Protocol to detect senescence-associated ß-galactosidase and immunoperoxidase activity in fresh-frozen murine tissues.

Double labeling to identify different markers in the same tissue section represents a useful tool either for in situ diagnosis or characterization of molecular associations. Here, we present a protocol to detect senescence-associated ß-galactosidase (SA-ßGal) and immunoperoxidase (IPO) activity in fresh-frozen murine tissues. We describe steps for tissue collection, solution preparation, SA-ßGal staining, IPO staining, hematoxylin counterstaining, microscopic observation, and signal quantification. This protocol can be used to detect in situ proteins alongside SA-ßGal activity. For complete details on the use and execution of this protocol, please refer to Pacheco-Rivera et al.1.

Systematic Review of Longitudinal Evidence and Methodologies for Research on Neighborhood Characteristics and Brain Health.

Objective: Synthesize longitudinal research evaluating neighborhood environments and cognition to identify methodological approaches, findings, and gaps. Methods: Included studies evaluated associations between neighborhood and cognition longitudinally among adults >45 years (or mean age of 65 years) living in developed nations. We extracted data on sample characteristics, exposures, outcomes, methods, overall findings, and assessment of disparities. Results: Forty studies met our inclusion criteria. Most (65%) measured exposure only once and a majority focused on green space and/or blue space (water), neighborhood socioeconomic status, and recreation/physical activity facilities. Similarly, over half studied incident impairment, cognitive function or decline (70%), with one examining MRI (2.5%) or Alzheimer's disease (7.5%). While most studies used repeated measures analysis to evaluate changes in the brain health outcome (51%), many studies did not account for any type of correlation within neighborhoods (35%). Less than half evaluated effect modification by race/ethnicity, socioeconomic status, and/or sex/gender. Evidence was mixed and dependent on exposure or outcome assessed. Conclusion: Although longitudinal research evaluating neighborhood and cognitive decline has expanded, gaps remain in types of exposures, outcomes, analytic approaches, and sample diversity.

A model of alcoholic liver disease based on different hepatotoxics leading to liver cancer.

The worst-case scenario related to alcoholic liver disease (ALD) arises after a long period of exposure to the harmful effect of alcohol consumption along with other hepatotoxics. ALD encompasses a broad spectrum of liver-associated disorders, such as steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Based on the chronic administration of different hepatotoxics, including ethanol, sucrose, lipopolysaccharide, and low doses of diethylnitrosamine over a short period, here we aimed to develop a multiple hepatotoxic (MHT)-ALD model in the mouse that recapitulates the human ALD-associated disorders. We demonstrated that the MHT-ALD model induces ADH1A and NXN, an ethanol metabolizer and a redox-sensor enzyme, respectively; promotes steatosis associated with the induction of the lipid droplet forming FSP27, inflammation identified by the infiltration of hepatic neutrophils-positive to LY-6G marker, and the increase of MYD88 level, a protein involved in inflammatory response; and stimulates the early appearance of cellular senescence identified by the senescence markers SA-ß-gal activity and p-H2A.XSer139. It also induces fibrosis associated with increased desmin, a marker of hepatic stellate cells whose activation leads to the deposition of collagen fibers, accompanied by cell death and compensatory proliferation revealed by increased CASP3-mediated apoptosis, and KI67- and PCNA-proliferation markers, respectively. It also induces histopathological traits of malignancy and the level of the HCC marker, GSTP1. In conclusion, we provide a useful model for exploring the chronological ALD-associated alterations and stages, and addressing therapeutic approaches.

Nucleoredoxin Redox Interactions Are Sensitized by Aging and Potentiated by Chronic Alcohol Consumption in the Mouse Liver.

Aging is characterized by increased reactive species, leading to redox imbalance, oxidative damage, and senescence. The adverse effects of alcohol consumption potentiate aging-associated alterations, promoting several diseases, including liver diseases. Nucleoredoxin (NXN) is a redox-sensitive enzyme that targets reactive oxygen species and regulates key cellular processes through redox protein-protein interactions. Here, we determine the effect of chronic alcohol consumption on NXN-dependent redox interactions in the liver of aged mice. We found that chronic alcohol consumption preferentially promotes the localization of NXN either into or alongside senescent cells, declines its interacting capability, and worsens the altered interaction ratio of NXN with FLII, MYD88, CAMK2A, and PFK1 proteins induced by aging. In addition, carbonylated protein and cell proliferation increased, and the ratios of collagen I and collagen III were inverted. Thus, we demonstrate an emerging phenomenon associated with altered redox homeostasis during aging, as shown by the declining capability of NXN to interact with partner proteins, which is enhanced by chronic alcohol consumption in the mouse liver. This evidence opens an attractive window to elucidate the consequences of both aging and chronic alcohol consumption on the downstream signaling pathways regulated by NXN-dependent redox-sensitive interactions.

Estimating the effect of latent time-varying count exposures using multiple lists.

A major challenge in longitudinal built-environment health studies is the accuracy of commercial business databases that are used to characterize dynamic food environments. Different databases often provide conflicting exposure measures on the same subject due to different source credibilities. As on-site verification is not feasible for historical data, we suggest combining multiple databases to correct the bias in health effect estimates due to measurement error in any 1 datasource. We propose a joint model for the time-varying health outcomes, observed count exposures, and latent true count exposures. Our model estimates the time-specific quality of sources and incorporates time dependence of true count exposure by Poisson integer-valued first-order autoregressive process. We take a Bayesian nonparametric approach to flexibly account for location-specific exposures. By resolving the discordance between different databases, our method reduces the bias in the longitudinal health effect of the true exposures. Our method is demonstrated with childhood obesity data in California public schools with respect to convenience store exposures in school neighborhoods from 2001 to 2008.

Temporal Patterns in Fruit and Vegetable Intake Among Racially and Ethnically Diverse Children and Adolescents in California.

Introduction: Childhood dietary behaviors, including fruit and vegetable intake, are associated with adult health. Most children do not meet daily recommended servings of fruits and vegetables. Less is known about temporal patterns in fruit and vegetable consumption or if they vary by race and ethnicity. We investigated temporal patterns in fruit and vegetable intake among California school-age children and adolescents overall and by race and ethnicity. Methods: We used 2-year cross-sectional datasets from the child and adolescent samples in the California Health Interview Surveys from 2011-2012 through 2019-2020 and modified Poisson regression models to estimate the likelihood of consuming 5 or more servings of fruits and vegetables in 2013-2016 and 2017-2020 compared with 2011-2012. Models controlled for age, race and ethnicity, gender, citizenship status, family income, and adult education and tested for differences by race and ethnicity. The samples included 16,125 children aged 5 to 11 years and 9,672 adolescents aged 12 to 17 years. Results: Overall, 29.3% of children and 25.9% of adolescents reported intake of 5 or more fruits and vegetables per day. Among children, adjusted prevalence ratios (PR) of fruit and vegetable intake were higher in 2013-2016 (PR,1.25; 95% CI, 1.11-1.42) and 2017-2020 (PR,1.13; 95% CI, 0.99-1.30) compared with 2011-2012. Among adolescents, the adjusted prevalence did not differ significantly over time. We found no evidence of differential associations by race and ethnicity for children and adolescents. Conclusion: We found favorable temporal changes in fruit and vegetable consumption among children, but not among adolescents. Monitoring temporal patterns in fruit and vegetable intake remains critical for planning population-level interventions to increase consumption.

Short-term associations between fine particulate air pollution and cardiovascular and respiratory mortality in 337 cities in Latin America.

Ambient air pollution is a health concern in Latin America given its large urban population exposed to levels above recommended guidelines. Yet no studies have examined the mortality impact of air pollutants in the region across a wide range of cities. We assessed whether short-term levels of fine particulate matter (PM2.5) from modeled estimates, are associated with cardiovascular and respiratory mortality among adults in 337 cities from 9 Latin American countries. We compiled mortality, PM2.5 and temperature data for the period 2009-2015. For each city, we evaluated the association between monthly changes in PM2.5 and cardiovascular and respiratory mortality for sex and age subgroups using Poisson models, adjusted for seasonality, long-term trend, and temperature. To accommodate possibly different associations of mortality with PM2.5 by age, we included interaction terms between changes in PM2.5 and age in the models. We combined the city-specific estimates using a random effects meta-regression to obtain mortality relative risks for each sex and age group. We analyzed 3,026,861 and 1,222,623 cardiovascular and respiratory deaths, respectively, from a study population that represents 41 % of the total population of Latin America. We observed that a 10 µg/m3 increase in monthly PM2.5 is associated with an increase of 1.3 % (95 % confidence interval [CI], 0.4 to 2.2) in cardiovascular mortality and a 0.9 % increase (95 % CI -0.6 to 2.4) in respiratory mortality. Increases in mortality risk ranged between -0.5 % to 3.0 % across 6 sex-age groups, were larger in men, and demonstrated stronger associations with cardiovascular mortality as age increased. Socioeconomic, environmental and health contexts in Latin America are different than those present in higher income cities from which most evidence on air pollution impacts is drawn. Locally generated evidence constitutes a powerful instrument to engage civil society and help drive actions to mitigate and control ambient air pollution.

Spatial scale effects on associations between built environment and cognitive function: Multi-Ethnic Study of Atherosclerosis.

Built environments have the potential to favorably support cognitive function. Despite growing work on this topic, most of the work has ignored variation in the spatial scale of the effect. The issue with spatial scale effects is that the size and shape of the areal unit within which built environment characteristics are measured naturally influence the built environment exposure metric and thus the estimated associations with health. We used spatial distributed lag modeling (DLM) to estimate how associations between built environment exposures (walkable destinations [WD], social destinations [SD]) and change in cognition varied across distance of these destinations from participants' residences. Cognition was assessed as maintained/improved processing speed (PS) and global cognition (GC). Person-level data from Exam 5 (2010-2012) and Exam 6 (2016-2018) of the Multi-Ethnic Study of Atherosclerosis was used (N = 1380, mean age 67). Built environment data were derived from the National Establishment Time Series. Higher availability of walkable and social destinations at closer distance from participants' residence was associated with maintained/improved PS. The adjusted associations between maintained/improved PS and destinations waned with increasing distance from the residence; associations were evident until approximately 1.9-km for WD and 1.5-km for SD. Associations were most apparent for participants living in areas with high population density. We found little evidence for associations between change in GC and built environment at any distance. These results highlight the importance of identifying appropriate spatial scale to understand the mechanisms for built environment-cognition associations.

"Competitive" food and beverage policies and weight status: A systematic review of the evidence among sociodemographic subgroups.

Prior studies identified variable associations between competitive food and beverage policies (CF&B) and youth obesity, potentially due to differences across population subgroups. This review summarizes the evidence on associations between CF&B policies and childhood obesity within gender, grade level/ age, race/ethnicity, and/or socioeconomic levels. PubMed, EMBASE, CINAHL, and ERIC database searches identified studies published in English in Canada and the United States between January 1, 2000, and February 28, 2022. Of the 18 selected studies, six were cross-sectional, two correlational, nine were before/after designs, and one study utilized both a cross-sectional and pre-post design. Twelve studies reported findings stratified by a single sociodemographic factor, with grade level/age as the most frequently reported. Although the evidence varied, greater consistency in direction of associations and strengths of evidence were seen among middle school students. Six studies reported findings jointly by multiple sociodemographic subgroups with evidence suggesting CF&B associations with slower rate of increase or plateaus or declines in obesity among multiple subgroups, though the strengths of evidence varied. Over the past two decades, there have been relatively limited subgroup analyses on studies about CF&B policies and childhood obesity. Studies are needed with stronger designs and analyses disaggregated, particularly by race/ethnicities and socioeconomic factors, across places and time.

¿Agua para todos? La intermitencia en el suministro de agua en los hogares en México.

OBJETIVO: Medir el acceso a través de la intermitencia en el suministro de agua potable en hogares mexicanos. Material y métodos. A través de la Encuesta Nacional de Salud y Nutrición 2022 (Ensanut 2022), se recolectó información sobre intermitencia en días por semana y horas por día durante las últimas cuatro semanas y el suministro de agua durante el año para la temporada de mayor escasez. RESULTADOS: 31.5% de los hogares recibieron agua los siete días de la semana, las 24 horas del día. De estos, 17.4% no tuvo escasez en los últimos 12 meses. La intermitencia es más común entre hogares de las regiones en el sur del país y entre los más pobres. El 81% de las familias almacena agua y 16% almacena en contenedores portátiles como cubetas. Conclusión. En este artículo se presentan por primera vez patrones de intermitencia en el suministro de agua a nivel nacional en México. La gran mayoría de las familias no reciben agua de forma continua y tienen que almacenar agua. El almacenamiento podría disminuir la calidad del agua y la falta de confianza para su consumo con consecuencias para la salud. La conexión al sistema potable no refleja el acceso real de las familias al agua.

Greenness and excess deaths from heat in 323 Latin American cities: Do associations vary according to climate zone or green space configuration?

Green vegetation may protect against heat-related death by improving thermal comfort. Few studies have investigated associations of green vegetation with heat-related mortality in Latin America or whether associations are modified by the spatial configuration of green vegetation. We used data from 323 Latin American cities and meta-regression models to estimate associations between city-level greenness, quantified using population-weighted normalized difference vegetation index values and modeled as three-level categorical terms, and excess deaths from heat (heat excess death fractions [heat EDFs]). Models were adjusted for city-level fine particulate matter concentration (PM2.5), social environment, and country group. In addition to estimating overall associations, we derived estimates of association stratified by green space clustering by including an interaction term between a green space clustering measure (dichotomized at the median of the distribution) and the three-level greenness variable. We stratified analyses by climate zone (arid vs. temperate and tropical combined). Among the 79 arid climate zone cities, those with moderate and high greenness levels had modestly lower heat EDFs compared to cities with the lowest greenness, although protective associations were more substantial in cities with moderate versus high greenness levels and confidence intervals (CI) crossed the null (Beta: -0.41, 95% CI: -1.06, 0.25; Beta -0.23, 95% CI: -0.95, 0.49, respectively). In 244 non-arid climate zone cities, associations were approximately null. We did not observe evidence of effect modification by green space clustering. Our results suggest that greenness may offer modest protection against heat-related mortality in arid climate zone Latin American cities.

The pregnancy research on inflammation, nutrition, & city environment: systematic analyses study (PRINCESA) cohort, 2009-2015.

The Pregnancy Research on Inflammation, Nutrition, & City Environment: Systematic Analyses Study (PRINCESA) cohort was set up to evaluate associations between air pollution and birth outcomes among pregnant persons in Mexico City. Specifically, the study was designed to improve air pollution exposure assessment and elucidate biological mechanisms underlying associations between maternal exposures and adverse pregnancy outcomes. Pregnant persons (all women) (N = 935) between ages 18-45 who lived and/or worked in metropolitan Mexico City, Mexico, from 2009 to 2015 and liveborn singleton infants (N = 815) of participants who completed follow-up were enrolled in the cohort. We followed participants monthly from enrollment to delivery and the following categories of data were obtained: demographic, medical and obstetric history, geo-referenced data, repeated measures on daily activity patterns, reported food intake, anthropometric, clinical and obstetric data, 20 serum and 20 cervicovaginal cytokines, and lower reproductive tract infection. Repeated ultrasound measures of fetal parameters and infant birth data are also included in the study's database. In addition, PRINCESA investigators calculated air pollution exposure measures for six pollutants measured by the Mexico City Atmospheric Monitoring System (SIMAT). These estimates utilize participants' addresses to account for spatial variation in exposure (nearest monitor, inverse distance weighting, and kriging) and are available daily during pregnancy for participants. To date, associations between environmental and nutritional impacts on maternal and child health outcomes have been evaluated. PRINCESA has a comprehensive database of maternal and infant data and biological samples and offers collaboration opportunities to study associations between environmental and other factors, including nutrition and pregnancy outcomes.

Association of service facilities and amenities with adolescent birth rates in Mexican cities.

BACKGROUND: The association of the built environment and the structural availability of services/amenities with adolescent birth rates (ABR) has been overlooked in Latin America. We investigated the association of the availability, and changes in the availability, of services/amenities with ABR in 92 Mexican cities. METHODS: We estimated ABR using data on live birth registration linked to municipality of residence at the time of birth from 2008-2017. The number of services/amenities were obtained from the National Statistical Directory of Economic Units in 2010, 2015, and 2020 and grouped as follows: education, health care, pharmacies, recreation, and on- and off-premises alcohol outlets. Data were linearly interpolated to obtain yearly estimates. We estimated densities per square km by municipality. We fitted negative binomial hybrid models, including a random intercept for municipality and city, and adjusted for other social environment variables. RESULTS: After adjustment a 1-unit increase in the density of recreation facilities, pharmacies, and off-premises alcohol outlets within municipalities was associated with a 5%, 4% and 12% decrease in ABR, respectively. Municipalities with higher density of education, recreational and health care facilities had a lower ABR; in contrast, municipalities with a higher density of on-premises alcohol experienced a higher ABR. CONCLUSION: Our findings highlight the importance of economic drivers and the need to invest in infrastructure, such as pharmacies, medical facilities, schools, and recreation areas and limit the availability of alcohol outlets to increase the impact of current adolescent pregnancy prevention programs.

Frailty in Older Adults and Internal and Forced Migration in Urban Neighborhood Contexts in Colombia.

Objective: We investigated the association between the density of internal human migration, in the urban neighborhood, on frailty in the older adult population in Colombia. Methods: The data used in this study are from four Colombian population surveys. We analyzed 633 census tracts with a sample of 2,194 adults 60 years and over for frailty (measured using the Fried criteria). We considered the proportion of inhabitants in a census tract with a history of internal migration as the exposure variable considering three temporalities. For contextual forced migration, we identified two types: 5-year, and 1-year. Poisson multivariable regression models with two hierarchical levels (individual and census tracts) were estimated. Results: The prevalence of pre-fragile/frailty was 80.63% [CI 95%: 77.67, 83.28]. The prevalence ratio were significantly higher for the older adults who live in neighborhoods where a higher proportion of internal migrants reside. Conclusion: We conclude that older adults who lived in neighborhoods with a high proportion of internal migrants experience more frailty. Potential explanations are that neighborhoods with high internal migration could experience social (l increase in cultural heterogeneity, in the perception of insecurity, violence and physical conditions (pressure on local economies and services, leading elderly residents to compete for neighborhood resources), translated into social stress.

Erratum to: Aqueous extracts from Tenebrio molitor larval and pupal stages inhibit early hepatocarcinogenesis in vivo.

Following an Assessment by the Autonomous University of Hidalgo State and the National Institute of Genomic Medicine, this erratum corrects the authorship of this article by adding Dulce María MORENO-GARCÍA as the first author.

Do diurnal salivary cortisol curves carry meaningful information about the regulatory biology of the HPA axis in healthy humans?

Salivary cortisol stress biomarkers have been extensively used in epidemiological work to document links between stress and ill health. There has been little effort to ground field friendly cortisol measures in the hypothalamic-pituitary-adrenal (HPA) axis regulatory biology that is likely relevant to delineating mechanistic pathways leading from stress exposure to detrimental health outcomes. Here, we utilized a healthy convenience sample (n = 140) to examine normal linkages between extensively collected salivary cortisol measures and available laboratory probes of HPA axis regulatory biology. Participants provided 9 saliva samples per day over 6 days within a month, while engaging in usual activities, and also participated in 5 regulatory tests (adrenocorticoptripin stimulation, dexamethasone/corticotropin-releasing-hormone stimulation, metyrapone, dexamethasone suppression, and Trier Social Stress Test). Logistical regression was used to test specific predictions linking cortisol curve components to regulatory variables and to explore widely for non-predicted associations. We found support for 2 of 3 original hypotheses, showing associations (1) between cortisol diurnal decline and feedback sensitivity as measured by dexamethasone suppression, and (2) between morning cortisol levels and adrenal sensitivity. We did not find links between central drive (metyrapone test) and end of day salivary levels. We confirmed an a priori expectation of limited linkage between regulatory biology and diurnal salivary cortisol measures, beyond those predicted. These data support an emerging focus on measures related to diurnal decline in epidemiological stress work. They raise questions about the biological meaning of other curve components, including morning cortisol levels, and perhaps CAR (Cortisol Awakening Response). If morning cortisol dynamics are linked to stress, more work on adrenal sensitivity in stress adaptation and stress-health links may be warranted.

Trends in school-neighbourhood inequalities and youth obesity: Repeated cross-sectional analyses of the public schools in the state of California.

BACKGROUND: It is currently unknown whether the relationship between affluence of school neighbourhoods and prevalence of youth overweight/obesity is uniform across demographic subgroups and areal context in the United States. METHODS: We examined association between school-neighbourhood income tertiles and school-level overweight/obesity (OVOB) prevalence, using data on body mass index of fifth, seventh, and nineth graders who attended public schools in California in 2001 and 2010 (n = 1 584 768), using multiple logistic regression models. RESULTS: Overall, OVOB prevalence was higher in lower-income school neighbourhoods, with a steeper income-OVOB gradient for girls. Among boys, the gradient became steeper in 2010 than 2000. Among Asian and White girls, the negative gradients were steepest in rural areas. For African-American students in all areas and Latino boys in rural areas, there was less clear evidence of inverse income-OVOB gradients. Addition of fast-food restaurant availability to the models did not change the observed inverse school-neighbourhood income-obesity gradients. CONCLUSIONS: The findings suggest the needs to investigate reasons for this variability with consideration to combinations of sociodemographic, economic, and environmental risk factors that may contribute to disparities in childhood obesity.

Modification of temperature-related human mortality by area-level socioeconomic and demographic characteristics in Latin American cities.

BACKGROUND: In Latin America, where climate change and rapid urbanization converge, non-optimal ambient temperatures contribute to excess mortality. However, little is known about area-level characteristics that confer vulnerability to temperature-related mortality. OBJECTIVES: Explore city-level socioeconomic and demographic characteristics associated with temperature-related mortality in Latin American cities. METHODS: The dependent variables quantify city-specific associations between temperature and mortality: heat- and cold-related excess death fractions (EDF, or percentages of total deaths attributed to cold/hot temperatures), and the relative mortality risk (RR) associated with 1 °C difference in temperature in 325 cities during 2002-2015. Random effects meta-regressions were used to investigate whether EDFs and RRs associated with heat and cold varied by city-level characteristics, including population size, population density, built-up area, age-standardized mortality rate, poverty, living conditions, educational attainment, income inequality, and residential segregation by education level. RESULTS: We find limited effect modification of cold-related mortality by city-level demographic and socioeconomic characteristics and several unexpected associations for heat-related mortality. For example, cities in the highest compared to the lowest tertile of income inequality have all-age cold-related excess mortality that is, on average, 3.45 percentage points higher (95% CI: 0.33, 6.56). Higher poverty and higher segregation were also associated with higher cold EDF among those 65 and older. Large, densely populated cities, and cities with high levels of poverty and income inequality experience smaller heat EDFs compared to smaller and less densely populated cities, and cities with little poverty and income inequality. DISCUSSION: Evidence of effect modification of cold-related mortality in Latin American cities was limited, and unexpected patterns of modification of heat-related mortality were observed. Socioeconomic deprivation may impact cold-related mortality, particularly among the elderly. The findings of higher levels of poverty and income inequality associated with lower heat-related mortality deserve further investigation given the increasing importance of urban adaptation to climate change.

Longitudinal neighbourhood determinants with cognitive health and dementia disparities: protocol of the Multi-Ethnic Study of Atherosclerosis Neighborhoods and Aging prospective cohort study.

INTRODUCTION: The burden of Alzheimer's disease (AD) and AD-related dementias (ADRD) is increasing nationally and globally, with disproportionate impacts on lower-income, lower education and systematically marginalised older adults. Presence of inequalities in neighbourhood factors (eg, social context, physical and built environments) may affect risk of cognitive decline and be key for intervening on AD/ADRD disparities at the population level. However, existing studies are limited by a dearth of longitudinal, detailed neighbourhood measures linked to rich, prospective cohort data. Our main objective is to identify patterns of neighbourhood change related to prevalence of-and disparities in-cognitive decline and dementia. METHODS AND ANALYSES: We describe the process of collecting, processing and linking extensive neighbourhood data to the Multi-Ethnic Study of Atherosclerosis (MESA), creating a 25+ years dataset. Within the MESA parent study, the MESA Neighborhoods and Aging cohort study will characterise dynamic, longitudinal neighbourhood social and built environment variables relevant to cognition for residential addresses of MESA participants. This includes administering new surveys, expanding residential address histories, calculating new measures derived from spatial data and implementing novel deep learning algorithms on street-level imagery. Applying novel statistical techniques, we will examine associations of neighbourhood environmental characteristics with cognition and clinically relevant AD/ADRD outcomes. We will investigate determinants of disparities in outcomes by socioeconomic position and race/ethnicity and assess the contribution of neighbourhood environments to these disparities. This project will provide new evidence about pathways between neighbourhood environments and cognitive outcomes, with implications for policies to support healthy ageing. ETHICS AND DISSEMINATION: This project was approved by the University of Washington and Drexel University Institutional Review Boards (protocols #00009029 and #00014523, and #180900605). Data will be distributed through the MESA Coordinating Center. Findings will be disseminated in peer-reviewed scientific journals, briefs, presentations and on the participant website.

Adolescent birth rates and the urban social environment in 363 Latin American cities.

INTRODUCTION: Latin America has the second-highest adolescent birth rate (ABR) worldwide. Variation between urban and rural areas and evidence linking country development to ABR points towards upstream factors in the causal pathway. We investigated variation in ABR within and between cities, and whether different features of urban social environments are associated with ABR. METHODS: We included 363 cities in 9 Latin American countries. We collected data on social environment at country, city and subcity levels and birth rates among adolescents (ages 15-19). We investigated variation in ABR within and between countries and cities along with associations between social environment and ABR by fitting three-level negative binomial models (subcities nested within cities nested within countries). RESULTS: The median subcity ABR was 58.5 per 1000 women 15-19 (IQR 43.0-75.3). We found significant variability in subcity ABR between countries and cities (37% of variance between countries and 47% between cities within countries). Higher homicide rates and greater population growth in cities were associated with higher ABR (rate ratio (RR) 1.09; 95% CI 1.06 to 1.12 and RR 1.02; 95% CI 1.00 to 1.04, per SD, respectively), while better living conditions and educational attainment in subcities were associated with lower ABR after accounting for other social environment characteristics (RR 0.95; 95% CI 0.92 to 0.98 and 0.78; 95% CI 0.76 to 0.79, per SD, respectively). CONCLUSIONS: The large heterogeneity of ABR found within countries and cities highlights the key role urban areas have in developing local policies. Holistic interventions targeting education inequalities and living conditions are likely important to reducing ABR in cities.