Songying Shen

Connections between the human gut microbiome and gestational diabetes mellitus

Abstract The human gut microbiome can modulate metabolic health and affect insulin resistance, and it may play an important role in the etiology of gestational diabetes mellitus (GDM). Here, we compared the gut microbial composition of 43 GDM patients and 81 healthy pregnant women via whole-metagenome shotgun sequencing of their fecal samples, collected at 21–29 weeks, to explore associations between GDM and the composition of microbial taxonomic units and functional genes. A metagenome-wide association study identified 154 837 genes, which clustered into 129 metagenome linkage groups (MLGs) for species description, with significant relative abundance differences between the 2 cohorts. Parabacteroides distasonis, Klebsiella variicola, etc., were enriched in GDM patients, whereas Methanobrevibacter smithii, Alistipes spp., Bifidobacterium spp., and Eubacterium spp. were enriched in controls. The ratios of the gross abundances of GDM-enriched MLGs to control-enriched MLGs were positively correlated with blood glucose levels. A random forest model shows that fecal MLGs have excellent discriminatory power to predict GDM status. Our study discovered novel relationships between the gut microbiome and GDM status and suggests that changes in microbial composition may potentially be used to identify individuals at risk for GDM.

Association between Temperature Change and Outpatient Visits for Respiratory Tract Infections among Children in Guangzhou, China

The current study examined the association between temperature change and clinical visits for childhood respiratory tract infections (RTIs) in Guangzhou, China. Outpatient records of clinical visits for pediatric RTIs, which occurred from 1 January 2012 to 31 December 2013, were collected from Guangzhou Women and Children’s Hospital. Records for meteorological variables during the same period were obtained from the Guangzhou Meteorological Bureau. Temperature change was defined as the difference between the mean temperatures on two consecutive days. A distributed lag non-linear model (DLNM) was used to examine the impact of temperature change on pediatric outpatient visits for RTIs. A large temperature decrease was associated with a significant risk for an RTI, with the effect lasting for ~10 days. The maximum effect of a temperature drop (−8.8 °C) was reached at lag 2~3 days. Children aged 0–2 years, and especially those aged <1 year, were particularly vulnerable to the effects of temperature drop. An extreme temperature decrease affected the number of patient visits for both upper respiratory tract infections (URTIs) and lower respiratory tract infections (LRTIs). A temperature change between consecutive days, and particularly an extreme temperature decrease, was significantly associated with increased pediatric outpatient visits for RTIs in Guangzhou.

Validity and Reproducibility of a Dietary Questionnaire for Consumption Frequencies of Foods during Pregnancy in the Born in Guangzhou Cohort Study (BIGCS)

This study aimed to examine the reproducibility and validity of a new food frequency questionnaire (FFQ) used in a birth cohort study to estimate the usual consumption frequencies of foods during pregnancy. The reference measure was the average of three inconsecutive 24 h diet recalls (24 HR) administrated between two FFQs, and the reproducibility was measured by repeating the first FFQ (FFQ1) approximately eight weeks later (FFQ2). A total of 210 pregnant women from the Born in Guangzhou Cohort Study (BIGCS) with full data were included in the analysis. The Spearman’s correlation coefficients of FFQ1 and FFQ2 ranged from 0.33 to 0.71. The intraclass correlation coefficients of the two FFQs ranged from 0.22 to 0.71. The Spearman’s correlation coefficients of the 24 HR and FFQ2 ranged from 0.23 to 0.62. Cross-classification analysis showed 65.1% of participants were classified into same and contiguous quintiles, while only 3.2% were misclassified into the distant quintiles. Bland-Altman methods showed good agreement for most food groups across the range of frequencies between FFQ1 and FFQ2. Our findings indicated that the reproducibility and validity of the FFQ used in BIGCS for assessing the usual consumption frequencies of foods during pregnancy were acceptable.

Does tea consumption during early pregnancy have an adverse effect on birth outcomes

BACKGROUND Tea, a common beverage, has been suggested to exhibit a number of health benefits. However, one of its active ingredients, caffeine, has been associated with preterm birth and low birthweight. We investigated whether tea consumption during early pregnancy is associated with an increased risk of preterm birth and abnormal fetal growth. METHODS A total of 8775 pregnant women were included from the Born in Guangzhou Cohort Study. Tea consumption (type, frequency, and strength) during their first trimester and social and demographic factors were obtained by way of questionnaires administered during pregnancy. Information on birth outcomes and complications during pregnancy was obtained from hospital medical records. RESULTS Overall habitual tea drinking (≥1 serving/week) prevalence among pregnant women was low, at 16%. After adjustment for potential confounding factors (eg, maternal age, educational level, monthly income) tea drinking during early pregnancy was not associated with an increased risk of preterm birth or abnormal fetal growth (small or large for gestational age) (P>.05). CONCLUSIONS We did not identify a consistent association between frequency of tea consumption or tea strength and adverse birth outcomes among Chinese pregnant women with low tea consumption. Our findings suggest that occasional tea drinking during pregnancy is not associated with increased risk of preterm birth or abnormal fetal growth. Given the high overall number of annual births in China, our findings have important public health significance.

Effect of Financially Punished Audit and Feedback in a Pediatric Setting in China, within an Antimicrobial Stewardship Program, and as Part of an International Accreditation Process

Background Prior authorization, audit and feedback, and pay for performance are the three core “active” strategies of antimicrobial stewardship program (ASP), yet little is known about the individual or combined benefits of such programs, particularly in a pediatric setting. Objectives The aim of this study was to compare these core ASP strategies and determine the incremental effect of financially punished audit and feedback. Methods During the journey to the Joint Commission International accreditation, a tertiary pediatric medical center performed two different hospital-wide stewardship interventions in succession. The first stage without formalized ASPs served as pre-intervention period, January 2011 to April 2011. The ASP used prior authorization alone during the first-intervention period, May 2011 to September 2011. In October 2011, financially punished audit and feedback was introduced, marking the start of the second-intervention period, October 2011 to November 2012. We compared the differences of the change in monthly average use of antibiotics and expenditure on antibiotics before and after the ASP changes by using interrupted time series via dynamic regression. The main end points included the proportions of antibiotic prescriptions and expenditure on antibacterial relative to all medications. Results Before the second-intervention period, neither the proportion of antibiotic prescriptions nor the proportion of expenditure on antibiotics declined significantly in both ambulatory and inpatient settings. However, after the introduction of financially punished audit and feedback, the proportion of both antibiotic prescriptions (β = −6.269, P < 0.001, and reduction = 59.4% for outpatients; β = −1.235, P < 0.001, and reduction = 19.8% for inpatients) and expenditure on antibiotics (β = −7.777, P < 0.001, and reduction = 46.7% for outpatients; β = −4.933, P = 0.001, and reduction = 16.3% for inpatients) dropped immediately. Conclusion The combination of more than one core strategies (prior authorization, audit and feedback, and pay for performance) will be more effective than one strategy alone.

Progesterone use in early pregnancy: a prospective birth cohort study in China

Abstract Background The US Food and Drug Administration recommended that the use of progesterone to reduce the risk of preterm births in women with a previous preterm birth should begin after the 16th week of gestation. In the USA, even a 4·5% reported rate of progesterone use in the first trimester is regarded as a high prescription for unknown fetal risk. Unfortunately, we identified a 10 times higher prevalence of progesterone prescription in early pregnancy in an ongoing study, the Born in Guangzhou Cohort Study (BIGCS) in China. We aimed to investigate the potential effects of progesterone use in early pregnancy on maternal and birth outcomes. Methods 6617 pregnant women were included from the BIGCS between January, 2013, and January, 2015. Progesterone use during early pregnancy ( Findings 2787 (42%) women reported progesterone use in early pregnancy. After adjusting for potential confounders, women who used progesterone had significantly higher risks of caesarean section (odds ratio 1·31 [95% CI 1·05–1·63]; p=0·0146) and post-partum depression (1·22 [1·00–1·49]; p=0·0497). No effect of progesterone use was reported for preterm-birth prevention, fetal growth, and gestational diabetes. Interpretation Progesterone use in early pregnancy gives no benefit and even results in harm for specific pregnancy outcomes. In view of the high use rate in China, progesterone prescription in early pregnancy should be regarded as an urgent public health concern. Monitoring of clinic practice, study of long-term effects on health, and evidence-based policy are needed. Funding Guangzhou Science and Technology Bureau, Guangzhou, China (2011Y2-00025, 2012J5100038, and 201508030037).

Effect of Interpregnancy Interval on Adverse Perinatal Outcomes in Southern China: A Retrospective Cohort Study, 2000-2015.

BACKGROUND In January 2016, a universal two-child policy was introduced in China. The association of interpregnancy interval (IPI) with perinatal outcomes has not previously been assessed among Chinese population. We investigated the effect of IPI after live birth on the risks of preterm delivery, and small, and large for gestational age births in China. METHODS We conducted a cohort study among 227 352 Chinese women with their first and second delivery during 2000 to 2015. IPI was calculated as months from first live delivery to conception of the second pregnancy. Poisson regression models with robust variance were fit to evaluate associations of IPI with risk of adverse perinatal outcomes, adjusted for potential confounders. RESULTS Compared to IPI of 24- <30 months, IPI <18 months was associated with higher risks of preterm birth (PTB) and small for gestational age (SGA). For IPI <6 months, the adjusted relative risks (RR) for PTB and SGA were 2.04 (95% confidence interval [CI] 1.83, 2.27) and 1.43 (95% CI 1.31, 1.57), respectively. Women with IPI ≥60 months had higher risks of PTB and large for gestational age (LGA). For IPI ≥120 months, the adjusted RRs for PTB and LGA were 1.67 (95% CI 1.43, 1.94) and 1.10 (95% CI 0.97, 1.26). CONCLUSIONS Women with IPI <18 months after live birth had higher risk of PTB and SGA, and IPI ≥60 months was associated with higher risk of PTB and LGA. These findings may provide information to Chinese couples about the appropriate interpregnancy interval for a second pregnancy.

Predictions of Preterm Birth from Early Pregnancy Characteristics: Born in Guangzhou Cohort Study

Preterm birth (PTB, <37 weeks) is the leading cause of death in children <5 years of age. Early risk prediction for PTB would enable early monitoring and intervention. However, such prediction models have been rarely reported, especially in low- and middle-income areas. We used data on a number of easily accessible predictors during early pregnancy from 9044 women in Born in Guangzhou Cohort Study, China to generate prediction models for overall PTB and spontaneous, iatrogenic, late (34–36 weeks), and early (<34 weeks) PTB. Models were constructed using the Cox proportional hazard model, and their performance was evaluated by Harrell’s c and D statistics and calibration plot. We further performed a systematic review to identify published models and validated them in our population. Our new prediction models had moderate discrimination, with Harrell’s c statistics ranging from 0.60–0.66 for overall and subtypes of PTB. Significant predictors included maternal age, height, history of preterm delivery, amount of vaginal bleeding, folic acid intake before pregnancy, and passive smoking during pregnancy. Calibration plots showed good fit for all models except for early PTB. We validated three published models, all of which were from studies conducted in high-income countries; the area under receiver operating characteristic for these models ranged from 0.50 to 0.56. Based on early pregnancy characteristics, our models have moderate predictive ability for PTB. Future studies should consider inclusion of laboratory markers for the prediction of PTB.