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Background Contemporary human populations are exposed to elevated concentrations of organophosphate esters (OPEs) and phthalates. Some metabolites have been linked with altered thyroid function, however, inconsistencies exist across thyroid function biomarkers. Research on OPEs is sparse, particularly during pregnancy, when maintaining normal thyroid function is critical to maternal and fetal health. In this paper, we aimed to characterize relationships between OPEs and phthalates exposure and maternal thyroid function during pregnancy, using a cross-sectional investigation of pregnant women nested within the Norwegian Mother, Father, and Child Cohort (MoBa). Methods We included 473 pregnant women, who were euthyroid and provided bio-samples at 17 weeks' gestation (2004–2008). Four OPE and six phthalate metabolites were measured from urine; six thyroid function biomarkers were estimated from blood. Relationships between thyroid function biomarkers and log-transformed concentrations of OPE and phthalate metabolites were characterized using two approaches that both accounted for confounding by co-exposures: co-pollutant adjusted general linear model (GLM) and Bayesian Kernal Machine Regression (BKMR). Results We restricted our analysis to common-detect OPE and phthalate metabolites (>94%): diphenyl phosphate (DPHP), di-n-butyl phosphate (DNBP), and all phthalate metabolites. In GLM, pregnant women with summed di-isononyl phthalate metabolites (∑DiNP) concentrations in the 75th percentile had a 0.37 ng/μg lower total triiodothyronine (TT3): total thyroxine (TT4) ratio (95% credible interval: [−0.59, −0.15]) as compared to those in the 25th percentile, possibly due to small but diverging influences on TT3 (−1.99 ng/dL [−4.52, 0.53]) and TT4 (0.13 μg/dL [−0.01, 0.26]). Similar trends were observed for DNBP and inverse associations were observed for DPHP, monoethyl phthalate, mono-isobutyl phthalate, and mono-n-butyl phthalate. Most associations observed in co-pollutants adjusted GLMs were attenuated towards the null in BKMR, except for the case of ∑DiNP and TT3:TT4 ratio (−0.48 [−0.96, 0.003]). Conclusions Maternal thyroid function varied modestly with ∑DiNP, whereas results for DPHP varied by the type of statistical models.

Prenatal exposure to organophosphorus pesticides (OPs) has been associated with different neurodevelopmental outcomes across different cohorts. A phenotypic approach may address some of these differences by incorporating information across scales and accounting for the complex correlational structure of neurodevelopmental outcomes. Additionally, Bayesian hierarchical modeling can account for confounding by collinear co-exposures. We use this framework to examine associations between prenatal exposure to OPs and behavior, executive functioning, and IQ assessed at age 6-9 years in a cohort of 404 mother/infant pairs recruited during pregnancy. We derived phenotypes of neurodevelopment with a factor analysis, and estimated associations between OP metabolites and these phenotypes in Bayesian hierarchical models for exposure mixtures. We report seven factors: 1) Impulsivity and Externalizing, 2) Executive Functioning, 3) Internalizing, 4) Perceptual Reasoning, 5) Adaptability, 6) Processing Speed, and 7) Verbal Intelligence. These, along with the Working Memory Index, were standardized and scaled so that positive values reflected positive attributes and negative values represented adverse outcomes. Standardized dimethylphosphate metabolites were negatively associated with Internalizing factor scores (β^ - 0.13, 95% CI - 0.26, 0.00) but positively associated with Executive Functioning factor scores (β^ 0.18, 95% CI 0.04, 0.31). Standardized diethylphosphate metabolites were negatively associated with the Working Memory Index (β^ - 0.17, 95% CI - 0.33, - 0.03). Associations with factor scores were generally stronger and more precise than associations with individual instrument-specific items. Factor analysis of outcomes may provide some advantages in etiological studies of childhood neurodevelopment by incorporating information across scales to reduce dimensionality and improve precision.

Background: Little is known about intergenerational differences in associations of urbanization-related lifestyle behaviors with cardiometabolic risk factors in children and their parents in rapidly urbanizing China.Objective: We tested the intergenerational differences in longitudinal associations of away-from-home eating, snacking, screen time, and leisure-time sports with high waist-to-height ratio (WHtR), elevated blood pressure (BP), elevated glycated hemoglobin (HbA1c), and elevated C-reactive protein (CRP) among Chinese children and their parents.Design: We studied children enrolled in the longitudinal China Health and Nutrition Survey (1991-2009, 7 surveys) aged 7-17 y in ≥2 surveys (average follow-up: 2.3 surveys out of a possible 4 surveys with the age restriction; n = 3875, including 1175 siblings) and their parents (2947 mothers, 2632 fathers) living in the same household. We used 3 consecutive interviewer-administered 24-h dietary recalls to derive a 3-d average for away-from-home eating (nonconsumer, >0 and 1 and ≤2, or >2 h/d) and leisure-time sports (any or none). Random-effects logistic regression was used to examine the associations of lagged (average: 3 y) behaviors with cardiometabolic risk factors (WHtR, BP, HbA1c, and CRP).Results: We detected intergenerational differences in associations between lagged behaviors and risk factors (P-interaction 2 compared with ≤1 h/d) was positively associated with parents' (OR: 2.58; 95% CI: 1.56, 4.28) and children's high WHtR (OR: 2.26; 95% CI: 1.06, 4.83).Conclusion: Parent-offspring differences in associations between lifestyle behaviors and cardiometabolic risk factors provide insight into intergenerational differences in cardiometabolic risk with urbanization.

Objectives We demonstrated recently that the T1 relaxation rate (R1) captured short-term Mn exposure in welders with chronic, relatively low exposure levels in a cross-sectional study. In the current study, we used a longitudinal design to examine whether R1 values reflect the short-term dynamics of Mn exposure. Methods Twenty-nine welders were evaluated at baseline and 12 months. Occupational questionnaires estimated short-term welding exposure using welding hours in the 90 days prior to each study visit (HrsW 90 ). In addition, blood Mn levels, the pallidal index (PI; globus pallidus T1-weighted intensity (T1WI)/frontal white matter T1WI), and R1 values in brain regions of interest (ROIs) were determined as Mn biomarkers at each visit. Associations between changes in estimated welding exposure and changes in purported Mn biomarkers were assessed by Spearman’s correlations with adjustment for age and baseline R1, HrsW 90 , and blood Mn values. Results Changes in welding hours (HrsW 90 : the short-term welding exposure estimate), was associated significantly with changes in R1 values in the putamen (r = 0.541, p = 0.005), caudate (R = 0.453, p = 0.023), globus pallidus (R = 0.430, p = 0.032), amygdala (R = 0.461, p = 0.020), and hippocampus (R = 0.447, p = 0.025), but not with changes in blood Mn levels or the PI. Discussion Changes in R1 values correlated with changes in the short-term welding exposure estimate, but not with more traditional measures of Mn exposure (blood Mn levels or PI). These results suggest that R1 may serve as a useful marker to capture the short-term dynamics in Mn brain accumulation related to welding exposure.

Purpose Both substance use and depression are common in adolescence and often comorbid. Past research has produced conflicting results on whether there is a temporal relationship, and if so, in which direction it operates and how it may vary by sex. We examined the longitudinal associations between substance use frequency and depressive symptoms from adolescence into young adulthood and whether the associations were moderated by sex. Methods With data from Waves I, III, and IV of the National Longitudinal Study of Adolescent to Adult Health (n = 9,816), we used growth curve models to test if depressive symptoms predicted marijuana use or binge drinking frequency (Self-Medication Model) or if substance use frequency predicted depressive symptoms (Stress Model). Moderation by sex and age was tested for both potential pathways. Results Increases in adolescent depressive symptoms, compared to no symptoms, were associated with a steeper predicted increase in marijuana use frequency from adolescence to young adulthood. Increases in persistent binge drinking or marijuana use frequency had concurrent positive associations with depressive symptoms from adolescence to young adulthood, and these associations were significantly stronger for females compared to males. Conclusions The results not only support the Self-Medication Model for marijuana use but also provide modest support for the Stress Model, that substance use is associated with depressive symptoms, especially for females.

Latent class analysis can identify unmeasured mutually exclusive categories (class membership) among participants for either observed categorical or continuous variables. More recently, latent class analysis has been applied to accelerometry to better understand the day-to-day patterns of physical activity and sedentary behavior. Typically, the class assignments are only relevant to the study for which they were derived and not made available for others to use. Using one-week accelerometry (ActiGraph #AM7164) data collected from the National Health and Nutrition Examination Survey during 2003–2006, latent classes of physical activity and sedentary behavior were derived separately for youths 6–17 years and adults >=18 years. The purpose of this article is to provide the latent class assignments developed on this source population (United States) available to others to apply to their studies using similarly collected accelerometry. This method will extend the usefulness of the latent class analysis and allow for comparisons across studies.

Background Emerging research suggests that young adult sexual minorities (identifying as lesbian, gay, or bisexual or engaging in same-sex attractions or behaviors) experience poorer health than their majority counterparts, but many measures of health inequity remain unexamined in population-based research. Purpose To describe a wide range of health status and healthcare access characteristics of sexual minorities in comparison with those of the majority population in a national sample of U.S. young adults. Methods Binary and multinomial logistic regression analyses of Wave IV data (2008) from the National Longitudinal Study of Adolescent Health (participants aged 24–32 years, n =13,088) were conducted. Health measures were self-rated health; diagnosis of any of several physical or mental illnesses or sexually transmitted infections; measured BMI; depression classified from self-reported symptoms; use of antidepressant and anxiolytic medication; uninsured; forgone care; and receipt of physical, dental, and psychological services. Analyses were conducted in 2012–2013. Results Sexual minority women had elevated odds of most adverse health conditions and lower odds of receiving a physical or dental examination. Sexual minority men had elevated odds of fewer adverse health conditions. Conclusions Young adult sexual minorities are at higher risk of poor physical and mental health. The results highlight the multidimensionality of sexual minority status and respond to calls for greater understanding of the health of this population.

Purpose Studies suggest exposure to ambient particulate matter less than 2.5 μg/m3 in aerodynamic diameter (PM2.5) may be associated with preterm birth (PTB), but few have evaluated how this is modified by ambient temperature. We investigated the relationship between PM2.5 exposure during pregnancy and PTB in infants without birth defects (1999–2006) and enrolled in the National Birth Defects Prevention Study and how it is modified by concurrent temperature. Methods PTB was defined as spontaneous or iatrogenic delivery before 37 weeks. Exposure was assigned using inverse distance weighting with up to four monitors within 50 kilometers of maternal residence. To account for state-level variations, a Bayesian two-level hierarchal model was developed. Results PTB was associated with PM2.5 during the third and fourth months of pregnancy (range: (odds ratio (95% confidence interval) = 1.00 (0.35, 2.15) to 1.49 (0.82, 2.68) and 1.31 (0.56, 2.91) to 1.62 (0.7, 3.32), respectively); no week of exposure conveyed greater risk. Temperature may modify this relationship; higher local average temperatures during pregnancy yielded stronger positive relationships between PM2.5 and PTB compared to nonstratified results. Conclusions Results add to literature on associations between PM2.5 and PTB, underscoring the importance of considering co-exposures when estimating effects of PM2.5 exposure during pregnancy.

To evaluate the change in premenstrual syndrome (PMS) symptoms in women with heavy periods who underwent endometrial ablation.The study used a prospective, single-arm cohort of adult women who were to undergo NovaSure endometrial ablation for heavy menses who also reported symptoms of PMS. A brief baseline survey was done to evaluate menstrual bleeding and baseline PMS symptoms, and two 30-day prospective validated measures of PMS were used. Follow-up surveys were sent at 4 to 6 months and included both the brief survey questions and the validated measures of PMS (Canadian Task Force classification II-3).Thirty-six women with heavy periods who were to undergo endometrial ablation had PMS symptoms and completed all surveys at baseline and follow-up. The mean age was 41.4 years, with a mean body mass index of 26.7. Most (27/36, 75%) had failed hormonal management. All measures of PMS showed significant improvement after endometrial ablation. Self-rating of PMS symptoms on a scale of 0 (none) to 10 (severe) improved from a baseline of 7.4 to a follow-up rating of 3.2 (p.05). The vast majority of women (35/36, 97%) reported improvement in PMS after undergoing endometrial ablation. Both validated measures of PMS, Daily Symptoms Report and Daily Record of Severity of Symptoms, showed statistically significant improvement in PMS symptoms.Women with heavy menses and associated PMS symptoms who undergo NovaSure endometrial ablation showed improvement in PMS symptoms, as well as reduced menstrual bleeding.

The obesity epidemic raises concerns about the impact of excessive and insufficient weight gain during pregnancy.We examined the association between gestational weight gain (GWG) and preterm birth, term small- and large-for-gestational-age (SGA and LGA), term birthweight, and term primary Cesarean delivery, considering prepregnancy body mass index (BMI) and ethnicity in a cohort of 33,872 New York City residents who gave birth between 1995 and 2003 and delivered in hospitals elsewhere in New York State.Preterm birth (37 weeks' gestation) showed a modest U-shaped relationship, with projected GWG of10 kg and 20+ kg associated with odds ratios of 1.4 and 1.3, respectively, relative to 10 to 14 kg. The pattern was stronger for preterm birth32 weeks' and for underweight women with low GWG and overweight/obese women with high GWG. Term SGA decreased and term LGA and birthweight increased monotonically with increasing GWG. Primary Cesarean delivery followed the same pattern as LGA, but less strongly.Although the study is limited by potential selection bias and measurement error, our findings support the contention that GWG may be a modifiable predictor of pregnancy outcome that warrants further investigation, particularly randomized trials, to assess whether the relation is causal.

Objective To determine whether pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) influence infant postnatal growth. Study design Participants were from the Pregnancy, Infection, and Nutrition study, a prospective pregnancy cohort. Term infants with weight or length measurements at approximately 6 months were included (n = 363). Multivariable regression estimated associations for weight-for-age (WAZ), length-for-age (LAZ), and weight-for-length z-scores (WLZ) and rapid infant weight gain with categorical maternal exposures defined with the 2009 Institute of Medicine recommendations. Results Pre-pregnancy overweight and obesity were associated with higher WAZ (linear regression coefficient [β], 0.32; 95% CI, 0.04-0.61) and WLZ (β, 0.39; 95% CI, 0.02-0.76), respectively. Pre-pregnancy BMI was not associated with LAZ. Excessive GWG was associated with higher WAZ (β, 0.39; 95% CI, 0.15-0.62) and LAZ (β, 0.34; 95% CI, 0.12-0.56). Excessive GWG ≥200% of recommended amount was associated with higher WAZ (β, 0.68; 95% CI, 0.28-1.07), LAZ (β, 0.45; 95% CI, 0.06-0.83), and WLZ (β, 0.43; 95% CI, 0.04-0.82). Risk of rapid weight gain increased across maternal exposure categories; however, none of the estimates were significant. Conclusions Pre-pregnancy BMI and GWG are modifiable intrauterine exposures that influence infant postnatal anthropometric outcomes. Further investigation with infant body composition measurements is warranted.

Empirical dietary patterns are derived predominantly using principal components, exploratory factor analysis (EFA), or cluster analysis. Interestingly, latent variable models are less used despite their being more flexible to accommodate important characteristics of dietary data and despite dietary patterns being recognized as latent variables. Latent class analysis (LCA) has been shown empirically to be more appropriate to derive dietary patterns than k-means clustering but has not been compared yet to confirmatory factor analysis (CFA). In this article, we derived dietary patterns using EFA, CFA, and LCA on food items, tested how well the classes from LCA were characterized by the factors from CFA, and compared participants' direct classification from LCA on food items compared with 2 a posteriori classifications from factor scores. Methods were illustrated with the Pregnancy, Infection and Nutrition Study, North Carolina, 2000-2005 (n = 1285 women). From EFA and CFA, we found that food items were grouped into 4 factors: Prudent, Prudent with coffee and alcohol, Western, and Southern. From LCA, pregnant women were classified into 3 classes: Prudent, Hard core Western, and Health-conscious Western. There was high agreement between the direct classification from LCA on food items and the classification from the 2-step LCA on factor scores [κ=0.70 (95% CI = 0.66, 0.73)] despite factors explaining only 25% of the total variance. We suggest LCA on food items to study the effect for mutually exclusive classes and CFA to understand which foods are eaten in combination. When interested in both benefits, the 2-step classification using LCA on previously derived factor scores seems promising.

Purpose Although first-trimester vaginal bleeding is an alarming symptom, few studies have investigated the prevalence and predictors of early bleeding. This study characterizes first trimester bleeding, setting aside bleeding that occurs at time of miscarriage. Methods Participants (n = 4539) were women ages 18 to 45 enrolled in Right From the Start , a community-based pregnancy study (2000−2008). Bleeding information included timing, heaviness, duration, color, and associated pain. Life table analyses were used to describe gestational timing of bleeding. Factors associated with bleeding were investigated by the use of multiple logistic regression with multiple imputation for missing data. Results Approximately one fourth of participants (n = 1207) reported bleeding (n = 1656 episodes), but only 8% of women with bleeding reported heavy bleeding. Of the spotting and light bleeding episodes (n = 1555), 28% were associated with pain. Among heavy episodes (n = 100), 54% were associated with pain. Most episodes lasted less than 3 days, and most occurred between gestational weeks 5 to 8. Twelve percent of women with bleeding and 13% of those without experienced miscarriage. Maternal characteristics associated with bleeding included fibroids and prior miscarriage. Conclusions Consistent with the hypothesis that bleeding is a marker for placental dysfunction, bleeding is most likely to be observed around the time of the luteal-placental shift.

Background Environmental, lifestyle, and occupational exposures on semen quality have been investigated in epidemiological studies with inconsistent results. Genetic factors involved in toxicant activation and detoxification have been examined in relation to the risk of outcomes such as cancer, cardiovascular, and neurologic disorders. However, the effect of common genetic variants in the metabolism of toxicants on semen quality parameters has rarely been evaluated. In this analysis, we evaluated functional SNPs of three genes of the glutathione-S-transferase (GSTM1, GSTT1, GSTZ1) enzyme family. Methods Participants were 228 presumed fertile men recruited as part of a community-based study. Semen outcome data from this study included total sperm count and concentration, sperm morphology, and sperm DNA integrity and chromatin maturity. DNA was obtained from 162 men from a mouth-rinse sample and genotyped for the presence of GSTT1-1 and GSTM1-1 null genotypes and the GSTZ1 SNPs at positions 94 (rs3177427) and 124 (rs3177429). We used multivariable linear regression to assess the relationship between each genotype and sperm outcomes. Results Overall, our results did not reveal a consistent pattern between GSTM1 and GSTZ genotypes and increased occurrence of adverse sperm outcomes. However, the GSTT1 non-null genotype yielded the coefficients with the largest magnitude for sperm count and sperm concentration ( β = −0.528, 95% CI −1.238 to 0.199 and β = −0.353, 95% CI −0.708 to 0.001, respectively), suggesting that it might be adverse. Conclusions These results indicate that common polymorphisms in GST genes do not negatively impact sperm parameters in healthy men with good semen quality. Contrary to expectations, the GSTT1 non-null genotype was associated with reduced sperm concentration and count in semen. Further study with a larger study size and inclusion of gene-exposure interactions is warranted.

Living in a socioeconomically deprived neighborhood has been associated with an increased risk of adverse birth outcomes. However, variation in the effect of neighborhood deprivation among diverse ethnic groups has not been studied.Using linked hospital discharge and birth data for 517,994 singleton live births in New York City from 1998 through 2002, we examined the association between neighborhood deprivation, preterm birth (PTB), and term low birthweight (TLBW) (or=37 weeks and2500g). Adjusted odds ratios (aORs) for PTB (32 and 33-36 weeks) and TLBW were estimated using logistic regression.The aOR for PTB of less than 32 weeks for the highest quartile of deprivation compared to the lowest was 1.24 (95% confidence limit [CL] = 1.13, 1.36), for PTB 33-36 weeks was 1.06 (95% CL = 1.01, 1.11), and for TLBW was 1.19 (95% CL = 1.11, 1.27). Measures of association varied by ethnicity; aORs of the greatest magnitude for PTB were found among Hispanic Caribbean women (PTB32 weeks: aOR = 1.63, 95% CL = 1.27, 2.10; PTB 33-36 weeks: aOR = 1.32, 95% CL = 1.02, 1.70), and for TLBW among African women (aOR = 1.47, 95% CL = 1.02, 2.13).The mechanisms linking neighborhood deprivation to adverse birth outcomes may differ depending on individual ethnicity and/or cultural context and should be investigated in future research.

Most pregnant women gain more weight than the ranges recommended. Excessive weight gain is linked to pregnancy complications and to long-term maternal and child health outcomes.The objective was to examine the impact of dietary glycemic load and energy density on total gestational weight gain and the weight gain ratio (observed weight gain/expected weight gain).Data are from 1231 women with singleton pregnancies who participated in the Pregnancy, Infection, and Nutrition Cohort Study. Dietary information was collected at 26-29 wk of gestation with the use of a semiquantified food-frequency questionnaire. Linear regression models were used to estimate the associations between quartiles of glycemic load and energy density with total gestational weight gain and weight gain ratio.Dietary patterns of pregnant women significantly differed across many sociodemographic and behavioral characteristics, with the greatest contrasts seen for glycemic load. After adjustment for covariates, compared with women in the first quartile consuming a mean dietary energy density of 0.71 kcal/g (reference), women in the third quartile consuming a mean energy density of 0.98 kcal/g gained an excess of 1.13 kg (95% CI: 0.24, 2.01), and women in the fourth quartile consuming a mean energy density of 1.21 kcal/g gained an excess of 1.08 kg (95% CI: 0.20, 1.97) and had an increase of 0.13 (95% CI: 0.006, 0.24) units in the weight gain ratio. All other comparisons of energy intakes were not statistically significant. Glycemic load was not associated with total gestational weight gain or weight gain ratio.Dietary energy density is a modifiable factor that may assist pregnant women in managing gestational weight gains.

The purpose of this study was to quantify the agreement between perceived and objective measures of the natural environment and to assess their associations with physical activity. Perception of the natural environment was obtained through survey data. Objective measures of weather and hills were created using Geographic Information Systems (GIS). When objective measures were compared to respondent's perceptions little agreement was found. Objective measures were not associated with any physical activity outcomes; however, several associations were seen between perceived measures and physical activity. These results indicate that researchers should consider perceptions of the natural environment when developing physical activity interventions.

Food insecurity represents a lack of access to enough food to meet basic needs. We hypothesized that food insecurity may increase birth defect risks, because it is an indicator of increased stress or compromised nutrition, which are both implicated in birth defect etiologies. This study used population-based case-control data. Included in the analysis were 1,189 case mothers and 695 control mothers who were interviewed by telephone. We calculated a food insecurity score as the number of affirmative responses to 5 questions from a shortened instrument designed to measure food insecurity. OR for the food insecurity score specified as a linear term indicated that a higher score was associated with increased risk of cleft palate, d-transposition of the great arteries, tetralogy of Fallot, spina bifida, and anencephaly, but not with cleft lip with or without cleft palate, after adjustment for maternal race-ethnicity, education, BMI, intake of folic acid-containing supplements, dietary intake of folate and energy, neighborhood crime, and stressful life events. In addition, several models suggested effect modification by certain factors. For example, for anencephaly, among women with the worst score for neighborhood crime (i.e. 6), the OR associated with a 1-unit change in the food insecurity score was 1.57 (95% CI 1.06, 2.33), whereas among women with a low crime score (i.e. 2), the corresponding OR was 1.16 (95% CI 0.96, 1.38). This study suggests that increased risks of certain birth defects may be included among the negative consequences of food insecurity.

Objective Based on current dietary intake recommendations and a recommendation to limit sedentary activity in preschoolers, an overall diet quality index for preschoolers (RC-DQI) incorporating a component for energy balance to measure adequacy of nutrition for growth, development, and disease prevention was developed. Design/subjects The newly developed index was used in nationally representative samples of 2- to 5-year-olds in the US Department of Agriculture Continuing Survey of Food Intakes by Individuals 1994-96 and 1998 (n=5,437). Index components included added sugar, total fat, polyunsaturated fatty acids, total and whole grains, fruits, vegetables, excess fruit juice, dairy, iron, and an interaction term of total daily energy intake and sedentary behavior (television time). Points were allocated to reflect deficient or excessive intakes. Statistical Analysis Performed Means and standard errors were used to describe food intakes and RC-DQI scores. Ability to differentiate diets was ascertained using mean intakes of food groups/nutrients followed by a nonparametric test of trends across ordered groups. Correlation coefficients measured dependence among RC-DQI components, nutrients, and overall energy intakes. Component scores of the highest and lowest quartile of RC-DQI were compared. Results Mean RC-DQI score was 64 points (range=28 to 93). Increasing RC-DQI scores were associated with improved diet quality. Children in the lowest RC-DQI quartile scored lower in all components. Conclusions The RC-DQI successfully differentiated diets by level of diet quality. Increasing scores were associated with decreasing consumption of added sugar and juices, and increasing intakes of fiber, essential fatty acids, fruits, and vegetables. The RC-DQI can be used to determine diet quality in groups of preschool-age children.

The purpose of this study was to show that maternal folate status during pregnancy may be related to preterm birth.Women were recruited at 24 to 29 weeks' gestation from 1995 to 2000 into the Pregnancy, Infection, and Nutrition Study. Those who completed an interview and a food frequency questionnaire, or provided a blood sample for radioassay of serum (n = 2026) and red blood cell (n = 1034) folate were included.Mean daily dietary folate intake was 463 microg (SD +/- 248). Intake/=500 microg was associated with increased preterm delivery (RR = 1.8, 95% CI 1.4-2.6) controlling for total energy intake. Serum folate levels16.3 ng/mL and red blood cell folate levels/=626.6 ng/mL yielded adjusted risk ratios of 1.8 (95% CI 1.3-2.5) and 1.7 (95% CI 1.1-2.6), respectively. Patterns were similar for spontaneous and overall preterm birth.These results support the hypothesis that low folate levels during the second trimester of pregnancy are associated with an increased risk of preterm birth.

Data from the first National Health and Nutrition Examination Survey Epidemiologic Followup Survey were used to examine whether weight change was associated with an increased relative risk of nursing care facility admission. Hazard ratios were calculated with Cox proportional hazards models and stratified by overweight status at baseline. Moderate and large weight loss was associated with an increased risk of nursing care facility admission in overweight and non-overweight subjects. Large weight gain was associated with an increased relative risk in only overweight subjects. In the process of functional decline that results in nursing care facility admission, weight loss may be a sign of acute illness, starvation, or aging. Preventing weight loss may help delay this process of decline. In overweight subjects, preventing weight gain may also be important in delaying this process of decline.

PURPOSE: We demonstrate modeling of community-level socioeconomic influences on risk of preterm birth (< 37 weeks gestation) in the Pregnancy, Infection, and Nutrition (PIN) Study. METHODS: Community-level information from the US Census was linked to 930 White and 817 African-American (Black) participants from a prospective cohort in central North Carolina through geocoded addresses, providing 123 census tracts with community-level and individual-level data for multi-level statistical analyses. RESULTS: Preterm delivery was experienced by 12.1% of Black and 10.4% of White participants. No appreciable aggregation of risk by community was discernable for White women. For Black women, random-coefficient logistic regression tract-specific preterm prevalence estimates ranged from 10.1% to 14.5%, “shrunk” from observed prevalences of 0% to 100%. Adding tract-level variables to the model representing median splits for household income and percent of single women heads of households with dependents, adjusting for individual-level maternal age and household income, accounted for much of the remaining between-tracts variation. CONCLUSIONS: Residing in a wealthier tract (> $30,000/year median income) was associated with reduced risk for Black women, adjusted OR = 0.59 (95% CI: 0.36, 0.96). The estimated conditional effect of lower community prevalence of female headed households was OR = 0.71 (95% CI: 0.43, 1.17).

Purpose Air pollution epidemiology traditionally focuses on the relationship between individual air pollutants and health outcomes (e.g., mortality). To account for potential copollutant confounding, individual pollutant associations are often estimated by adjusting or controlling for other pollutants in the mixture. Recently, the need to characterize the relationship between health outcomes and the larger multipollutant mixture has been emphasized in an attempt to better protect public health and inform more sustainable air quality management decisions. Methods New and innovative statistical methods to examine multipollutant exposures were identified through a broad literature search, with a specific focus on those statistical approaches currently used in epidemiologic studies of short-term exposures to criteria air pollutants (i.e., particulate matter, carbon monoxide, sulfur dioxide, nitrogen dioxide, and ozone). Results Five broad classes of statistical approaches were identified for examining associations between short-term multipollutant exposures and health outcomes, specifically additive main effects, effect measure modification, unsupervised dimension reduction, supervised dimension reduction, and nonparametric methods. These approaches are characterized including advantages and limitations in different epidemiologic scenarios. Discussion By highlighting the characteristics of various studies in which multipollutant statistical methods have been used, this review provides epidemiologists and biostatisticians with a resource to aid in the selection of the most optimal statistical method to use when examining multipollutant exposures.

We tested the hypothesis that the protective effect of parity on fibroids is due to direct pregnancy-related effects by following women from early pregnancy to postpartum period with ultrasound. Of 171 women with one initial fibroid, 36% had no identifiable fibroid at the time of postpartum ultrasound, and 79% of the remaining fibroids decreased in size.

Epidermal growth factor enhances proliferation and differentiation of cells during growth, maturation, and tissue healing. The objectives were to localize the epidermal growth factor in paradental cells and to determine the effect of orthodontic treatment on its concentrations in periodontal ligament fibroblasts, alveolar bone surface lining cells, and epithelial rests of Malassez. Sixty male cats, 1 year old, were divided into 2 groups: active and sham, and further divided into 10 time groups. In the active group, 1 maxillary canine was retracted by 80 g force; in the sham group, the animals received an inactive appliance. Sagittal sections of each half maxilla were stained for epidermal growth factor; staining intensity was measured microphotometrically in 10 periodontal ligament fibroblasts, alveolar bone surface lining cells, and epithelial rests of Malassez cells in sites of periodontal ligament tension and compression, and in corresponding sites near control and sham canines. The overall mean staining intensity of the cells of the active group animals was 30.47%, whereas that of the sham group was 21.78% (P