Prenatal metal mixture exposure and birth weight: A two-stage analysis in two prospective cohort studies.

The understanding of the impact of prenatal exposure to metal mixtures on birth weight is limited. We aimed to identify metal mixture components associated with birth weight and to determine additional pairwise interactions between metals showing such associations. Concentrations of 18 metals were measured using inductively coupled plasma mass spectrometry in urine samples collected in the 3rd trimester from a prenatal cohort (discovery; n = 1849) and the Healthy Baby Cohort (replication; n = 7255) in Wuhan, China. In the discovery set, we used two penalized regression models, i.e., elastic net regression for main effects and a lasso for hierarchical interactions, to identify important mixture components associated with birth weight, which were then replicated. We observed that 8 of the 18 measured metals were retained by elastic net regression, with five metals (vanadium, manganese, iron, cesium, and barium) showing negative associations with Z-scores for birth weight and three metals (cobalt, zinc, and strontium) showing positive associations. In replication set, associations remained significant for vanadium (ß = -0.035; 95% confidence interval [CI], -0.059 to -0.010), cobalt (ß = 0.073; 95% CI, 0.049 to 0.097), and zinc (ß = 0.040; 95% CI, 0.016 to 0.065) after Bonferroni correction. We additionally identified and replicated a single pairwise interaction between iron and copper exposure on birth weight (P < 0.001). Using a two-stage analysis, we identified and replicated individual metals and additional pairwise interactions-associated birth weight. The approach could be used in other studies estimating the effect of complex mixtures on human health.

Long-term association of serum selenium levels and the diabetes risk: Findings from a case-control study nested in the prospective Jinchang Cohort.

An increasing body of evidence implicates high levels of selenium intake in the development of diabetes, although prospective studies remain sparse. We conducted a nested case-control study of 622 diabetes incident cases and 622-age, sex, and follow-up time-matched controls in the prospective Jinchang cohort of 48,001 participants with a median of 5.8 years of follow-up. Inductively coupled plasma mass spectrometry (ICP-MS) was used to measure all 622 case-control pairs' baseline serum levels of selenium (Se), which were then categorized into quartiles based on the frequency distribution among the controls. Multivariable adjusted conditional logistic regression and restricted cubic splines (RCS) models were applied to evaluate independent odds ratios (OR) as estimates for relative risks (RR) of diabetes according to quartiles (Q) of selenium levels. Compared to the lowest quartile (Q1 as reference), significantly greater diabetes risks (with 95% confidence interval) were observed in Q3 (OR = 1.62, 1.17-2.35) and Q4 (OR = 1.79, 1.21-2.64). Sub-analyses showed these increased risks of diabetes by serum levels of Se. appeared to differ by sex, age, BMI status, history of hypertension, and dyslipidemia. Further, application of RSC models showed that serum Se levels between 95 and 120 µg/L were significantly and positively associated with diabetes risk whereas no apparent relation exists when Se levels were under 95 µg/L in this cohort population.

Dataset of testicular germ cell tumors (TGCT) risk associated with serum polychlorinated biphenyl (PCB) by age at diagnosis and histologic types.

In a population-based case control study of testicular germ cell tumors (TGCT), we reported a strong positive association between serum levels of Wolff's Group 1 (potentially estrogenic) polychlorinated biphenyl (PCBs) and risk of TGCT, and the observed associations were similar for both seminoma and non-seminoma. While the observed specific associations between TGCT and Wolff's Group 1 PCBs cannot be easily explained by bias or confounding, a question can still be asked, that is, could the relationship between PCBs and TGCT differ by age at diagnosis? PCBs tend to bioaccumulate, with more heavily chlorinated PCB congeners tending to have longer half-lives. Half-lives of PCB congeners were reported ranging from 4.6 years for PCB-28 to 41.0 years for PCB-156. The half-life for the heavy PCB congeners (17.8 years) was found to be approximately twice that for the light PCBs (9.6 years) in early studies. Therefore, the same PCB concentration measured in a 20-year-old vs. a 55-year-old is unlikely to represent the same lifetime PCB exposure or type of PCB exposure. In this analysis, we stratified the data by median age of diagnosis of TGCT and further stratified by histologic type of TGCT (seminoma vs non-seminoma) to explore if the risk of TGCT associated with PCB exposures differs by age.

Serum polychlorinated biphenyl (PCB) levels and risk of testicular germ cell tumors: A population-based case-control study in Connecticut and Massachusetts.

The incidence rate of testicular germ cell tumors (TGCT) has continuously increased in Western countries over the last several decades. Some epidemiologic studies have reported that the endocrine disrupting polychlorinated biphenyls (PCBs) in serum may be associated with TGCT risk, but the evidence is inconsistent. Our goal was to investigate whether serum levels of PCBs are associated with the increase of TGCT risk. We conducted a population-based case-control study of 308 TGCT cases and 323 controls, all residents of Connecticut and Massachusetts. Serum levels of 56 PCBs congeners were measured using gas chromatography and unconditional logistic regression model was used to evaluate the risk of TGCT associated with total PCBs exposure, groups of PCBs categorized by Wolff's functional groups, and individual PCB congeners. The results showed that there was no association between total serum levels of PCBs and risk of TGCT overall (quartile 4 (Q4) vs. quartile 1 (Q1) odds ratio (OR) and 95% confidence interval (C.I.) = 1.0 (0.6-1.9), ρ trend = 0.9). However, strong positive association was observed between total serum levels of Wolff's Group 1 (potentially estrogenic) PCBs and risk of overall TGCT (Q4 vs. Q1 OR = 2.5, 95% CI = 1.3-4.7, ρ trend <0.05) as well as seminoma and non-seminoma subtypes. Wolff's Group 1 PCB congeners that showed an increased risk of TGCT included: 25, 44, 49, 52, 70, 101, 174, and 201/177. Considering the continuing increase of TGCT, these associations should be replicated in different populations with larger sample size.

Associations of Trimester-Specific Exposure to Bisphenols with Size at Birth: A Chinese Prenatal Cohort Study.

BACKGROUND: Bisphenol A (BPA) is an endocrine disruptor that affects fetal growth in experimental studies. Bisphenol F (BPF) and bisphenol S (BPS), which have been substituted for BPA in some consumer products, have also shown endocrine-disrupting effects in experimental models. However, the effects of BPF and BPS on fetal growth in humans are unknown. OBJECTIVES: Our goal was to investigate trimester-specific associations of urinary concentrations of BPA, BPF, and BPS with size at birth. METHODS: The present study included 845 pregnant women from Wuhan, China (2013-2015), who provided one urine sample in each of the first, second, and third trimesters. Linear regressions with generalized estimating equations were applied to estimate trimester-specific associations of urinary bisphenol concentrations with birth weight, birth length, and ponderal index. Linear mixed-effects models were used to identify potential critical windows of susceptibility to bisphenols by comparing the exposure patterns of newborns in the 10th percentile of each birth anthropometric measurement to that of those in the 90th percentile. RESULTS: Medians (25th-75th percentiles) of urinary concentrations of BPA, BPF, and BPS were 1.40 (0.19-3.85), 0.65 (0.34-1.39), and 0.38 (0.13-1.11) ng/mL, respectively. Urinary BPA concentrations in different trimesters were inversely, but not significantly, associated with birth weight and ponderal index. Urinary concentrations of BPF and BPS during some trimesters were associated with significantly lower birth weight, birth length, or ponderal index, with significant trend p-values (ptrend<0.05) across quartiles of BPF and BPS concentrations. The observed associations were unchanged after additionally adjusting for other bisphenols. In addition, newborns in the 10th percentile of each birth anthropometry measure had higher BPF and BPS exposures during pregnancy than newborns in the 90th percentile of each outcome. CONCLUSIONS: Prenatal exposure to BPF and BPS was inversely associated with size at birth in this cohort. Replication in other populations is needed. https://doi.org/10.1289/EHP4664.

The long-term rapid increase in incidence of adenocarcinoma of the kidney in the USA, especially among younger ages.

BACKGROUND: We previously observed a rapid increase in the incidence of renal cell carcinoma (RCC) in men and women between 1935 and 1989 in the USA, using data from the Connecticut Tumor Registry. This increase appeared to be largely explained by a positive cohort effect, but no population-based study has been conducted to comprehensively examine age-period-cohort effects by histologic types for the past decade. METHODS: We calculated age-adjusted and age-specific incidence rates of the two major kidney-cancer subtypes RCC and renal urothelial carcinoma, and conducted an age-period-cohort analysis of 114 138 incident cases of kidney cancer reported between 1992 and 2014 to the Surveillance, Epidemiology, and End Results programme. RESULTS: The age-adjusted incidence rates of RCC have been increasing consistently in the USA among both men and women (from 12.18/100 000 in 1992-1994 to 18.35/100 000 in 2010-2014 among men; from 5.77/100 000 in 1992-1994 to 8.63/100 000 in 2010-2014 among women). Incidence rates generally increased in successive birth cohorts, with a continuing increase in rates among the younger age groups (ages 0-54 years) in both men and women and among both Whites and Blacks. These observations were confirmed by age-period-cohort modelling, which suggested an increasing birth-cohort trend for RCC beginning with 1955 birth cohorts, regardless of the assumed value for the period effect for both men and women and for Whites and Blacks. CONCLUSIONS: Known risk factors for kidney cancer may not fully account for the observed increasing rates or the birth-cohort pattern for RCC, prompting the need for additional etiologic hypotheses (such as environmental exposures) to investigate these descriptive patterns.

Impact of the 2017 ACC/AHA Guideline for High Blood Pressure on Evaluating Gestational Hypertension-Associated Risks for Newborns and Mothers.

RATIONALE: In 2017, the American College of Cardiology (ACC)/American Heart Association (AHA) released a new hypertension guideline for nonpregnant adults, using lower blood pressure values to identify hypertension. However, the impact of this new guideline on the diagnosis of gestational hypertension and the associated maternal and neonatal risks are unknown. OBJECTIVE: To estimate the impact of adopting the 2017 ACC/AHA guideline on detecting gestational blood pressure elevations and the relationship with maternal and neonatal risk in the perinatal period using a retrospective cohort design. METHODS AND RESULTS: This study included 16 345 women from China. Systolic and diastolic blood pressures of each woman were measured at up to 22 prenatal care visits across different stages of pregnancy. Logistic and linear regressions were used to estimate associations of blood pressure categories with the risk of preterm delivery, early-term delivery, and small for gestational age, and indicators of maternal liver, renal, and coagulation functions during pregnancy. We identified 4100 (25.1%) women with gestational hypertension using the 2017 ACC/AHA guideline, compared with 4.2% using the former definition. Gestational hypertension, but not elevated blood pressure (subclinical blood pressure elevation), was significantly associated with altered indicators of liver, renal, and coagulation functions during pregnancy for mothers and increased risk of adverse birth outcomes for newborns; adjusted odds ratios (95% CIs) for gestational hypertension stage 2 were 2.23 (1.18-4.24) for preterm delivery, 2.05 (1.67-2.53) for early-term delivery, and 1.43 (1.13-1.81) for small for gestational age. CONCLUSIONS: Adopting the 2017 ACC/AHA guideline would result in a substantial increase in the prevalence of gestational hypertension; subclinical blood pressure elevations during late pregnancy were not associated with increased maternal and neonatal risk in this cohort. Therefore, the 2017 ACC/AHA guideline may improve the detection of high blood pressure during pregnancy and the efforts to reduce maternal and neonatal risk. Replications in other populations are required.

Effects of trimester-specific exposure to vanadium on ultrasound measures of fetal growth and birth size: a longitudinal prospective prenatal cohort study.

BACKGROUND: Identification of windows of heightened vulnerability to environmental factors has substantial public health implications. Prenatal exposure to vanadium has been linked to adverse birth outcomes; however, critical windows for such exposure during fetal growth remain unknown. We aimed to assess trimester-specific associations of vanadium exposure with ultrasound measures of fetal growth and birth size in a Chinese longitudinal cohort. METHODS: The present study was embedded in our ongoing prospective prenatal cohort study at the Wuhan Women and Children Medical Care Center (Wuhan, Hubei, China). Pregnant women were eligible for inclusion if they provided signed informed consent and were less than 16 weeks pregnant with a single gestation, and agreed to take in-person interviews, undergo ultrasound examinations, and provide blood and urine samples. We collected urine samples and measured urinary vanadium concentrations using inductively coupled plasma mass spectrometry. We calculated SD scores for ultrasound-measured biparietal diameter, head circumference, occipitofrontal diameter, abdominal circumference, femur length, and estimated fetal weight at 16, 24, and 31 weeks of gestation. We applied linear regressions with generalised estimating equations to estimate associations of urinary vanadium concentrations in each trimester with ultrasound-measured fetal growth parameters or neonatal size at birth. FINDINGS: As of Oct 12, 2016, we recruited 3075 women who were non-smokers and non-drinkers during pregnancy, provided up to three urine samples during the first, second, and third trimesters, and gave birth to live singletons without birth defects. We excluded women who did not provide information on ultrasound measurements (n=20) or who only had one ultrasound measurement of fetal crown-rump length at the first trimester (n=14). We excluded another 16 women because they had missing values for confounding variables, leaving 3025 women retained in the study. Every doubling of urinary vanadium concentration in the first trimester was associated with a significant increase in femur length (adjusted percentage change 6·4%, 95% CI 0·7 to 12·1) at 16 weeks of gestation and reductions in biparietal diameter (-4·2%, -8·2 to -0·1), head circumference (-6·0%, -10·1 to -1·9), occipitofrontal diameter (-5·7%, -9·9 to -1·5), and abdominal circumference (-5·3%, -9·4 to -1·2) at 31 weeks of gestation. Every doubling of urinary vanadium concentration in the second trimester was significantly associated with reductions in SD scores for head circumference (-7·2%, -14·1 to -0·3) and abdominal circumference (-6·9%, -13·8 to -0·1) at 31 weeks of gestation. The highest quartile of urinary vanadium concentration (>1·18 µg/L) in the first trimester, when compared with the lowest quartile (≤0·60 µg/L), was associated with a mean decrease in birthweight of 12·6 g (95% CI 2·5-22·8; ptrend=0·0055) and a mean decrease in ponderal index of 0·07 kg/m3 (0·01-0·12; ptrend=0·0053). Moreover, newborns with restricted birth size had higher vanadium exposure in the first and third trimesters. INTERPRETATION: Vanadium might be toxic to humans and impair fetal growth. The first, early second, and late third trimesters could be critical windows for heightened vulnerability to vanadium for fetal growth. Our findings require further investigation in other populations. FUNDING: National Key R&D Plan of China, National Natural Science Foundation of China, and Fundamental Research Funds for the Central Universities, Huazhong University of Science and Technology.

Critical Windows for Associations between Manganese Exposure during Pregnancy and Size at Birth: A Longitudinal Cohort Study in Wuhan, China.

BACKGROUND: Prenatal overexposure to manganese (Mn), an essential micronutrient, is related to impaired fetal growth and development. Fetuses appear to be highly sensitive to Mn during short periods of gestation. However, little is known about the critical windows of susceptibility to Mn for humans. OBJECTIVES: Our objective was to estimate trimester-specific associations of exposure to Mn with size at birth. METHODS: Urine samples of 3,022 women were collected repeatedly in the first, second, and third trimesters in Wuhan, China. Urinary concentrations of Mn and other toxic metals were measured using an inductively coupled plasma mass spectrometry. Trimester-specific associations of specific gravity­adjusted urinary Mn concentrations with birth weight, birth length, and ponderal index were estimated using multivariable linear regressions with generalized estimating equations. Linear mixed models were applied to evaluate the windows of susceptibility to Mn exposure by comparing the pattern of Mn exposure among newborns with restricted size at birth to those without. RESULTS: When compared with the third quintile of urinary Mn concentrations, both higher and lower quintiles of urinary Mn concentrations in the second and third trimesters were related to reduced birth weight, birth length, and ponderal index. But the observed associations for higher quintiles were stronger and more likely to be statistically significant [e.g., for women who were in the fifth quintile of Mn concentration in the third trimester, the reduction in birth weight was [Formula: see text] (95% CI: [Formula: see text], [Formula: see text]) g and in birth length was [Formula: see text] (95% CI: [Formula: see text], 0.00) cm]. Moreover, newborns with restricted size at birth, compared with those without, had higher levels of Mn exposure in the second and third trimesters. CONCLUSIONS: This prospective prenatal cohort study revealed an association of exposure to Mn during pregnancy, especially late pregnancy, with restricted size at birth. Replications are needed. https://doi.org/10.1289/EHP3423.

Critical Windows of Prenatal Exposure to Cadmium and Size at Birth.

Prenatal cadmium (Cd) exposure has been associated with adverse birth outcomes, but the findings of previous studies are inconsistent. We measured Cd concentrations in urine samples at or near 13, 24, and 35 gestational weeks from 282 women in Wuhan, China. We used generalized estimating equation models to assess the associations between maternal creatinine adjusted urinary Cd concentrations at each trimester and birth size. A significant inverse association was observed between higher maternal Cd levels measured during the 1st trimester and birth size in girls. For each log unit increase in Cd (µg/g creatinine) levels from the 1st trimester, there was a decrease in birth weight by 116.99 g (95% confidence interval (CI): -208.87, -25.11 g). The Cd levels from the 1st and 2nd trimesters were also borderline significantly associated with ponderal index in girls. Joint estimation of trimester-specific effects suggested that associations with Cd levels for ponderal index (pint = 0.02) were significantly different across trimesters, and differences for effects across trimesters for birth weight were marginally significant (pint = 0.08) in girls. No significant associations were observed between Cd levels from any trimester and birth size in boys. Maternal Cd exposure during earlier periods of pregnancy may have a larger impact on delayed fetal growth.

Association of adverse birth outcomes with prenatal exposure to vanadium: a population-based cohort study.

BACKGROUND: Vanadium, an important pollutant produced from anthropogenic activities, has been suggested to be embryotoxic and fetotoxic in animal studies. However, little is known about its effects on humans. We aimed to assess the association of prenatal exposure to vanadium with the risk of adverse birth outcomes in babies born to women in China. METHODS: For this population-based cohort study, the Healthy Baby Cohort, women were recruited from three cities in Hubei Province, China. Women included in this analysis were recruited from Wuhan Women and Children Medical Care Center, Wuhan. We measured urinary concentrations of vanadium and other metals simultaneously using inductively coupled plasma mass spectrometry. We used multivariable logistic regressions, with adjustment for potential confounders, to estimate the associations of natural logarithm transformed creatinine-corrected urinary vanadium (Ln-vanadium) concentrations as continuous variables and categorised into quartiles (Q; Q1: ≤0·84 µg/g creatinine, Q2: 0·84-1·40 µg/g creatinine, Q3: 1·40-2·96 µg/g creatinine, Q4: >2·96 µg/g creatinine, with the lowest quartile set as reference) with preterm delivery, early-term delivery, low birthweight, and being small for gestational age. We applied restricted cubic spline models to evaluate the dose-response relationships. FINDINGS: Data from 7297 women recruited between Sept 22, 2012, and Oct 22, 2014, were included in this study. Urinary Ln-vanadium concentrations showed non-linear dose-response relationships with risk of preterm delivery (S-shaped, p<0·0001) and low birthweight (J-shaped, p=0·0001); the adjusted odds ratios (ORs) for increasing quartiles of urinary vanadium were 1·76 (95% CI 1·05-2·95) for Q2, 3·17 (1·96-5·14) for Q3, and 8·86 (5·66-13·86) for Q4 for preterm delivery, and 2·29 (95% CI 1·08-4·84) for Q2, 3·22 (1·58-6·58) for Q3, and 3·56 (1·79-7·10) for Q4 for low birthweight. Ln-vanadium concentrations were linearly associated with the risk of early-term delivery (linear, p<0·0001) and being small for gestational age (linear, p=0·0027), with adjusted ORs of 1·15 (95% CI 1·10-1·21) for early-term delivery and 1·12 (1·04-1·21) for being small for gestational age per unit increase in Ln-vanadium concentrations. INTERPRETATION: Our findings reveal a relationship between prenatal exposure to higher levels of vanadium and increased risk of adverse birth outcomes, suggesting that vanadium might be a potential toxic metal for human beings. Further studies are needed to replicate the observed associations and investigate the interaction effects of prenatal exposure to different metals on adverse birth outcomes. FUNDING: National Key R&D Plan of China, National Natural Science Foundation of China, and Fundamental Research Funds for the Central Universities, Key Laboratory of Environment and Health.

Effects of Environmental Exposures on Fetal and Childhood Growth Trajectories.

Delayed fetal growth and adverse birth outcomes are some of the greatest public health threats to this generation of children worldwide because these conditions are major determinants of mortality, morbidity, and disability in infancy and childhood and are also associated with diseases in adult life. A number of studies have investigated the impacts of a range of environmental conditions during pregnancy (including air pollution, endocrine disruptors, persistent organic pollutants, heavy metals) on fetal and child development. The results, while provocative, have been largely inconsistent. This review summarizes up to date epidemiologic studies linking major environmental pollutants to fetal and child development and suggested future directions for further investigation.

Green tea consumption and risk of cardiovascular and ischemic related diseases: A meta-analysis.

BACKGROUND: The effects of green tea intake on risk of cardiovascular disease (CVD) have not been well-defined. The aim of this meta-analysis was to evaluate the association between green tea consumption, CVD, and ischemic related diseases. METHODS: All observational studies and randomized trials that were published through October 2014 and that examined the association between green tea consumption and risk of cardiovascular and ischemic related diseases as the primary outcome were included in this meta-analysis. The quality of the included studies was evaluated according to the Cochrane Handbook 5.0.2 quality evaluation criteria. RESULTS: A total of 9 studies including 259,267 individuals were included in the meta-analysis. The results showed that those who didn't consume green tea had higher risks of CVD (OR=1.19, 95% CI: 1.09-1.29), intracerebral hemorrhage (OR=1.24, 95% CI: 1.03-1.49), and cerebral infarction (OR=1.15, 95% CI: 1.01-1.30) compared to <1 cup green tea per day. Those who drank 1-3 cups of green tea per day had a reduced risk of myocardial infarction (OR=0.81, 95% CI: 0.67-0.98) and stroke (OR=0.64, 95% CI: 0.47-0.86) compared to those who drank <1 cup/day. Similarly, those who drank ≥4 cups/day had a reduced risk of myocardial infarction compared to those who drank <1 cup/day (OR=0.68, 95% CI: 0.56-0.84). Those who consumed ≥10 cups/day of green tea were also shown to have lower LDL compared to the <3 cups/day group (MD=-0.90, 95% CI: -0.95 to -0.85). CONCLUSIONS: Our meta-analysis provides evidence that consumption of green tea is associated with favorable outcomes with respect to risk of cardiovascular and ischemic related diseases.

Distributions of heavy metals in maternal and cord blood and the association with infant birth weight in China.

OBJECTIVE: To measure serum levels of heavy metals in Chinese pregnant women and their newborns, and to evaluate the association of these metals with infant birth weight. STUDY DESIGN: We measured serum concentrations of lead (Pb), thallium (Tl), cadmium (Cd), selenium (Se), arsenic (As), nickle (Ni), vanadium (V), cobalt (Co), and mercury (Hg) in 81 mother-infant pairs using an inductively coupled plasma mass spectrometry method. Multiple linear regression analyses were used to evaluate the associations of these heavy metals with infant birth weight. RESULTS: Se, Pb, As, and Cd showed the highest detection rates (98.8%) in both the maternal and cord blood, followed by Tl, which was detected in 79.0% and 71.6% of the maternal and cord blood samples, respectively. Pb had the highest concentrations in both the maternal and cord blood samples of all toxic metals detected, with concentrations of 23.1 ng/g and 22.0 ng/g, respectively. No significant associations were observed between any heavy metals and birth weight. However, Tl in the maternal and cord blood was most notably inversely associated with birth weight. CONCLUSION: Se intake was low in Chinese women and their newborns, whereas Pb had the highest concentrations in both the maternal and cord blood samples of all toxic metals detected. Tl was a unique pollution source in this population, and Tl levels were shown to have the largest effect on decreasing infant birth weight in this pilot study. Further research incorporating larger sample sizes is needed to investigate the effects of prenatal exposure to heavy metals--especially Tl and Pb--on birth outcome in Chinese infants.

A birth cohort analysis of the incidence of adenocarcinoma of the uterine cervix in the USA.

We investigated the incidence trends for adenocarcinoma (AC) of the cervix among individuals belonging to the 20-44-year age group in the USA and compared the observed birth cohort incidence patterns with the changing patterns of exposure to potential risk factors associated with AC of the cervix, such as infection with human papillomavirus, use of diethylstilbestrol (DES), obesity, and use of oral contraceptives. Using data from the National Cancer Institute's Surveillance, Epidemiology, and End Results program for 1973-2010, we conducted age-period-cohort modeling to evaluate birth cohort patterns on incidence trends of AC of the cervix over time. The increase in the incidence of AC of the cervix started among those born around the mid 1940s and accelerated up until around the mid 1960s birth cohort in both whites and all races combined, regardless of the assumed period slope. There was a suggestion that the incidence rates of AC of the cervix slowed down after the 1975 birth cohort in both whites and all races combined. DES was used by millions of women in the USA as a synthetic estrogen between the years 1940 and 1971. This time period of DES use among pregnant women parallels the observed birth cohort trends in our study, whereby a notable acceleration in the incidence rates of AC of the cervix was observed among those born in the mid 1940s through the mid 1975s. Thus, our results appear to suggest that in-utero exposure to DES might be at least partly responsible for the observed incidence pattern of AC of the cervix as observed in this study.

Prenatal exposure to organochlorine pesticides and infant birth weight in China.

In utero exposure to organochlorine pesticides (OCPs) is thought to be potentially harmful to fetal development. We aimed to investigate the associations of maternal and cord serum OCPs levels with infant birth weight in China. In this study, we measured serum levels of 18 OCPs in 81 mother-infant pairs, including DDT, hexachlorocyclohexanes (BHC), hexachlorobenzene (HCB), heptachlors, chlordanes, endosulfan-I, and mirex using a high-resolution-gas-chromatography with high-resolution-mass-spectrometry method. We found that p,p'-DDE and ß-BHC had the highest detection rate in both maternal and cord blood serum (97.2% and 96.7%, respectively), followed by HCB (93.0%, 51.7%), p,p'-DDT (88.7%, 36.7%), and p,p'-DDD (83.1%, 60.0%). Among all OCPs, the concentration of p,p'-DDE was the highest (mothers geometric mean (GM): 203.54ngg(-1), newborns GM: 116.14ngg(-1)), followed by HCB (70.62ngg(-1), 65.16ngg(-1)), and ß-BHC (67.67ngg(-1), 33.39ngg(-1)). Multiple linear regression analyses showed that each 1ngg(-1) increment of cord serum p,p'-DDE, total DDT, and ß-BHC was associated with a 0.10g, 0.10g, and 0.92g decrease in infant birth weight, respectively, and as the cord serum concentrations of p,p'-DDT, p,p'-DDD, HCB and mirex increased, the infant birth weight was also decreased, although the associations were not statistically significant due to the relatively small sample size. These results suggest that p,p'-DDE, ß-BHC, and HCB were the predominant OCPs in the serum of Chinese pregnant women and cord blood of their newborns. Prenatal exposure to DDT, ß-BHC, HCB, and mirex were associated with a decrease in birth weight, but these results need validation in larger sample-sized studies.

Different time trends by gender for the incidence of Hodgkin's lymphoma among young adults in the USA: a birth cohort phenomenon.

OBJECTIVES: Hodgkin's lymphoma (HL) is one of the most common cancers among young adults. We investigated the time trends for HL among the 20-44 age group in the USA by gender to identify the potential factors accounting for the incidence trends. METHODS: Using data from the National Cancer Institute's Surveillance, Epidemiology, and End Results program for 1973-2010, we conducted age-period-cohort modeling to evaluate birth cohort patterns on incidence trends of HL over time. RESULTS: For all races combined, the age-adjusted incidence patterns were similar to that of whites. The birth cohort patterns for whites and all races were similar, but the patterns differed according to gender. Specifically, except for the 1970-1975 birth cohort, all other birth cohorts showed an increasing birth cohort trend for females. Conversely, there was a decreasing cohort trend in males beginning in the 1960 birth cohort regardless of the assumptions of the period effect. CONCLUSION: The established risk factors for HL can seemingly not explain the gender disparities of the cohort pattern, which necessitates further analytical epidemiological studies to explore the risk factors for this disease with respect to potential differences by gender and by histological subtype.

[Epidemiological study of high risk human papillomavirus infection in 25 to 54 years old married women in Beijing.].

OBJECTIVE: To investigate high risk human papillomavirus (HR-HPV) prevalence among married women in Beijing and to study the high risk factors. METHODS: During March 2007 to September 2008, a total of 6185 married women sampled from 137 communities in 12 districts were screened by HR-HPV DNA test and cytological test. The interview was carried out with unified questionnaires. The database was set up and twice entered in EpiData 3.0. After checked up, the data were analyzed in SPSS 15.0. RESULTS: (1) The HR-HPV infection rate was 9.89%. The HR-HPV infection rate of the city zone, the suburb and the exurb were 9.34%, 10.51% and 9.51% (P > 0.05). The HR-HPV infection rate of the native and the outlander were 9.53%, 11.30% (P < 0.05). (2) The age distribution of HR-HPV infection was that the rate was around 10% among 25 to 44 age groups, which was the highest (11.21%) in 30 to 34 age group; then the rate was descended as the age raising, the rate of 50 to 54 age group was the lowest (7.78%). (3) Multiple logistic regression showed that the related risk factors of HR-HPV infection mainly included 1000 RMB and above of family income per person per month, possessing more than 1 sexual partner of her husband, outlander and high levels of education. (4) The prevalence of cervical intraepithelial neoplasia (CIN) in HR-HPV positive group was significantly higher than that in HR-HPV negative group (29.76% vs 3.32%, P < 0.01). CONCLUSIONS: (1) The HR-HPV infection rate among aged 25 to 54 years was 9.9% and there was no significant difference in area distribution. (2) The high risk population which should strengthen screening was the married bearing-age women with high level of family income, outlander, high levels of education and her husband possessing more than 1 sexual partner. (3) HR-HPV infection is the main risk factor for CIN and cervical cancer, while does not provide a causal relationship with them. The high risk population should be checked regularly to understand the development of HR-HPV infection and CIN incidence.