Carcinogenic, non-carcinogenic risk, and attributable cases to organochlorine pesticide exposure in women from Northern Mexico.

This study aimed to estimate the carcinogenic and non-carcinogenic risk as well as the attributable cases due to exposure to organochlorine pesticides (OCPs): hexachlorobenzene (HCB), dichlorophenyltrichloroethane (DDT), hexachlorocyclohexane (HCH), heptachlor, and chlordane. From serum concentrations of pesticides of interest in a sample of 908 women from Northern Mexico, the risk for both cancer and non-cancer health effects was evaluated. The population attributable fraction (PAF) was also calculated based on summary association estimates between exposure to OCPs and different health events. Findings revealed that due to their OCP exposure slightly less than half of the women in the sample were at increased risk of developing non-cancerous diseases. Moreover, approximately 25% and 75% of participants were at risk of develop some type of cancer associated with their HCB and DDE concentrations, respectively. In addition, it was estimated that 40.5% of type 2 diabetes, 18.7% of endometriosis, and 23.1% of non-Hodgkin's lymphoma cases could have been prevented if women had not been exposed to these OCPs. Results suggest that the use of OCPs may have contributed to the disease burden in the study area and, based on the time required for these substances to be eliminated from the body, there are probably some women who are still at elevated risk of developing diseases associated to OCPs.

"Western" and "prudent" dietary patterns are associated with breast cancer among Mexican pre- and postmenopausal women.

Breast cancer (BC) is the leading cancer worldwide among women. "Prudent" dietary patterns have been consistently and negatively associated with the risk of BC. However, prospective studies have shown a positive association between "Western" dietary patterns and the risk of BC, but only among postmenopausal women. In this regard, evidence from Latin America is scarce. Our aim was to assess the hypothesis that 2 dietary patterns (Western or prudent) were contrastingly associated with BC in pre- and postmenopausal women from Northern Mexico. We recruited 1045 BC incident cases and 1030 age matched (±5 years) population controls. Sociodemographic, reproductive, and dietary characteristics were obtained by direct interviews. We used a semiquantitative food frequency questionnaire to obtain information about diet 1 year before diagnosis for cases and 1 year before the interview for controls. Dietary patterns were identified through factor analysis. A Western-like pattern, which was mainly determined by positive loads in red and processed meats and foods rich in fats and sugars, was positively associated with BC both in pre- (odds ratio [OR] =23.47; 95% CI, 14.01-36.96) and in postmenopausal women (OR = 18.85; 95% CI, 13.74-25.87). In contrast, a prudent-like pattern, which was characterized by positive loads of vegetables, legumes, and corn, was negatively associated with pre- (OR = 0.35; 95% CI, 0.26-0.49) and postmenopausal BC (OR = 0.25; 95% CI, 0.19-0.32). Our results show the importance of dietary patterns in BC development regardless of menopausal status.

Dietary contribution to total urinary arsenic in Mexican women.

Exposure to inorganic arsenic (iAs) damages health in many ways. The main routes of human exposure are consumption of contaminated water and diet, but evidence regarding the dietary contribution of iAs is limited. The objective of this work was to determine the foods and beverages that contribute to urinary total arsenic levels (TAs). This is a secondary analysis of an original study of breast cancer cases and population controls carried out in northern Mexico during the period 2007-2011, from which 1,462 women without a history of diabetes were selected. We estimated the consumption of the food and beverage groups with a frequency questionnaire. We measured the concentrations of urinary iAs metabolites by high performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP-MS). Total arsenic ranged from 0.5 to 2,360 µg/g creatinine. After adjusting for covariates, we observed a positive association between TAs (with arsenobetaine) with non-bottled drinking water intake, as well as the consumption of root vegetables, vegetables and fruits rich in water, eggs, fish and shellfish. Our findings highlight the relevance of water consumption and some foods for TAs exposure. Food quality monitoring deserves attention in high-risk regions of arsenic contamination.

Metal exposure and breast cancer among Northern Mexican women: assessment of genetic susceptibility.

This study aims to assess breast cancer (BC) association with metals and whether polymorphisms in CYP1A1, CYP1B1, GSTM1 and GSTT1 act as confounders or as modifiers of those relationships. We performed a secondary analysis of 499 histologically confirmed BC cases and the same number of age-matched population controls. We measured urinary concentrations of 18 metals with mass spectrometry. We determined the genetic variants of interest by allelic discrimination and multiplex PCR. After adjusting for covariates, we found BC negatively associated with arsenic, barium, cobalt, copper, magnesium, molybdenum and vanadium concentrations and positively with those of caesium, manganese, tin and thallium. Most associations remained after stratifying by the genetic variants. We identified that polymorphisms in CYP1B1, CYP1A1 and GSTM1 genes interacted with some metals on BC: interaction p-values CYP1B1 G119T × antimony= 0.036, CYP1B1 G119T × cobalt <0.001, CYP1B1 G119T × tin= 0.032, CYP1A1 A4889G × aluminium= 0.018, CYP1A1 A4889G × arsenic= 0.031, CYP1A1 A4889G × nickel= 0.036, CYP1A1 A4889G × vanadium= 0.031 and GSTM1 deletion × barium= 0.035. Exposure to various individual metals, along with genetic characteristics may contribute to BC development. Further studies are warranted to confirm our results.

Breast cancer and urinary metal mixtures in Mexican women.

Humans are environmentally exposed to many metals throughout their lives. Simultaneous exposure to several metals could result in synergistic or antagonistic toxicological effects among them; however, the information on exposure to mixtures of metals and breast cancer (BC) is scarce. The objective of this report was to compare metals considered human carcinogens, individually and as mixtures, in women with and without BC. This is a secondary analysis of a population-based case-control study that was carried out from 2007 to 2011 in Northern Mexico. A total of 499 histologically confirmed BC cases and 499 controls were included. Information about sociodemographic, lifestyle and reproductive characteristics was obtained by in-person interviews. Urinary concentrations of aluminum (Al), cadmium (Cd), chromium (Cr), nickel (Ni), lead (Pb), antimony (Sb), cobalt (Co), molybdenum (Mo), tin (Sn), and vanadium (V) were determined by inductively coupled plasma triple quadrupole. Metal mixtures were identified by principal component analysis with creatinine-corrected metals. Over 90% of subjects had metal measurements above the detection limit except tin (86%) and antimony (78.4%). After adjusting by selected covariables, we observed that the individual urinary concentrations of V, Co, and Mo were lower among cases compared to controls; in contrast to Sn that had higher concentrations. We identified two principal component mixtures with opposite relationships with BC: Cr, Ni, Sb, Al, Pb and Sn (OR = 1.15; CI95% 1.06,1.25) and Mo and Co (OR = 0.56; CI95% 0.49,0.64). This is the first study that identified urinary metal mixtures that differed between women with and without BC. Our results warrant confirmation in further prospective epidemiological studies. In addition, the elucidation of underlying mechanisms of metal interactions on BC risk deserves further research.

Tobacco Smoke Exposure and Urinary Cadmium in Women from Northern Mexico.

Cadmium (Cd), a carcinogenic metal also related to reproductive and cardiovascular diseases, is contained in tobacco and elevated concentrations of it in humans have been consistently associated with first-hand tobacco smoke; however, there is scarce and inconclusive evidence of the relationship between Cd and secondhand smoke (SHS) exposure. Our aim was to evaluate the association between exposure to tobacco, both active and SHS, with urinary Cd concentrations in Mexican women. In a cross-sectional analysis that included 998 women living in northern Mexico, we measured the concentration of creatinine-adjusted urinary Cd (µg-cadmium/g-creatinine) using inductively coupled plasma triple quadrupole (ICP-QQQ) in tandem mass spectrometry mode (MS/MS). We gathered tobacco smoking information through an in-person interview and formed seven groups: non-smokers without SHS exposure; non-smokers with SHS exposure; ex-smokers without SHS exposure <1 year of quitting; ex-smokers without SHS exposure ≥1 year of quitting, ex-smokers with SHS exposure <1 year of quitting; ex-smokers with SHS exposure ≥1 year of quitting and current smokers. The interview also yielded sociodemographic characteristics. We used linear multivariable regression models to estimate the association between Cd concentrations and tobacco smoke exposure. Compared to non-smokers without SHS exposure, we found higher Cd concentrations in ex-smokers with SHS exposure <1 year of quitting and current smokers (adjusted geometric means 0.51 vs. 1.01 and 0.69 µg-cadmium/g-creatinine, respectively). Our results do not support a conclusion that SHS exposure is a source of Cd body burden.

PM2.5 exposure as a risk factor for type 2 diabetes mellitus in the Mexico City metropolitan area.

BACKGROUND: Exposure to air pollution is the main risk factor for morbidity and mortality in the world. Exposure to particulate matter with aerodynamic diameter ≤ 2.5 µm (PM2.5) is associated with cardiovascular and respiratory conditions, as well as with lung cancer, and there is evidence to suggest that it is also associated with type II diabetes (DM). The Mexico City Metropolitan Area (MCMA) is home to more than 20 million people, where PM2.5 levels exceed national and international standards every day. Likewise, DM represents a growing public health problem with prevalence around 12%. In this study, the objective was to evaluate the association between exposure to PM2.5 and DM in adults living in the MCMA. METHODS: Data from the 2006 or 2012 National Health and Nutrition Surveys (ENSANUT) were used to identify subjects with DM and year of diagnosis. We estimated PM2.5 exposure at a residence level, based on information from the air quality monitoring system (monitors), as well as satellite measurements (satellite). We analyzed the relationship through a cross-sectional approach and as a case - control study. RESULTS: For every 10 µg/m3 increase of PM2.5 we found an OR = 3.09 (95% CI 1.17-8.15) in the 2012 sample. These results were not conclusive for the 2006 data or for the case - control approach. CONCLUSIONS: Our results add to the evidence linking PM2.5 exposure to DM in Mexican adults. Studies in low- and middle-income countries, where PM2.5 atmospheric concentrations exceed WHO standards, are required to strengthen the evidence.

Exposure to PM2.5 and Obesity Prevalence in the Greater Mexico City Area.

Exposure to PM2.5 has been associated with the prevalence of obesity. In the Greater Mexico City Area (GMCA), both are ranked among the highest in the world. Our aim was to analyze this association in children, adolescents, and adults in the GMCA. We used data from the 2006 and 2012 Mexican National Surveys of Health and Nutrition (ENSANUT). Participants' past-year exposure to ambient PM2.5 was assessed using land use terms and satellite-derived aerosol optical depth estimates; weight and height were measured. We used survey-adjusted logistic regression models to estimate the odds ratios (ORs) of obesity (vs. normal-overweight) for every 10 µg/m3 increase in annual PM2.5 exposure for children, adolescents, and adults. Using a meta-analysis approach, we estimated the overall odds of obesity. We analyzed data representing 19.3 million and 20.9 million GMCA individuals from ENSANUT 2006 and 2012, respectively. The overall pooled estimate between PM2.5 exposure and obesity was OR = 1.96 (95% CI: 1.21, 3.18). For adolescents, a 10 µg/m3 increase in PM2.5 was associated with an OR of 3.53 (95% CI: 1.45, 8.58) and 3.79 (95% CI: 1.40, 10.24) in 2006 and 2012, respectively. More studies such as this are recommended in Latin American cities with similar air pollution and obesity conditions.

Prenatal PM2.5 exposure and neurodevelopment at 2 years of age in a birth cohort from Mexico city.

BACKGROUND: Recent studies have reported that air pollution exposure may have neurotoxic properties. OBJECTIVE: To examine longitudinal associations between prenatal particles less than 2.5 µm in diameter (PM2.5) exposure and neurodevelopment during the first two years of children's life. METHODS: Analysis was conducted in PROGRESS, a longitudinal birth cohort between 2007 and 2013 in Mexico City. We used satellite data to predict daily PM2.5 concentrations at high spatial resolution. Multivariate mixed-effect regression models were adjusted to examine cognitive, language and motor scores in children up to 24 months of age (n = 740) and each trimester-specific and whole pregnancy exposure to PM2.5. RESULTS: Models adjusted by child sex, gestational age, birth weight, smoking and mother's IQ, showed that each increase of 1 µg/m3 of PM2.5 was associated with a decreased language function of -0.38 points (95% CI: -0.77, -0.01). PM2.5 exposure at third trimester of pregnancy contributed most to the observed association. CONCLUSION: Our findings suggest that language development up to 24 months of age may be particularly sensitive to PM2.5 exposure during pregnancy.

A cumulative index of exposure to endogenous estrogens and breast cancer by molecular subtypes in northern Mexican women.

PURPOSE: To evaluate breast cancer (BC) molecular subtypes association with reproductive characteristics and an index of cumulative exposure to endogenous estrogens (EEI) in Mexican women. METHODS: We performed a study of incident cases and population controls in northern Mexico. We included BC cases with tumor molecular classification in their medical records (n = 509), and classified them as HR+/HER2- (ER+ and/or PR+ and HER2-) (n = 289), HER2+ (HR+ or HR-) (n = 117) or triple negative (TN) (n = 103). We matched controls (n = 1030) by age and place of residence with index cases. Women were interviewed about their reproductive history, from which the EEI was developed. We used logistic regression models to estimate BC molecular subtypes associations with reproductive characteristics and EEI. RESULTS: The EEI was higher in all subtypes compared to controls (Median HR+/HER2- 27.25, HER2+ 26.8, TN 24.2 vs. controls 22.8 years, p < 0.05), and was associated with HR+/HER2- (ORT3 vs. T1 = 2.58, 95% CI 1.77-3.55, p-trend < 0.001) and HER2+ (ORT3 vs. T1 = 4.17, 95% CI 2.15-8.08, p-trend < 0.001) BC. Additionally, HR+/HER2- tumors were positively associated with age at first pregnancy and age at menopause, and negatively with age at menarche, parity and breastfeeding. The HER2+ subtype was associated in the same direction as HR+/HER2- tumors with all the reproductive characteristics except for age at menarche. TN tumors were negatively associated with parity and breastfeeding. CONCLUSION: Endogenous estrogens exposure throughout Mexican women reproductive life may contribute to the development of all but TN BC, however, these findings should be confirmed in other Hispanic populations.

Children's acute respiratory symptoms associated with PM2.5 estimates in two sequential representative surveys from the Mexico City Metropolitan Area.

BACKGROUND: Respiratory diseases are a major component of morbidity in children and their symptoms may be spatially and temporally exacerbated by exposure gradients of fine particulate matter (PM2.5) in large polluted urban areas, like the Mexico City Metropolitan Area (MCMA). OBJECTIVES: To analyze the association between satellite-derived and interpolated PM2.5 estimates with children's (≤9 years old) acute respiratory symptoms (ARS) in two probabilistic samples representing the MCMA. METHODS: We obtained ARS data from the 2006 and 2012 National Surveys for Health and Nutrition (ENSaNut). Two week average exposure to PM2.5 was assessed for each household with spatial estimates from a hybrid model with satellite measurements of aerosol optical depth (AOD-PM2.5) and also with interpolated PM2.5 measurements from ground stations, from the Mexico City monitoring network (MNW-PM2.5). We used survey-adjusted logistic regressions to analyze the association between PM2.5 estimates and ARS reported on children. RESULTS: A total of 1,005 and 1,233 children were surveyed in 2006 and 2012 representing 3.1 and 3.5 million children, respectively. For the same years and over the periods of study, the estimated prevalence of ARS decreased from 49.4% (95% CI: 44.9,53.9%) to 37.8% (95% CI: 34,41.7%). AOD-PM2.5 and MNW-PM2.5 estimates were associated with significantly higher reports of ARS in children 0-4 years old [OR2006 = 1.29 (95% (CI): 0.99,1.68) and OR2006 = 1.24 (95% CI: 1.08,1.42), respectively]. We observed positive non-significant associations in 2012 in both age groups and in 2006 for children 5-9 years old. No statistically significant differences in health effect estimates of PM2.5 were found comparing AOD-PM2.5 or MNW-PM2.5 for exposure assessment. CONCLUSIONS: Our findings suggest that PM2.5 is a risk factor for the prevalence of ARS in children and expand the growing evidence of the utility of new satellite AOD-based methods for estimating health effects from acute exposure to PM2.5.

Relationship between internal and external factors and the activity of PON1.

Paraoxonase 1 (PON1) is an A-esterase calcium-dependent enzyme that is associated with high-density lipoprotein (HDL) and capable of hydrolyzing a wide variety of substrates, including organophosphate (OP) pesticides. The PON1 phenotype can be modulated by multiple internal and external factors, thereby affecting the catalytic capacity of the enzyme. The aim of this study was to evaluate factors that could modulate PON1 activity in a sample occupationally exposed to pesticides. A cross-sectional, descriptive, and analytical study was carried out with 240 workers. The participants were stratified according to their level of pesticide exposure as reference, moderate-exposure, and high-exposure groups. PON1 activities (arylesterase/AREase, CMPAase, and ssPONase (salt-stimulated)) were determined by spectrophotometry, and the Q192R and L55MPON1 genotypes by real-time PCR. The most frequent genotypes were heterozygous (QR) and homozygous (LL) for PON1Q192R and PON1L55M polymorphisms, respectively. The internal factors associated with the activity of PON1 were the PON1 genotypes (55 and 192) and biochemical parameters related to the lipid profile, in contrast, various external factors related to diet and harmful habits as well as with exposure to pesticides were associated with the activity of PON1. However, using a multivariate mixed ordinal regression model, we found a significant reduction of ssPONase activity in the high-exposure group compared with the reference group only in haplotypes QQLL and RRLL.

Polyunsaturated fatty acids and child neurodevelopment among a population exposed to DDT: a cohort study.

BACKGROUND: Child neurodevelopment has been positively linked to maternal intake of polyunsaturated fatty acids (PUFAs) during pregnancy; however, it is unknown if that relationship persists among populations exposed to environmental neurotoxicants. OBJECTIVE: The aim of this work was to assess whether maternal dietary intake of PUFAs during pregnancy is positively associated with child neurodevelopment, whose mothers were environmentally exposed to 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT). METHODS: A prospective cohort study with 276 mother-child pairs was performed in Mexico. Neurodevelopment was assessed by Bayley Scales II from children age 1 to 30 months. Dietary PUFAs intake was estimated by Food Frequency Questionnaire at 1st and 3rd trimester of pregnancy. DDE (1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene, the main metabolite of DDT) maternal serum levels were determined by electron capture gas chromatography. Longitudinal multivariate linear mixed-effects analysis, which combines mental (MDI) and motor (PDI) Bayley scales in a single model, were performed. RESULTS: Our results show that in a sample environmentally exposed to DDT, maternal ingestion of DPA during the first trimester of pregnancy was positively associated with MDI (ß = 0.10, 95% CI 0.02, 0.18) in children from 1 to 30 months. Likewise, our results suggest that dietary ALA may be also related to MDI. CONCLUSION: DPA may benefit neurodevelopment even in populations exposed to DDT. Our results strengthen the importance of PUFAs intake during the prenatal period.

Which ICD-9-CM codes should be used for bronchiolitis research?

BACKGROUND: Bronchiolitis is a common respiratory disorder in children. Although there are specific ICD-9-CM diagnosis codes for bronchiolitis, the illness is often coded using broader diagnosis codes. This creates the potential for subject misclassification if researchers rely on specific diagnosis codes when assembling retrospective cohorts. Here we challenge the common research practice of relying on specific diagnosis codes for bronchiolitis. METHODS: We examined the use of diagnosis codes for the first episode of bronchiolitis, bronchitis, acute asthma, and bronchospasm and wheezing, in children younger than six and 24 months in the State of California Medic-Aid database. We categorized codes as narrow or broad diagnosis codes. We compared patient, geographic, and temporal characteristics of the different diagnoses codes. RESULTS: We identified visits from 48,732 children for first episode of wheezing illness. We retained 48,269 who had the diagnosis codes and data of interest. Diagnosis codes for acute asthma were widely used, even in children younger than six months in whom a diagnosis code for bronchiolitis would have been anticipated. The temporal pattern was similar across all diagnoses. Antipyretics were prescribed more often in those with diagnosis codes for bronchiolitis and bronchitis. Other statistically significant differences were too small to usefully distinguish the groups. There was substantial geographic variability in the diagnosis codes selected. CONCLUSION: Users of Medic-Aid administrative data should generally favor broad rather than narrow definitions of bronchiolitis and should perform sensitivity analysis comparing broad and narrow definitions.

Children's Blood Lead Concentrations from 1988 to 2015 in Mexico City: The Contribution of Lead in Air and Traditional Lead-Glazed Ceramics.

Despite the removal of lead from gasoline in 1997, elevated blood lead levels (BLLs) > 5 µg/dL are still detectable in children living in Mexico City. The use of lead-glazed ceramics may explain these persistent exposure levels. Mexico lacks a national surveillance program for BLL, but temporal trends can be derived from epidemiological studies. With this approach, we leveraged a series of birth cohorts to report BLL trends from 1987 to 2002 and expanded our analysis to 2015. Data were from 1⁻5-year-old children from five Mexico City cohorts followed between 1988 and 2015. BLLs are reported on 1963 children, who contributed 4975 BLLs. We estimated the trend of mean BLL, which decreased from 15.7 µg/dL in 1988, to 7.8 µg/dL in 1998 (a year after the total ban of lead in gasoline), to 1.96 µg/dL in 2015. The proportion of BLL ≥ 5 µg/dL decreased from 92% (1988⁻1998) to 8% (2008⁻2015). The use of lead-glazed ceramics was associated with an 11% increase in BLLs throughout the study period. Replacing lead-based glazes in traditional ceramics may be the key to further reducing exposure, but this presents challenges, as it involves a cultural tradition deeply rooted in Mexico. In addition, the creation of a rigorous, standardized, and on-going surveillance program of BLL is necessary for identifying vulnerable populations.

Wheezing after the use of acetaminophen and or ibuprofen for first episode of bronchiolitis or respiratory tract infection.

BACKGROUND: Bronchiolitis sometimes triggers the development of subsequent recurrent wheezing. Treatment with either acetaminophen or ibuprofen during the initial episode may affect the occurrence of subsequent wheezing. MATERIALS AND METHODS: We did a retrospective study comparing the effect of prescribing acetaminophen, ibuprofen, or neither for a first episode of bronchiolitis on medical attendances for subsequent wheezing in infants younger than 12 months. We created our cohorts using California Medicaid data from 2003 to 2010. We used propensity score derived inverse probability weights to adjust for non-random drug assignment. We used robust negative binomial regression to model incident rate ratios (IRR) for medical attendances at 365, 30, and 14-day follow-up. We did similar analyses for the effect of antipyretics for a first medically attended upper respiratory tract infection (URI) on subsequent wheezing. RESULTS: Compared with no antipyretic, treatment with acetaminophen or ibuprofen for a first episode of bronchiolitis was associated with decreased wheezing at 365-day follow-up (IRR 0.18, 95% CI 0.15-0.22), and ibuprofen plus acetaminophen over ibuprofen (IRR at 0.12, 95% CI 0.05-0.32). The results were similar at 30 and 14-day follow-up. Ibuprofen alone and ibuprofen plus acetaminophen were associated with decreased visits for subsequent wheezing at 365-day (IRR 0.79, 95% CI 0.68-0.92), but not earlier timepoints, when compared with acetaminophen. A smaller effect was seen for ibuprofen at one year if prescribed for a URI (IRR 0.87, 95% CI 0.76-1.00) but not at earlier follow-up. CONCLUSION: Children who are prescribed antipyretics for a first episode of bronchiolitis may have less subsequent wheezing than those who are not. We found fewer visits for subsequent wheezing for those prescribed ibuprofen, and ibuprofen combined with acetaminophen, compared with acetaminophen alone.

Child dietary intake of folate and vitamin B12 and their neurodevelopment at 24 and 30 months of age.

OBJECTIVE: To evaluate whether child dietary intake of folate and vitamin B12, is associated with mental and psychomotor development in Mexican children, respectively, at 24 and 30 months of age. MATERIALS AND METHODS: Information about neurodevelopment and dietary intake of folate and vitamin B12 at 24 and 30 months of age among 229 children belonging to a perinatal cohort was analyzed longitudinally. Dietary information was assessed using a semi-quantitative food frequency questionnaire, and neurodevelopment by Bayley Scale of Infant Development II. RESULTS: At 30 months of age, dietary folate intake was marginally associated with increased Mental Development Index (MDI) (b=8.33; 95%CI -0.48, 17.14; p=0.06). Nonsignificant positive associations of vitamin B12 with MDI were found. Psychomotor Development Index (PDI) was not associated with these nutrients. CONCLUSIONS: Dietary folate intake in early childhood may benefit the mental development of children.

Child dietary intake of folate and vitamin B12 and their neurodevelopment at 24 and 30 months of age / Ingesta de folato y vitamina B12 en la dieta del niño y su neurodesarrollo a los 24 y 30 meses de edad

Abstract Objective To evaluate whether child dietary intake of folate and vitamin B12, is associated with mental and psychomotor development in Mexican children, respectively, at 24 and 30 months of age. Materials and methods Information about neurodevelopment and dietary intake of folate and vitamin B12 at 24 and 30 months of age among 229 children belonging to a perinatal cohort was analyzed longitudinally. Dietary information was assessed using a semi-quantitative food frequency questionnaire, and neurodevelopment by Bayley Scale of Infant Development II. Results At 30 months of age, dietary folate intake was marginally associated with increased Mental Development Index (MDI) (β=8.33; 95%CI -0.48, 17.14; p=0.06). Non-significant positive associations of vitamin B12 with MDI were found. Psychomotor Development Index (PDI) was not associated with these nutrients. Conclusion Dietary folate intake in early childhood may benefit the mental development of children.

Resumen Objetivo Evaluar si la ingesta dietética infantil de folato y vitamina B12 se asocia con el desarrollo mental y psicomotor en niños mexicanos de 24 y 30 meses de edad. Material y métodos La información del neurodesarrollo y la ingesta dietética de folato y B12 a los 24 y 30 meses de edad de 229 niños pertenecientes a una cohorte perinantal, se analizó longitudinalmente. La información dietética se obtuvo por un cuestionario de frecuencia de alimentos semicuantitativo y el neurodesarrollo mediante la Escala de Desarrollo Infantil de Bayley II. Resultados A los 30 meses de edad, la ingesta dietética de folato se asoció marginalmente con un incremento del Índice de Desarrollo Infantil (IDM) (β=8.33; IC95% -0.48, 17.14; p=0.06). Se observaron asociaciones positivas no significativas entre la B12 y el IDM. El Índice de Desarrollo Psicomotor (IDP) no se asoció con dichos nutrientes. Conclusión La ingesta dietética infantil de folato puede beneficiar el desarrollo mental.

Cardiovascular and Cerebrovascular Mortality Associated With Acute Exposure to PM2.5 in Mexico City.

BACKGROUND AND PURPOSE: Acute exposure to particulate matter with aerodynamic diameter <2.5 µm (PM2.5) is associated with acute cardiovascular and cerebrovascular mortality. The aim of this study was to evaluate these associations with specific causes of cardiovascular and cerebrovascular mortality in Mexico City. METHODS: We obtained daily mortality records for Mexico City from 2004 to 2013 for cardiovascular and cerebrovascular causes in people ≥25 and ≥65 years old. Exposure to PM2.5 was assessed with daily estimates from a new hybrid spatiotemporal model using satellite measurements of aerosol optical depth PM2.5 and compared to ground level PM2.5 measurements with missing data estimated with generalized additive models PM2.5. We fitted Poisson regression models with distributed lags for all mortality outcomes. RESULTS: An increase of 10 µg/m3 in aerosol optical depth PM2.5 was associated with increased cardiovascular (1.22%; 95% confidence interval, 0.17-2.28) and cerebrovascular mortality (3.43%; 95% confidence interval, 0.10-6.28) for lag days 0 to 1 (lag 0-1). Stronger effects were identified for hemorrhagic stroke and people ≥65 years. Associations were slightly smaller using generalized additive models PM2.5. CONCLUSIONS: These results support the evidence that acute exposure to PM2.5 is associated with increased risk of specific cardiovascular and cerebrovascular mortality causes.