Role of African ancestry and gene-environment interactions in predicting preterm birth.

Objective: To estimate whether African ancestry, specific gene polymorphisms, and gene-environment interactions could account for some of the unexplained preterm birth variance within African American women.

Methods: We genotyped 1,509 African ancestry-informative markers, cytochrome P450 1A1 (CYP1A1), and glutathione S-transferases Theta 1 (GSTT1) variants in 1,030 self-reported African American mothers. We estimated the African ancestral proportion using the ancestry-informative markers for all 1,030 self-reported African American mothers.

Short sleep duration is associated with insulin resistance independent of adiposity in Chinese adult twins.

Objective: To investigate the association between sleep duration and insulin resistance in rural Chinese adults and examine whether any such associations are independent of adiposity.

Methods: This is a cross-sectional analysis of 854 men and 640 women aged 20 to 70 years from the Anqing Twin Cohort. The following measures were obtained for each subject: Body mass index (BMI) and percentage of trunk fat (%TF), fasting plasma glucose, homeostatic model assessment of insulin resistance index (HOMA-IR), self-reported sleep duration and measures of snoring and sleep disturbance from the Pittsburgh Sleep Quality Indices (PSQI) questionnaire were modified for a Chinese population.

A population-based twin study on sleep duration and body composition.

The aim of this study is to investigate the relationship between sleep duration and body composition and to estimate the genetic contribution of sleep duration and body composition in a Chinese twin population. This cross-sectional analysis included 738 men and 511 women aged 21-72 year. Anthropometric and dual-energy X-ray absorptiometry (DXA) measures of body composition were used.

C-reactive protein in adolescent twins: patterns and relationship to adiposity.

Context: Elevated C-reactive protein (CRP) is a marker of cardiovascular risk in adults. Patterns and determinants of CRP in adolescents have not been well described.

Objective: This study aimed to determine how CRP varies by age, gender, Tanner stage, and body fat composition in rural Chinese adolescents and to what degree adiposity-CRP associations are attributable to shared genetic and environmental factors.

Gender-specific association of sleep duration with blood pressure in rural Chinese adults.

Background: There are limited data about the role of gender on the relationship between sleep duration and blood pressure (BP) from rural populations.

Methods: We conducted a cross-sectional rural population-based study. This report includes 1033 men and 783 women aged 18-65 years from a cohort of twins enrolled in Anhui, China, between 2005 and 2008.

Association of adipokines with blood pressure in rural Chinese adolescents.

Previous research has demonstrated that adipokines influence blood pressure (BP). Limited data exist in healthy adolescents, who are in a critical period for preventing the development of high BP. This study investigated the association of leptin, adiponectin and the leptin-to-adiponectin ratio (LAR) with BP in rural Chinese adolescents.

Gene polymorphisms, breast-feeding, and development of food sensitization in early childhood.

Background: The effect of breast-feeding on the development of allergic disease is uncertain. There are no data that show whether this relationship varies by individual genotypes.

Objective: We sought to evaluate the effect of breast-feeding and gene-breast-feeding interactions on food sensitization (FS) in a prospective US birth cohort.

Cord blood immune biomarkers in small for gestational age births.

Fetal growth restriction is a risk factor for development of adulthood diseases, but the biological mechanism of this association remains unknown. Limited biomarkers have been studied in settings of preterm birth and maternal inflammation, but the relationship between a wide range of immune biomarkers and fetal growth has not been studied. The hypothesis of this study was that fetal growth restriction is associated with altered immune biomarker levels.

Does genetic regulation of IgE begin in utero? Evidence from T(H)1/T(H)2 gene polymorphisms and cord blood total IgE.

Background: Elucidation of early life factors is critical to understand the development of allergic diseases, especially those manifesting in early life such as food allergies and atopic dermatitis. Cord blood IgE (CBIgE) is a recognized risk factor for the subsequent development of allergic diseases. In contrast with numerous genetic studies of total serum IgE in children and adults, limited genetic studies on CBIgE have been conducted.

Percent fat mass is inversely associated with bone mass and hip geometry in rural Chinese adolescents.

This study was an attempt to examine the phenotypic, genetic, and environmental correlations between percent fat mass (PFM) and bone parameters, especially hip geometry, among 786 males and 618 females aged 13 to 21 years from a Chinese twin cohort. PFM, bone area (BA), bone mineral content (BMC), cross-sectional area (CSA), and section modulus (SM) were obtained by dual-energy X-ray absorptiometry. Multiple linear regression models were used to assess the PFM-bone relationships.

Plasma adipokines, bone mass, and hip geometry in rural Chinese adolescents.

Context: Adipokines have been linked to bone phenotypes recently, but with conflicting results. Few such studies have been conducted in adolescents.

Objective: The aim of the study was to examine the associations of adiponectin and leptin with multiple bone phenotypes in Chinese adolescents and estimate the genetic contribution to these associations.

Genetics of food allergy.

Purpose Of Review: Food allergy, a growing clinical and public health problem in the United States and worldwide, is likely determined by multiple environmental and genetic factors. The purpose of this review is to summarize recent advances in food allergy genetic research.

Recent Findings: There is compelling evidence that genetic factors may play a role in food allergy.

Association of plasma leptin concentrations with adiposity measurements in rural Chinese adolescents.

Context: There is evidence that leptin is involved in the etiology of obesity-related cardiovascular disease in adults. This raises the question of whether leptin levels in adolescence are indicative of adiposity-related cardiovascular risk.

Objective: This study investigated gender-specific patterns of plasma leptin during adolescence, assessed which adiposity measurements are most strongly associated with plasma leptin, and estimated to what degree leptin-adiposity associations are influenced by genetic factors.

Heritability and environmental factors affecting vitamin D status in rural Chinese adolescent twins.

Context: Factors associated with the high prevalence of vitamin D deficiency in China are not well described, especially among Chinese adolescents.

Objectives: The aim of the study was to examine important environmental or sociodemographic factors influencing 25-hydroxyvitamin D [25(OH)D] levels and estimate its heritability.

Design: A sample of 226 male and female adolescent twins aged 13-20 yr from a large prospective twin cohort of rural Chinese children and adolescents that has been followed for 6 yr were evaluated.

Association of genetic ancestry with preterm delivery and related traits among African American mothers.

Objective: In the United States, the rate of preterm delivery (PTD) is higher in African Americans (17.8%) than non-Hispanic whites (11.5%).

Genetic and environmental contributions to phenotypic components of metabolic syndrome: a population-based twin study.

The increasing prevalence of metabolic syndrome (MS) poses a serious public-health problem worldwide. Effective prevention and intervention require improved understanding of the factors that contribute to MS. We analyzed data on a large twin cohort to estimate genetic and environmental contributions to MS and to major MS components and their intercorrelations: waist circumference (WC), systolic (SBP) and diastolic blood pressure (DBP), fasting plasma glucose (FPG), triglycerides (TGs), and high-density lipoprotein-cholesterol (HDL-C).

Association of surrogate and direct measures of adiposity with risk of metabolic syndrome in rural Chinese women.

Background: Most studies linking obesity and metabolic syndrome (MS) have used body mass index (BMI) and waist circumference (WC) to measure obesity. While BMI is correlated with direct measures of total and central adiposity, it is influenced by lean body and bone mass. We hypothesize that direct measures of adiposity may help develop further insight into the link between obesity and MS, thus more accurately identifying individuals at high risk for MS.

Food allergy is associated with an increased risk of asthma.

Background: The atopic march is well documented, but the interrelationship of food allergy (FA) and asthma is not well understood.

Objective: The aim of this study was to examine the strength of the association and temporal relationships between FA and asthma.

Methods: This analysis included 271 children >or=6 years (older group) and 296 children <6 years (younger group) from a family-based FA cohort in Chicago, IL.

Adiposity, serum lipid levels, and allergic sensitization in Chinese men and women.

Background: Obesity and allergic diseases have increased dramatically in recent decades. Although adiposity has been associated with asthma, associations with allergic sensitization have been inconsistent.

Objective: To examine the association of adiposity and lipid profiles with allergic sensitization.

The joint association between F5 gene polymorphisms and maternal smoking during pregnancy on preterm delivery.

Factor V (F5) genetic variants and maternal smoking during pregnancy individually has been associated with increased risk of preterm delivery (PTD). We hypothesize that F5 gene and maternal smoking may synergistically increase the risk of PTD. Three single nucleotide polymorphisms (SNPs) in F5 gene (rs6019, rs2213869 and rs6022) were genotyped in 542 mothers with PTD and 1,141 mothers with term deliveries at the Boston Medical Center.

Familial aggregation of food allergy and sensitization to food allergens: a family-based study.

Background: The increasing prevalence of food allergy (FA) is a growing clinical and public health problem. The contribution of genetic factors to FA remains largely unknown.

Objective: This study examined the pattern of familial aggregation and the degree to which genetic factors contribute to FA and sensitization to food allergens.

Cysteinyl leukotriene receptor 1 gene variation and risk of asthma.

Although it has been recognised that genetics plays an important role in the development of asthma, important causal loci remain to be identified. The aim of the present study was to examine the association of known and novel candidate genes with asthma. Two independent samples, including 170 asthmatic cases and 347 controls in the initial sample, and 202 asthmatic cases and 332 controls in the confirmation sample, were recruited from the same region of China.

A large-scale genome-wide linkage analysis to map loci linked to stature in Chinese population.

Context: A number of genome-wide scans of stature have been reported previously, but with inconsistent results. The inconsistency may be partly due to differential population characteristics and gender- and/or age-specific effects on this trait.

Objective: This study aimed to identify the quantitative trait loci (QTLs) underlying the variation of stature in Chinese population, and to evaluate age- and gender-specific linkage for stature.

Adiposity measures and blood pressure in Chinese children and adolescents.

Objective: To investigate the association of adiposity measures with blood pressure (BP) in Chinese children and adolescents.

Design: A cross-sectional study.

Participants: 1330 boys and 1170 girls aged 6-18 years from a rural population-based cohort of twins studied in Anhui, China, 1998-2000.

Maternal cigarette smoking, metabolic gene polymorphisms, and preterm delivery: new insights on GxE interactions and pathogenic pathways.

Preterm delivery (PTD, <37 weeks of gestation) is a significant clinical and public health problem. Previously, we reported that maternal smoking and metabolic gene polymorphisms of CYP1A1 MspI and GSTT1 synergistically increase the risk of low birth weight. This study investigates the relationship between maternal smoking and metabolic gene polymorphisms of CYP1A1 MspI and GSTT1 with preterm delivery (PTD) as a whole and preterm subgroups.