Trends of Underweight and Overweight/Obesity Among Japanese Schoolchildren From 2003 to 2012, Defined by Body Mass Index and Percentage Overweight Cutoffs

Background

We investigated the prevalence and trends of underweight and overweight/obesity in a population-based sample of Japanese schoolchildren from 2003 to 2012, defined by body mass index (BMI) and percentage overweight (POW).

Methods

Subjects comprised fourth and seventh graders from the town of Ina, Japan, from 2003 to 2012. The height and weight of each subject were measured. Children were classified as underweight, normal weight, or overweight/obese using two criteria: BMI cutoff points proposed by the International Obesity Task Force and cutoffs based on POW in Japan.

Results

Data from 4367 fourth graders and 3724 seventh graders were analyzed. The prevalence of underweight and overweight as defined by POW criteria were lower than those based on BMI criteria. There was a decrease in the prevalence of overweight among fourth-grade boys and girls and seventh-grade girls according to BMI; this decrease was also observed when POW criteria were used for the definition of overweight.

Conclusions

The prevalence and trends of both underweight and overweight as defined by POW were underestimated among Japanese schoolchildren compared to those determined using BMI. The results of this study also suggest that trends in underweight and overweight/obesity using POW criteria are similar to those based on BMI criteria among schoolchildren in Japan.Key words: body mass index, percentage overweight, schoolchildren, secular trends, Japanese     

Perfluorinated chemicals and fetal growth: a study within the Danish National Birth Cohort

Background

Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) are man-made, persistent organic pollutants widely spread throughout the environment and human populations. They have been found to interfere with fetal growth in some animal models, but whether a similar effect is seen in humans is uncertain.

Objectives

We investigated the association between plasma levels of PFOS and PFOA in pregnant women and their infants’ birth weight and length of gestation.

Methods

We randomly selected 1,400 women and their infants from the Danish National Birth Cohort among those who completed all four computer-assisted telephone interviews, provided the first blood samples between gestational weeks 4 and 14, and who gave birth to a single live-born child without congenital malformation. PFOS and PFOA were measured by high performance liquid chromatography–tandem mass spectrometer.

Results

PFOS and PFOA levels in maternal plasma were on average 35.3 and 5.6 ng/mL, respectively. Only PFOA levels were inversely associated with birth weight (adjusted β = −10.63 g; 95% confidence interval, −20.79 to −0.47 g). Neither maternal PFOS nor PFOA levels were consistently associated with the risk for preterm birth or low birth weight. We observed no adverse effects for maternal PFOS or PFOA levels on small for gestational age.

Conclusion

Our nationwide cohort data suggest an inverse association between maternal plasma PFOA levels and birth weight. Because of widespread exposure to these chemicals, our findings may be of potential public health concern.     

Gestational Weight Gain and Overweight in Children Aged 3–6 Years

Objective

To determine whether gestational weight gain (GWG) was associated with increased odds of childhood overweight after accounting for pre-pregnancy BMI.

Methods

In a prospective cohort study based on a premarital and perinatal health care system in China, data of 100 612 mother-child pairs were obtained. The main exposure was GWG as both a continuous and categorical variable. The outcome measure was overweight, defined by age- and sex-specific cutoff values for body mass index (BMI) in children aged 3–6 years.

Results

A 1-kg increase in maternal GWG was associated with an increase of 0.009 (95% confidence interval [CI]: 0.007–0.010, P < 0.001) in children’s mean BMI; in the subgroup of pre-pregnancy overweight/obese mothers, the increase in children’s BMI was 0.028 (95% CI, 0.017–0.039, P < 0.001). Excessive GWG played an important role in childhood overweight when adequate GWG was used as the reference, with an odds ratio (OR) of 1.21 (95% CI, 1.12–1.29). The risk was highest (OR 2.22; 95% CI, 1.79–2.76) in the children of mothers who were overweight/obese before pregnancy and gained excessive weight during pregnancy.

Conclusions

Greater maternal GWG was associated with greater offspring BMI, and the risk of overweight was doubled in children whose mothers were overweight/obese before pregnancy and gained excessive weight during pregnancy. As a result, maintenance of appropriate weight gain during pregnancy and prophylaxis of maternal overweight/obesity before pregnancy should be a strategy for preventing childhood overweight/obesity.Key words: cohort study, gestational weight gain, childhood overweight, birth weight, maternal pre-pregnancy BMI     

Exposure to Endocrine-Disrupting Chemicals during Pregnancy and Weight at 7 Years of Age: A Multi-pollutant Approach

Background

Prenatal exposure to endocrine-disrupting chemicals (EDCs) may induce weight gain and obesity in children, but the obesogenic effects of mixtures have not been studied.

Objective

We evaluated the associations between pre- and perinatal biomarker concentrations of 27 EDCs and child weight status at 7 years of age.

Methods

In pregnant women enrolled in a Spanish birth cohort study between 2004 and 2006, we measured the concentrations of 10 phthalate metabolites, bisphenol A, cadmium, arsenic, and lead in two maternal pregnancy urine samples; 6 organochlorine compounds in maternal pregnancy serum; mercury in cord blood; and 6 polybrominated diphenyl ether congeners in colostrum. Among 470 children at 7 years, body mass index (BMI) z-scores were calculated, and overweight was defined as BMI > 85th percentile. We estimated associations with EDCs in single-pollutant models and applied principal-component analysis (PCA) on the 27 pollutant concentrations.

Results

In single-pollutant models, HCB (hexachlorobenzene), βHCH (β-hexachlorocyclohexane), and polychlorinated biphenyl (PCB) congeners 138 and 180 were associated with increased child BMI z-scores; and HCB, βHCH, PCB-138, and DDE (dichlorodiphenyldichloroethylene) with overweight risk. PCA generated four factors that accounted for 43.4% of the total variance. The organochlorine factor was positively associated with BMI z-scores and with overweight (adjusted RR, tertile 3 vs. 1: 2.59; 95% CI: 1.19, 5.63), and these associations were robust to adjustment for other EDCs. Exposure in the second tertile of the phthalate factor was inversely associated with overweight.

Conclusions

Prenatal exposure to organochlorines was positively associated with overweight at age 7 years in our study population. Other EDCs exposures did not confound this association.

Citation

Agay-Shay K, Martinez D, Valvi D, Garcia-Esteban R, Basagaña X, Robinson O, Casas M, Sunyer J, Vrijheid M. 2015. Exposure to endocrine-disrupting chemicals during pregnancy and weight at 7 years of age: a multi-pollutant approach. Environ Health Perspect 123:1030–1037; http://dx.doi.org/10.1289/ehp.1409049     

Lifestyle and Overweight Among Japanese Adolescents: The Toyama Birth Cohort Study

Objective

To investigate the effects of lifestyle factors on overweight among Japanese adolescents.

Methods

We studied 5753 junior high school students (2842 boys and 2911 girls) aged 12 to 13 years. The students were residents of Toyama prefecture, Japan and completed a questionnaire about their height, weight, and lifestyle factors, in June and July 2002. Subjects with a body-mass index (BMI) higher than age- and sex-specific cut-off points were defined as obese. Parental overweight was defined as a BMI of 25 or higher. Logistic regression analysis was used to examine associations between lifestyle factors and overweight.

Results

Skipping breakfast, eating quickly, excessive eating, physical inactivity, and long hours of TV watching were positively and significantly associated with overweight in both sexes. There was a negative association between snacking and overweight in girls (P < 0.001); no such association was found in boys (P > 0.05). Nighttime snacking was negatively associated with overweight in boys and girls (P < 0.05). Extended video game playing (≥2 hours; OR = 2.00, P = 0.012) and short sleep duration (<7 hours; OR = 1.81, P = 0.004) were significantly associated with overweight in girls only. The respective risks of overweight that derived from the subjects’ fathers and mothers were 2.0 and 2.5 times, respectively, in boys and 1.9 and 3.0 times in girls.

Conclusions

Parental overweight, skipping breakfast, eating quickly, excessive eating, long hours of TV watching, long hours of video game playing, physical inactivity, and short sleep duration were associated with adolescent overweight. Furthermore, there were significant negative associations between adolescent overweight and snacking in girls and nighttime snacking in both sexes.Key words: overweight, lifestyle factors, adolescents, Japan, Toyama birth cohort study     

Mendelian Randomization Analysis of the Effect of Maternal Homocysteine During Pregnancy,as Represented by Maternal MTHFR C677T Genotype,on Birth Weight

Background

We used Mendelian randomization analysis to investigate the causal relationship between maternal homocysteine level, as represented by maternal methylenetetrahydrofolate reductase (MTHFR) C677T genotype, with the birth weight of offspring.

Methods

We recruited women at 24 to 28 weeks’ gestation who visited Ewha Womans University Hospital for prenatal care during the period from August 2001 to December 2003. A total of 473 newborns with a gestational age of at least 37 weeks were analyzed in this study. We excluded twin births and children of women with a history of gestational diabetes, gestational hypertension, or chronic renal disease. The association of maternal homocysteine concentration with the birth weight of infants was analyzed using 2-stage regression.

Results

MTHFR C677T genotype showed a dose–response association with homocysteine concentration for each additional T allele (P_trend < 0.01). Birth weight decreased from 120 to 130 grams as maternal homocysteine level increased, while controlling for confounding factors; however, the association was of marginal significance (P = 0.06).

Conclusions

Our results suggest an adverse relationship between maternal homocysteine level and birth weight. A reduction in homocysteine levels might positively affect birth outcomes.Key words: birth weight, homocysteine, intrauterine environment, Mendelian randomization, methylenetetrahydrofolate reductase     

Midwifery Care at a Freestanding Birth Center: A Safe and Effective Alternative to Conventional Maternity Care

Objective

To estimate the effect of a midwifery model of care delivered in a freestanding birth center on maternal and infant outcomes when compared with conventional care.

Data Sources/Study Setting

Birth certificate data for women who gave birth in Washington D.C. and D.C. residents who gave birth in other jurisdictions.

Study Design

Using propensity score modeling and instrumental variable analysis, we compare maternal and infant outcomes among women who receive prenatal care from birth center midwives and women who receive usual care. We match on observable characteristics available on the birth certificate, and we use distance to the birth center as an instrument.

Data Collection/Extraction Methods

Birth certificate data from 2005 to 2008.

Principal Findings

Women who receive birth center care are less likely to have a C-section, more likely to carry to term, and are more likely to deliver on a weekend, suggesting less intervention overall. While less consistent, findings also suggest improved infant outcomes.

Conclusions

For women without medical complications who are able to be served in either setting, our findings suggest that midwife-directed prenatal and labor care results in equal or improved maternal and infant outcomes.     

Birth Weight among Singletons Born to Foreign-Born Mothers in Taiwan: A Population-Based Birth Register Study

Background

We compared the birth weight of newborns born to foreign-born mothers (FBMs) and Taiwan-born mothers (TBMs), using data from the 2005–2006 Taiwan Birth Registry of singleton live births.

Methods

The Wilcox–Russell method, data restriction, and multiple linear regression were used to analyze the data. The rates of low birth weight (<2500 g) with 95% confidence intervals were computed for TBMs, and for each of the nationalities of FBMs.

Results

The mean birth weight of newborns of FBMs was 3157 g, which was higher than that of newborns of TBMs (3109 g). On analysis using the Wilcox–Russell method, both the rate and residual proportion of low-birth-weight (LBW) births were lower among newborns of FBMs (4.1% and 1.1%, respectively) than among newborns of TBMs (5.9% and 1.7%, respectively). After adjusting for sex, mode of delivery, maternal age, smoking status, predisposing maternal risk factors, and condition during pregnancy, the newborns of FBMs weighed 72.9 g (95% CI, 68.8 g to 77.0 g) more than the newborns of TBMs. When data were restricted to mothers without any adverse conditions and adjusted for maternal age, the differences in birth weight between the 2 groups remained unchanged. The rates of LBW deliveries among FBMs in Taiwan were significantly lower than those in their respective countries of origin.

Conclusions

In Taiwan, newborns of FBMs had a higher birth weight than those of TBMs, even after accounting for potential confounding factors, and had lower rates of LBW deliveries than did mothers in their respective countries of origin.Key words: birth weight, transnational marriage, foreign-born mothers     

The Associations of Month of Birth With Body Mass Index,Waist Circumference,and Leg Length: Findings From the China Kadoorie Biobank of 0.5 Million Adults

Background

Season of birth (SoB) has been linked with various health outcomes. This study aimed to examine the associations between month of birth (MoB) and adult measures of leg length (LL), body mass index (BMI), and waist circumference (WC).

Methods

We analysed survey data from 10 geographically diverse areas of China obtained through the China Kadoorie Biobank. Analysis included 487 529 adults with BMI ≥ 18.5 kg/m². A general linear model was used to examine the associations between MoB and adult measures of LL, BMI, and WC, adjusted for survey site, sex, age, education level, smoking habit, alcohol consumption, physical activity level, sedentary leisure time, height (only for WC and LL), and hip circumference (only for LL).

Results

MoB was independently associated with both BMI and WC. Birth months in which participants had higher measures of adiposity were March–July for BMI and March–June for WC. The peak differences were 0.14 kg/m² for BMI and 0.47 cm for WC. The association between MoB and LL depended on survey site. Participants who were born in February–August in four sites (Harbin, Henan, Gansu, and Hunan) had the shortest LL (all P < 0.01). The peak difference in mean LL was 0.21 cm. No statistically significant association between MoB and LL was noted in the other sites (Qingdao, Suzhou, Sichuan, Zhejiang, Liuzhou, and Haikou).

Conclusions

These findings suggest that MoB is associated with variations in adult adiposity measures and LL among Chinese adults. Low exposure to ultraviolet B radiation and subsequent reduced levels of vitamin D during the late second and early third trimesters may be involved in these phenomena.Key words: month of birth, BMI, waist circumference, leg length, vitamin D deficiency     

Impact of Parental Socioeconomic Status on Childhood and Adolescent Overweight and Underweight in Korea

Background

The prevalence of overweight and underweight is steadily increasing among children and adolescents. To explore the relationship between parental socioeconomic status and body mass index, we examined levels of overweight and underweight among representative samples of children and adolescents in South Korea.

Methods

We analyzed data from the 2009 Korean Survey on the Obesity of Youth and Children, conducted by the National Youth Policy Institute. The sample response rate for this survey was 93.9%. After excluding 745 subjects who had missing information on age, height, or weight, 9411 subjects were included. To measure parental socioeconomic status, 4 categories were assessed by using a structured questionnaire: subjective economic status, parental education level, parental occupational status, and family structure. We used the chi-squared test in univariable analysis and multinomial logistic regression in multivariable analysis.

Results

Multinomial logistic regression analysis identified sex, education level, parental interest in weight management, and parental body shapes as statistically significant characteristics affecting overweight in children, and sex, place of residence, parental interest in weight management, and paternal and maternal body shapes as statistically significant characteristics affecting underweight (P < 0.05).

Conclusions

Underweight and overweight coexist among adolescent Korean males of low socioeconomic status, which indicates that these conditions can coexist in developed countries. Appropriate interventions to address both overweight and underweight in adolescents are required.Key words: childhood and adolescent overweight and underweight, Korea, parental factors, risk factor, socioeconomic status     

Maternal height as an independent risk factor for neonatal size among adolescent bengalees in kolkata, India

Background

Low Birth Weight is a major public health problem in developing countries. The causes of LBW are multifactorial including complication during pregnancy, genetic, environmental, social-cultural, demographic and nutritional variables. Comparison of anthropometric risk factors for neonatal size of adolescent mothers are lacking from West Bengal. Therefore, this study was undertaken to identify maternal anthropometric characteristics, which most strongly influence neonate weight and length among Bengalee mothers.

Methods

A hospital based cross-sectional study was undertaken during 2004 in a Government general hospital in South Kolkata, India. A total of 76 adolescent (age<20years) pregnant women were enrolled from obstetric ward who were admitted for delivery. Due to 4 perinatal deaths; a total of 72 adolescent mother- baby pairs were included in this analysis. Anthropometric measurements were undertaken immediately after delivery following stabilization as well maternal body mass index (BMI) was calculated using standard formula.

Results

The prevalence of low birth weight (LBW) in the present study was 52.8%. The results revealed that 30.6% of mothers were undernourished (BMI<19.8 kg/m²). It was noted that about 64% of undernourished mothers delivered LBW baby. Linear regression analyses of neonatal weight and length as dependent variables revealed that in both cases, maternal height had the most significant impact. It showed 12.9% (birth weight) and 16.1% (birth length) of variation. Moreover, the proportion of LBW was 75%, 52.3% and 25% among short (height ≤145 cm), average (146–155cm) and tall (>155cm) mothers (x²=6.855, p<0.01), respectively. Short mothers had 2.74 and 9.0 fold greater risk of delivering LBW baby than average and tall mothers. In contrast, mean birth weight and length of baby was lower in short mother than their counterparts.

Conclusion

This study revealed that maternal height had the strongest significant impact on neonate size. This strong association could have serious health implications for Bengalee adolescent mothers. However, since this is a preliminary finding, it needs validation using a larger sample of adolescent mothers.     

Correlation of obesity with elevated blood pressure among racial/ethnic minority children in two Los Angeles middle schools

Introduction

To identify anthropometric and fitness correlates of elevated blood pressure, serum cholesterol, and glycated hemoglobin, we examined anthropometric and physiologic biomarkers among racial/ethnic minority children aged 11 to 13 years in two urban Los Angeles middle schools. We explored the potential for using obesity or fitness level as screening variables for cardiovascular disease risk factors in these students.

Methods

During regularly scheduled physical education classes, we collected data on demographic characteristics, height, weight, blood pressure, nonfasting total serum cholesterol, glycated hemoglobin, time to run/walk 1 mile, and a range of self-reported behaviors. A total of 199 sixth-graders (121 Latinos, 78 African Americans) participated in the study.

Results

Bivariate analyses indicated that 48.6% of sixth-graders were of desirable weight, 17.5% were overweight, 29.9% were at risk for overweight, and 4.0% were underweight. Higher weight was associated with higher levels of serum cholesterol, systolic blood pressure, and diastolic blood pressure (P values for all associations <.02) but not with glycated hemoglobin. Multivariate analyses maintained the findings with regard to blood pressure but not serum cholesterol.

Conclusion

Overweight status could be a screening variable for identifying youth at risk for high blood pressure. Obesity prevention and intervention programs and policies need to target low-income racial/ethnic minority children. Assessment of hypertension status also seems warranted in low-income racial/ethnic minority sixth-graders, as does early intervention for children at high risk.     

Prenatal Phthalate,Perfluoroalkyl Acid,and Organochlorine Exposures and Term Birth Weight in Three Birth Cohorts: Multi-Pollutant Models Based on Elastic Net Regression

Background

Some legacy and emerging environmental contaminants are suspected risk factors for intrauterine growth restriction. However, the evidence is equivocal, in part due to difficulties in disentangling the effects of mixtures.

Objectives

We assessed associations between multiple correlated biomarkers of environmental exposure and birth weight.

Methods

We evaluated a cohort of 1,250 term (≥ 37 weeks gestation) singleton infants, born to 513 mothers from Greenland, 180 from Poland, and 557 from Ukraine, who were recruited during antenatal care visits in 2002‒2004. Secondary metabolites of diethylhexyl and diisononyl phthalates (DEHP, DiNP), eight perfluoroalkyl acids, and organochlorines (PCB-153 and p,p´-DDE) were quantifiable in 72‒100% of maternal serum samples. We assessed associations between exposures and term birth weight, adjusting for co-exposures and covariates, including prepregnancy body mass index. To identify independent associations, we applied the elastic net penalty to linear regression models.

Results

Two phthalate metabolites (MEHHP, MOiNP), perfluorooctanoic acid (PFOA), and p,p´-DDE were most consistently predictive of term birth weight based on elastic net penalty regression. In an adjusted, unpenalized regression model of the four exposures, 2-SD increases in natural log–transformed MEHHP, PFOA, and p,p´-DDE were associated with lower birth weight: –87 g (95% CI: –137, –340 per 1.70 ng/mL), –43 g (95% CI: –108, 23 per 1.18 ng/mL), and –135 g (95% CI: –192, –78 per 1.82 ng/g lipid), respectively; and MOiNP was associated with higher birth weight (46 g; 95% CI: –5, 97 per 2.22 ng/mL).

Conclusions

This study suggests that several of the environmental contaminants, belonging to three chemical classes, may be independently associated with impaired fetal growth. These results warrant follow-up in other cohorts.

Citation

Lenters V, Portengen L, Rignell-Hydbom A, Jönsson BA, Lindh CH, Piersma AH, Toft G, Bonde JP, Heederik D, Rylander L, Vermeulen R. 2016. Prenatal phthalate, perfluoroalkyl acid, and organochlorine exposures and term birth weight in three birth cohorts: multi-pollutant models based on elastic net regression. Environ Health Perspect 124:365–372; http://dx.doi.org/10.1289/ehp.1408933     

Peer Reviewed: Low Awareness of Overweight Status Among Parents of Preschool-Aged Children,Minnesota, 2004-2005

Introduction

Many studies have found that parents of overweight children do not perceive their child to be overweight. Little is known, however, about the extent to which such misperceptions exist among parents of preschool-aged children.

Methods

We analyzed data that were collected in 2004-2005 from parents of 593 preschool-aged children in 20 child care centers in the Minneapolis-St. Paul, Minnesota, metropolitan area. Parents were asked how they would classify their preschooler''s weight, and children''s height and weight were measured.

Results

Of the predominantly white, educated sample, most parents (90.7%) of overweight preschoolers classified their child as normal weight. An even higher percentage (94.7%) of children at risk for overweight were classified as normal weight by their parents. Most parents of normal-weight children classified their child''s weight as average. However, 16.0% classified their normal-weight child as underweight or very underweight.

Conclusion

Results indicate that parents are unlikely to recognize childhood overweight among preschool-aged children, which is concerning because parents of overweight children may be unlikely to engage in obesity prevention efforts for their child if they do not recognize their child''s risk status. A notable proportion of parents of normal-weight children perceived their child to be underweight, which suggests that parents of normal-weight children may be more concerned with undernutrition than overnutrition.     

Prenatal organochlorine compound exposure, rapid weight gain, and overweight in infancy

Background

Although it has been hypothesized that fetal exposure to endocrine-disrupting chemicals may increase obesity risk, empirical data are limited, and it is uncertain how early in life any effects may begin.

Objectives

We explored whether prenatal exposure to several organochlorine compounds (OCs) is associated with rapid growth in the first 6 months of life and body mass index (BMI) later in infancy.

Methods

Data come from the INMA (Infancia y Medio-Ambiente) Child and Environment birth cohort in Spain, which recruited 657 women in early pregnancy. Rapid growth during the first 6 months was defined as a change in weight-for-age z-scores > 0.67, and elevated BMI at 14 months, as a z-score ≥ the 85th percentile. Generalized linear models were used to estimate the risk of rapid growth or elevated BMI associated with 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene (DDE), hexachlorobenzene, β-hexachlorohexane, and polychlorinated biphenyls in first-trimester maternal serum.

Results

After multivariable adjustment including other OCs, DDE exposure above the first quartile was associated with doubling of the risk of rapid growth among children of normal-weight (BMI < 25 kg/m²), but not overweight, mothers. DDE was also associated with elevated BMI at 14 months (relative risk per unit increase in log DDE = 1.50; 95% confidence interval, 1.11–2.03). Other OCs were not associated with rapid growth or elevated BMI after adjustment.

Conclusions

In this study we found prenatal DDE exposure to be associated with rapid weight gain in the first 6 months and elevated BMI later in infancy, among infants of normal-weight mothers. More research exploring the potential role of chemical exposures in early-onset obesity is needed.     

Family History of Hypertension and the Risk of Overweight in Japanese Children: Results From the Toyama Birth Cohort Study

Background

Family history can be a useful screening tool in the assessment and management of the risk for noncommunicable disease. However, no data have yet been reported on family history of hypertension and its effect on children’s overweight.

Methods

A total of 7249 Japanese children enrolled in the Toyama Birth Cohort Study were followed until 2002 (mean age: 12.3 years). Family history of hypertension was ascertained by asking children’s parents whether children’s biological parents or grandparents had doctor-diagnosed hypertension. Child overweight was defined according to international criteria for age- and sex-specific body mass index.

Results

The prevalence of child overweight at age 12 was 21.7% for males and 15.9% for females. After adjusting for family structure, parental employment status, and lifestyle factors, we found that a maternal family history of hypertension was positively associated with the risk of child overweight at age 12 (adjusted odds ratio [OR] 1.21, 95% confidence interval [CI] 1.04–1.39). The adjusted OR increased from 1.16 (95% CI 0.99–1.35) to 1.42 (95% CI 1.04–1.92) to 4.75 (95% CI 1.35–16.69) as the number of family members with hypertension increased from 1 to 2 to 3, respectively. There was no significant difference in the prevalence of overweight between children with a paternal family history of hypertension and those without.

Conclusions

A maternal family history of hypertension was positively associated with the risk of overweight in children at age 12.Key words: family history, hypertension, overweight, the Toyama study     

Is Maternal Smoking during Early Pregnancy a Risk Factor for All Low Birth Weight Infants?

Background

Low birth weight (LBW) infants do not form a homogeneous group; LBW can be caused by prematurity or poor fetal growth manifesting as small for gestational age (SGA) infants or intrauterine growth retardation. We aimed to clarify the relationship of maternal smoking with both SGA and preterm LBW infants.

Methods

The study population comprised pregnant women who registered at the Koshu City between January 1, 1995, and December 31, 2000, and their children. We performed multivariate analyses using multiple logistic regression models to clarify the relationship of maternal smoking during pregnancy with the SGA outcome and preterm birth in LBW infants.

Results

In this study period, 1,329 pregnant women responded to questionnaires, and infant data were collected from 1,100 mothers (follow-up rate: 82.8%). The number of LBW infants was 81 (7.4%). In this cohort, maternal smoking during early pregnancy was associated with LBW and the SGA outcome. Maternal smoking during early pregnancy was a risk factor for LBW with SGA outcome and for LBW with full-term birth. However, it was not a risk factor for LBW with appropriate weight for gestational age (AGA) and LBW with preterm birth.

Conclusion

These results suggested that LBW with AGA and LBW with preterm birth were associated with other risk factors that were not considered in this study, such as periodontal disease. For the prevention of LBW, not only abstinence from smoking during pregnancy but also other methods such as establishing a clinical setting should be adopted.Key words: Infant, Low Birth Weight; Pregnancy; Risk Factors; Smoking     

The Association of Prenatal Exposure to Perfluorinated Chemicals with Maternal Essential and Long-Chain Polyunsaturated Fatty Acids during Pregnancy and the Birth Weight of Their Offspring: The Hokkaido Study

Background

Fatty acids (FAs) are essential for fetal growth. Exposure to perfluorinated chemicals (PFCs) may disrupt FA homeostasis, but there are no epidemiological data regarding associations of PFCs and FA concentrations.

Objectives

We estimated associations between perfluorooctane sulfonate (PFOS)/perfluorooctanoate (PFOA) concentrations and maternal levels of FAs and triglyceride (TG) and birth size of the offspring.

Methods

We analyzed 306 mother–child pairs in this birth cohort between 2002 and 2005 in Japan. The prenatal PFOS and PFOA levels were measured in maternal serum samples by liquid chromatography–tandem mass spectrometry. Maternal blood levels of nine FAs and TG were measured by gas chromatography–mass spectrometry and TG E-Test Wako kits, respectively. Information on infants’ birth size was obtained from participant medical records.

Results

The median PFOS and PFOA levels were 5.6 and 1.4 ng/mL, respectively. In the fully adjusted model, including maternal age, parity, annual household income, blood sampling period, alcohol consumption, and smoking during pregnancy, PFOS but not PFOA had a negative association with the levels of palmitic, palmitoleic, oleic, linoleic, α-linolenic, and arachidonic acids (p < 0.005) and TG (p-value = 0.016). Female infants weighed 186.6 g less with mothers whose PFOS levels were in the fourth quartile compared with the first quartile (95% CI: –363.4, –9.8). We observed no significant association between maternal levels of PFOS and birth weight of male infants.

Conclusions

Our data suggest an inverse association between PFOS exposure and polyunsaturated FA levels in pregnant women. We also found a negative association between maternal PFOS levels and female birth weight.

Citation

Kishi R, Nakajima T, Goudarzi H, Kobayashi S, Sasaki S, Okada E, Miyashita C, Itoh S, Araki A, Ikeno T, Iwasaki Y, Nakazawa H. 2015. The association of prenatal exposure to perfluorinated chemicals with maternal essential and long-chain polyunsaturated fatty acids during pregnancy and the birth weight of their offspring: the Hokkaido Study. Environ Health Perspect 123:1038–1045; http://dx.doi.org/10.1289/ehp.1408834     

Peer Reviewed: Association Between Sedentary Behavior, Physical Activity, and Obesity: Inactivity Among Active Kids

Introduction

Sedentary behavior and physical activity are not mutually exclusive behaviors. The relative risk of overweight for adolescents who are highly sedentary and highly physically active is unclear. A better understanding of the relationship between sedentary behaviors, physical activity, and body mass index (BMI) would provide insight for developing interventions to prevent or reduce overweight.

Methods

Using the physical activity module of the School Health Action, Planning and Evaluation System (SHAPES), we collected data from 25,060 students in grades 9 through 12 from 76 secondary schools in Ontario, Canada. Sex-specific logistic regression analyses were performed to examine how BMI, weight perceptions, social influences, team sports participation, and smoking behavior were associated with being 1) high active-high sedentary, 2) low active-low sedentary, and 3) low active-high sedentary.

Results

Low active-high sedentary boys were more likely to be overweight than high active-low sedentary boys (adjusted odds ratio [AOR], 1.60; 95% confidence interval [CI], 1.01-2.58). When compared with high active-low sedentary girls, girls who were low active-high sedentary (OR, 2.24; 95% CI, 1.23-4.09) or high active-high sedentary (OR, 1.91; 95% CI, 1.01-3.61) were more likely to be overweight.

Conclusion

Sedentary behavior may moderate the relationship between physical activity and overweight. Developing a better understanding of sedentary behavior in relation to physical activity and overweight is critical for preventing and reducing overweight among youth.