Lipoprotein particle concentration measured by nuclear magnetic resonance spectroscopy is associated with gestational age at delivery: a prospective cohort study.

OBJECTIVE: To estimate the association between lipoprotein particle concentrations in pregnancy and gestational age at delivery. DESIGN: Prospective cohort study. SETTING: The study was conducted in the USA at the University of North Carolina. POPULATION: We assessed 715 women enrolled in the Pregnancy, Infection, and Nutrition study from 2001 to 2005. METHODS: Fasting blood was collected at two time points (<20 and 24-29 weeks of gestation). Nuclear magnetic resonance (NMR) quantified lipoprotein particle concentrations [low-density lipoprotein (LDL), high-density lipoprotein (HDL), very-low density lipoprotein (VLDL)] and 10 subclasses of lipoproteins. Concentrations were assessed as continuous measures, with the exception of medium HDL which was classified as any or no detectable level, given its distribution. Cox proportional hazards models estimated hazard ratios (HR) for gestational age at delivery adjusting for covariates. MAIN OUTCOME MEASURES: Gestational age at delivery, preterm birth (<37 weeks of gestation), and spontaneous preterm birth. RESULTS: At <20 weeks of gestation, three lipoproteins were associated with later gestational ages at delivery [large LDLNMR (HR 0.78, 95% CI 0.64-0.96), total VLDLNMR (HR 0.77, 95% CI 0.61-0.98), and small VLDLNMR (HR 0.78, 95% CI 0.62-0.98], whereas large VLDLNMR (HR 1.19, 95% CI 1.01-1.41) was associated with a greater hazard of earlier delivery. At 24-28 weeks of gestation, average VLDLNMR (HR 1.25, 95% CI 1.03-1.51) and a detectable level of medium HDLNMR (HR 1.90, 95% CI 1.19-3.02) were associated with earlier gestational ages at delivery. CONCLUSION: In this sample of pregnant women, particle concentrations of VLDLNMR , LDLNMR , IDLNMR , and HDLNMR were each independently associated with gestational age at delivery for all deliveries or spontaneous deliveries <37 weeks of gestation. These findings may help formulate hypotheses for future studies of the complex relationship between maternal lipoproteins and preterm birth. TWEETABLE ABSTRACT: Nuclear magnetic resonance spectroscopy may identify lipoprotein particles associated with preterm delivery.

Nonparametric Bayes modeling with sample survey weights.

In population studies, it is standard to sample data via designs in which the population is divided into strata, with the different strata assigned different probabilities of inclusion. Although there have been some proposals for including sample survey weights into Bayesian analyses, existing methods require complex models or ignore the stratified design underlying the survey weights. We propose a simple approach based on modeling the distribution of the selected sample as a mixture, with the mixture weights appropriately adjusted, while accounting for uncertainty in the adjustment. We focus for simplicity on Dirichlet process mixtures but the proposed approach can be applied more broadly. We sketch a simple Markov chain Monte Carlo algorithm for computation, and assess the approach via simulations and an application.

Multilevel examination of diabetes in modernising China: what elements of urbanisation are most associated with diabetes?

AIMS/HYPOTHESIS: The purpose of this study was to examine the association between urbanisation-related factors and diabetes prevalence in China. METHODS: Anthropometry, fasting blood glucose (FBG) and community-level data were collected for 7,741 adults (18-90 years) across 217 communities and nine provinces in the 2009 China Health and Nutrition Survey to examine diabetes (FBG ≥7.0 mmol/l or doctor diagnosis). Sex-stratified multilevel models, clustered at the community and province levels and controlling for individual-level age and household income were used to examine the association between diabetes and: (1) a multicomponent urbanisation measure reflecting overall modernisation and (2) 12 separate components of urbanisation (e.g., population density, employment, markets, infrastructure and social factors). RESULTS: Prevalent diabetes was higher in more-urbanised (men 12%; women 9%) vs less-urbanised (men 6%; women 5%) areas. In sex-stratified multilevel models adjusting for residential community and province, age and household income, there was a twofold higher diabetes prevalence in urban vs rural areas (men OR 2.02, 95% CI 1.47, 2.78; women, OR 1.94, 95% CI 1.35, 2.79). All urbanisation components were positively associated with diabetes, with variation across components (e.g. men, economic and income diversity, OR 1.42, 95% CI 1.20, 1.66; women, transportation infrastructure, OR 1.18, 95% CI 1.06, 1.32). Community-level variation in diabetes was comparatively greater for women (intraclass correlation [ICC] 0.03-0.05) vs men (ICC ≤0.01); province-level variation was greater for men (men 0.03-0.04; women 0.02). CONCLUSIONS/INTERPRETATION: Diabetes prevention and treatment efforts are needed particularly in urbanised areas of China. Community economic factors, modern markets, communications and transportation infrastructure might present opportunities for such efforts.

Expressive Dominant Versus Receptive Dominant Language Patterns in Young Children: Findings from the Study to Explore Early Development.

We examined language profiles of 2571 children, 30-68 months old, with autism spectrum disorder (ASD), other developmental disabilities (DD), and typical development from the general population (POP). Children were categorized as expressive dominant (ED), receptive dominant (RD), or nondominant (ND). Within each group, the ED profile was the least frequent. However, children in the ASD group were more likely to display an ED profile than those in the DD or POP groups, and these children were typically younger, had lower nonverbal cognitive skills, and displayed more severe social-affect symptoms of ASD compared to their peers with RD or ND profiles. These findings have research and clinical implications related to the focus of interventions targeting young children with ASD and other DDs.

Ethnicity and gestational diabetes in New York City, 1995-2003.

OBJECTIVE: To characterise the patterns of occurrence of gestational diabetes among a wide range of ethnic groups that reside in New York City. DESIGN: Birth records and hospital discharge data were linked to more accurately assess the risk of gestational diabetes by ethnicity, compare risk in US-born to foreign-born women, and assess time trends. SETTING: New York City. POPULATION: All singleton live births occurring between 1995 and 2003. METHODS: Multivariable binomial regression analysis of ethnicity and gestational diabetes, yielding adjusted risk ratios with non-Hispanic white women as the referent. MAIN OUTCOME MEASURE: Diagnosis of gestational diabetes on birth certificate or in hospital discharge. RESULTS: Adjusted relative risks (aRRs) were modestly elevated for African-Americans and sub-Saharan Africans and somewhat higher (<2.0) for non-Hispanic Caribbeans, Hispanic Caribbeans, Central Americans, and South Americans. The aRR was 4.7 (95% CI = 4.6-4.9) for South Central Asians (with an absolute gestational diabetes risk of 14.3%), 2.8 (95% CI = 2.7-3.0) among South-East Asian and Pacific Islanders, and 2.3 (95% CI = 2.2-2.4) among East Asians. Among South Central Asians, the greatest risks were found for women from Bangladesh (aRR = 7.1, 95% CI = 6.8-7.3). Foreign-born women consistently had higher risk than US-born women. Risk for gestational diabetes increased over time among South Central Asians, some Hispanic groups, and African-Americans. CONCLUSIONS: Risk of gestational diabetes appears to vary markedly among ethnic groups, subject to potential artefacts associated with screening and diagnosis. These differences would have direct implications for health care and may suggest aetiologic hypotheses.

Stress and placental resistance measured by Doppler ultrasound in early and mid-pregnancy.

OBJECTIVES: To examine the association between self reports and biomarkers of stress and placental resistance (measured by Doppler ultrasound of the uterine and umbilical arteries), to determine if restriction of blood flow to the placenta is a mechanism by which stress might affect health during pregnancy. METHODS: Eight hundred and seventy-two women had ultrasound examinations of the uterine artery at 15-19 weeks' gestation and the uterine and umbilical arteries at 24-29 weeks, and resistance and pulsatility indices were calculated. Psychosocial stress was measured by telephone interview and self-administered questionnaire using several validated tools twice during the pregnancy. Cortisol and corticotropin-releasing hormone (CRH) were measured twice during the pregnancy. Linear and hierarchical models were used to examine the relationships among reported stress, stress hormones and placental Doppler indices. RESULTS: The umbilical artery resistance index was higher in younger women, those with less education, those who were single and those who smoked. The uterine artery pulsatility index was higher in women with pre-eclampsia, those living alone, those with high body mass index, and those who gained the least weight during pregnancy. A higher CRH level was associated with small increases in uterine artery pulsatility and umbilical artery resistance indices. Psychosocial measures of stress were not consistently associated with higher placental resistance. CONCLUSIONS: Increased CRH levels may be associated with increased placental resistance. Otherwise, these findings do not support the hypothesis that restriction of blood flow to the fetus is a major mechanism by which stress affects infant health.

Bayesian Local Extremum Splines.

We consider shape restricted nonparametric regression on a closed set [Formula: see text], where it is reasonable to assume the function has no more than H local extrema interior to [Formula: see text]. Following a Bayesian approach we develop a nonparametric prior over a novel class of local extremum splines. This approach is shown to be consistent when modeling any continuously differentiable function within the class considered, and is used to develop methods for testing hypotheses on the shape of the curve. Sampling algorithms are developed, and the method is applied in simulation studies and data examples where the shape of the curve is of interest.

Concordance of haemoglobin A1c, blood pressure and C-reactive protein between children and their parents in Chinese households.

BACKGROUND: China has the world's highest diabetes prevalence, which along with hypertension and inflammation continues to grow particularly among children. Little is known about the strength of the association of these cardiometabolic risk factors between parents and their children; thus, the potential of household-based strategies to reduce risk is unknown. OBJECTIVES: The objective of the study is to examine the parent-child association for haemoglobin A1c (HbA1c), blood pressure (BP) and C-reactive protein (CRP) in a large, geographically diverse Chinese sample. METHODS: In 940 parent-child pairs (children aged 7-17 years) who participated in the 2009 China Health and Nutrition Survey, we measured each individual's HbA1c and CRP using fasting blood and BP. We used sex-specific random-effects linear regression to examine the parent-child association for these risk factors, accounting for within-family clustering. RESULTS: Child's HbA1c was positively associated with parental HbA1c. Beta coefficients ranged from 0.06 (95% CI 0.03-0.12) for father-daughter to 0.43 (95% CI 0.28-0.58) for mother-son pairs. We also detected a positive mother-daughter association for BP and positive father-child associations for CRP. CONCLUSION: The statistically significant parent-child association for HbA1c, BP and CRP in Chinese families suggests that household-based interventions could be useful for confronting the high rates of diabetes, hypertension and inflammation in China.

Implications of iron deficiency/anemia on the classification of diabetes using HbA1c.

BACKGROUND/OBJECTIVES: Nonglycemic factors like iron deficiency (ID) or anemia may interfere with classification of diabetes and prediabetes using hemoglobin A1c (HbA1c). However, few population-based studies of diabetes in areas with endemic ID/anemia have been conducted. We aimed to determine how mutually exclusive categories of ID alone, anemia alone and iron-deficiency anemia (IDA) were each associated with prediabetes and diabetes prevalence using fasting blood glucose (FBG) versus HbA1c in a population-based study of adults with endemic ID/anemia. SUBJECTS/METHODS: We used data from the China Health and Nutrition Survey, a longitudinal, population-based study across 228 communities within nine provinces of China. This analysis included 7308 adults seen in the 2009 survey aged 18-75 years. We used descriptive and covariate-adjusted models to examine relative risk of prediabetes and diabetes using FBG alone, HbA1c alone, HbA1c and FBG, or neither (normoglycemia) by anemia alone, ID alone, IDA or normal iron/hemoglobin. RESULTS: Approximately 65% of individuals with diabetes in our sample were concordantly classified with diabetes using both FBG and HbA1c, while 35% had a discordant diabetes classification: they were classified using either FBG or HbA1c, but not both. Fewer participants with ID alone versus normal iron/hemoglobin were classified with diabetes using HbA1c only. From covariate-adjusted, multinomial regression analyses, the adjusted prevalence of prediabetes using HbA1c only was 22% for men with anemia alone, but 13% for men with normal iron/hemoglobin. In contrast, the predicted prevalence of prediabetes using HbA1c only was 8% for women with ID alone, compared with 13% for women with normal iron/hemoglobin. CONCLUSIONS: These findings suggest potential misclassification of diabetes using HbA1c in areas of endemic ID/anemia. Estimating diabetes prevalence using HbA1c may result in under-diagnosis in women with ID and over-diagnosis in men with anemia.

Cardiovascular malformations: changes in prevalence and birth status, 1972-1990.

Through an ongoing hospital-based active malformation surveillance program, we identified cardiovascular malformations (CVMs) in 3.3 per 1,000 liveborn and stillborn infants, and fetuses from pregnancies terminated electively during a 15-year period. We excluded the children of mothers who had planned delivery elsewhere, but were transferred for care of anomalies that had been detected in prenatal screening. Birth status changed markedly during the study with a significant increase in elective terminations of fetuses with a CVM from 0 to 22% (P < 0.01 based on a test for trend). The proportion of liveborn infants with CVMs decreased from 90% to 73% (P < 0.01); the frequency of stillbirths did not change. During the study period, there was a significant increase in the prevalence of CVMs in all births (P < 0.01) and elective terminations (P < 0.01). The increase in liveborn prevalence was not statistically significant (P = 0.08). Stillborn prevalence was unchanged. The number of mothers having prenatal ultrasonography (P < 0.01 for trend) and amniocentesis (P < 0.01 for trend) increased steadily. There were significant increases in the proportion of mothers having any ultrasound examination (P < 0.01 for trend), the number of initial ultrasound examinations occurring in the second trimester (P < 0.01 for trend), and the proportion of mothers having amniocentesis (P < 0.01 for trend). There was a significant increasing trend in the proportion of mothers who were 35 years and older (10% in 1972-1974, 26% in 1988-1990, P < 0.01). This hospital-based active surveillance program suggests that more frequent elective terminations had a significant effect on overall birth prevalence of CVMs. This trend would not have been detected by most other surveillance systems which determine prevalence of common birth defects from birth certificates and other forms of administrative reporting, and exclude elective terminations of pregnancy.

Infant BMI trajectories are associated with young adult body composition.

The dynamic aspect of early life growth is not fully captured by typical analyses, which focus on one specific time period. To better understand how infant and young child growth relate to the development of adult body composition, the authors characterized body mass index (BMI) trajectories using latent class growth analysis (LCGA) and evaluated their association with adult body composition. Data are from the Cebu Longitudinal Health and Nutrition Survey, which followed a birth cohort to age 22 years (n = 1749). In both males and females, LCGA identified seven subgroups of respondents with similar BMI trajectories from 0 to 24 months (assessed with bimonthly anthropometrics). Trajectory groups were compared with conventional approaches: (1) accelerated growth between two time points (0-4 months), (2) continuous BMI gain between two points (0-4 months and 0-24 months) and (3) BMI measured at one time point (24 months) as predictors of young adult body composition measures. The seven trajectory groups were distinguished by age-specific differences in tempo and timing of BMI gain in infancy. Infant BMI trajectories were better than accelerated BMI gain between 0 and 4 months at predicting young adult body composition. After controlling for BMI at age 2 years, infant BMI trajectories still explained variation in adult body composition. Using unique longitudinal data and methods, we find that distinct infant BMI trajectories have long-term implications for the development of body composition.

Gestational weight gain and predicted changes in offspring anthropometrics between early infancy and 3 years.

OBJECTIVE: To determine how gestational weight gain (GWG), categorized using the 2009 Institute of Medicine recommendations, relates to changes in offspring weight-for-age (WAZ), length-for-age (LAZ) and weight-for-length z-scores (WLZ) between early infancy and 3 years. METHODS: Women with singleton infants were recruited from the third cohort of the Pregnancy, Infection, and Nutrition Study (2001-2005). Term infants with at least one weight or length measurement during the study period were included (n = 476). Multivariable linear mixed effects regression models estimated longitudinal changes in WAZ, LAZ and WLZ associated with GWG. RESULTS: In early infancy, compared with infants of women with adequate weight gain, those of women with excessive weight gains had higher WAZ, LAZ and WLZ. Excessive GWG ≥ 200% of the recommended amount was associated with faster rates of change in WAZ and LAZ and noticeably higher predicted mean WAZ and WLZ that persisted across the study period. CONCLUSIONS: GWG is associated with significant differences in offspring anthropometrics in early infancy that persisted to 3 years of age. More longitudinal studies that utilize maternal and paediatric body composition measures are necessary to understand the nature of this association.

Neighborhood deprivation and adverse birth outcomes among diverse ethnic groups.

PURPOSE: 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. METHODS: 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 and <2500g). Adjusted odds ratios (aORs) for PTB (<32 and 33-36 weeks) and TLBW were estimated using logistic regression. RESULTS: 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 (PTB < 32 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). CONCLUSIONS: 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.

Psychological and biological markers of stress and bacterial vaginosis in pregnant women.

OBJECTIVES: To determine whether stress is associated with risk of bacterial vaginosis (BV) in pregnant women. DESIGN: Prospective cohort study. SETTING: The prenatal care clinics at the University of North Carolina. The residents' clinic sees mostly government-insured and uninsured women, and the physicians' clinic sees mostly those with private health insurance. POPULATION: A total of 897 women gave samples for BV analysis. Study participants were 22% African-American, 68% white; 24% unmarried and 44% nulliparous. More than half had completed college. METHODS: Women completed two questionnaires and two interviews reporting stress and psychological aspects of their lives. Measurement scales included the Sarason life events questionnaire, the Cohen perceived stress scale, Spielberger state-trait anxiety, the John Henryism coping style and the Medical Outcomes Study social support inventory. Two stress hormones, corticotrophin-releasing hormone and cortisol, were also measured. MAIN OUTCOME MEASURES: BV at 15-19 and 24-29 weeks of gestation was diagnosed by Gram's stain. RESULTS: Women in the highest quartile of stress measures, particularly state anxiety (OR=2.0, 95% CI 1.2-3.3), perceived stress (OR=2.4, 95% CI 1.5-3.9) and total life events (OR=2.0, 95% CI 1.3-3.2), had the highest risk of BV. Adjustment for confounders, especially age, race, and income, reduced these associations (state anxiety: OR=1.3, 95% CI 0.7-2.4; perceived stress: OR=1.4, 95% CI 0.8-2.5; total life events: OR=1.3, 95% CI 0.7-2.4). No clear pattern of association was seen between stress hormones and BV. CONCLUSIONS: Few associations between stress and BV were seen after adjustment for confounders.

Relation between ambient air quality and selected birth defects, seven county study, Texas, 1997-2000.

A population-based case-control study investigated the association between maternal exposure to air pollutants, carbon monoxide, nitrogen dioxide, ozone, sulfur dioxide, and particulate matter <10 microm in aerodynamic diameter during weeks 3-8 of pregnancy and the risk of selected cardiac birth defects and oral clefts in livebirths and fetal deaths between 1997 and 2000 in seven Texas counties. Controls were frequency matched to cases on year of birth, vital status, and maternal county of residence at delivery. Stationary monitoring data were used to estimate air pollution exposure. Logistic regression models adjusted for covariates available in the vital record. When the highest quartile of exposure was compared with the lowest, the authors observed positive associations between carbon monoxide and tetralogy of Fallot (odds ratio = 2.04, 95% confidence interval: 1.26, 3.29), particulate matter <10 microm in aerodynamic diameter and isolated atrial septal defects (odds ratio = 2.27, 95% confidence interval: 1.43, 3.60), and sulfur dioxide and isolated ventricular septal defects (odds ratio = 2.16, 95% confidence interval: 1.51, 3.09). There were inverse associations between carbon monoxide and isolated atrial septal defects and between ozone and isolated ventricular septal defects. Evidence that air pollution exposure influences the risk of oral clefts was limited. Suggestive results support a previously reported finding of an association between ozone exposure and pulmonary artery and valve defects.

Immunohistochemical localization of epidermal growth factor in cat paradental tissues during tooth movement.

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 <.0001). In all 3 types, cells near the actively treated canines stained significantly darker (P <.0001) than cells near the sham or control canines, particularly between 12 hours and 7 days. These results demonstrate that orthodontic forces increase epidermal growth factor concentrations in paradental cells, suggesting that epidermal growth factor participates in the tissue remodeling that facilitates tooth movement.