Obstetric risk profiles and causes of death: Estimating their association with cesarean sections among maternal deaths in Mexico.

BACKGROUND: Maternal mortality is a critical indicator of healthcare quality, and in Mexico, this has become increasingly concerning due to the stagnation in its decline, alongside a concurrent increase in cesarean section (C-section) rates. This study characterizes maternal deaths in Mexico, focusing on estimating the association between obstetric risk profiles, cause of death, and mode of delivery. METHODS: Utilizing a retrospective observational design, 4,561 maternal deaths in Mexico from 2010-2014 were analyzed. Data were sourced from the Deliberate Search and Reclassification of Maternal Deaths database, alongside other national databases. An algorithm was developed to extract the Robson Ten Group Classification System from clinical summaries text, facilitating a nuanced analysis of C-section rates. Information on the reasons for the performance of a C-section was also obtained. Logistic regression and multinomial logistic regression models were used to estimate the relation between obstetric risk factors, mode of delivery and causes of maternal death, adjusting for covariates. RESULTS: Among maternal deaths in Mexico from 2010-2014, 47.1% underwent a C-section, with a significant history of previous C-sections observed in 31.4% of these cases, compared to 17.4% for vaginal deliveries (p<0.001). Early prenatal care in the first trimester was more common in C-section cases (46.8%) than in vaginal deliveries (38.3%, p<0.001). A stark contrast was noted in the place of death, with 82.4% of post-C-section deaths occurring in public institutions versus 69.1% following vaginal births. According to Robson's classification, the highest C-section rates were in Group 4 (67.2%, p<0.001) and Group 8 (66.9%, p<0.001). Logistic regression analysis revealed no significant difference in the odds of receiving a C-section in private versus other settings after adjusting for Robson criteria (OR: 1.21; 95% CI: 0.92, 1.60). A prior C-section significantly increased the likelihood of another (OR: 2.38; CI 95%: 2.01, 2.81). The analysis also indicated C-sections were significantly tied to deaths from hypertensive disorders (RRR = 1.25, 95% CI [1.12, 1.40]). In terms of indications, 6.3% of C-sections were performed under inadequate indications, while the indication was not identifiable in 33.1% of all C-sections. CONCLUSIONS: This study highlights a significant overuse of C-sections among maternal deaths in Mexico (2010-2014), revealed through the Robson classification and ana analysis of the reported indications for the procedure. It underscores the need for revising clinical decision-making to promote evidence-based guidelines and favor vaginal deliveries when possible. High C-section rates, especially noted disparities between private and public sectors, suggest economic and non-clinical factors may be at play. The importance of accurate data systems and further research with control groups to understand C-section practices' impact on maternal health is emphasized.

A surge in food insecurity during the COVID-19 pandemic in a cohort in Mexico City.

BACKGROUND: The COVID-19 pandemic has not only caused tremendous loss of life and health but has also greatly disrupted the world economy. The impact of this disruption has been especially harsh in urban settings of developing countries. We estimated the impact of the pandemic on the occurrence of food insecurity in a cohort of women living in Mexico City, and the socioeconomic characteristics associated with food insecurity severity. METHODS: We analyzed data longitudinally from 685 women in the Mexico City-based ELEMENT cohort. Food insecurity at the household level was gathered using the Latin American and Caribbean Food Security Scale and measured in-person during 2015 to 2019 before the pandemic and by telephone during 2020-2021, in the midst of the pandemic. Fluctuations in the average of food insecurity as a function of calendar time were modeled using kernel-weighted local polynomial regression. Fixed and random-effects ordinal logistic regression models of food insecurity were fitted, with timing of data collection (pre-pandemic vs. during pandemic) as the main predictor. RESULTS: Food insecurity (at any level) increased from 41.6% during the pre-pandemic period to 53.8% in the pandemic stage. This increase was higher in the combined severe-moderate food insecurity levels: from 1.6% pre-pandemic to 16.8% during the pandemic. The odds of severe food insecurity were 3.4 times higher during the pandemic relative to pre-pandemic levels (p<0.01). Socioeconomic status quintile (Q) was significantly related to food insecurity (Q2 OR = 0.35 p<0.1, Q3 OR = 0.48 p = 0.014, Q4 OR = 0.24 p<0.01, and Q5 OR = 0.17 p<0.01), as well as lack of access to social security (OR = 1.69, p = 0.01), and schooling (OR = 0.37, p<0.01). CONCLUSIONS: Food insecurity increased in Mexico City households in the ELEMENT cohort as a result of the COVID-19 pandemic. These results contribute to the body of evidence suggesting that governments should implement well-designed, focalized programs in the context of economic crisis such as the one caused by COVID-19 to prevent families from the expected adverse health and well-being consequences associated to food insecurity, especially for the most vulnerable.

Associations between prenatal metal and metalloid mixtures in teeth and reductions in childhood lung function.

BACKGROUND: Metal(oid)s have been cross-sectionally associated with lung function outcomes in childhood but there is limited data on their combined effects starting in utero. Child sex may further modify these effects. OBJECTIVE: Examine associations between in utero and early life exposure to metals assessed via novel dentine biomarkers and childhood lung function and explore effect modification by child sex. METHODS: Analyses included 291 children enrolled in the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) study, a longitudinal birth cohort study in Mexico City. Weekly dentine levels of arsenic (As), cadmium (Cd), cobalt (Co), copper (Cu), manganese (Mn), nickel (Ni), and lead (Pb) were measured from 15 weeks pre-birth to 15 weeks post birth in deciduous children's teeth. Lung function was tested at ages 8-14 years and then modeled as age, height and sex adjusted z-scores. Associations were modeled using lagged weighted quantile sum (LWQS) regression to evaluate the potential for a time-varying mixture effect adjusting for maternal age and education at enrollment and exposure to environmental tobacco smoke in pregnancy. Models were also stratified by sex. RESULTS: We identified a window of susceptibility at 12-15 weeks pre-birth in which the metal mixture was associated with lower FVC z-scores in children aged 8-14 years. Cd and Mn were the largest contributors to the mixture effect (70 %). There was also some evidence of effect modification by sex, in which the mean weights and weighted correlations over the identified window was more evident in males when compared to females. In the male stratum, Cd, Mn and additionally Pb also dominated the mixture association. CONCLUSIONS: Prenatal metal(oid) exposure was associated with lower lung function in childhood. These findings underscore the need to consider both mixtures and windows of susceptibility to fully elucidate effects of prenatal metal(oid) exposure on childhood lung function.

Lead Levels in the Most Consumed Mexican Foods: First Monitoring Effort.

Globally, there is growing concern over the presence of lead (Pb) in foods because it is a heavy metal with several toxic effects on human health. However, monitoring studies have not been conducted in Mexico. In this study, we estimated the concentrations of Pb in the most consumed foods and identified those that exceeded the maximum limits (MLs) for Pb in foods established by the International Standards. Based on the Mexican National Health and Nutrition Survey, 103 foods and beverages were selected and purchased in Mexico City retail stores and markets. Samples were analyzed twice using atomic absorption spectrophotometry. Values above the limit of quantification (0.0025 mg/kg) were considered to be detected. The percentage of detected values was 18%. The highest concentration was found in infant rice cereal (1.005 mg/kg), whole wheat bread (0.447 mg/kg), pre-cooked rice (0.276 mg/kg), black pepper (0.239 mg/kg), and turmeric (0.176 mg/kg). Among the foods with detected Pb, the levels in infant rice cereal, whole wheat bread, pre-cooked rice, and soy infant formula exceeded the MLs. The food groups with the highest percentages of exceeded MLs were baby foods (18%) and cereals (11%). Monitoring the concentration of contaminants in foods is essential for implementing food safety policies and protecting consumer health.

A high density of ultra-processed food, alcohol & tobacco retail stores, and social inequalities are associated with higher mortality rates of non-communicable diseases in Mexican adults: 2005 to 2021.

BACKGROUND: Non-communicable diseases (NCDs) are the leading causes of mortality in Mexico. Factors contributing to NCDs-related deaths may vary across small geographic areas such as municipalities. We aimed to predict municipal-level factors associated with NCD mortality in Mexican adults from 2005 to 2021 using the small-area analysis (SSA) approach. METHODS: We gathered data on population sociodemographic, access to healthcare services, and mortality records at the municipal-level from census and public institutions from 2005 to 2021. We identified municipal predictors of NCDs mortality rates (MR) using negative binomial regression models. RESULTS: A total of 584,052 observations of Mexican adults were analyzed. The national expected NCDs MR per 100,000 inhabitants was 210.7 (95%CI: 196.1-226.7) in 2005 and increased to 322.4 (95%CI: 300.3-346.4) by 2021. Predictors of NCDs mortality (quintile 5 vs. quintile 1) included; indigeneity (IRR = 1.15, 95%CI: 1.12-1.19), poverty (IRR = 1.14, 95%CI: 1.13-1.15), affiliation with Mexican Social Security Institute (IRR = 1.11, 95%CI: 1.09-1.14), households with television (IRR = 1.14, 95%CI: 1.11-1.17), and high density of ultra-processed food, alcohol & tobacco retail stores (IRR = 1.15, 95%CI: 1.13-1.17). The greatest increases in MR were observed in municipalities from Oaxaca (>200% increments). CONCLUSION: There was an overall increase in NCDs MR from 2005 to 2021, with a significant geographic variation among Mexican municipalities. The results of this study highlight the importance of identifying priority areas in the country that urgently require public policies focused on local factors associated with deaths from NCDs, such as the regulation of the ultra-processed food, alcohol & tobacco retail stores, and efforts to reduce social inequalities.

Single nucleotide polymorphisms of ANKK1, DDR4, and GRIN2B genes predict behavior in a prospective cohort of Mexican children and adolescents.

Numerous studies have established associations between single nucleotide polymorphisms (SNPs) and various behavioral and neurodevelopmental conditions. This study explores the links between SNPs in candidate genes involved in central nervous system (CNS) physiology and their implications for the behavioral and emotional aspects in children and teenagers. A total of 590 participants, aged 7-15 years, from the Early Life Exposures In Mexico To Environmental Toxicants (ELEMENT) cohort study in Mexico City, underwent genotyping for at least one of 15 CNS gene-related SNPs at different timepoints. We employed multiple linear regression models to assess the potential impact of genetic variations on behavioral and cognitive traits, as measured by the Behavioral Assessment System for Children (BASC) and Conners parent rating scales. Significant associations were observed, including the rs1800497 TC genotype (ANKK1) with the Cognitive Problems/Inattention variable (p value = 0.003), the rs1800955 CT genotype (DDR4) with the Emotional Lability Global index variable (p value = 0.01), and the rs10492138 GA and rs7970177 TC genotypes (GRIN2B) with the Depression variable (p values 0.007 and 0.012, respectively). These finds suggest potential genetic profiles associated with "risk" and "protective" behaviors for these SNPs. Our results provide valuable insights into the role of genetic variations in neurobehavior and highlight the need for further research in the early identification and intervention in individuals at risk for these conditions.

Design and implementation of AMBAR: an innovative evidence-based training program for childbirth and newborn care.

OBJECTIVE: To present the development of a training model called AMBAR (Atención a la mujer embarazada y al recién nacido [Care for pregnant women and newborns]), which was designed to improve the quality of attention of health personnel responsible for obstetric care. MATERIALS AND METHODS: AMBAR was designed based on the results of a qualitative study exploring public health providers' needs and experiences. It was implemented in three health networks, and a total of 339 health personnel participated. RESULTS: The educational design of the course was appealing to the trained personnel, and the inclusion of simulations in all modules encouraged interest, participation, as well as the integration of new knowledge and skills into practice. CONCLUSION: AMBAR can promote better practices and increase the quality of birth care. With the proper support and willingness of staff and management, AMBAR can be implemented in all health services, both public and private.

The Cervical Cancer Treatment Gap in Mexico Under Seguro Popular, 2006-2016.

From 2005 to 2019, the Mexican government financed cervical cancer treatment for individuals without social security insurance through Seguro Popular's Fund for Protection against Catastrophic Health Expenses. To better understand the impact of this program on access to treatment, we estimated the cervical cancer treatment gap (the proportion of patients with cervical cancer in this population who did not receive treatment). To calculate the expected number of incident cervical cancer cases we used national surveys with information on insurance affiliation and incidence estimates from the Global Burden of Disease study. We used a national claims database to determine the number of cases whose treatment was financed by Seguro Popular. From 2006 to 2016, the national cervical cancer treatment gap changed from 0.61 (95% CI 0.59 to 0.62) to 0.45 (95% CI 0.43 to 0.48), with an average yearly reduction of -0.012 (95% CI -0.024 to -0.001). The gap was greater in states with higher levels of marginalization and in the youngest and oldest age groups. Although the cervical cancer treatment gap among individuals eligible for Seguro Popular decreased after the introduction of public financing for treatment, it remained high. Seguro Popular was eliminated in 2019; however, individuals without social security have continued to receive cancer care financed by the government in the same healthcare facilities. These results suggest that barriers to care persisted after the introduction of public financing for treatment. These barriers must be reduced to improve cervical cancer care in Mexico, particularly in states with high levels of marginalization.

Plasma Fatty Acid Biomarkers of Dairy Consumption Are Associated with Sex-Dependent Effects on Metabolic Syndrome Components in Mexican Adolescents.

INTRODUCTION: During adolescence, dairy product intake has shown conflicting associations with metabolic syndrome (MetS) components, which are risk factors for cardiovascular disease (CVD). This study aims to investigate the association between plasma fatty acids (FAs) C15:0, C17:0, and t-C16:1n-7, as biomarkers of dairy intake, with MetS and its components in Mexican adolescents. METHODS: A sample of 311 participants from the Early Life Exposure in Mexico City to Environmental Toxicants (ELEMENT) cohort was included in this cross-sectional analysis. FA concentrations were measured in plasma as a percentage of total FA. We used quantile regression models stratified by sex to evaluate the association between FA quantiles and MetS components, adjusting for age, socioeconomic status (SES), sedentary behavior, BMI z-score, pubertal status, and energy intake. RESULTS: We found significant associations between dairy biomarkers and the median of MetS variables. In females, t-C16:1n-7 was associated with a decrease of 2.97 cm in WC (Q4 vs. Q1; 95% CI: -5.79, -0.16). In males, C15:0 was associated with an increase of 5.84 mm/Hg in SBP (Q4 vs. Q1; CI: 1.82, 9.85). For HDL-C, we observed opposite associations by sex. C15:0 in males was associated with decreased HDL-C (Q3 vs. Q1: ß = -4.23; 95% CI: -7.98, -0.48), while in females, C15:0 and t-C16:1n-7 were associated with increased HDL-C (Q3 vs. Q1: ß = 4.75; 95% CI: 0.68, 8.82 and Q4 vs. Q1: ß = 6.54; 95% CI: 2.01, 11.07), respectively. Additionally, in both sexes, different levels of C15:0, C17:0, and t-C16:1n-7 were associated with increased triglycerides (TG). CONCLUSION: Our results suggest that adolescent dairy intake may be associated in different directions with MetS components and that associations are sex-dependent.

Associations between early-life exposure to PM2.5 and reductions in childhood lung function in two North American longitudinal pregnancy cohort studies.

Data integration of epidemiologic studies across different geographic regions can provide enhanced exposure contrast and statistical power to examine adverse respiratory effects of early-life exposure to particulate matter <2.5 microns in diameter (PM2.5). Methodological tools improve our ability to combine data while more fully accounting for study heterogeneity. Methods: Analyses included children enrolled in two longitudinal birth cohorts in Boston, Massachusetts, and Mexico City. Propensity score matching using the 1:3 nearest neighbor with caliper method was used. Residential PM2.5 exposure was estimated from 2 months before birth to age 6 years using a validated satellite-based spatiotemporal model. Lung function was tested at ages 6-11 years and age, height, race, and sex adjusted z scores were estimated for FEV1, FVC, FEF25-75%, and FEV1/FVC. Using distributed lag nonlinear models, we examined associations between monthly averaged PM2.5 levels and lung function outcomes adjusted for covariates, in unmatched and matched pooled samples. Results: In the matched pooled sample, PM2.5 exposure between postnatal months 35-44 and 35-52 was associated with lower FEV1 and FVC z scores, respectively. A 5 µg/m3 increase in PM2.5 was associated with a reduction in FEV1 z score of 0.13 (95% CI = -0.26, -0.01) and a reduction in FVC z score of 0.13 (95% CI = -0.25, -0.01). Additionally PM2.5 during postnatal months 23-39 was associated with a reduction in FEF25-75% z score of 0.31 (95% CI = -0.57, -0.05). Conclusions: Methodological tools enhanced our ability to combine multisite data while accounting for study heterogeneity. Ambient PM2.5 exposure in early childhood was associated with lung function reductions in middle childhood.

Burden, Incidence, Mortality and Lethality of Maternal Disorders in Mexico 1990-2019: An Analysis for the Global Burden of Disease Study 2019.

BACKGROUND: Estimates of the sub-national distribution of maternal disorders in Mexico beyond Maternal Mortality Ratios are scarce. Characterizing the sub-national variation of maternal disorders may make it possible to focus more on interventions and thereby reduce their occurrence in a more meaningful and sustained manner. AIM: To analyze and describe the sub-national distribution, magnitude, trends and changes in the contribution of maternal causes to women's loss of health in Mexico from 1990-2019. METHODS: Using estimates from the Global Burden of Disease (GBD) 2019 study, we describe the distribution and trends of maternal mortality ratio (MMR), mortality rate, case-fatality rate and disability-adjusted life years (DALYs) due to maternal causes, at both national and state levels. RESULTS: Between 1990 and 2019, DALYs attributable to maternal causes had decreased 59.5%, mortality 63.8%, and incidence 46.5%. However, Maternal Mortality Ratio only decreased by 33%. The case-fatality rate of maternal disorders decreased by 50% overall; although for obstructed labor and uterine rupture, it remained unchanged. Lethality showed great variation between states, with a 3 fold difference between the maximum and minimum values. CONCLUSIONS: Although mortality and incidence of maternal causes in Mexico have greatly decreased in the last 30 years, these changes mostly reflect declines in fertility. The decrease seen in case-fatality rates is driven by decreases in causes such as hypertension and hemorrhage, though for others it remained constant. Efforts should be directed at improving access to, and management of, locally frequent maternal emergencies, formulating tailor-made regional interventions for maternal health.

AMBAR: A midwifery-led training program to improve obstetric and neonatal practices among low-risk births in Mexico.

BACKGROUND: Birth care in Mexican health institutions is highly medicalized and of poor quality because of the prevalence of outdated and dangerous practices. AMBAR-a training program for health care providers on the use of evidence-based midwifery practices-was implemented during 2016-2018 and evaluated to assess the impact of training on key practices. METHODS: For this mixed-methods study, we evaluated the effects of a training program implemented in three public hospital networks in Mexico. Qualitative data were collected and integrated into the program before evaluating the effects of the intervention on 10 birth practices, 5 beneficial and 5 potentially harmful. Quantitative data on birth practices and covariates were collected at six time points (baseline and 5 follow-ups) in a final sample of 330 direct observations. Effect estimates were obtained by longitudinal logistic and Poisson regression models, adjusted for confounding variables. RESULTS: AMBAR had a significant effect on 4 of the 10 birth practices that were evaluated. Beneficial practices, such as skin-to-skin contact (P = 0.003) and delayed cord clamping (P = 0.039), increased significantly. Harmful when overused birth practices, such as vaginal examinations (P = 0.001), and cesarean birth (P < 0.001) decreased significantly. CONCLUSIONS: Midwifery-based training programs for health care providers can have an impact on the quality of care of birthing people and newborns, increasing the use of evidence-based practices and decreasing frequently overused practices.

Use of self-help groups by people living with HIV in Central America.

Self-help groups (SHGs) for people living with HIV (PLHIV) are organizations created by the community to provide individuals with security, affection, improved self-esteem, and a sense of belonging. However, SHGs have also been used by the government to help implement HIV control policies. This study aimed to identify the characteristics associated with the use of SHGs by PLHIV and the routes and displacement patterns adopted by users. An analytical cross-sectional study was conducted based on data collected in six Central American countries during 2012. Using a list of SHGs, a random sampling was conducted in two stages. Firstly, the SHGs were selected. Then, the selected SHGs were visited and every third user who attended the SHG was surveyed. Logistic regression models were used to identify the characteristics associated with the use of SHGs and with attending the nearest SHGs. A spatial analysis was performed to identify the routes followed by users to reach the SHGs from their home communities. We found that the characteristics significantly associated with higher odds of SHG usage were country of residence and schooling level. The average and median distances traveled by users to attend SHGs were 20 and 5 kilometers, respectively. PLHIV do not use the SHGs closest to their locality, perhaps for fear of stigma and discrimination. We recommend that research on this topic use a mixed qualitative-quantitative methodology to better understand utilization decisions, user expectations, and the degree to which these are being met.

Early life exposure to lead and its association with parent-reported aggression and conduct problems during childhood and adolescence.

BACKGROUND AND AIM: An association between lead (Pb) exposure and antisocial behaviors has been documented, but findings have been inconclusive. We aimed to estimate the association between prenatal, early childhood, and preadolescent/adolescent (periadolescent) Pb exposure and aggression and conduct problems in periadolescent residents of Mexico City. METHODS: Using information from the ELEMENT cohort study, we assessed prenatal Pb exposure through maternal patella Pb (MPPb) measurement during the puerperium, early childhood (birth to 5 years of age) exposure through a cumulative blood lead index (CBLI), and periadolescent exposure through a blood Pb (BPb) measurement concurrent with the evaluation of the outcomes. Outcomes were assessed during periadolescence using the parent-reported scales of aggression and conduct problems of the Behavioral Assessment System for Children-2nd version (BASC-2). We modeled the association between Pb exposure at each stage and each outcome (defined as a T-score ≥60 in the corresponding behavioral scale) using logistic regression, adjusting for sex, maternal age at delivery, maternal education, and household socioeconomic status (SES). The differential effect by sex was assessed with an interaction term in the models. RESULTS: 743, 704, and 595 participants were respectively eligible for inclusion in final models of prenatal, early childhood, and periadolescent Pb exposure. Median Pb exposure at each stage was 9.9 µg/g for MPPb (prenatal), 5.19 µg/dl for CBLI (early childhood), and 2.62 µg/dl for concurrent BPb (periadolescence). 12 % of participants met the criterion for aggression, and 15 % for conduct problems. In adjusted models, a one interquartile range increase in MPPb increased the odds of conduct problems (OR:1.31; 95 % CI: 1.01, 1.70) and aggression (OR=1.24; 95 % CI: 0.93, 1.65) during periadolescence. Pb exposure during early childhood or periadolescence was not associated with either outcome. We found no evidence of interactions by sex. CONCLUSIONS: Exposure to Pb during the prenatal stage was associated with aggression and conduct problems during periadolescence.

Pre-pregnancy body mass index and gestational weight-gain predict maternal hemoglobin levels and are jointly associated with neonatal outcomes in a Mexican birth cohort.

Introduction: Introduction: there is scarce evidence of the effects of obesity and gestational weight- gain (GWG) on hemoglobin (Hb) levels in pregnancy. Little is known about the implications in offspring when pregnant mothers present with both at delivery. Aim: to identify if pre-pregnancy body mass index (BMI) and GWG are associated with Hb levels at pregnancy third trimester; and identify if the BMI status plus anemia at delivery could influence offspring anthropometry. Methods: in a sub-sample of pregnant women (n = 108) and their offspring (n = 63) from a Mexican birth cohort, information from medical files and questionnaires were used to obtain pre-pregnancy BMI (categorized as normal, overweight, and obese), GWG, and Hb during pregnancy; at delivery and postpartum anthropometric measures were obtained for offspring. Adjusted regression models predicted Hb levels according to pre-pregnancy BMI and GWG; offspring growth trajectories from birth to 3 months old were compared according to mother´s BMI status and anemia combinations at delivery. Results: pre-pregnancy normal (N), overweight (OV), and obesity (OB) were present in 48 %, 40 %, and 12 % of the participants, respectively. Anemia was detected in 22.8 % of the participants at third trimester. Hb levels in the third trimester were significantly lower in those with pre-pregnancy OB-BMI and excessive GWG (12.1 g/dL, 95 % CI: 10.7-13.5) compared to those with pre-pregnancy OB-BMI and insufficient GWG (13.3g/dL, 95 %CI: 11.9-14.8) (p = 0.04). At delivery, 11 % presented with OB-BMI and anemia. Women with OB-BMI and normal Hb levels had children with higher scores in Weight-for-Length-Z score and triceps skinfold. Conclusion: among OB women, excessive GWG was associated with having lower Hb levels in the third trimester. Newborns had higher scores in growth patterns related to adiposity from birth to 3 months old if mothers had normal Hb levels and OB.

Introducción: Introducción: existe escasa evidencia de los efectos de obesidad y ganancia de peso gestacional (GPG) y niveles de hemoglobina (Hb) durante el embarazo. Poco se conoce sobre las implicaciones en la descendencia cuando las embarazadas presentan ambos en el momento del parto. Objetivos: identificar si el índice de masa corporal (IMC) previo al embarazo y el GPG están asociados con los niveles de Hb en el tercer trimestre del embarazo; e identificar si el IMC más la anemia en el momento del parto podrían influir en la antropometría de la descendencia. Metodología: se utilizó información de expedientes médicos y cuestionarios para obtener el IMC antes del embarazo (categorizado como normal, con sobrepeso y obesidad), GPG y Hb durante el embarazo; en el momento del parto y posparto se obtuvieron medidas antropométricas para la descendencia de una submuestra de mujeres embarazadas (n = 108) y su descendencia (n = 63) de una cohorte mexicana. Los modelos de regresión ajustados predijeron los niveles de Hb según IMC y GPG antes del embarazo; se compararon las trayectorias de crecimiento de la descendencia desde el nacimiento hasta los 3 meses de edad según el estado de IMC de la madre y las combinaciones de anemia en el momento del parto. Resultados: peso preembarazo normal (N), sobrepeso (SP) y obesidad (OB) estuvieron presentes en 48 %, 40 % y 12 % de las participantes, respectivamente. Se diagnosticó anemia en el 22,8 % de las participantes en el tercer trimestre. Los niveles de Hb en el tercer trimestre fueron significativamente más bajos en aquellas con IMC-OB antes del embarazo y GPG excesivo (12,1 g/dL, IC del 95 %: 10,7-13,5) en comparación con aquellas con IMC-OB antes del embarazo y GPG insuficiente (13,3 g/dl, IC del 95 %: 11,9-14,8) (p = 0,04). Al momento del parto, el 11 % presentó OB-BMI y anemia. Las mujeres con OB-BMI y niveles normales de Hb tenían hijos con puntuaciones más altas en puntuación Z de peso para longitud y pliegue cutáneo del tríceps. Conclusión: la GPG excesiva entre las mujeres OB se asoció con niveles más bajos de Hb en el tercer trimestre. Los recién nacidos tenían puntajes más altos en los patrones de crecimiento relacionados con la adiposidad desde el nacimiento hasta los 3 meses de edad si las madres tenían niveles normales de Hb y OB.

Pre-pregnancy body mass index and gestational weight-gain predict maternal hemoglobin levels and are jointly associated with neonatal outcomes in a Mexican birth cohort / Índice de masa corporal y ganancia de peso durante el embarazo como predictores de niveles de hemoglobina materna y su asociación con desenlaces neonatales en una cohorte mexicana

Introduction: there is scarce evidence of the effects of obesity and gestational weight- gain (GWG) on hemoglobin (Hb) levels in pregnancy. Little is known about the implications in offspring when pregnant mothers present with both at delivery. Aim: to identify if pre-pregnancy body mass index (BMI) and GWG are associated with Hb levels at pregnancy third trimester; and identify if the BMI status plus anemia at delivery could influence offspring anthropometry. Methods: in a sub-sample of pregnant women (n = 108) and their offspring (n = 63) from a Mexican birth cohort, information from medical files and questionnaires were used to obtain pre-pregnancy BMI (categorized as normal, overweight, and obese), GWG, and Hb during pregnancy; at delivery and postpartum anthropometric measures were obtained for offspring. Adjusted regression models predicted Hb levels according to pre-pregnancy BMI and GWG; offspring growth trajectories from birth to 3 months old were compared according to mother´s BMI status and anemia combinations at delivery. Results: pre-pregnancy normal (N), overweight (OV), and obesity (OB) were present in 48 %, 40 %, and 12 % of the participants, respectively. Anemia was detected in 22.8 % of the participants at third trimester. Hb levels in the third trimester were significantly lower in those with pre-pregnancy OB-BMI and excessive GWG (12.1 g/dL, 95 % CI: 10.7-13.5) compared to those with pre-pregnancy OB-BMI and insufficient GWG (13.3g/dL, 95 %CI: 11.9-14.8) (p = 0.04). At delivery, 11 % presented with OB-BMI and anemia. Women with OB-BMI and normal Hb levels had children with higher scores in Weight-for-Length-Z score and triceps skinfold. Conclusion: among OB women, excessive GWG was associated with having lower Hb levels in the third trimester. Newborns had higher scores in growth patterns related to adiposity from birth to 3 months old if mothers had normal Hb levels and OB (AU)

Introducción: existe escasa evidencia de los efectos de obesidad y ganancia de peso gestacional (GPG) y niveles de hemoglobina (Hb) durante el embarazo. Poco se conoce sobre las implicaciones en la descendencia cuando las embarazadas presentan ambos en el momento del parto. Objetivos: identificar si el índice de masa corporal (IMC) previo al embarazo y el GPG están asociados con los niveles de Hb en el tercer trimestre del embarazo; e identificar si el IMC más la anemia en el momento del parto podrían influir en la antropometría de la descendencia. Metodología: se utilizó información de expedientes médicos y cuestionarios para obtener el IMC antes del embarazo (categorizado como normal, con sobrepeso y obesidad), GPG y Hb durante el embarazo; en el momento del parto y posparto se obtuvieron medidas antropométricas para la descendencia de una submuestra de mujeres embarazadas (n = 108) y su descendencia (n = 63) de una cohorte mexicana. Los modelos de regresión ajustados predijeron los niveles de Hb según IMC y GPG antes del embarazo; se compararon las trayectorias de crecimiento de la descendencia desde el nacimiento hasta los 3 meses de edad según el estado de IMC de la madre y las combinaciones de anemia en el momento del parto. Resultados: peso preembarazo normal (N), sobrepeso (SP) y obesidad (OB) estuvieron presentes en 48 %, 40 % y 12 % de las participantes, respectivamente. Se diagnosticó anemia en el 22,8 % de las participantes en el tercer trimestre. Los niveles de Hb en el tercer trimestre fueron significativamente más bajos en aquellas con IMC-OB antes del embarazo y GPG excesivo (12,1 g/dL, IC del 95 %: 10,7-13,5) en comparación con aquellas con IMC-OB antes del embarazo y GPG insuficiente (13,3 g/dl, IC del 95 %: 11,9-14,8) (p = 0,04). Al momento del parto, el 11 % presentó OB-BMI y anemia. Las mujeres con OB-BMI y niveles normales de Hb tenían hijos con puntuaciones más altas en puntuación Z de peso para longitud y pliegue cutáneo del tríceps (AU)

Heavy Metals in Unprocessed or Minimally Processed Foods Consumed by Humans Worldwide: A Scoping Review.

Heavy metals (HM) can be accumulated along the food chain; their presence in food is a global concern for human health because some of them are toxic even at low concentrations. Unprocessed or minimally processed foods are good sources of different nutrients, so their safety and quality composition should be guaranteed in the most natural form that is obtained for human consumption. The objective of this scoping review (ScR) is to summarize the existing evidence about the presence of HM content (arsenic (As), lead (Pb), cadmium (Cd), mercury (Hg), methylmercury (MeHg), and aluminum (Al)) in unprocessed or minimally processed foods for human consumption worldwide during the period of 2011-2020. As a second objective, we identified reported HM values in food with respect to Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO) International Food Standards for Maximum Limits (MLs) for contaminants in food. This ScR was conducted in accordance with the Joanna Briggs Institute (JBI) methodology and PRISMA Extension for Scoping Reviews (PRISMA-ScR); advance searches were performed in PubMed, ScienceDirect and FAO AGRIS (Agricultural Science and Technology Information) databases by two reviewers who independently performed literature searches with specific eligibility criteria. We classified individual foods in food groups and subgroups according to the Global Individual Information Food Consumption Data Tool (FAO/WHO GIFT). We homologated all the reported HM units to parts per million (ppm) to determine the weighted mean HM concentration per country and food group/subgroup of the articles included. Then, we compared HM concentration findings with FAO/WHO MLs. Finally, we used a Geographic Information System (GIS) to present our findings. Using our search strategy, we included 152 articles. Asia was the continent with the highest number of publications (n = 79, 51.3%), with China being the country with the largest number of studies (n = 34). Fish and shellfish (n = 58), followed by vegetables (n = 39) and cereals (n = 38), were the food groups studied the most. Fish (n = 42), rice (n = 33), and leafy (n = 28) and fruiting vegetables (n = 29) were the most studied food subgroups. With respect to the HM of interest, Cd was the most analyzed, followed by Pb, As, Hg and Al. Finally, we found that many of the HM concentrations reported exceeded the FAO/OMS MLs established for Cd, Pb and As globally in all food groups, mainly in vegetables, followed by the roots and tubers, and cereals food groups. Our study highlights the presence of HM in the most natural forms of food around the world, in concentrations that, in fact, exceed the MLs, which affects food safety and could represent a human health risk. In countries with regulations on these topics, a monitoring system is recommended to evaluate and monitor compliance with national standards. For countries without a regulation system, it is recommended to adopt international guidelines, such as those of FAO, and implement a monitoring system that supervises national compliance. In both cases, the information must be disseminated to the population to create social awareness. This is especially important to protect the population from the consumption of internal production and for the international markets of the globalized world.

Reduction in the Treatment Gap for Breast Cancer in Mexico under Seguro Popular, 2007 to 2016.

As Mexico's government restructures the health system, a comprehensive assessment of Seguro Popular's Fund for Protection against Catastrophic Expenses (FPGC) can help inform decision makers to improve breast cancer outcomes and health system performance. This study aimed to estimate the treatment gap for breast cancer patients treated under FPGC and assess changes in this gap between 2007 (when coverage started for breast cancer treatment) and 2016. We used a nationwide administrative claims database for patients whose breast cancer treatment was financed by FPGC in this period (56,847 women), Global Burden of Disease breast cancer incidence estimates, and other databases to estimate the population not covered by social security. We compared the observed number of patients who received treatment under FPGC to the expected number of breast cancer cases among women not covered by social security to estimate the treatment gap. Nationwide, the treatment gap was reduced by more than half: from 0.71, 95% CI (0.69, 0.73) in 2007 to 0.15, 95%CI (0.09, 0.22) in 2016. Reductions were observed across all states . This is the first study to assess the treatment gap for breast cancer patients covered under Seguro Popular. Expanded financing through FPGC sharply increased access to treatment for breast cancer. This was an important step toward improving breast cancer care, but high mortality remains a problem in Mexico. Increased access to treatment needs to be coupled with effective interventions to assure earlier cancer diagnosis and earlier initiation of high-quality treatment.

Differential fat accumulation in early adulthood according to adolescent-BMI and heavy metal exposure.

INTRODUCTION: Heavy metals such as Lead (Pb) and Mercury (Hg) can affect adipose tissue mass and function. Considering the high prevalence of exposure to heavy metals and obesity in Mexico, we aim to examine if exposure to Pb and Hg in adolescence can modify how fat is accumulated in early adulthood. METHODS: This study included 100 participants from the ELEMENT cohort in Mexico. Adolescent Pb and Hg blood levels were determined at 14-16 years. Age- and sex-specific adolescent BMI Z-scores were calculated. At early adulthood (21-22 years), fat accumulation measurements were performed (abdominal, subcutaneous, visceral, hepatic, and pancreatic fat). Linear regression models with an interaction between adolescent BMI Z-score and Pb or Hg levels were run for each adulthood fat accumulation outcome with normal BMI as reference. RESULTS: In adolescents with obesity compared to normal BMI, as Pb exposure increased, subcutaneous (p-interaction = 0.088) and visceral (p-interaction < 0.0001) fat accumulation increases. Meanwhile, Hg was associated with subcutaneous (p-interaction = 0.027) and abdominal (p-interaction = 0.022) fat deposition among adolescents with obesity. CONCLUSIONS: Heavy metal exposure in adolescence may alter how fat is accumulated in later periods of life.

Alcances de la aleatorización mendeliana para el control de confusores no observables en epidemiología / Scope of Mendelian randomization to control for unobserved confounding in epidemiology

La aleatorización mendeliana es un método epidemiológico propuesto para controlar las asociaciones espurias en los estudios observacionales. Estas asociaciones suelen estar causadas por la confusión derivada de factores sociales, ambientales y de comportamiento, que pueden ser difíciles de medir. La aleatorización mendeliana se basa en la selección de variantes genéticas que se utilizan como variables instrumentales, y que influyen en los patrones de exposición o están asociadas con un fenotipo intermedio de la enfermedad. El presente trabajo pretende discutir cómo seleccionar las variantes genéticas adecuadas como variables instrumentales y presentar las potenciales herramientas metodológicas para lidiar con las limitaciones propias de este método epidemiológico. El uso de variables instrumentales para exposiciones modificables tiene el potencial de atenuar los efectos de limitaciones comunes, como la confusión, cuando se eligen variantes genéticas robustas como variables instrumentales. (AU)

The Mendelian randomization is an epidemiologic method proposed to control for spurious associations in observational studies. These associations are commonly caused by confusion derived from social, environmental, and behavioral factors, which can be difficult to measure. Mendelian randomization is based on the selection of genetic variants that are used as instrumental variables that influence exposure patterns or are associated with an intermediate phenotype of the disease. The present work aims to discuss how to select the appropriate genetic variants as instrumental variables and to present methodological tools to deal with the limitations of this epidemiological method. The use of instrumental variables for modifiable exposures has the potential to mitigate the effects of common limitations, such as confusion, when robust genetic variants are chosen as instrumental variables. (AU)