OP pesticide exposure. In NHANES 2003-2004, dimethylthiophosphate was detected most frequently with median and 95th percentile concentrations of 2.03 and 35.3 μg/L, respectively. Adolescents were two to three times more likely to have diethylphosphate concentrations above the 95th percentile estimate of 15.5 μg/L than adults and senior adults. Conversely, for dimethyldithiophosphate, senior adults were 3.8 times and 1.8 times more likely to be above the 95th percentile than adults and adolescents, respectively, while adults were 2.1 times more likely to be above the 95th percentile than the adolescents. Our data indicate that the most vulnerable segments of our population-children and older adults-have higher exposures to OP pesticides than other population segments. However, according to DAP urinary metabolite data, exposures to OP pesticides have declined during the last six years at both the median and 95th percentile levels.     

Association of Individual and Neighborhood Factors with Home Food Availability: Evidence from the National Health and Nutrition Examination Survey

Background

Accumulating evidence suggests the important role of the home food environment in an individual’s dietary intake.

Association between Dietary Niacin Intake and Migraine among American Adults: National Health and Nutrition Examination Survey

Migraine is related to brain energy deficiency. Niacin is a required coenzyme in mitochondrial energy metabolism. However, the relationship between dietary niacin and migraines remains uncertain. We aimed to evaluate the relationship between dietary niacin and migraine. This study used cross-sectional data from people over 20 years old who took part in the National Health and Nutrition Examination Survey between 1999 and 2004, collecting details on their severe headaches or migraines, dietary niacin intake, and several other essential variables. There were 10,246 participants, with 20.1% (2064/10,246) who experienced migraines. Compared with individuals with lower niacin consumption Q1 (≤12.3 mg/day), the adjusted OR values for dietary niacin intake and migraine in Q2 (12.4–18.3 mg/day), Q3 (18.4–26.2 mg/day), and Q4 (≥26.3 mg/day) were 0.83 (95% CI: 0.72–0.97, p = 0.019), 0.74 (95% CI: 0.63–0.87, p < 0.001), and 0.72 (95% CI: 0.58–0.88, p = 0.001), respectively. The association between dietary niacin intake and migraine exhibited an L-shaped curve (nonlinear, p = 0.011). The OR of developing migraine was 0.975 (95% CI: 0.956–0.994, p = 0.011) in participants with niacin intake < 21.0 mg/day. The link between dietary niacin intake and migraine in US adults is L-shaped, with an inflection point of roughly 21.0 mg/day.     

Blood pressure in Mexican Americans, whites, and blacks. The Second National Health and Nutrition Examination Survey and the Hispanic Health and Nutrition Examination Survey

Previous studies of Mexican Americans have shown mean diastolic and systolic blood pressures and prevalence rates of hypertension which are either lower than or similar to those for non-Hispanic whites despite the predominance of obesity in Mexican Americans. However, those results are based on restricted samples from California and Texas. Using data from the Second National Health and Nutrition Examination Survey (1976-1980) and the Hispanic Health and Nutrition Examination Survey (1982-1984), the authors examined ethnic differences in blood pressure and hypertension. Regression analyses, stratified by sex, were used to compare mean blood pressures and rates of hypertension in Mexican Americans with those for whites and blacks. Mean diastolic and systolic blood pressures, as well as the prevalence of hypertension, were lower in Mexican Americans than in non-Hispanic whites or in blacks, with whom they shared a remarkably similar risk profile. This effect was unchanged after adjustment for age, body mass index (weight (kg)/height (cm)2 x 100), and education, indicating that blood pressure differences between Mexican Americans, whites, and blacks were not explained by the established correlates of high blood pressure. There are several possible reasons for lower blood pressure in Mexican Americans, including genetic, life-style, and cultural factors.     

Serum vitamins, carotenoids, and angina pectoris: findings from the National Health and Nutrition Examination Survey III

PURPOSE: Whether various vitamins and carotenoids can protect against ischemic heart disease remains an unsettled question. METHODS: We performed a cross-sectional analysis of data from National Health and Nutrition Examination Survey III (1988-1994) and examined the associations between serum vitamins A, C, E, and B12, serum folate, red blood cell folate, serum carotenoids, and angina pectoris in a representative population-based sample of 11,327 men and women aged 35->90 years. RESULTS: After adjusting for age, sex, race or ethnicity, education, smoking status, systolic blood pressure, serum cholesterol, high-density lipoprotein cholesterol, history of diabetes mellitus, body mass index, and physical activity with multiple logistic regression analysis, no significant associations were present for any of the serum vitamin concentrations and angina pectoris. Significant linear trends were observed for serum concentrations of alpha-carotene (p < 0.001), beta-carotene (p = 0.026), and beta-cryptoxanthin (p = 0.003). Compared with participants with carotenoid concentrations in the lowest quartile, participants with concentrations in the highest quartile had odds ratios for angina pectoris of 0.45 (95% confidence interval (CI) 0.31-0.65), 0.57 (95% CI 0.38-0.86), and 0.57 (95% CI 0.38-0.84) for alpha-carotene, beta-carotene, and beta-cryptoxanthin, respectively. CONCLUSIONS: These results provide little support for a cross-sectional association between angina pectoris and serum and red blood cell folate concentrations or concentrations of vitamins A, C, E, and B12. Several serum carotenoid concentrations were associated with a reduced risk for angina pectoris, however.     

Serum alpha-tocopherol status in the United States population: findings from the Third National Health and Nutrition Examination Survey.

Despite the role vitamin E may have in protecting against various chronic conditions, little is known about vitamin E status in the US population. Using data from the Third National Health and Nutrition Examination Survey (1988-1994), the authors examined the distribution and correlates of serum alpha-tocopherol among 16,295 US adults aged 18 or more years. The mean concentration of alpha-tocopherol was 26.8 micromol/liter (geometric mean, 25.0 micromol/liter).The 25th, 50th, and 75th percentiles were 19.6, 24.1, and 30.4 micromol/liter, respectively.The mean alpha-tocopherol/cholesterol ratio was 5.1 (geometric mean, 4.9); the 25th, 50th, and 75th percentiles were 4.1, 4.7, and 5.5 (10(-3)), respectively. About 27% of the US population had a low alpha-tocopherol concentration (<20 micromol/liter). After age standardization, 29% of the men, 28% of the women, 26% of the Whites (men, 27%, and women, 26%), 41% of the African Americans (men, 42%, and women, 40%), 28% of the Mexican Americans (men, 29%, and women, 27%), and 32% of the other participants (men, 36%, and women, 29%) had this low concentration. For all participants, age, educational attainment, serum cholesterol, and several serum vitamins and carotenoids were directly related to and high density lipoprotein cholesterol was inversely related to serum alpha-tocopherol concentration in multiple linear regression analysis. Men had a higher concentration than did women, and African Americans had the lowest concentration of any racial or ethnic group. These results show that important proportions of US adults have a low serum alpha-tocopherol concentration, which may increase their risk for chronic diseases in which low dietary intake or blood concentration of alpha-tocopherol have been implicated.     

Serum total homocysteine concentrations in adolescent and adult Americans: results from the third National Health and Nutrition Examination Survey

BACKGROUND: The elevation of circulating total homocysteine concentrations in a fasting state is associated with an increased risk of occlusive vascular disease. OBJECTIVE: The primary goals of this study were to describe the distribution of serum total homocysteine concentrations in the United States and to test for differences in homocysteine concentrations among sex, age, and race-ethnicity categories. DESIGN: Using surplus sera from phase 2 of the third National Health and Nutrition Examination Survey, we measured serum total homocysteine concentrations for a nationally representative sample of 3766 males and 4819 females aged > or = 12 y. RESULTS: Age-adjusted geometric mean total homocysteine concentrations were 9.6 and 7.9 mmol/L in non-Hispanic white males and females, 9.8 and 8.2 mmol/L in non-Hispanic black males and females, and 9.4 and 7.4 mmol/L in Mexican American males and females, respectively. Age-adjusted geometric mean total homocysteine concentrations were significantly lower in females than in males in each race-ethnicity group (P < 0.01) and were significantly lower in Mexican American females than in non-Hispanic white and non-Hispanic black females (P < 0.01). There was a significant age-sex interaction (P < 0.01), reflecting the fact that homocysteine concentrations in females tended to diverge from those in males at younger ages and converge with those in males at older ages. CONCLUSIONS: The first data on homocysteine concentrations in a nationally representative sample of Americans confirm the age and sex differences reported previously in nonrepresentative samples. These data also indicate that differences between Mexican American and non-Hispanic females may influence circulating homocysteine concentrations.     

Concentrations of the sunscreen agent benzophenone-3 in residents of the United States: National Health and Nutrition Examination Survey 2003--2004

BACKGROUND: The capability of benzophenone-3 (BP-3) to absorb and dissipate ultraviolet radiation facilitates its use as a sunscreen agent. BP-3 has other uses in many consumer products (e.g., as fragrance and flavor enhancer, photoinitiator, ultraviolet curing agent, polymerization inhibitor). OBJECTIVES: Our goal was to assess exposure to BP-3 in a representative sample of the U.S. general population > or = 6 years of age. METHODS: Using automated solid-phase extraction coupled to high-performance liquid chromatography-tandem mass spectrometry, we analyzed 2,517 urine samples collected as part of the 2003--2004 National Health and Nutrition Examination Survey. RESULTS: We detected BP-3 in 96.8% of the samples. The geometric mean and 95th percentile concentrations were 22.9 microg/L (22.2 microg/g creatinine) and 1,040 microg/L (1,070 microg/g creatinine), respectively. Least-square geometric mean (LSGM) concentrations were significantly higher (p < or = 0.04) for females than for males, regardless of age. LSGM concentrations were significantly higher for non-Hispanic whites than for non-Hispanic blacks (p < or = 0.01), regardless of age. Females were more likely than males [adjusted odds ratio (OR) = 3.5; 95% confidence interval (95% CI), 1.9-6.5], and non-Hispanic whites were more likely than non-Hispanic blacks (adjusted OR = 6.8; 95% CI, 2.9-16.2) to have concentrations above the 95th percentile. CONCLUSIONS: Exposure to BP-3 was prevalent in the general U.S. population during 2003--2004. Differences by sex and race/ethnicity probably reflect differences in use of personal care products containing BP-3.