The Omicron wave in Mexico: vaccine protection against progression to severe Covid-19 in SARS-CoV-2-infected workers.

OBJECTIVE: To assess the effectiveness of seven Covid-19 vaccines in preventing disease progression (DP) using data from national private sector workers during the Omicron wave in Mexico from January 2 to March 5, 2022. MATERIALS AND METHODS: This study employed an administrative retrospective cohort design, analyzing DP (hospitalization or death due to respiratory disease) among workers who filed a respiratory short-term disability claim and tested positive for SARS-CoV-2. Risk ratios (RRadj) were estimated using Poisson regression models adjusted for various factors. RESULTS: Vaccinated individuals had a lower risk of hospitalization and death compared with unvaccinated individuals. The overall RRadj for hospitalization and death were 0.36 (95%CI 0.32, 0.41) and 0.24 (0.17, 0.33), respectively. When evaluating vaccines individually, the RRadj for hospitalization were as follows Pfizer BioNTech 0.27 (95%CI 0.22, 0.33), Moderna 0.29 (95%CI 0.15, 0.57), Sinovac 0.32 (95%CI 0.25, 0.41), AstraZeneca 0.39 (95%CI 0.34, 0.46), Sputnik 0.39 (95%CI 0.28, 0.53), CanSino 0.41 (95%CI 0.24, 0.7), and Janssen 0.53 (95%CI 0.39, 0.72). The RRadj for death were as follows: Pfizer BioNTech 0.12 (95%CI 0.07, 0.19), Sputnik 0.15 (95%CI 0.06, 0.38), Sinovac 0.29 (95%CI 0.16, 0.53), AstraZeneca 0.30 (95%CI 0.20, 0.44), CanSino 0.38 (95%CI 0.1, 1.4), and Janssen 0.50 (95%CI 0.26, 0.97). CONCLUSION: Covid-19 vaccines significantly reduced the risk of severe disease during the Omicron wave in Mexico.

Accessing medical care for infertility: a study of women in Mexico.

Objective: To investigate barriers in accessing care for infertility in Mexico, because little is known about this issue for low and middle-income countries, which comprise 80% of the world's population. Design: Cross-sectional analysis. Setting: Mexcian Teachers' Cohort. Patients: A total of 115,315 female public school teachers from 12 states in Mexico. Interventions: None. Main Outcome Measures: The participants were asked detailed questions about their demographics, lifestyle characteristics, access to the health care system, and infertility history via a self-reported questionnaire. Log-binomial models, adjusted a priori for potential confounding factors, were used to estimate the prevalence ratios (PRs) and 95% confidence intervals ( CIs) of accessing medical care for infertility among women reporting a history of infertility. Results: A total of 19,580 (17%) participants reported a history of infertility. Of those who experienced infertility, 12,470 (63.7%) reported seeking medical care for infertility, among whom 8,467 (67.9%) reported undergoing fertility treatments. Among women who reported a history of infertility, women who taught in a rural school (PR, 0.95; 95% CI, 0.92-0.97), spoke an indigenous language (PR, 0.88; 95% CI, 0.84-0.92), or had less than a university degree (PR, 0.93; 95% CI, 0.90-0.97) were less likely to access medical care for fertility. Women who had ever had a mammogram (PR, 1.07; 95% CI, 1.05-1.10), had a pap smear in the past year (PR, 1.08; 95% CI, 1.06-1.10), or who had used private health care regularly or in times of illness were more likely to access medical care for fertility. Conclusions: The usage of infertility care varied by demographic, lifestyle, and access characteristics, including speaking an indigenous language, teaching in a rural school, and having a private health care provider.

Sun Exposure and Intima-Media Thickness in the Mexican Teachers' Cohort Study.

Objective: To determine whether long-term sun exposure has a protective role in subclinical cardiovascular disease in adult Mexican women. Materials and Methods: We conducted a cross-sectional analysis of a sample of women from the Mexican Teachers' Cohort (MTC) study. Sun exposure was assessed in the MTC 2008 baseline questionnaire, in which women were asked about their sun-related behavior. Vascular neurologists measured carotid intima-media thickness (IMT) using standard techniques. Multivariate linear regression models were used to estimate the difference in mean IMT and 95% confidence intervals (95% CIs), according to categories of sun exposure and multivariate logistic regression models were used to estimate the odds ratio (OR) and 95% CIs for carotid atherosclerosis. Results: The mean age of participants was 49.6 ± 5.5 years, the mean IMT was 0.678 ± 0.097 mm, and the mean accumulated hours of weekly sun exposure were 2.9 ± 1.9. Prevalence of carotid atherosclerosis was 20.9%. Compared with women in the lowest quartile of sun exposure, women in the highest quartile had lower mean IMT, but this was not significant in the multivariable adjusted analysis. (Adjusted mean % difference: -0.8; 95% CI: -2.3 to 0.8). The multivariate adjusted ORs of carotid atherosclerosis were 0.54 (95% CI: 0.24-1.18) for women who were exposed 9 hours. For women who denied regular sunscreen use, those in the higher exposure category (9 hours) had lower mean IMT compared with those in the lower category (multivariable-adjusted mean % difference = -2.67; 95% CI: -6.9 to -1.5). Conclusions: We observed that cumulative sun exposure was inversely associated with IMT and subclinical carotid atherosclerosis. If these findings are further replicated and seen for other cardiovascular outcomes, sun exposure could be an easy, affordable strategy to lower overall cardiovascular risk.

EAT-Lancet Healthy Reference Diet score and diabetes incidence in a cohort of Mexican women.

To improve the health of our planet and develop sustainable food policies, it is important to understand the health impact of a diet pattern that considers planetary and population health. We used data from the Mexican Teachers' Cohort (MTC) to estimate the association between the EAT-Lancet healthy reference diet (EAT-HRD) and type 2 diabetes (T2D) incidence. We included 74,671 women aged ≥25 years, free of T2D at baseline. A validated food frequency questionnaire (FFQ) was used to assess dietary intake. We created an EAT-HRD score based on 15 food groups recommended by the EAT-Lancet Commission (range from 0 to 15). T2D cases were identified through self-report and cross-linkage with clinical and administrative databases. We used Cox proportional hazards models to estimate the association between categories of the EAT-HRD score with T2D incidence. During a median follow-up of 2.16 y (IQR 1.8-4.3 y), we identified 3241 T2D incident cases. The median EAT-HRD score was 6 (IQR 5-7). In multivariable analyses, when comparing extreme categories, higher adherence to the EAT-HRD score was associated with lower T2D incidence (HR 0.90; 95% CI 0.75, 1.10), yet, the estimation was imprecise. Compared to those who did not meet the EAT-HRD recommendations, adhering to the red meat, legumes, and fish recommendations was associated with lower T2D incidence. Meeting the recommendation of dairy and added sugars was associated with an increased incidence of T2D. Higher adherence to a diet designed to promote environmental and human health may help prevent T2D incidence among women in a middle-income country.

The Mexican Consortium of Epidemiological Studies for the Prevention, Diagnosis, and Treatment of Chronic Kidney Disease: a review of collaborating studies.

OBJECTIVE: To harmonize participants' information from five epidemiological studies. MATERIALS AND METHODS: The Mexican Consortium of Epidemiological Studies for the Prevention, Diagnosis, and Treatment of Chronic Kidney Disease (RenMex, by its Spanish acronym) was established in 2018. RenMex is a consortium of five studies: The Mexican Teachers Cohort Study; the Mexico City Diabetes Study; the Health Workers Cohort Study; the Comitán Study; and the Salt Consumption in Mexico Study, which assessed baseline serum creatinine, albumin, and C-reactive protein, all performed with standardized techniques. RESULTS: RenMex includes 3 133 participants, with a mean age of 44.8 years, 68.8% women, 10.8% with a previous medical diagnosis of type 2 diabetes, and 24.1% living with obesity. CONCLUSIONS: In the future, RenMex will work on more detailed analyses with each cohort allowed to opt in or out for each topic according to their individual data.

Sugar- and artificially-sweetened soda consumption and subclinical atherosclerosis among Mexican women.

BACKGROUND AND AIMS: Sugar-sweetened soda consumption is associated with most cardiometabolic risk factors. The role of artificially-sweetened beverages in cardiovascular disease (CVD) is inconclusive, but their consumption correlates with health impairment. Little is known about the contribution of soda consumption in subclinical stages of atherosclerosis. Therefore, we evaluated the relation between sugar- and artificially-sweetened soda consumption and carotid intima-media thickness (IMT) among Mexican women. METHODS AND RESULTS: We cross-sectionally evaluated 1093 women enrolled in the Mexican Teachers' Cohort who were free of CVD, diabetes or cancer. Sugar- and artificially-sweetened soda consumption was estimated from a validated 140-item food frequency questionnaire in 2008 and all women underwent a carotid ultrasound assessment three years later. Participants were categorized into tertiles of soda consumption in servings/week. Subclinical atherosclerosis was defined as a mean left and/or right IMT ≥0.8 mm or the presence of plaque on either common carotid artery. In multivariable regression models, women in the highest tertile of sugar-sweetened soda consumption had 2.6% (95%CI: 0.8, 4.5) mean increased IMT, and had 2-fold the risk of carotid atherosclerosis (PR: 2.0, 95%CI: 1.3, 3.2) compared to those in the lowest tertile. In stratified analyses, older and postmenopausal women who consumed sugar-sweetened soda had an increased IMT and atherosclerosis risk. Artificially-sweetened soda consumption was not associated with IMT or carotid atherosclerosis. CONCLUSIONS: Sugar-sweetened soda consumption was associated with subclinical atherosclerosis among disease-free Mexican women. Public health strategies to decrease CVD should consider the impact of sugar-sweetened soda consumption, particularly in older women.

The association of age at menarche and adult height with mammographic density in the International Consortium of Mammographic Density.

BACKGROUND: Early age at menarche and tall stature are associated with increased breast cancer risk. We examined whether these associations were also positively associated with mammographic density, a strong marker of breast cancer risk. METHODS: Participants were 10,681 breast-cancer-free women from 22 countries in the International Consortium of Mammographic Density, each with centrally assessed mammographic density and a common set of epidemiologic data. Study periods for the 27 studies ranged from 1987 to 2014. Multi-level linear regression models estimated changes in square-root per cent density (√PD) and dense area (√DA) associated with age at menarche and adult height in pooled analyses and population-specific meta-analyses. Models were adjusted for age at mammogram, body mass index, menopausal status, hormone therapy use, mammography view and type, mammographic density assessor, parity and height/age at menarche. RESULTS: In pooled analyses, later age at menarche was associated with higher per cent density (ß√PD = 0.023 SE = 0.008, P = 0.003) and larger dense area (ß√DA = 0.032 SE = 0.010, P = 0.002). Taller women had larger dense area (ß√DA = 0.069 SE = 0.028, P = 0.012) and higher per cent density (ß√PD = 0.044, SE = 0.023, P = 0.054), although the observed effect on per cent density depended upon the adjustment used for body size. Similar overall effect estimates were observed in meta-analyses across population groups. CONCLUSIONS: In one of the largest international studies to date, later age at menarche was positively associated with mammographic density. This is in contrast to its association with breast cancer risk, providing little evidence of mediation. Increased height was also positively associated with mammographic density, particularly dense area. These results suggest a complex relationship between growth and development, mammographic density and breast cancer risk. Future studies should evaluate the potential mediation of the breast cancer effects of taller stature through absolute breast density.

Leading causes of excess mortality in Mexico during the COVID-19 pandemic 2020-2021: A death certificates study in a middle-income country.

Background: The death toll after SARS-CoV-2 emergence includes deaths directly or indirectly associated with COVID-19. Mexico reported 325,415 excess deaths, 34.4% of them not directly related to COVID-19 in 2020. In this work, we aimed to analyse temporal changes in the distribution of the leading causes of mortality produced by COVID-19 pandemic in Mexico to understand excess mortality not directly related to the virus infection. Methods: We did a longitudinal retrospective study of the leading causes of mortality and their variation with respect to cause-specific expected deaths in Mexico from January 2020 through December 2021 using death certificate information. We fitted a Poisson regression model to predict cause-specific mortality during the pandemic period, based on the 2015-2019 registered mortality. We estimated excess deaths as a weekly difference between expected and observed deaths and added up for the entire period. We expressed all-cause and cause-specific excess mortality as a percentage change with respect to predicted deaths by our model. Findings: COVID-19 was the leading cause of death in 2020-2021 (439,582 deaths). All-cause total excess mortality was 600,590 deaths (38⋅2% [95% CI: 36·0 to 40·4] over expected). The largest increases in cause-specific mortality, occurred in diabetes (36·8% over expected), respiratory infections (33·3%), ischaemic heart diseases (32·5%) and hypertensive diseases (25·0%). The cause-groups that experienced significant decreases with respect to the expected pre-pandemic mortality were infectious and parasitic diseases (-20·8%), skin diseases (-17·5%), non-traffic related accidents (-16·7%) and malignant neoplasm (-5·3%). Interpretation: Mortality from COVID-19 became the first cause of death in 2020-2021, the increase in other causes of death may be explained by changes in the health service utilization patterns caused by hospital conversion or fear of the population using them. Cause-misclassification cannot be ruled out. Funding: This study was funded by Conacyt.

Validity and reliability of the International Physical Activity Questionnaire (IPAQ) long-form in a subsample of female Mexican teachers.

OBJECTIVE: To evaluate the test-retest reliability and validity of the long-form International Physical Activity Questionnaire (IPAQ-long form). MATERIALS AND METHODS: A subsample of 86 teachers underwent telephone interviews and clinic visits in Mexico City. Through 22 months, physical activity (PA) levels were obtained from accelerometers (months 6 and 22) and IPAQ long-form (months 1, 3, 6, 9 and 12). Minutes per week of moderate (MPA), walking (WPA), vigorous (VPA) and moderate-to-vigorous physical activity (MVPA) were calculated for each intensity and domain. Variables were loga-rithmically transformed. Intra-class and Pearson correlations were used to determine the relationship between instru-ments. RESULTS: Test-retest reliability of the average IPAQs long-form varied across intensities and domains (ranged from r= 0.24 to r= 0.65). Minutes per week of VPA and MVPA ac-celerometer 1 (AC1) were fairly associated to International Physical Activity Questionnaire-long form 3 (IPAQ3) (r= 0.60 and r= 0.31, respectively) one week apart. CONCLUSIONS: IPAQ long-form is fairly reliable for MVPA and valid for as-sessing MVPA and VPA in a subsample of Mexican teachers.

Liver cancer mortality in Mexico: trend analysis from 1998 to 2018.

OBJECTIVE: To examine overall, sex, and state-specific liver cancer mortality trends in Mexico. Materials and meth-ods. Joinpoint regression was used to examine the trends in age-standardized mortality rates of liver cancer between 1998-2018. Estimated annual percent change with 95% confi-dence intervals (95%CI) were computed. Age-period-cohort models were used to assess the effects of age, calendar year, and birth cohort. RESULTS: The state-specific mortality rates ranged from 3.34 (Aguascalientes) to 7.96 (Chiapas) per 100 000 person-years. Sex-specific rates were roughly equal, nationwide. Overall, we observed a statistically significant decrease in liver cancer mortality rates between 1998-2018 (annual percent change, -0.8%; 95%CI -1.0, -0.6). The overall age-period-cohort models suggest that birth cohort may be the most important factor driving the trends. CONCLUSIONS: While there was overall decline in liver cancer mortality, differences in rates by region were observed. The regional differences may inform future studies of liver cancer etiology across the country.

Volviéndonos mejores: necesidad de acción inmediata ante el reto de la obesidad. Una postura de profesionales de la salud / Becoming better: the need for immediate action to address obesity. A position statement from health professionals

resumen está disponible en el texto completo

Abstract: In recent decades, the growing obesity epidemic in Mexico has become one of the most important public health challenges faced by the country. With support from the World Obesity Federation, we formed a working group in 2021 to identify and summarize priority actions that Mexico can take to face this epidemic. More than 1 000 health professionals joined the development and discussion process. Recommendations from previously published, high-level documents and guidelines were taken into account. In commemoration of World Obesity Day 2022, this statement is presented as input for health care professionals to develop actions to address obesity. The statement includes 10 recommendations that include population-level and individual-level actions. It emphasizes the importance of social participation, comprehensive interventions with a person- centered perspective, planetary sustainability, on improving education and communication campaigns, as well as fostering a built environment that promotes active living, and shielding prevention and control efforts from conflicts of interest. The statement calls for obesity to be treated seriously, based on scientific evidence, in a timely and comprehensive manner, employing a life-course and ethical approach that does not perpetuate weight stigma in society.

Liver cancer mortality in Mexico: trend analysis from 1998 to 2018 / Mortalidad por cáncer hepático en México: análisis de tendencias de 1998 a 2018

Abstract: Objective: To examine overall, sex, and state-specific liver cancer mortality trends in Mexico. Materials and methods: Joinpoint regression was used to examine the trends in age-standardized mortality rates of liver cancer between 1998-2018. Estimated annual percent change with 95% confidence intervals (95%CI) were computed. Age-period-cohort models were used to assess the effects of age, calendar year, and birth cohort. Results: The state-specific mortality rates ranged from 3.34 (Aguascalientes) to 7.96 (Chiapas) per 100 000 person-years. Sex-specific rates were roughly equal, nationwide. Overall, we observed a statistically significant decrease in liver cancer mortality rates between 1998-2018 (annual percent change, -0.8%; 95%CI -1.0, -0.6). The overall age-period-cohort models suggest that birth cohort may be the most important factor driving the trends. Conclusions: While there was overall decline in liver cancer mortality, differences in rates by region were observed. The regional differences may inform future studies of liver cancer etiology across the country.

Resumen: Objetivo: Examinar la tendencia general, por sexo y estado, de mortalidad por cáncer hepático en México. Material y métodos: Se utilizó regresión joinpoint para examinar las tendencias en las tasas de mortalidad estandarizadas por edad de cáncer hepático (1998-2018). Se estimó el cambio porcentual anual con intervalos de confianza al 95% (IC95%). Se usaron modelos de edad-periodo-cohorte para evaluar el efecto de edad, año calendario y cohorte de nacimiento. Resultados: La mortalidad osciló entre 3.34 (Aguascalientes) y 7.96 (Chiapas) por 100 000 años-persona. La mortalidad por sexo fue relativamente similar a nivel nacional. La mortalidad general disminuyó entre 1998-2018 (cambio porcentual anual, -0.8%; IC95% -1.0, -0.6). La cohorte de nacimiento parece ser el factor más importante que afecta las tendencias. Conclusiones: A pesar de la disminución de mortalidad por cáncer hepático, se observó variación regional en las tasas. Estas diferencias podrían informar estudios futuros sobre la etiología de cáncer hepático en México.

Perceived Stress Scale, a tool to explorepsychological stress in Mexican women / Escala de Estrés Percibido, un instrumento para explorar estrés psicológico en mujeres mexicanas

Abstract: Objective: To examine the factor structure of the 4- and 10-item Perceived Stress Scale (PSS) among 1 310 Mexican women participating in a prospective cancer cohort study. Materials and methods: We performed exploratory and confirmatory factor analyses in two sub-samples of the Mexican Teachers' Cohort. We evaluated internal consistency, estimated the correlation between PSS-4 and PSS-10, and assessed their correlation with a depressive symptoms scale. Results: Two-factor models were the solutions with the best fit to the data for both PSS-4 and -10, exhibiting strong factor loadings (0.39 to 0.75) and high internal consistency (Cronbach's alpha 0.72 and 0.83). The correlation between PSS-4 and PSS-10 was r=0.91 and the correlations of these two scales with a depressive symptoms scale were r=0.41 and r=0.46, respectively. Conclusions: PSS might be an adequate scale to assess perceived stress in this prospective cancer cohort study. PSS-4 may be advantageous due to its simplicity, low cost, and short application time in multicountry studies on stress and cancer.

Resumen: Objetivo: Evaluar la estructura factorial de la Escala de Estrés Percibido (PSS, por sus siglas en inglés) de 4 y 10 ítems en 1 310 mujeres mexicanas que participan en un estudio de cohorte sobre cáncer. Material y métodos: Se realizó análisis factorial exploratorio y confirmatorio en dos submuestras distintas del estudio ESMaestras. También se evaluó la consistencia interna, la correlación entre la PSS-4 y la PSS-10, y la correlación de estas escalas con una escala de síntomas depresivos. Resultados: El modelo de dos factores fue la solución con los mejores índices para ambas escalas, exhibiendo cargas factoriales fuertes (0.39-0.75), y alta consistencia interna (alfa de Cronbach=0.72 y 0.83). La correlación entre la PSS-4 y la PSS-10 fue r=0.91 y la correlación de estas escalas con la escala de síntomas depresivos fue r=0.41 y 0.46. Conclusiones: La PSS es una escala adecuada para evaluar el estrés percibido en este estudio de cohorte sobre cáncer. La PSS-4 puede ser ventajosa por su simplicidad, bajo costo y corto tiempo de aplicación en estudios multipaís sobre estrés y cáncer.

Validity and reliability of the International Physical Activity Questionnaire (IPAQ) long-form in a subsample of female Mexican teachers / Validez y confiabilidad el Cuestionario Internacional de Actividad Física versión larga en una submuestra de maestras mexicanas

Abstract: Objective: To evaluate the test-retest reliability and validity of the long-form International Physical Activity Questionnaire (IPAQ-long form). Materials and methods: A subsample of 86 teachers underwent telephone interviews and clinic visits in Mexico City. Through 22 months, physical activity (PA) levels were obtained from accelerometers (months 6 and 22) and IPAQ long-form (months 1, 3, 6, 9 and 12). Minutes per week of moderate (MPA), walking (WPA), vigorous (VPA) and moderate-to-vigorous physical activity (MVPA) were calculated for each intensity and domain. Variables were logarithmically transformed. Intra-class and Pearson correlations were used to determine the relationship between instruments. Results: Test-retest reliability of the average IPAQs long-form varied across intensities and domains (ranged from r= 0.24 to r= 0.65). Minutes per week of VPA and MVPA accelerometer 1 (AC1) were fairly associated to International Physical Activity Questionnaire-long form 3 (IPAQ3) (r= 0.60 and r= 0.31, respectively) one week apart. Conclusions: IPAQ long-form is fairly reliable for MVPA and valid for assessing MVPA and VPA in a subsample of Mexican teachers.

Resumen: Objetivo: Evaluar la confiabilidad y validez del Cuestionario Internacional de Actividad Física versión larga (por sus siglas en inglés IPAQ-long form). Material y métodos: Un total de 86 maestras realizaron entrevistas y visitas a clínicas en la Ciudad de México. En un periodo de 22 meses, se obtuvieron los niveles de actividad física (AF) por medio de un acelerómetro (AC) (meses 6 y 22) y autorreporte de actividad física por medio del IPAQ versión larga (meses 1, 3, 6, 9 y 12). Se estimaron los minutos por semana de actividad física moderada (AFM), caminando (AFC), vigorosa (AFV) y actividad física moderada-vigorosa (AFMV) para cada intensidad y dominio. Las variables se transformaron logarítmicamente. Se utilizaron correlaciones de intraclase y de Pearson para determinar la relación de los minutos por semana de AFM, AFC, AFMV entre instrumentos. Resultados: La confiabilidad entre el promedio de los IPAQs varió entre intensidades y dominios (de r = 0.24 a r = 0.65). Los minutos por semana de AFV y AFMV del acelerómetro 1 (AC1) se asociaron con los del Cuestionario Internacional de Actividad Física 3 (IPAQ3) (r = 0.60 y r = 0.31, respectivamente) reportado una semana después. Conclusiones: La versión larga del IPAQ es confiable para estimar AFMV y válido para evaluar AFMV y AFV en una submuestra de maestras mexicanas.

Operation of research ethics committees in Colombia, Costa Rica, Guatemala, and Mexico: Mesoamerican Project / Funcionamiento de los comités de ética en investigación en Colombia, Costa Rica, Guatemala y México: Proyecto Mesoamericano

Abstract: Objective: To attain a better understanding of the structure and processes of Research Ethics Committees (REC) in the low-and middle-income countries of the Mesoamerican region. The objectives are knowing the operational practices of the RECs regarding project evaluation, training needs, and infrastructure. Materials and methods: The REC training and needs assessment involved an online survey of all the RECs (n=55) identified in Colombia (n=11), Costa Rica (n=5), Guatemala (n=5), and Mexico (n=34). Results: Participants reported inadequate infrastructure for its proper operation (only 49.1 %, or 27/55, have an exclusive office to safeguard files); insufficient administrative staff (47.3%, 26/55), or financial resources to conduct active site monitoring (85.6%, 47/55) to ensure the protection of rights and welfare of study participants. Conclusions: Investments in REC member training and infrastructure are needed to ensure compliance of REC evaluations with the standards for ethical conduct of research.

Resumen: Objetivo: Comprender la estructura y procesos de los Comités de Ética en Investigación (CEI) en países mesoamericanos de ingresos bajos y medios. Conocer las prácticas operativas en evaluación de proyectos, necesidades de capacitación e infraestructura. Material y métodos: Encuesta en línea para evaluar necesidades de capacitación de los CEI (n=55) identificados en Colombia (n=11), Costa Rica (n=5), Guatemala (n=5) y México (n=34). Resultados: Los participantes reportaron una infraestructura inadecuada para su correcto funcionamiento (oficina exclusiva para archivos 49.1%, 27/55); personal administrativo insuficiente (47.3%, 26/55), recursos financieros insuficientes para monitoreo del sitio (85.6%, 47/55), para garantizar protección de derechos y bienestar de los participantes. Conclusiones: Se necesita invertir en capacitación de los miembros e infraestructura del CEI, para garantizar la conducción ética de la investigación.

Fraction of COVID-19 hospitalizations and deaths attributable to chronic diseases.

Evidence shows that chronic diseases are associated with COVID-19 severity and death. This study aims to estimate the fraction of hospitalizations and deaths from COVID-19 attributable to chronic diseases associated to poor nutrition and smoking among adults who tested positive to COVID-19 in Mexico. We analyzed 1,006,541 adults aged ≥20 who tested positive for COVID-19 from March 23 to December 5, 2020. Six chronic diseases were considered: obesity, chronic obstructive pulmonary disease (COPD), hypertension, diabetes, cardiovascular disease, and chronic kidney disease (CKD). We calibrated the database using a bias quantification method to consider undiagnosed disease cases. To estimate the total impact of multiple diseases, we defined a multimorbidity variable according to the number of diseases. Risks of hospitalization and death were estimated with Poisson regression models and used to calculate population attributable fractions (PAFs). Chronic diseases accounted for to 25.4% [95% CI: 24.8%-26.1%], 28.3% (95% CI: 27.8%-28.7%) and 15.3% (95% CI: 14.9%-15.7%) of the hospitalizations among adults below 40, 40-59, and 60 years and older, respectively. For COVID-19-related deaths, 50.1% (95% CI: 48.6%-51.5%), 40.5% (95% CI: 39.7%-41.3%), and 18.7% (95% CI, 18.0%-19.5%) were attributable to chronic diseases in adults under 40, 40-59, and 60 years and older, respectively. Chronic diseases linked to poor nutrition and smoking could have contributed to a large burden of hospitalization and deaths from COVID-19 in Mexico, particularly among younger adults. Medical and structural interventions to curb chronic disease incidence and facilitate disease control are urgently needed.

Air pollution exposure and incidence of type 2 diabetes in women: A prospective analysis from the Mexican Teachers' Cohort.

BACKGROUND: Air pollution is a risk factor for type 2 diabetes (T2D). However, scarse longitudinal studies have evaluated this association in low- and middle-income countries, where 80% of the worldwide cases of T2D occur. OBJECTIVE: Our aim was to estimate the association between PM2.5 and NO2 exposure and incident T2D, in the Mexican Teachers' Cohort (MTC). METHODS: We selected a subsample of female teachers from the MTC from Mexico City metropolitan area (MCMA), recruited in 2008 and with active follow-up every three years. We assigned the monthly time-weighted exposures (PM2.5 and NO2) using home and work addresses, until failure, censoring or death. We developed two high resolution (1 × 1-km) spatiotemporal predictive generalized additive models of PM2.5 and NO2. Incident diabetes was identified through self-report and two administrative databases of registered diabetes patients. We fitted time-varying Cox models to estimate hazard ratios of the relation between PM2.5 and NO2 and incident T2D, adjusting for confounding variables that were identified using a causal model. RESULTS: A total of 13,669 teachers were followed-up for a maximum of 11.5 years, over which 996 incident T2D cases (88 cases per 100,000 person-months) occurred. Incident T2D increased by 72% (HR = 1.72 [1.47-2.01]) for each 10 µg/m3 increase of PM2.5, and 52% for each 10 ppb of NO2 (HR = 1.52 [1.37-1.68]). DISCUSSION: Mid-term exposure to PM2.5 and NO2 was associated with a higher risk of T2D after adjusting for indoor wood smoke, socioeconomic status, and physical activity. These associations were attenuated in two-pollutant models but remained positive when evaluated long-term exposure. This is the first prospective study to evaluate T2D risk by exposure to both pollutants, PM2.5 and NO2 in a population from an upper middle-income country in the Americas.

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.

Estimación del exceso de mortalidad por todas las causas durante la pandemia del Covid-19 en México.

 Objetivo. Estimar el exceso de defunciones por todas las causas en México durante 2020. Material y métodos. Se construyó un canal endémico con las defunciones (2015- 2019), estableciendo el umbral epidémico en el percentil 90, y se comparó con las actas de defunción para estimar el exceso de mortalidad. Resultados. A la semana 53, ocurrieron 326 612 defunciones en exceso (45.1%), con un máximo en la semana 28 (98.0%) y un mínimo en la semana 41 (35.2%); después de la semana 4 los hombres (51.3%), principalmente de 45-64 años de edad, sin embargo, en los de 60 años o más ocurrió el mayor nú-mero de defunciones. Conclusión. En México, el exceso de mortalidad ha sido prolongado en comparación con otros países, con alta variabilidad interestatal. Esto podría deberse a las condiciones socioeconómicas y a la alta prevalencia de comorbilidades que aumentan el riesgo de morir en la población mexicana.

Dairy consumption and subclinical atherosclerosis: A cross-sectional study among middle-aged Mexican women.

BACKGROUND AND AIMS: Many dietary guidelines encourage low-fat dairy products; however, recent studies have found null and inverse associations between high-fat dairy intake and cardiovascular disease (CVD) risk. We examined the association between the intake of total dairy and different types of dairy and carotid intima-media thickness (IMT), a marker of subclinical atherosclerosis, in Mexican women. METHODS AND RESULTS: Dairy consumption was assessed using a validated food-frequency questionnaire (FFQ) in 1759 women in the Mexican Teachers' Cohort (MTC) study who were free of CVD or cancer. We categorized participants according to total dairy intake and consumption of four mutually exclusive dairy groups: high-fat, low-fat, yogurt, and dairy with added sugars. IMT and atherosclerotic plaque were measured by B-mode ultrasonography. Subclinical atherosclerosis was defined as an IMT ≥0.8 mm and/or the presence of plaque. Multivariable linear regression and logistic regression models were used to respectively assess the mean percentage difference of mean IMT and odds ratios (OR) for subclinical atherosclerosis across quantiles of dairy consumption. Mean (±SD) age was 45.4 ± 5.0 years and the median (interquartile range: IQR) total dairy consumption was 11.0 (6.6, 17.1) servings/week. After adjusting for lifestyle, clinical, and dietary factors, comparing the highest category of consumption, to the lowest, total dairy was associated with increased IMT (2.6%, 95% confidence interval (CI): 0.6, 4.3; p-trend<0.01). Moreover, yogurt consumption was associated with lower odds of subclinical atherosclerosis (OR = 0.65, 95% CI: 0.47, 0.91; p-trend = 0.01). CONCLUSIONS: While total dairy consumption was associated with carotid wall thickening, yogurt consumption was related to lower subclinical atherosclerosis.