Exposure to the pesticide DDT and risk of diabetes and hypertension: Systematic review and meta-analysis of prospective studies.

BACKGROUND: Experimental evidence suggests that p,p'-DDE might be involved in the development of diabetes and hypertension (HTN); however, the evidence in humans is inconclusive. OBJECTIVE: To summarize the epidemiological evidence for the association of p,p'-DDT exposure and its breakdown products with the risk of diabetes and HTN from prospective studies. METHODS: We performed a systematic review and meta-analysis based on the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Eligible studies (prospective) were search in PubMed, Web of Science, EBSCO, and SciELO databases (July 11, 2020). Different search algorithms were used for diabetes and HTN. Pooled odds ratios (ORs) were estimated from meta-analysis with random effects for each exposure and outcome. RESULTS: A total of 23 prospective studies were included in this review, 16 assessed diabetes and seven HTN; very few measured p,p'-DDT. Exposure to p,p'-DDE was associated with a slightly increased risk of type 2 diabetes (T2D) (pooled OR = 1.44; 95%CI: 1.00, 2.07; p = 0.049) and HTN (pooled OR = 1.21; 95%CI: 1.07, 1.38). Dose-response meta-analysis suggested a non-linear relation between p,p'-DDE and T2D. Exposure to p,p'-DDE was not associated with gestational diabetes (pooled OR = 1.01; 95%CI: 0.94, 1.09); similarly, p,p'-DDT was not associated with T2D (pooled OR = 1.03; 95%CI: 0.79, 1.35). CONCLUSIONS: Evidence from prospective studies suggests that exposure to p,p'-DDE, the main breakdown product of p,p'-DDT, might increase the risk of developing T2D; such increase may be apparent only at low levels. Exposure to p,p'-DDE may also increase the risk of having HTN; however, further evidence is required.

Violencia de pareja y depresión en mujeres que trabajan en una institución de salud de México / Intimate partner violence and depression among adult women working in a health facility in Mexico

Objetivo: Evaluar el efecto de la violencia de pareja, experimentada en los últimos 12 meses, sobre el riesgo de depresión y la sintomatología depresiva en mujeres adultas. Método: Se analizaron los datos de 470 mujeres de la Cohorte de Trabajadores de la Salud de México. El tipo y la gravedad de la violencia de pareja se midieron en los años 2004 y 2011. El evento principal fue el diagnóstico médico de depresión (2011). Un evento secundario fue la sintomatología depresiva (2004 y 2011), evaluada mediante la Escala de Depresión del Centro de Estudios Epidemiológicos (CES-D). El riesgo de depresión y la sintomatología depresiva en relación con la violencia se evaluaron con modelos de regresión de efectos aleatorios logísticos y lineales, respectivamente. Resultados: El 41,9% experimentó violencia de pareja en la medición basal. La incidencia de depresión fue del 7,2%. El riesgo de depresión aumentó con la violencia de pareja de cualquier tipo (odds ratio ajustada [ORa]=2,9; intervalo de confianza del 95% [IC95%]: 1,4-6,2) y con las violencias física (ORa=4,3; IC95%: 1,8-10,1), psicológica (ORa=3,1; IC95%: 1,4-6,6) y sexual (ORa=3,1; IC95%: 1,2--8,2). Los síntomas depresivos (CES-D) aumentaron ligeramente con las violencias física y sexual. Conclusiones: La violencia de pareja se asoció a un mayor riesgo de depresión en mujeres trabajadoras de una institución de salud de México. Los resultados indican la necesidad de contar con infraestructura, implementar estrategias de atención y consejería, y brindar un ambiente seguro en los lugares de trabajo para quienes sufren violencia de pareja. (AU)

Objective: To assess the effect of intimate partner violence on the risk of depression and depressive symptoms among adult women. Method: We analyzed data from the Mexican Health Workers' Cohort study (n=470). Type and severity of intimate partner violence was ascertained between 2004 and 2011. Self-reported medical diagnosis of depression (2011) was the main outcome; depressive symptoms ascertained with the Centre for Epidemiologic Studies-Depression (CES-D) scale was the secondary outcome. Random-effects regressions were run to model the risk of depression (logistic) and depressive symptoms (linear) in relation to intimate partner violence. Results: 41.9% women experienced intimate partner violence at baseline. The incidence of depression was 7.2%. The risk of depression increased with any type of IPV (adjusted odds ratio [aOR]=2.9; 95% confidence interval [95%CI]: 1.4-6.2) and with physical (aOR=4.3; 95%CI: 1.8-10.1), psychological (aOR=3.1; 95%CI: 1.4-6.6) and sexual (aOR=3.1; 95%CI: 1.2-8.2) violence. Depressive symptoms (CES-D) increased slightly with physical and sexual intimate partner violence. Conclusions: Intimate partner violence was associated with a higher risk of depression in this sample of women working in a Mexican health facility. Our results indicate the need to develop infrastructure, to implement strategies of attention and counselling, and to provide a safe environment in the workplace for women who experience intimate partner violence. (AU)

[Intimate partner violence and depression among adult women working in a health facility in Mexico]. / Violencia de pareja y depresión en mujeres que trabajan en una institución de salud de México.

OBJECTIVE: To assess the effect of intimate partner violence on the risk of depression and depressive symptoms among adult women. METHOD: We analyzed data from the Mexican Health Workers' Cohort study (n=470). Type and severity of intimate partner violence was ascertained between 2004 and 2011. Self-reported medical diagnosis of depression (2011) was the main outcome; depressive symptoms ascertained with the Centre for Epidemiologic Studies-Depression (CES-D) scale was the secondary outcome. Random-effects regressions were run to model the risk of depression (logistic) and depressive symptoms (linear) in relation to intimate partner violence. RESULTS: 41.9% women experienced intimate partner violence at baseline. The incidence of depression was 7.2%. The risk of depression increased with any type of IPV (adjusted odds ratio [aOR]=2.9; 95% confidence interval [95%CI]: 1.4-6.2) and with physical (aOR=4.3; 95%CI: 1.8-10.1), psychological (aOR=3.1; 95%CI: 1.4-6.6) and sexual (aOR=3.1; 95%CI: 1.2-8.2) violence. Depressive symptoms (CES-D) increased slightly with physical and sexual intimate partner violence. CONCLUSIONS: Intimate partner violence was associated with a higher risk of depression in this sample of women working in a Mexican health facility. Our results indicate the need to develop infrastructure, to implement strategies of attention and counselling, and to provide a safe environment in the workplace for women who experience intimate partner violence.

Exposure to DDT from indoor residual spraying and biomarkers of inflammation among reproductive-aged women from South Africa.

BACKGROUND: Evidence from animal studies suggests that DDT and DDE can adversely affect immuno-competence while human data are less conclusive. We aimed to assess the association of plasma concentrations of DDT and DDE with biomarkers of inflammation among reproductive-aged women residing in homes sprayed with DDT through Indoor Residual Spraying (IRS). METHODS: This study included 416 women from the Study of Women and Babies, South Africa (2010-2011). DDT, DDE, and biomarkers of inflammation (immunoglobulins A, G and M, interleukins 1ß, 6, and 8, tumor necrosis factor-α, C-reactive protein, serum amyloid-A, intercellular adhesion molecule-1, vascular cell adhesion molecule-1) were quantified in plasma. Linear regression was used to assess associations of DDT and DDE with each natural log-transformed biomarker. Models were adjusted for age, body mass index, parity, income, and season; beta estimates were expressed as percent differences. RESULTS: Compared to women with the lowest plasma concentrations of DDT and DDE, those with the highest concentrations of both compounds had higher levels IL-1ß, IL6, and TNF- α. While associations were statistically significant for both DDT and DDE, the magnitude of the associations was slightly stronger for DDT. Compared to women in the lowest quintile of DDT, women in the highest quintile were estimated to have 53.0% (95%CI: 21.7%, 84.4%), 28.1% (95%CI: 6.4%, 49.8%), and 26.6% (95%CI: 12.0%, 41.1%) higher levels of IL-1ß, IL6, and TNF- α, respectively. CONCLUSIONS: Our results suggest that increased plasma concentrations of DDT and DDE resulting from exposure to IRS may increase concentrations of pro-inflammatory biomarkers among reproductive-aged women in South Africa.

[Predictors of kidney function in a cohortof Mexican adults]. / Predictores de la función renal en una cohorte de adultos mexicanos.

OBJECTIVE: Our aim was to examine prospectively predictors of subclinical renal alterations among adults without chronic kidney disease. MATERIALS AND METHODS: We analyzed data from a cohort of Mexican adults (n=757). Kidney function (2010) was assessed with the estimated glomerular filtration rate (eGFR-Cr), serum creatinine and uric acid. Predictors of each kidney function marker (2004) were identified with linear and logistic regression models. RESULTS: 33% had an eGFR-Cr 40 years old and users of antihypertensive medication; and higher among those with a high protein intake. Serum creatinine predictors were similar to those observed for eGFR-Cr. Uric acid decreased in men, among those with obesity, hypertension and high cholesterol. CONCLUSIONS: Conventional kidney function biomarkers are useful to identify subclinical alterations. Some predictors of kidney function are potentially modifiable, therefore susceptible for intervention among high-risk groups.

OBJETIVO: Examinar prospectivamente los predictores de alteraciones subclínicas de la función renal en adultos sin diagnóstico previo de enfermedad renal crónica. MATERIAL Y MÉTODOS: Se analizaron datos de una cohorte de adultos mexicanos (n=757). La función renal (2010) se midió mediante la tasa de filtración glomerular estimada (TFGECr), creatinina y ácido úrico séricos. Los predictores (2004) se identificaron con modelos de regresión lineal y logística. RESULTADOS: Se clasificó 33% con TFGE-Cr disminuida.La TFGE-Cr fue menor en hombres, en >40 años y en usuarios de antihipertensivos; y fue mayor en aquellos con consumo proteico alto. Los predictores de la creatinina fueron similares a los de la TFGE-Cr. El ácido úrico disminuyó en participantes hombres, con obesidad, hipertensión e hipercolesterolemia. CONCLUSIONES: Los biomarcadores séricos convencionales son útiles para identificar alteraciones subclínicas de la función renal. Algunos predictores de la función renal son potencialmente modificables, por tanto susceptibles de intervención.

Predictores de la función renal en una cohorte de adultos mexicanos / Predictors of kidney function in a cohort of Mexican adults

Resumen: Objetivo: Examinar prospectivamente los predictores de alteraciones subclínicas de la función renal en adultos sin diagnóstico previo de enfermedad renal crónica. Material y métodos: Se analizaron datos de una cohorte de adultos mexicanos (n=757). La función renal (2010) se midió mediante la tasa de filtración glomerular estimada (TFGE-Cr), creatinina y ácido úrico séricos. Los predictores (2004) se identificaron con modelos de regresión lineal y logística. Resultados: Se clasificó 33% con TFGE-Cr disminuida. La TFGE-Cr fue menor en hombres, en >40 años y en usuarios de antihipertensivos; y fue mayor en aquellos con consumo proteico alto. Los predictores de la creatinina fueron similares a los de la TFGE-Cr. El ácido úrico disminuyó en participantes hombres, con obesidad, hipertensión e hipercolesterolemia. Conclusión. Los biomarcadores séricos convencionales son útiles para identificar alteraciones subclínicas de la función renal. Algunos predictores de la función renal son potencialmente modificables, por tanto susceptibles de intervención.

Abstract: Objectives: Our aim was to examine prospectively predictors of subclinical renal alterations among adults without chronic kidney disease. Materials and methods: We analyzed data from a cohort of Mexican adults (n=757). Kidney function (2010) was assessed with the estimated glomerular filtration rate (eGFR-Cr), serum creatinine and uric acid. Predictors of each kidney function marker (2004) were identified with linear and logistic regression models. Results: 33% had an eGFR-Cr <90 ml/min/1.73 m2. eGFR-Cr was lower among men, those >40 years old and users of antihypertensive medication; and higher among those with a high protein intake. Serum creatinine predictors were similar to those observed for eGFR-Cr. Uric acid decreased in men, among those with obesity, hypertension and high cholesterol. Conclusion: Conventional kidney function biomarkers are useful to identify subclinical alterations. Some predictors of kidney function are potentially modifiable, therefore susceptible for intervention among high-risk groups.

In utero exposure to DDT and incidence of diarrhea among boys from tropical Mexico.

BACKGROUND: A higher incidence rate (IR) of acute gastrointestinal (GI) infections associated with prenatal exposure to p,p'-DDE was suggested by the results in two studies. Given the high mortality rate due to childhood diarrhea in some countries with ongoing use of DDT, additional data on this association is relevant for those making decisions about vector-borne disease control. OBJECTIVE: To evaluate whether higher levels of prenatal exposure to p,p'-DDE and p,p'-DDT increase the risk of having diarrhea in a birth cohort of boys from tropical Mexico. METHODS: Our analysis was based on 747 boys whose exposure was measured in maternal serum collected at delivery (2002-2003). Mothers reported the number of diarrhea episodes of their children during in-person interviews. The median age of the children at their last interview was 21.4 months. Poisson regression models were fitted to estimate adjusted incidence rate ratios (aIRR) of diarrhea by levels of p,p'-DDE and p,p'-DDT. RESULTS: Overall, there were 1.7 episodes of diarrhea per child-year. Among those in the highest category of exposure (> 9µg DDE/g serum lipid), the aIRR for diarrhea was 1.14 (95% CI: 0.94, 1.30) compared to those in the lowest category of exposure (≤ 3µg/g). Among boys living in the urban area, the corresponding aIRR was 1.39 (95% CI: 1.07-1.80). Among rural boys, no associations emerged. CONCLUSION: Although the results were consistent with a small positive association, the overall estimate was not precise. While urban boys in this study appeared to be more susceptible to DDE-associated diarrhea, a ready explanation for such increased susceptibility was not apparent.

[CONSUMPTION OF OMEGA- 3 FATTY ACIDS AND DEPRESSIVE SYMPTOMS IN COLLEGE STUDENTS FROM SONORA, MEXICO]. / CONSUMO DE ÁCIDOS GRASOS OMEGA-3 Y SÍNTOMAS DEPRESIVOS EN UNIVERSITARIOS DE SONORA, MÉXICO.

INTRODUCTION: recent studies suggest that low serum levels of polyunsaturated fatty acids omega-3 are associated with a higher prevalence of depression. OBJECTIVE: to evaluate whether low consumption of Omega-3 fatty acids is associated with a higher prevalence of depressive symptoms in a sample of college students from the Northwest of Mexico, and to assess the potential effect modification by alcohol consumption. METHODS: we conducted a cross-sectional study in a sample of 706 college students (males and females) aged 18 to 24. The presence of depressive symptoms was identified with the Depression Scale of the Center for Epidemiologic Studies (CES-D), using a cutoff point of ≥ 24. The intake of omega-3 was obtained by a food frequency questionnaire validated for Mexican population. We estimated the weekly intake of alpha-linolenic fatty acid (ALA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) derived from the diet in mg/g of food. The association between omega-3 from diet and the presence of depressive symptoms was assessed using logistic regression models adjusted for potential confounders. RESULTS: 67% of the participants were females; 16.6% were classified as having depressive symptoms. A low intake of ALA and EPA + DHA was not associated with depressive symptoms before and after adjusting for confounders. Median levels of ALA (from nuts only) were significantly lower among those with depressive symptoms compared to those without these symptoms. CONCLUSIONS: in this population of Mexican college students, a low intake of omega-3 fatty acids was not associated with depressive symptoms. The potential association between nut consumption and depressive symptoms deserve more attention.

Introducción: estudios recientes sugieren que los niveles bajos de acidos grasos poliinsaturados omega-3 se relacionan con una mayor prevalencia de depresion; sin embargo, los resultados no son concluyentes. Objetivo: evaluar la asociacion entre el bajo consumo de acidos grasos omega-3 y la presencia de sintomas depresivos en jovenes universitarios del noroeste de Mexico. Métodos: se realizo un estudio transversal en una muestra de 706 universitarios de 18 a 24 anos de edad de ambos sexos. La presencia de sintomatologia depresiva se estimo con la escala de Depresion del Centro de Estudios Epidemiologicos (CES-D) empleando un punto de corte ≥ 24. El consumo semanal de acidos grasos alfalinolenico (ALA) y de eicosapentaenoico (EPA) mas docosahexaenoico (DHA) en mg/g de alimento se estimo por medio de un cuestionario de frecuencia de consumo de alimentos validado para la poblacion mexicana. La asociacion del consumo de omega-3 con la presencia de sintomas depresivos se evaluo con modelos de regresion logistica. Resultados: el 67% de los participantes fueron mujeres; en general, el 16,6% presentaron sintomatologia depresiva. El consumo bajo de ALA y EPA + DHA no se asocio con mayor prevalencia de sintomatologia depresiva antes y despues de ajustar por confusores. En aquellos casos con sintomatologia depresiva, los niveles ALA derivados solo de las nueces fueron significativamente menores. Conclusiones: en esta poblacion no se observo asociacion entre el bajo consumo de acidos grasos omega-3 y la sintomatologia depresiva. La posible asociacion entre el consumo de nueces y la sintomatologia depresiva requiere de mas estudios.

Consumo de ácidos grasos omega-3 y síntomas depresivos en universitarios de Sonora, México / Consumption of omega- 3 fatty acids and depressive symptoms in college students from Sonora, Mexico

Introducción: estudios recientes sugieren que los niveles bajos de ácidos grasos poliinsaturados omega-3 se relacionan con una mayor prevalencia de depresión; sin embargo, los resultados no son concluyentes. Objetivo: evaluar la asociación entre el bajo consumo de ácidos grasos omega-3 y la presencia de síntomas depresivos en jóvenes universitarios del noroeste de México. Métodos: se realizó un estudio transversal en una muestra de 706 universitarios de 18 a 24 años de edad de ambos sexos. La presencia de sintomatología depresiva se estimó con la escala de Depresión del Centro de Estudios Epidemiológicos (CES-D) empleando un punto de corte ≥ 24. El consumo semanal de ácidos grasos alfalinolénico (ALA) y de eicosapentaenóico (EPA) más docosahexaenóico (DHA) en mg/g de alimento se estimó por medio de un cuestionario de frecuencia de consumo de alimentos validado para la población mexicana. La asociación del consumo de omega-3 con la presencia de síntomas depresivos se evaluó con modelos de regresión logística. Resultados: el 67% de los participantes fueron mujeres; en general, el 16,6% presentaron sintomatología depresiva. El consumo bajo de ALA y EPA + DHA no se asoció con mayor prevalencia de sintomatología depresiva antes y después de ajustar por confusores. En aquellos casos con sintomatología depresiva, los niveles ALA derivados solo de las nueces fueron significativamente menores. Conclusiones: en esta población no se observó asociación entre el bajo consumo de ácidos grasos omega-3 y la sintomatología depresiva. La posible asociación entre el consumo de nueces y la sintomatología depresiva requiere de más estudios (AU)

Introduction: recent studies suggest that low serum levels of polyunsaturated fatty acids omega-3 are associated with a higher prevalence of depression. Objective: to evaluate whether low consumption of Omega-3 fatty acids is associated with a higher prevalence of depressive symptoms in a sample of college students from the Northwest of Mexico, and to assess the potential effect modification by alcohol consumption. Methods: we conducted a cross-sectional study in a sample of 706 college students (males and females) aged 18 to 24. The presence of depressive symptoms was identified with the Depression Scale of the Center for Epidemiologic Studies (CES-D), using a cutoff point of ≥ 24. The intake of omega-3 was obtained by a food frequency questionnaire validated for Mexican population. We estimated the weekly intake of alpha-linolenic fatty acid (ALA), eicosapentaenoic (EPA) and docosahexaenoic (DHA) derived from the diet in mg/g of food. The association between omega-3 from diet and the presence of depressive symptoms was assessed using logistic regression models adjusted for potential confounders. Results: 67% of the participants were females; 16.6% were classified as having depressive symptoms. A low intake of ALA and EPA + DHA was not associated with depressive symptoms before and after adjusting for confounders. Median levels of ALA (from nuts only) were significantly lower among those with depressive symptoms compared to those without these symptoms. Conclusions: in this population of Mexican college students, a low intake of omega-3 fatty acids was not associated with depressive symptoms. The potential association between nut consumption and depressive symptoms deserve more attention (AU)

Recreational Exercise Before and During Pregnancy in Relation to Plasma C-Reactive Protein Concentrations in Pregnant Women.

BACKGROUND: Pregnant women who are physically active have a lower risk of preeclampsia and gestational diabetes than women who are less active. One possible mechanism is a reduction in low-grade inflammation, as measured by plasma concentrations of C-reactive protein (CRP). The association between exercise and CRP in pregnant women, however, has not been adequately investigated. METHODS: A total of 537 pregnant women, enrolled around the 17th week of gestation in the Norwegian Mother and Child Cohort Study in 2003 to 2004, were studied. Self-reported recreational exercise was recalled for both 3 months before pregnancy and early pregnancy. The total energy expenditure from recreational exercise (total recreational exercise, metabolic equivalent of task [MET]-hr/week) was estimated, and low-, moderate- and vigorous-intensity exercise was defined. Plasma CRP concentrations were measured during pregnancy. RESULTS: In adjusted linear regression models, mean CRP concentration was 1.0% lower [95% CI = -1.9% to 0.2%] with each 1 MET-hr/week of total recreational exercise before pregnancy. In addition, vigorous-intensity exercise before pregnancy was more strongly related to a reduction in CRP levels than low- or moderate-intensity exercise. However, we observed no association between recreational exercise during pregnancy and plasma CRP levels. CONCLUSIONS: Recreational exercise before pregnancy, especially vigorous exercise, may reduce the risk of maternal inflammation during pregnancy.

Prenatal exposure to p,p'-DDE and p,p'-DDT in relation to lower respiratory tract infections in boys from a highly exposed area of Mexico.

BACKGROUND: Prenatal exposure to 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE), the major breakdown product of DDT, has been associated with recurrent lower respiratory tract infections (LRTIs) in infants. However, epidemiological investigations are limited. OBJECTIVE: To assess the association of prenatal exposure to p,p'-DDE and p,p'-DDT with the occurrence of LRTI in boys from Chiapas, a highly exposed area of Mexico. METHODS: We analyzed data from 747 singleton boys whose prenatal exposure to p,p'-DDE and p,p'-DDT was determined in maternal serum drawn at delivery (2002-2003). LRTI (i.e., pneumonia, bronchiolitis, and other illness of the bronchi) experienced by the children were reported by their mothers during in-person interviews. The median age of the children when they were last seen was 21.4 months (quartiles 19.1 and 25.3 months). RESULTS: Median exposure to p,p'-DDE in this population was higher (2.7 µg/g lipid) than recent U.S. levels (0.20 µg/g). There were 0.19 episodes of LRTI per child-year. After adjusting for potential confounders, children in the highest category of p,p'-DDE (>9.00 µg/g) exposure compared to those in the lowest (≤ 3.00 µg/g) had an adjusted incidence rate ratio (aIRR) of LRTI of 0.77 (95% confidence interval [CI], 0.41-1.46). The corresponding aIRR for p,p'-DDT (≥ 2.00 µg/g compared to ≤ 0.25 µg/g) was 0.65 (95% CI: 0.30-1.39). CONCLUSION: An association of prenatal exposure to p,p'-DDE and p,p'-DDT with LRTI during childhood was not supported in this population with relatively high levels of exposure.

Prenatal exposure to persistent organochlorines and childhood obesity in the US collaborative perinatal project.

BACKGROUND: In some previous studies, prenatal exposure to persistent organochlorines such as 1,1,-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p´-DDE), polychlorinated biphenyls (PCBs), and hexachlorobenzene (HCB) has been associated with higher body mass index (BMI) in children. OBJECTIVE: Our goal was to evaluate the association of maternal serum levels of ß-hexachlorocyclohexane (ß-HCH), p,p´-DDE, dichlorodiphenyltrichloroethane (p,p´-DDT), dieldrin, heptachlor epoxide, HCB, trans-nonachlor, oxychlordane, and PCBs with offspring obesity during childhood. METHODS: The analysis was based on a subsample of 1,915 children followed until 7 years of age as part of the U.S. Collaborative Perinatal Project (CPP). The CPP enrolled pregnant women in 1959-1965; exposure levels were measured in third-trimester maternal serum that was collected before these organochlorines were banned in the United States. Childhood overweight and obesity were defined using age- and sex-specific cut points for BMI as recommended by the International Obesity Task Force. RESULTS: Adjusted results did not show clear evidence for an association between organochlorine exposure and obesity; however, a suggestive finding emerged for dieldrin. Compared with those in the lowest quintile (dieldrin, < 0.57 µg/L), odds of obesity were 3.6 (95% CI: 1.3, 10.5) for the fourth and 2.3 (95% CI: 0.8, 7.1) for the highest quintile. Overweight and BMI were unrelated to organochlorine exposure. CONCLUSIONS: In this population with relatively high levels of exposure to organochlorines, no clear associations with obesity or BMI emerged.

450K epigenome-wide scan identifies differential DNA methylation in newborns related to maternal smoking during pregnancy.

BACKGROUND: Epigenetic modifications, such as DNA methylation, due to in utero exposures may play a critical role in early programming for childhood and adult illness. Maternal smoking is a major risk factor for multiple adverse health outcomes in children, but the underlying mechanisms are unclear. OBJECTIVE: We investigated epigenome-wide methylation in cord blood of newborns in relation to maternal smoking during pregnancy. METHODS: We examined maternal plasma cotinine (an objective biomarker of smoking) measured during pregnancy in relation to DNA methylation at 473,844 CpG sites (CpGs) in 1,062 newborn cord blood samples from the Norwegian Mother and Child Cohort Study (MoBa) using the Infinium HumanMethylation450 BeadChip (450K). RESULTS: We found differential DNA methylation at epigenome-wide statistical significance (p-value < 1.06 × 10-7) for 26 CpGs mapped to 10 genes. We replicated findings for CpGs in AHRR, CYP1A1, and GFI1 at strict Bonferroni-corrected statistical significance in a U.S. birth cohort. AHRR and CYP1A1 play a key role in the aryl hydrocarbon receptor signaling pathway, which mediates the detoxification of the components of tobacco smoke. GFI1 is involved in diverse developmental processes but has not previously been implicated in responses to tobacco smoke. CONCLUSIONS: We identified a set of genes with methylation changes present at birth in children whose mothers smoked during pregnancy. This is the first study of differential methylation across the genome in relation to maternal smoking during pregnancy using the 450K platform. Our findings implicate epigenetic mechanisms in the pathogenesis of the adverse health outcomes associated with this important in utero exposure.

Exposure to tobacco smoke in utero and subsequent plasma lipids, ApoB, and CRP among adult women in the MoBa cohort.

BACKGROUND: Recent findings suggest that maternal smoking during pregnancy may play a role in the development of metabolic alterations in offspring during childhood. However, whether such exposure increases the risk of developing similar metabolic alterations during adulthood is uncertain. OBJECTIVE: We evaluated the association of in utero exposure to maternal tobacco smoke with plasma lipids, apolipoprotein B (apoB), and C-reactive protein (CRP) in adulthood. METHODS: The study was based on a subsample of the Norwegian Mother and Child Cohort Study (MoBa) and included 479 pregnant women with plasma lipids, apoB, and CRP measurements. Information on in utero exposure to tobacco smoke, personal smoking, and other factors were obtained from the women by a self-completed questionnaire at enrollment, at approximately 17 weeks of gestation. RESULTS: Women exposed to tobacco smoke in utero had higher triglycerides [10.7% higher; 95% confidence interval (CI): 3.9, 17.9] and lower high-density lipoprotein cholesterol (HDL) (-1.9 mg/dL; 95% CI: -4.3, 0.5) compared with unexposed women, after adjusting for age, physical activity, education, personal smoking, and current body mass index (BMI). Exposed women were also more likely to have triglycerides ≥ 200 mg/dL [adjusted odds ratio (aOR) = 2.5; 95% CI: 1.3, 5.1] and HDL < 50 mg/dL (aOR = 2.3; 95% CI: 1.1, 5.0). Low-density lipoprotein cholesterol, total cholesterol, and apoB were not associated with the exposure. CRP was increased among exposed women; however, after adjustment for BMI, the association was completely attenuated. CONCLUSIONS: In this population, in utero exposure to tobacco smoke was associated with high triglycerides and low HDL in adulthood, 18-44 years after exposure.

Perfluorinated compounds in relation to birth weight in the Norwegian Mother and Child Cohort Study.

Perfluorooctane sulfonate and perfluorooctanoic acid are perfluorinated compounds (PFCs) widely distributed in the environment. Previous studies of PFCs and birth weight are equivocal. The authors examined this association in the Norwegian Mother and Child Cohort Study (MoBa), using data from 901 women enrolled from 2003 to 2004 and selected for a prior case-based study of PFCs and subfecundity. Maternal plasma samples were obtained around 17 weeks of gestation. Outcomes included birth weight z scores, preterm birth, small for gestational age, and large for gestational age. The adjusted birth weight z scores were slightly lower among infants born to mothers in the highest quartiles of PFCs compared with infants born to mothers in the lowest quartiles: for perfluorooctane sulfonate, ß = -0.18 (95% confidence interval: -0.41, 0.05) and, for perfluorooctanoic acid, ß = -0.21 (95% confidence interval: -0.45, 0.04). No clear evidence of an association with small for gestational age or large for gestational age was observed. Perfluorooctane sulfonate and perfluorooctanoic acid were each associated with decreased adjusted odds of preterm birth, although the cell counts were small. Whether some of the associations suggested by these findings may be due to a noncausal pharmacokinetic mechanism remains unclear.

In utero exposure to maternal tobacco smoke and subsequent obesity, hypertension, and gestational diabetes among women in the MoBa cohort.

BACKGROUND: Environmental factors influencing the developmental origins of health and disease need to be identified and investigated. In utero exposure to tobacco smoke has been associated with obesity and a small increase in blood pressure in children; however, whether there is a corresponding increased risk of conditions such as diabetes and hypertension during adulthood remains unclear. OBJECTIVE: Our goal was to assess the association of self-reported in utero exposure to tobacco smoke with the prevalence of obesity, hypertension, type 2 diabetes mellitus (T2DM), and gestational diabetes mellitus (GDM) in women 14-47 years of age. METHODS: We conducted a cross-sectional analysis of the Norwegian Mother and Child Cohort Study, which enrolled pregnant women in Norway from 1999 thorough 2008. Exposure to tobacco smoke in utero (yes vs. no) was ascertained on the baseline questionnaire (obtained at ~ 17 weeks' gestation); the outcomes were ascertained from the Medical Birth Registry of Norway and the questionnaire. Our analysis included 74,023 women. RESULTS: Women exposed to tobacco smoke in utero had 1.53 times the odds of obesity [95% confidence interval (CI): 1.45, 1.61] relative to those unexposed, after adjusting for age, education, and personal smoking. After further adjustment for body mass index, the odds ratio for hypertension was 1.68 (95% CI: 1.19, 2.39); for T2DM 1.14 (95% CI: 0.79, 1.65); and for GDM 1.32 (95% CI: 1.10, 1.58) among exposed compared with unexposed. CONCLUSIONS: Exposure to tobacco smoke in utero was associated with obesity, hypertension, and GDM in adult women. The possibility that the associations were attributable to unmeasured confounding cannot be excluded.

Reproducibility of reported in utero exposure to tobacco smoke.

PURPOSE: In studies of the fetal origins of disease and life course epidemiology, measures of fetal exposure may be based on information reported by the adults who were exposed in utero. In particular, the full spectrum of consequences of in utero exposure to maternal tobacco smoking is now an area of active investigation, and the ability to report such exposure reproducibly is of interest. We evaluated the reproducibility of in utero exposure to tobacco smoke, reported by the adult daughter during consecutive pregnancies. METHODS: This study was based on 11,257 women who enrolled for more than one pregnancy in the Norwegian Mother and Child Cohort Study (MoBa). Participants completed a questionnaire around 17 weeks of gestation, which asked about their in utero exposure to tobacco smoke. Kappa statistics were calculated. Determinants of agreement were evaluated using logistic regression. RESULTS: Weighted Kappa for in utero exposure for the first and second reports was 0.80. Determinants of agreement were higher education (better) and longer time between reports (worse). CONCLUSIONS: Information on in utero exposure to maternal tobacco smoking provided by adult women was highly reproducible in this population.

Prenatal exposure to the major DDT metabolite 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) and growth in boys from Mexico.

Recent data suggest that prenatal exposure to p,p'-DDE may reduce height and increase body mass index (BMI) in childhood, thus potentially raising the risk of adult health problems. The association between prenatal DDE exposure and growth was evaluated in 788 boys from Chiapas, an area of Mexico where DDT was recently used. The median DDE levels in maternal serum at birth (2002-2003) were 2.7 microg/g lipid. 2633 measurements of height (cm) and weight (kg) were obtained in 2004-2005. The median age of the children during follow-up was 18 months (quartiles 14 and 22 months). Height and body mass index (kg/m(2)) were age-standardized and expressed as standard deviation scores (SDS). Multivariate random-effect models for longitudinal data were fitted and predicted height and BMI SDS were estimated from the adjusted models. Overall, associations between prenatal DDE level and height or BMI SDS at any given age were not observed. For example, the predicted values showed that children with the highest exposure (DDE: >9.00 microg/g) compared to those least exposed (DDE: <3.01 microg/g) grew similarly and they had a BMI SDS similar to the referent group. The results do not support the prior findings of an association of DDE exposure with childhood height or BMI.

Reliability of reported breastfeeding duration among reproductive-aged women from Mexico.

Breastfed children have lower risk of infectious diseases, post-neonatal mortality and chronic diseases later in life. Because epidemiologic studies usually rely on reported history of previous breastfeeding, data on the accuracy and precision of recalled histories allow improved interpretation of the epidemiologic findings. We evaluated the reliability of two reported breastfeeding durations in 567 reproductive-aged women from Mexico using information obtained from nearly identical sets of questions applied at different times after weaning. We compared differences between reports, and examined the intraclass correlation coefficient (ICC) for any and for exclusive breastfeeding (EBF). Logistic regression was used to evaluate the determinants of poor recall (difference between reports of >20%). The reliability of duration of any breastfeeding was high (ICC 0.94). Overall, differences between reports of duration were usually <1 month, and for 385/567, the difference was < or =0.5 months. Predictors of poorer recall were having > or =4 children, and time between reports of >2 months. The only predictor of better recall was greater age of the baby at weaning. The reliability of EBF duration was lower (ICC 0.49). In this population with a relatively long duration of breastfeeding, reliability of any breastfeeding duration was high. Age, education and previous breastfeeding were not important predictors of recall, in contrast to findings in earlier studies. Consistent with previous reports, however, parity and length of recall were associated with poorer recall of duration of any breastfeeding. Future studies that use reported breastfeeding duration may want to consider the effect of these variables on recall.

DDE, a degradation product of DDT, and duration of lactation in a highly exposed area of Mexico.

BACKGROUND: Higher levels of 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), the major degradation product of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT), have been related to shorter duration of breast-feeding in previous studies. If DDE truly shortens lactation, this has public health importance regarding infant mortality and the use of DDT for malaria control. OBJECTIVE: Our aim was to assess the relationship of maternal DDE concentrations with length of subsequent lactation. METHODS: We conducted a relatively large study in a highly exposed area of Mexico. We followed 784 mother-son pairs to determine length of lactation. DDE and DDT were measured in maternal serum obtained within a day of delivery. We fit proportional hazard models with and without stratifying by previous breast-feeding, because an association of DDE with duration of lactation among those who breast-fed previously could be attributed to a noncausal mechanism. RESULTS: Compared with those with DDE concentrations < or = 3.00 microg/g, the adjusted hazard ratios of weaning according to DDE category were, for concentrations 3.01-6.00 microg/g, 1.27 [95% confidence interval (CI), 1.04-1.55]; for concentrations 6.01-9.00 microg/g, 1.23 (95% CI, 0.92-1.63); and for concentrations > 9.00 microg/g, 1.17 (95% CI, 0.92-1.49). The corresponding ratios for women who previously breast-fed were 1.40 (95% CI, 1.06-1.87); 1.91 (95% CI, 1.24-2.93); and 1.76 (95% CI, 1.22-2.53). Those for women who had not breast-fed previously were 1.14 (95% CI, 0.86-1.52); 0.90 (95% CI, 0.61-1.31); and 0.91 (95% CI, 0.66-1.26). CONCLUSIONS: Data from our relatively large study in a highly exposed area of Mexico did not support the hypothesis that exposure to DDE shortens length of lactation. The association seen in women who previously breast-fed was likely attributed to a noncausal mechanism. Nonetheless, whether DDT has other important adverse effects on humans is still an open question.