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.

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.

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.

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.

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.

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.

Nomograms for incident risk of post-partum type 2 diabetes in Chinese women with prior gestational diabetes mellitus.

OBJECTIVE: Counselling patients with gestational diabetes mellitus (GDM) on their individual risk of post-partum type 2 diabetes (T2D) is challenging. This study aimed to develop nomograms for predicting incident risk of post-partum T2D in women with GDM diagnosed by WHO 1998 criteria. METHODS: We performed a retrospective cohort study in 1263 Chinese women with GDM, of whom 83 were diagnosed as T2D at 2.3 years post-partum. Multivariate Cox proportional hazards models were used to investigate the independent predictors for post-partum T2D. The results of multivariate analyses were used to formulate nomograms for predicting incident risk of post-partum T2D. The predictive accuracy was evaluated using the area under the receiver operating characteristic curve (AUROC). RESULTS: On multivariate analysis, independent predictors of post-partum T2DM in women with GDM included family history of diabetes [hazard ratio (HR) and its 95% confidential interval (95% CI): 2.06 (95% CI: 1.32-3.22)], history of pregnancy-induced hypertension [3.11 (95% CI: 1.86-5.21)], pre-pregnancy BMI [1.00, 1.90 (95% CI: 1.14-3.16), and 3.67 (95% CI: 2.03-6.63) for BMI <24, 24-28, and ≥28 kg/m2 ], and 2-hour glucose at 26-30 gestational weeks [1.00, 2.84 (95% CI: 1.42-5.69), and 9.42 (95% CI: 4.46-19.90) for 2-hour glucose at 7.8 ~ <8.5, 8.5 ~ <11.1, and ≥11.1 mmol/L). The overall AUROC of nomogram was 82.8% (95% CI: 78.1%-87.5%), with AUROCs of 85.9% (95% CI: 79.7%-92.1%) and 83.2% (95% CI: 77.9%-88.6%) for post-partum 2-year and 3-year risk of T2D, respectively. CONCLUSIONS: This easy-to-use nomogram, with non-invasive clinical characteristics, can accurately predict the risk of post-partum T2D in women with GDM. It may facilitate risk communication between patients and clinicians.

Lactation intensity and duration to postpartum diabetes and prediabetes risk in women with gestational diabetes.

OBJECTIVE: To investigate the association of lactation intensity and duration with postpartum diabetes and prediabetes risks among Chinese women with a history of gestational diabetes (GDM). METHODS: We included 1260 women with a history of GDM who participated in the whole population's GDM universal screening survey by using the 1999 World Health Organization's criteria. Lactation intensity and lactation duration were collected by a standardized questionnaire. Postpartum diabetes and prediabetes risk were confirmed by an oral glucose tolerance test. RESULTS: During a mean postpartum period of 3.65 years, we identified 114 cases of diabetes and 417 cases of prediabetes. The multivariable-adjusted hazard ratios based on different lactation intensity (exclusive formula, mixed feeding, and exclusive lactation) were 1.00, 0.68, 0.45 for diabetes (Ptrend  = 0.008), and 1.00, 0.74, and 0.61 for prediabetes (Ptrend  = 0.006), respectively. The multivariable-adjusted hazard ratios associated with different lactation duration (none, 0-6 months, 6-12 months, 12-18 months, and ≥18 months) were 1.00, 0.66, 0.42, 0.66, and 0.25 for diabetes (Ptrend  = 0.013), and 1.00, 0.82, 0.62, 0.67, and 0.63 for prediabetes (Ptrend  = 0.021), respectively. A restricted cubic spline curve showed a graded inverse association of lactation duration with the risks of diabetes and prediabetes (Ptrend  < 0.001). CONCLUSIONS: Higher-lactation intensity and longer-lactation duration were significantly associated with lower risks of postpartum diabetes and prediabetes among Chinese women with a history of GDM.

One-year weight losses in the Tianjin Gestational Diabetes Mellitus Prevention Programme: A randomized clinical trial.

AIMS: To report the weight loss findings after the first year of a lifestyle intervention trial among women with gestational diabetes mellitus (GDM). METHODS: A total of 1180 women with GDM were randomly assigned (1:1) to receive a 4-year lifestyle intervention (intervention group, n = 586) or standard care (control group, n = 594) between August 2009 and July 2011. Major elements of the intervention included 6 face-to-face sessions with study dieticians and two telephone calls in the first year, and two individual sessions and two telephone calls in each subsequent year. RESULTS: Among 79% of participants who completed the year 1 trial, mean weight loss was 0.82 kg (1.12% of initial weight) in the intervention group and 0.09 kg (0.03% of initial weight) in the control group (P = .001). In a prespecified subgroup analysis of people who completed the trial, weight loss was more pronounced in women who were overweight (body mass index ≥24 kg/m2 ) at baseline: mean weight loss 2.01 kg (2.87% of initial weight) in the intervention group and 0.44 kg (0.52% of initial weight) in the control group (P < .001). Compared with those in the control group, women in the intervention group had a greater decrease in waist circumference (1.76 cm vs 0.73 cm; P = .003) and body fat (0.50% vs 0.05% increase; P = .001). CONCLUSION: The 1-year lifestyle intervention led to significant weight losses after delivery in women who had GDM, and the effect was more pronounced in women who were overweight at baseline.

Effects of the interaction between glycated haemoglobin genetic risk score and postpartum weight reduction on glycaemic changes: A gene-weight interaction analysis.

AIM: To investigate the effects of the interaction between glycated haemoglobin (HbA1c) genetic risk score and weight changes during and after pregnancy (postpartum weight reduction and gestational weight gain) on long-term glycaemic changes in the largest cohort of women with a history of gestational diabetes mellitus (GDM). METHODS: This was a retrospective cohort using the baseline data from the Tianjin Gestational Diabetes Mellitus Prevention Programme. A genetic risk score was established by combining 10 HbA1c-related single-nucleotide polymorphisms, which were identified by genome-wide association studies. General linear regression models were applied to evaluate the effect of interaction between HbA1c genetic risk score and weight changes during and after pregnancy (postpartum weight reduction and gestational weight gain) on glycaemic changes. RESULTS: 'A total of 1156 women with a history of GDM were included in this respective cohort study. Statistical differences in pre-pregnancy weight, pre-delivery weight and postpartum weight were evidenced across different groups of postpartum weight reduction. After adjusting for covariates, statistical significance for changes in HbA1c level was only observed in the postpartum weight reduction <5 kg/y group (P = 0.002), and a significant effect of interaction between HbA1c genetic risk score and postpartum weight reduction on long-term changes in HbA1c was evidenced (P interaction = 0.01). In women with postpartum weight reduction ≥8 kg/y, those with a lower HbA1c genetic risk score had a greater decrease in HbA1c level. CONCLUSIONS: HbA1c genetic risk score interacts with postpartum weight reduction to affect long-term changes in HbA1c levels among women with a history of GDM.

Design and baseline characteristics of a population-based study of eye disease in southern Chinese people: the Dongguan Eye Study.

BACKGROUND: To describe the study design, methodology and baseline characteristics of the Dongguan Eye Study. DESIGN: Population-based, cross-sectional study PARTICIPANTS: A total of 8952 rural-dwelling residents aged 40 years or older in Hengli, Dongguan. METHODS: The Dongguan Eye Study was conducted from September 2011 to February 2012. The interview covered demographic data, socio-economic status and health- and vision-related quality of life. Physical measurements included height, weight, waist and hip circumference, heart rate and blood pressure. Laboratory tests included fasting blood glucose, haemoglobin A1c, oral glucose tolerance, serum total cholesterol, triglycerides, high-density lipoprotein-cholesterol, low-density lipoprotein-cholesterol, serum creatinine, blood urea nitrogen and uric acid. Ophthalmic examinations included visual acuity and autorefraction testing, intraocular pressure measurement, slit-lamp examination, ocular biometry, gonioscopy, fundus photography, retinal nerve fibre layer imaging and visual field testing. MAIN OUTCOME MEASURES: Prevalence and risk factors for visual impairment, blindness, eye diseases and their associations with systemic medical indicators or health-related lifestyles, as well as epidemiological data on diabetic subjects. Methodology, response rates and baseline characteristics are presented. RESULTS: Of the 11 357 individuals eligible for the Dongguan Eye Study, 8952 (78.82%) subjects participated. All participants were self-identified Han Chinese. The average age was 54.0 years, 59.9% were female, 48.4% were farmers and 77.2% had elementary or junior middle school educational levels. The average body mass index and waist-hip ratio were 24.6 ± 3.9 kg/m(2) and 0.9 ± 0.2. CONCLUSIONS: Data from the Dongguan Eye Study provide information concerning the prevalence, risk factors and impacts of eye diseases in rural residents undergoing urbanization in southern China.

Pregnancy outcomes of Chinese women with gestational diabetes mellitus defined by the IADPSG's but not by the 1999 WHO's criteria.

OBJECTIVE: To compare pregnancy outcomes of women with gestational diabetes mellitus (GDM) newly defined by the International Association of Diabetes and Pregnancy Study Group (IADPSG)'s criteria vs GDM cases missed by a shift from the 1999 World Health Organization (WHO)'s criteria to the IADPSG's. METHODS: From 2010 to 2012, we recruited 17 808 women who registered within 12 weeks of gestation in Tianjin, China. All women underwent a 50-g 1-h glucose challenge test (GCT) at 24-28 weeks of gestation and further underwent a 75-g 2-h oral glucose tolerance test (OGTT) if the GCT result was ≥7·8 mmol/l. Women were divided into four groups, i.e., GDM defined by both criteria, GDM defined by the IADPSG's only, GDM defined by the 1999 WHO's only and non-GDM by either of them. Large for gestational age (LGA), macrosomia, pregnancy-induced hypertension (PIH) and preterm birth were compared among the four groups. Logistic regression was used to control for confounders. RESULTS: The use of IADPSG's and the 1999 WHO's criteria detected that 7·7% (n = 1378) and 6·8% (n = 1206) of women had GDM, respectively, with 429 GDM newly identified and 257 women missed by a shift from the 1999 WHO's to the IADPSG's. The IADPSG's newly defined GDM had significantly increased risks of LGA (adjusted OR: 2·23, 95%CI: 1·36-3·64) and macrosomia (2·65, 95%CI: 1·50-4·66) than the 1999 WHO's only defined GDM cases. CONCLUSIONS: A shift of the 1999 WHO's criteria to the IADPSG's diagnosed more GDM cases who had worse pregnancy outcomes than those cases missed.

[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.

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.

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.

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.

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.

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.

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]).