Exploring secondary aerosol formation associated with elemental carbon in the lower free troposphere.

The variability of element carbon (EC) mixed with secondary species significantly complicates the assessment of its environmental impact, reflecting the complexity and diversity of EC-containing particles' composition and morphology during their ascent and regional transport. While the catalytic role of EC in secondary aerosol formation is recognized, the effects of heterogeneous chemistry on secondary species formation within diverse EC particle types are not thoroughly understood, particularly in the troposphere. Alpine sites offer a prime environment to explore EC properties post-transport from the ground to the free troposphere. Consequently, we conducted a comprehensive study on the genesis of secondary aerosols in EC-containing particles at Mt. Hua (altitude: 2069 m) from 1 May to 10 July, using a single particle aerosol mass spectrometer (SPAMS). Our analysis identified six major EC particle types, with EC-K, EC-SN, and EC-NaK particles accounting for 27.6 %, 27.0 %, and 19.6 % of the EC particle population, respectively. The concentration-weighted trajectory (CWT) indicated that the lower free troposphere over Mt. Hua is significantly affected by anthropogenic emissions at ground-level, predominantly from northwestern and eastern China. Atmospheric interactions are crucial in generating high sulfate levels in EC-SN and EC-OC particles (> 70 %) and notable nitrate levels in EC-K, EC-BB, and EC-Fe particles (> 80 %). The observed high chloride content in EC-OC particles (56 ± 32 %) might enhance chlorine's reactivity with organic compounds via heterogeneous reactions within the troposphere. Distinct diurnal cycles for sulfate and nitrate are mainly driven by varying transport dynamics and formation processes, showing minimal dependency on EC particle types. Enhanced nocturnal oxalate conversion in EC-Fe particles is likely due to the aqueous oxidation of precursors, with Fe-catalyzed Fenton reactions enhancing OH radical production. This investigation provides critical insights into EC's role in secondary aerosol development during its transport in the lower free troposphere.

[Components Characteristic and Source Apportionment of Fine Particulate Matter in Transition Period of Heating Season in Xi'an with High Time Resolution].

Influenced by heating, the concentration of atmospheric fine particulate matter (PM2.5) rises in autumn and winter in northern cities. In this study, Q-ACSM, AE33, and Xact 625 were used to carry out online monitoring of PM2.5 chemical components with high time resolution in Xi'an from October 25 to November 17, 2019, to analyze the characteristics of PM2.5 pollution during the transition period of the heating season. Additionally, we analyzed the sources of PM2.5 in combination with the positive matrix factorization model. The results showed that the average PM2.5 concentration during the observation period was (78.3 ± 38.5) µg·m-3, and the main chemical components were organic matter (OA), secondary inorganic ions (SIA), and dust, which accounted for 38.7%, 31.6%, and 21.2%, respectively. The average concentrations of sulfate, nitrate, and ammonium were (4.0 ± 3.1), (14.9 ± 13.7), and (5.8 ± 4.8) µg·m-3, and the average concentrations of the major metals potassium, calcium, and iron were (1.0 ± 0.4), (1.5 ± 1.1), and (1.4 ± 0.9) µg·m-3. Black carbon, chloride ions, and trace elements contributed relatively little to PM2.5 (5.7%, 1.3%, and 1.5%, respectively). In the pollution development and maintenance stage, the concentration of OA and SIA increased by 137.7% to 537.0%, whereas in the pollution dissipation stage, only the concentration of dust gradually increased. The source apportionment results showed that secondary sources, biomass burning, dust, vehicle emission, industrial emission, and coal combustion were the main sources of PM2.5 during the observation period, contributing 29.1%, 21.1%, 15.3%, 12.9%, 11.4%, and 10.2%, respectively. The contribution rate of secondary sources and biomass burning was higher in the pollution development and maintenance stage, and dust was higher in the pollution dissipation stage.

Source-specific light absorption and radiative effects decreases and indications due to the lockdown.

The 'extreme' emission abatement during the lockdown (from the end of 2019 to the early 2020) provided an experimental period to investigate the corresponding source-specific effects of aerosol. In this study, the variations of source-specific light absorption (babs) and direct radiative effect (DRE) were obtained during and after the lockdown period by using the artificial neural network (ANN) and source apportionment environmental receptor model. The results showed that the babs decreased for all sources during the two periods. The most reductions were observed with ∼90% for traffic-related emissions (during the lockdown) and ∼85% for coal combustion (after the lockdown), respectively. Heightened babs (370 nm) values were obtained for coal and biomass burning during the lockdown, which was attributed to the enhanced atmospheric oxidization capacity. Nevertheless, the variations of babs (880 nm) after the lockdown was mainly due to the weakening of oxidation and reduced emissions of secondary precursors. The present study indicated that the large-scale emission reduction can promote both reductions of babs (370 nm) and DRE (34-68%) during the lockdown. The primary emissions decrease (e.g., Traffic emission) may enhance atmosphere oxidation, increase the ultraviolet wavelength light absorption and DRE efficiencies. The source-specific emission reduction may be contributed to various radiation effects, which is beneficial for the adopting of control strategies.

The impacts of regional transport on anthropogenic source contributions of PM2.5 in a basin city, China.

PM2.5 pollution events are often happened in urban agglomeration locates in mountain-basin regions due to the complex terra and intensive emissions. Source apportionment is essential for identifying the pollution sources and important for developing local mitigation strategies, however, it is influenced by regional transport. To understand how the regional transport influences the atmospheric environment of a basin, we connected the PM2.5 source contributions estimated by observation-based receptor source apportionment and the regional contributions estimated by a tagging technology in the comprehensive air quality model with extensions (CAMx) via an artificial neural network (ANNs). The result shows that the PM2.5 in Xi'an was from biomass burning, coal combustion, traffic related emissions, mineral dust, industrial emissions, secondary nitrate and sulfate. 48.8 % of the PM2.5 in study period was from Xi'an, then followed by the outside area of Guanzhong basin (28.2 %), Xianyang (14.6 %) and Weinan (5.8 %). Baoji and Tongchuan contributed trivial amount. The sensitivity analysis showed that the transported PM2.5 would lead to divergent results of source contributions at Xi'an. The transported PM2.5 from the outside has great a potential to alter the source contributions implying a large uncertainty of the source apportionment introduced when long-range transported pollutants arrived. It suggests that a full comprehension on the impacts of regional transport can lower the uncertainty of the local PM2.5 source apportionment and reginal collaborative actions can be of great use for pollution mitigation.

Maternal gestational diabetes and childhood adiposity risk from 6 to 8 years of age.

BACKGROUND/OBJECTIVE: Previous studies found conflicting results on the association between maternal gestational diabetes mellitus (GDM) and childhood overweight/obesity. This study was to assess the association between maternal GDM and offspring's adiposity risk from 6 to 8 years of age. METHODS: The present study longitudinally followed 1156 mother-child pairs (578 GDM and 578 non-GDM) at 5.9 ± 1.2 years postpartum and retained 912 mother-child pairs (486 GDM and 426 non-GDM) at 8.3 ± 1.6 years postpartum. Childhood body mass index (BMI), waist circumference, body fat and skinfold were measured using standardized methods. RESULTS: Compared with the counterparts born to mothers with normal glucose during pregnancy, children born to mothers with GDM during pregnancy had higher mean values of adiposity indicators (waist circumference, body fat, subscapular skinfold and suprailiac skinfold) at 5.9 and 8.3 years of age. There was a positive association of maternal GDM with changes of childhood adiposity indicators from the 5.9-year to 8.3-year visit, and ß values were significantly larger than zero: +0.10 (95% CI: 0.02-0.18) for z score of BMI for age, +1.46 (95% CI: 0.70-2.22) cm for waist circumference, +1.78% (95% CI: 1.16%-2.40%) for body fat, +2.40 (95% CI: 1.78-3.01) mm for triceps skinfold, +1.59 (95% CI: 1.10-2.09) mm for subscapular skinfold, and +2.03 (95% CI: 1.35-2.71) mm for suprailiac skinfold, respectively. Maternal GDM was associated with higher risks of childhood overweight/obesity, central obesity, and high body fat (Odd ratios 1.41-1.57 at 5.9 years of age and 1.73-2.03 at 8.3 years of age) compared with the children of mothers without GDM. CONCLUSIONS: Maternal GDM was a risk factor of childhood overweight/obesity at both 5.9 and 8.3 years of age, which was independent from several important confounders including maternal pre-pregnancy BMI, gestational weight gain, children's birth weight and lifestyle factors. This significant and positive association became stronger with age.

Effects of a Lifestyle Intervention in Young Women with GDM and Subsequent Diabetes.

The purpose of this study was to examine whether a 9-month intensive lifestyle intervention could lead to weight loss and improve cardiovascular risk factors among young women with both gestational diabetes mellitus (GDM) and newly diagnosed diabetes. A total of 83 young women, who had GDM and were subsequently diagnosed as type 2 diabetes at an average of 2.6 years after delivery, participated in a 9-month intensive lifestyle intervention and a follow-up survey at 6-9 years postintervention. After the 9-month intervention, these women had a weight loss of 2.90 kg (-4.02% of initial weight), decreased waist circumference (-3.12 cm), body fat (-1.75%), diastolic blood pressure (-3.49 mmHg), fasting glucose (-0.98 mmol/L) and HbA1c (-0.72%). During the 6-9 years postintervention period, they still had lower weight (-3.71 kg; -4.62% of initial weight), decreased waist circumference (-4.56 cm) and body fat (-2.10%), but showed a slight increase in HbA1c (0.22%). The prevalence of using glucose-lowering agents increased from 2.4% at baseline to 34.6% after the 9-month lifestyle intervention, and to 48.4% at 6-9 years postintervention. A 9-month intensive lifestyle intervention can produce beneficial effects on body weight, HbA1c and other cardiovascular risk factors among young women with previous GDM who subsequently developed new diabetes.

Relationship between gestational body mass index change and the risk of gestational diabetes mellitus: a community-based retrospective study of 41,845 pregnant women.

BACKGROUND: Gestational diabetes mellitus (GDM) is associated with adverse health consequences for women and their offspring. It is associated with maternal body mass index (BMI) and may be associated with gestational weight gain (GWG). But due to the heterogeneity of diagnosis and treatment and the potential effect of GDM treatment on GWG, the association between the two has not been thoroughly clarified. Compared to body weight, BMI has the advantage that it considers height during the whole course of pregnancy. Understanding BMI changes during pregnancy may provide new evidence for the prevention of GDM. METHODS: This study investigated the BMI change of pregnant women based on a retrospective study covering all communities in Tianjin, China. According to the results of GDM screening at 24-28 weeks of gestation, pregnancies were divided into the GDM group and the non-GDM group. We compared gestational BMI change and GWG in the two groups from early pregnancy to GDM screening. GWG was evaluated according to the IOM guidelines. Logistic regression was applied to determine the significance of variables with GDM. RESULTS: A total of 41,845 pregnant women were included in the final analysis (GDM group, n = 4257 vs. non-GDM group, n = 37,588). BMI gain has no significant differences between the GDM and non-GDM groups at any early pregnancy BMI categories (each of 2 kg/m2), as well as weight gain (P > 0.05). Early pregnancy BMI was a risk factor for GDM (OR 1.131, 95% CI 1.122-1.139). And BMI gain was associated with a decreased risk of GDM in unadjusted univariate analysis (OR 0.895, 95% CI 0.869-0.922). After adjusting on early pregnancy BMI and other confounding factors, the effect of BMI gain was no longer significant (AOR 1.029, 95% CI 0.999-1.061), as well as weight gain (AOR 1.006, 95% CI 0.995-1.018) and GWG categories (insufficient: AOR 1.016, 95% CI 0.911-1.133; excessive: AOR 1.044, 95% CI 0.957-1.138). CONCLUSIONS: BMI in early pregnancy was a risk factor for GDM, while BMI gain before GDM screening was not associated with the risk of GDM. Therefore, the optimal BMI in early pregnancy is the key to preventing GDM.

Study Design and Baseline Profiles of Participants in the Tianjin Birth Cohort (TJBC) in China.

BACKGROUND: To investigate the causal link between early-life exposures and long-term health consequences, we established the Tianjin Birth Cohort (TJBC), a large-scale prospective cohort in northern China. METHODS: TJBC aims to enroll 10,000 families with follow-ups from pregnancy until children's six year-old. Pregnant women and their spouses were recruited through a three-tier antenatal healthcare system at early pregnancy, with follow-ups at mid-pregnancy, late pregnancy, delivery, 42 days after delivery, 6 months after delivery, and each year until 6 years old. Antenatal/neonatal examination, biological samples and questionnaires were collected. RESULTS: From August 2017 to January 2019, a total of 3,924 pregnant women have already been enrolled, and 1,697 women have given birth. We observed the prevalence of gestational diabetes mellitus as 18.1%, anemia as 20.4%, and thyroid hypofunction as 2.0%. In singleton live births, 5.6% were preterm birth (PTB), 3.7% were low birth weight, and 7.3% were macrosomia. Based on current data, we also identified maternal/paternal factors which increased the risk of PTB, including paternal age (OR 1.07; 95% CI, 1.01-1.14 for each year increase), vaginal bleeding during pregnancy (OR 2.82; 95% CI, 1.54-5.17) and maternal early-pregnancy BMI (OR 1.08; 95% CI, 1.01-1.15 for each kg/m2 increase). CONCLUSION: TJBC has the strength of collecting comprehensive maternal, paternal, and childhood information. With a diverse range of biological samples, we are also engaging with emerging new technologies for multi-omics research. The study would provide new insight into the causal link between macro/micro-environmental exposures of early life and short/long-term health consequences.

Association of leukocyte counts in the first trimester with glucose intolerance during pregnancy.

AIMS/INTRODUCTION: We investigated the association between leukocyte counts and glucose challenge test (GCT) level during pregnancy. MATERIALS AND METHODS: We collected prenatal information of women who had their first clinic visit in early pregnancy. Women underwent GCT at 24-28 gestational weeks, and a result of ≥7.8 mmol/L was considered positive. Participants were divided into quartiles of leukocyte counts, and association with GCT results and positive rate were analyzed by logistic regression. RESULTS: Among 20,707 pregnant women, the median of leukocyte counts was higher in the positive group than the normal group (8.5 × 109 /L vs 8.2 × 109 /L, P < 0.01). There was a linear trend in GCT results and positive rate with increasing leukocyte quartiles. Compared with the lowest quartile, the highest leukocyte quartile (>9.70 × 109 /L) was significantly associated with positive GCT results (adjusted odds ratio 1.378, 95% confidence interval 1.246-1.524), and the linear relationship between increased risk of positive result and increasing leukocyte quartiles persisted (P for linear trend <0.01). In multivariable analysis, the risk of a positive result increased by 2.2% with each 1-unit increase in leukocyte counts (adjusted odds ratio 1.022, 95% confidence interval 1.011-1.033). CONCLUSIONS: Elevated leukocyte counts in early pregnancy were independently and linearly associated with the risk of positive GCT levels, indicating that inflammation might play an important role in the development of gestational diabetes mellitus.

Novel epigenetic link between gestational diabetes mellitus and macrosomia.

Background & objectives: Examine maternal gestational diabetes mellitus (GDM), macrosomia and DNA methylation in candidate genes IGF1, IGF2, H19, ARHGRF11, MEST, NR3C1, ADIPOQ and RETN. Materials & methods: A total of 1145 children (572 GDM cases and 573 controls) from the Tianjin GDM study, including 177 with macrosomia, had blood DNA collection at median age 5.9 (range: 3.1-10.0). We used logistic regression to screen for associations with GDM and model macrosomia on 37 CpGs, and performed mediation analysis. Results: One CpG was associated with macrosomia at false discovery rate (FDR) <0.05 (cg14428359 in MEST); two (cg19466922 in MEST and cg26263166 in IGF2) were associated at p < 0.05 but mediated 26 and 13%, respectively. Conclusion:MEST and IGF2 were previously identified for potential involvement in fetal growth and development (Trial Registration number: NCT01554358 [ClinicalTrials.gov]).

Lay abstract Many women who get gestational diabetes during pregnancy go on to give birth to larger (macrosomic) babies. These babies then grow up to have greater risk of being overweight or obese, and all the health concerns this entails. We sought to examine whether epigenetic factors could help explain this link, by examining the blood of some children whose mothers were enrolled in a gestational diabetes study in China. We identified three sites on two different genes as being associated with both gestational diabetes and macrosomia. The way these genes work suggest a mechanism for how they contribute to macrosomia, providing a promising new avenue for future research, early detection and precision prevention (Trial Registration number: NCT01554358 [ClinicalTrials.gov]).

Maternal gestational diabetes and childhood hyperlipidemia.

AIMS: Aim of this study is to assess dyslipidemia risk between children exposed to maternal gestational diabetes mellitus (GDM) and those not exposed. METHODS: We recruited 1144 mother-child pairs (572 GDM and 572 non-GDM women matched by their offspring's age and sex). The age of offspring ranged from 3 to 9 years old. We used general linear models to compare mean values of different lipid profiles among children born to mothers with and without GDM. Logistic regression models were used to assess associations of maternal GDM with abnormal lipid profiles in offspring. RESULTS: After adjustment for maternal and children's characteristics, children born to mothers with GDM had lower mean values of high-density-lipoprotein (HDL) cholesterol (1.40 ± 0.01 vs. 1.50 ± 0.01; p < 0.001) and higher mean levels of triglycerides/HDL cholesterol ratio (0.37 ± 0.01 vs. 0.35 ± 0.01; p < 0.05) in comparison with their counterparts born to mothers without GDM. Multivariate-adjusted odds ratios among children exposed to mothers with GDM compared with the counterparts were 2.11 (95% confidence interval [CI 1.15-3.88]) for low HDL cholesterol and 1.35 (95% CI 1.00-1.81) for high triglycerides/HDL cholesterol ratio, respectively. CONCLUSIONS: Maternal GDM was associated with an increased risk of hyperlipidemia in the offspring during early childhood aged from 3 to 9 years old.

Risks of Macrosomia Associated with Catechol-O-Methyltransferase Genotypes and Genetic-Epigenetic Interactions among Children with and without Gestational Diabetes Exposure.

Background: Gestational diabetes mellitus (GDM) is a major macrosomia risk factor. Variations in the catechol-O-methyltransferase (COMT; rs4680) genotypes are associated with heightened susceptibility to environmental exposures and nutritional conditions. However, macrosomia risks associated with COMT genetics, epigenetics, and the interaction between genetic and epigenetics among children with and without exposure to GDM are unknown. Methods: Data from women/children pairs (n = 1087) who participated in the Tianjin Gestational Diabetes Birth Cohort were used to examine the odds of being born with macrosomia associated with COMT-genotypes, 55 CpG sites located on the COMT gene, and genetic and epigenetic interactions. Odds of macrosomia associated with COMT genetic, epigenetic, genetic and epigenetic interactions, and moderations with GDM were tested using adjusted logistic regression models. Results: Overall, 16.1% (n = 175) of children were born with macrosomia. Models showed that children with at least one copy of the minor allele (A) had higher odds of macrosomia (odds ratio, 1.82; 95% confidence interval 1.25-2.64) compared with children with the GG-genotype. After false discovery rate corrections, none of the 55 CpG sites located on the COMT gene was associated with odds of macrosomia. The genetic and epigenetic associations were not modified by exposure to GDM. Conclusion: Findings suggest carriers of the COMT GG-genotype had lower odds of macrosomia, and this association was not modified by epigenetics or exposure to GDM.

Impacts of primary emissions and secondary aerosol formation on air pollution in an urban area of China during the COVID-19 lockdown.

Restrictions on human activities were implemented in China to cope with the outbreak of the Coronavirus Disease 2019 (COVID-19), providing an opportunity to investigate the impacts of anthropogenic emissions on air quality. Intensive real-time measurements were made to compare primary emissions and secondary aerosol formation in Xi'an, China before and during the COVID-19 lockdown. Decreases in mass concentrations of particulate matter (PM) and its components were observed during the lockdown with reductions of 32-51%. The dominant contributor of PM was organic aerosol (OA), and results of a hybrid environmental receptor model indicated OA was composed of four primary OA (POA) factors (hydrocarbon-like OA (HOA), cooking OA (COA), biomass burning OA (BBOA), and coal combustion OA (CCOA)) and two oxygenated OA (OOA) factors (less-oxidized OOA (LO-OOA) and more-oxidized OOA (MO-OOA)). The mass concentrations of OA factors decreased from before to during the lockdown over a range of 17% to 58%, and they were affected by control measures and secondary processes. Correlations of secondary aerosols/ΔCO with Ox (NO2 + O3) and aerosol liquid water content indicated that photochemical oxidation had a greater effect on the formation of nitrate and two OOAs than sulfate; however, aqueous-phase reaction presented a more complex effect on secondary aerosols formation at different relative humidity condition. The formation efficiencies of secondary aerosols were enhanced during the lockdown as the increase of atmospheric oxidation capacity. Analyses of pollution episodes highlighted the importance of OA, especially the LO-OOA, for air pollution during the lockdown.

Prenatal gestational diabetes mellitus exposure and accelerated offspring DNA methylation age in early childhood.

Background: We investigated the association between prenatal GDM exposure and offspring DNA methylation (DNAm) age at 3-10 years of age in the Tianjin GDM Observational Study. Methods: This study included 578 GDM and 578 non-GDM mother-child pairs. Children underwent an exam with anthropometric measurements and blood draw for DNAm analysis (Illumina 850 K array) at a median age of 5.9 years (range 3.1-10.2). DNAm age was calculated using two epigenetic clock algorithms (Horvath and Hannum). The residual resulting from regressing DNAm age on chronological age was used as a metric for age acceleration. Results: Chronological age was positively correlated with Horvath DNAm age (r = 0.53, p < 0.0001) and Hannum DNAm age (r = 0.38, p < 0.0001). Offspring age acceleration was higher in the GDM group than non-GDM group after adjustment for potential confounders (Horvath: 4.96 months higher, adjusted for sex, pre-pregnancy BMI, cell-type proportions, and technical bias, p = 0.0002; Hannum: 11.2 months higher, adjusted for cell-type proportions and technical bias, p < 0.0001). Increased offspring DNAm age acceleration was associated with increased offspring weight-for-age Z-score, BMI-for-age-Z-score, waist circumference, body fat percentage, subscapular skinfold, suprailiac skinfold, upper-arm circumference, and blood pressure; findings were stronger in the GDM group. Conclusions: We found that offspring of women with GDM exhibit accelerated epigenetic age compared to control participants, independent of other maternal factors. Epigenetic age in offspring was associated with cardiometabolic risk factors, suggesting that GDM and GDM-associated factors may have long-term effects on offspring epigenetic age and contribute to health outcomes.

Maternal GDM Status, Genetically Determined Blood Glucose, and Offspring Obesity Risk: An Observational Study.

OBJECTIVE: The purpose of this study was to estimate the associations of genetically determined maternal blood glucose levels with obesity-related outcomes among children from pregnancies with and without gestational diabetes mellitus (GDM). METHODS: A total of 1,114 mothers with (N = 560) and without (N = 554) GDM and their children were included in the present study. A maternal genetic risk score (GRS) for blood glucose was constructed on the basis of 17 single-nucleotide polymorphisms identified from a recent genome-wide association study. RESULTS: It was found that maternal GRS for blood glucose showed different associations with offspring risk of overweight and obesity, as well as adiposity measures (all P for interaction < 0.05). Among mothers without GDM, genetically determined maternal blood glucose levels were associated with an 89% higher risk of overweight in their children (95% CI: 42%-152% per SD increase in GRS, P = 1.40 × 10-5 ) and a 120% higher risk of obesity (44%-235%, P = 2.61 × 10-4 ) after adjustment for covariates. In addition, higher maternal GRS for blood glucose was associated with children's increased obesity-related traits (all P < 0.05). However, no significant associations were observed among children of mothers with GDM. CONCLUSIONS: This study indicates that GDM status may modify the relation between genetically determined glucose levels and obesity risk among children.

ß-Cell function or insulin resistance was associated with the risk of type 2 diabetes among women with or without obesity and a history of gestational diabetes.

INTRODUCTION: To evaluate the single association of postpartum ß-cell dysfunction and insulin resistance (IR), as well as different combinations of postpartum ß-cell dysfunction, IR, obesity, and a history of gestational diabetes mellitus (GDM) with postpartum type 2 diabetes risk. RESEARCH DESIGN AND METHODS: The study included 1263 women with prior GDM and 705 women without GDM. Homeostatic model assessment was used to estimate homeostatic model assessment of ß-cell secretory function (HOMA-%ß) and homeostatic model assessment of insulin resistance (HOMA-IR). RESULTS: Multivariable-adjusted ORs of diabetes across quartiles of HOMA-%ß and HOMA-IR were 1.00, 1.46, 2.15, and 6.25 (ptrend <0.001), and 1.00, 2.11, 5.59, and 9.36 (ptrend <0.001), respectively. Women with IR only had the same diabetes risk as women with ß-cell dysfunction only. Obesity, together with IR or ß-cell dysfunction, had a stronger effect on diabetes risk. This stronger effect was also found for a history of GDM with IR or ß-cell dysfunction. Women with three risk factors, including obesity, a history of GDM and ß-cell dysfunction/IR, showed the highest ORs of diabetes. CONCLUSIONS: ß-cell dysfunction or IR was significantly associated with postpartum diabetes. IR and ß-cell dysfunction, together with obesity and a history of GDM, had the highest ORs of postpartum diabetes risk.

Effects of rapid growth in early childhood on metabolic and cardiovascular diseases among preschool-aged children.

BACKGROUND AND OBJECTIVES: To investigate whether the tempo of weight gain of children during infancy (from birth up to two years of age) or childhood (between two and five years old) is associated with metabolic and cardiovascular disease. METHODS AND STUDY DESIGN: Cluster sampling was employed to obtain a random sample of preschool children. In total, 1450 children aged five to six years participated in this survey. We obtained data on body weight, height, blood pressure (BP), and serum levels of total cholesterol, triglycerides, glucose, and uric acid, as well as anthropometry at birth and at age 2. RESULTS: The prevalence of obesity at five years old was 14.5%. At five years of age, children with rapid growth (change in body mass index, BMI z-score >0.67) during infancy had a higher odds ratio (OR) of childhood obesity (OR: 2.97 [95% CI: 2.15-4.11]) compared to children with non-rapid growth (change in BMI z-score ≤0.67). Also, children with rapid growth during childhood had a higher OR of childhood obesity (OR: 17.90 [95% CI: 12.31-26.04]), higher systolic BP (OR: 2.38 [95% CI: 1.68-3.39]), higher diastolic BP (OR: 2.42 [95% CI: 1.53-3.83]), and higher triglycerides (OR: 4.09 [95% CI: 1.47-11.33]) or hyperuricemia (OR: 2.23 [95% CI: 1.51-3.29]). CONCLUSIONS: Rapid growth in early childhood is associated with risk factors for both cardiovascular outcomes and metabolic outcomes among preschool children. Developing effective prevention and intervention programs for pre-school children might be important to reduce incidence of long-term metabolic and cardiovascular disease as adults.

Maternal Gestational Diabetes Mellitus Modifies the Relationship Between Genetically Determined Body Mass Index During Pregnancy and Childhood Obesity.

OBJECTIVE: To analyze the interactions between maternal gestational diabetes mellitus (GDM) and genetically determined maternal body mass index (BMI) during pregnancy on offspring childhood obesity. RESEARCH DESIGN AND METHODS: A total of 1114 Chinese mother-child pairs (560 GDM and 554 non-GDM) were included between August 2009 and July 2011. Maternal genetic risk score (GRS) of BMI during pregnancy was derived on the basis of 12 single nucleotide polymorphisms identified from a genome-wide association study. Offspring's BMI, BMI-for-age z score, weight, weight-for-age z score, waist circumference, sum of skinfolds, and body fat percentage during childhood were measured or calculated. RESULTS: Maternal GRS of BMI during pregnancy significantly interacted with maternal GDM status on childhood risks of overweight and obesity (all P for interaction <.05). After multivariable adjustment, per unit of GRS was associated with a 24% (P<.001) and a 28% (P<.001) increased risk of overweight and obesity among children of GDM mothers, whereas no significant associations were observed among children of mothers without GDM. In addition, per unit GRS of BMI during pregnancy was significantly associated with 0.16 kg/m2 higher BMI (P=.002), 0.09 higher BMI-for-age z score (P=.002), 0.24 kg higher weight (P=.04), 0.06 higher weight-for-age z score (P=.02), 0.28 cm higher waist circumference (P=.03), 0.94 mm higher sum of skinfolds (P=.004), and 0.37% higher body fat percentage (P=.03) among children of GDM mothers. There were no significant associations between maternal GRS of BMI during pregnancy and offspring's obesity-related outcomes among children of mothers without GDM. CONCLUSION: Our findings for the first time indicate that maternal GDM status may modify the relation between genetically determined maternal BMI during pregnancy and offspring's obesity risk during childhood.

Daily Branched-Chain Amino Acid Intake and Risks of Obesity and Insulin Resistance in Children: A Cross-Sectional Study.

OBJECTIVE: This study aimed to investigate the association of daily branched-chain amino acid (BCAA) intake with the risks of obesity and insulin resistance in children of mothers with gestational diabetes mellitus (GDM). METHODS: Daily BCAA intake was calculated by using a validated food frequency questionnaire in 996 children of mothers with GDM. The odds ratios (ORs) (95% CI) of childhood obesity and insulin resistance were obtained using logistic regression models. RESULTS: The multivariable-adjusted ORs for overweight and insulin resistance increased across quartiles of daily BCAA intake (P < 0.05 for trend). Multivariable-adjusted ORs for each 1-SD increase in BCAA intake were 1.37 (1.16-1.62) for overweight and 1.19 (1.02-1.38) for insulin resistance. After additional adjustment of children's daily total energy intake, the OR was still significant for overweight risk but no longer significant for insulin resistance. There were positive associations of daily leucine, isoleucine, and valine intake with the risks for overweight and insulin resistance. CONCLUSIONS: Daily BCAA intake was associated with increased risks for overweight and insulin resistance in children of mothers with GDM, but this association was not fully independent of children's daily energy intake. Restriction in dietary BCAA may help prevent childhood obesity and insulin resistance.

Glucose metabolism among obese and non-obese children of mothers with gestational diabetes.

OBJECTIVES: Abdominal obesity is more closely associated with diabetes than general obesity in adults, however, it is unknown which kind of obesity is more closely associated with abnormal glucose metabolism in children. RESEARCH DESIGN AND METHODS: We recruited 973 children (aged 3.08±1.06) of mothers with prior gestational diabetes mellitus (GDM). Children's height, weight, waist circumstance, fasting glucose and insulin were measured using standardized methods. Logistic regression models were used to assess the single and joint associations of general and abdominal obesity with the risks of hyperglycemia (the upper quartile of fasting glucose), insulin resistance (the upper quartile of homeostatic model assessment of insulin resistance (HOMA-IR)), and ß-cell dysfunction (the lower quartile of HOMA-%ß). RESULTS: Compared with normal weight children, children with general overweight/obesity had higher levels of HOMA-IR and HOMA-%ß, higher ORs for hyperglycemia (1.56, 95% CI 1.06 to 2.30) and insulin resistance (3.44, 95% CI 2.32 to 5.09), but a lower OR for ß-cell dysfunction (0.65, 95% CI 0.41 to 1.04). Children with abdominal obesity had an increased risk of insulin resistance (2.54, 95% CI 1.71 to 3.76) but not hyperglycemia and ß-cell dysfunction compared with children with normal waist circumstance. In the joint analyses, general overweight children with and without abdominal obesity had an increased risk of hyperglycemia and insulin resistance compared with normal weight children. CONCLUSIONS: General obesity was more closely associated with abnormal glucose metabolism than abdominal obesity in children of mothers with GDM.