Martin Lajous

Instituto Nacional de Salud Pública | INSP · Centro de Investigacion en Salud Poblacional

Objective To investigate barriers in accessing care for infertility in Mexico, as 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 Mexican Teachers’ Cohort Patients 115,315 female public-school teachers from 12 states in Mexico Interventio...

Many dietary guidelines recommend restricting the consumption of processed red meat (PRM) in favour of healthier foods such as fish, to reduce the risk of chronic conditions such as hypertension and diabetes. The objective of this study was to estimate the potential effect of replacing PRM for fatty fish, lean fish, red meat, eggs, pulses, or veget...

Avocado is a fruit rich in dietary fiber, potassium, magnesium, mono and polyunsaturated fatty acids, and bioactive phytochemicals, which are nutritional components that have been associated with cardiovascular health. Yet, despite the boom in avocado consumption, we lack evidence on its association with cardiovascular disease risk in the general p...

Hair cortisol concentration (HCC) represent a potential biomarker of chronic psychological stress. Previous studies exploring the association between perceived stress and HCC have been limited to relatively small and selected populations. We collected hair samples from 881 women from the Mexican Teachers’ Cohort (MTC) and 398 women from the Iceland...

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 M...

Background and Aims Sugar-sweetened soda consumption is associated with most of the 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 a...

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...

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 a...

Objective: To estimate Covid-19 and pre-pandemic low respiratory infection (LRI) mortality in children and adolescents in Mexico. Materials and methods: We estimated the percentage of total mortality attributable to Covid-19 (95% confidence intervals; 95%CI) and made the corresponding estimates for pre-pandemic LRI mortality. Results: In 2019,...

Purpose In several studies, exploratory dietary patterns (DP), derived by principal component analysis, were inversely or positively associated with incident type 2 diabetes (T2D). However, findings remained study-specific, inconsistent and rarely replicated. This study aimed to investigate the associations between DPs and T2D in multiple cohorts a...

PURPOSE Hispanics and Indigenous women are underrepresented in cancer research. We aimed to estimate the incidence of breast cancer (BC) among indigenous and non-indigenous women and describe reproductive and lifestyle risk factors. METHODS The baseline questionnaire was completed by 115,307 women (2006-2008). Indigenous ancestry was defined by se...

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 (mon...

Purpose. To investigate the association between serious financial difficulties (SFD), stress, and cardiovascular health in women. Methods. We categorized 1759 employed and insured disease-free women from the Mexican Teachers’ Cohort according to their response to a question on SFD included in the Life Stressor Checklist-Revised administered in 2012...

Objective: To determine the exposure to aflatoxin B1 (AFB1) in southern Mexico and the presence of the aflatoxin signature mutation in hepatocellular carcinoma (HCC) tissue from patients from a cancer referral center. Materials and methods: We estimated the prevalence and distribution of AFB1 in a representative sample of 100 women and men from...

Objective: To estimate the sensitivity and specificity of two Mexican death registries for the identification of vital status using a publicly available record-linkage tool. Materials and methods: We selected all reported deaths (n=581) and 575 alive participants in an epidemiologic cohort with active follow-up. Individual records were cross-lin...

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 mo...

In 2014, a partnership was established between the Univer­sity of California and Mexico, which subsequently catalyzed formation of collaborations between cancer researchers at University of California, San Francisco and in Mexico. Over the past two decades cancer burden has dramatically increased in Mexicans on both sides of the California - Mexico...

Background Investigating the burden of access to infertility treatment has primarily been conducted in high-income countries, with little known for low- and middle-income countries, which comprise 80% of the world’s population. The objective of this study was to investigate access to infertility care in Mexico. Methods This was a cross-sectional a...

Background Women are exposed to a variety of life stressors, particularly violence, during their lifetime which increases the risk of developing various psychiatric and somatic diseases, with dysregulated secretion of cortisol as one potential biological mechanism. We examined the association between violence and other life stressors and hair corti...

Background: Reliable and valid instruments are needed to estimate physical activity levels. The purposes of this study were to estimate the reliability and validity of the Physical Activity Questionnaire (MTPAQ) in a subsample of the Mexican Teachers Cohort study. Methods: We completed telephone interviews and clinical examinations of 82 teachers....

Objetivo. Estimar la seroprevalencia de SARS-CoV-2 en población de edad escolar en México. Material y métodos. Se categorizaron a niños y adolescentes que participaron en la Encuesta Nacional de Salud y Nutrición 2020 sobre Covid-19 (Ensanut 2020 Covid-19) por edad escolar y nivel educativo. En participantes seropositivos, se identificó la proporci...

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' Coh...

Background Evidence on concurrent changes in overall diet quality and weight and waist circumference in women of reproductive age from low- and middle-income countries is limited. Objectives We examined the associations of changes in the Global Diet Quality Score (GDQS) and each GDQS food group with concurrent weight and waist circumference change...

Objectives. To estimate all-cause excess deaths in Mexico City (MXC) and New York City (NYC) during the COVID-19 pandemic. Methods. We estimated expected deaths among residents of both cities between March 1 and August 29, 2020, using log-linked negative binomial regression and compared these deaths with observed deaths during the same period. We c...

Objective: To estimate COVID-19 and pre-pandemic low respiratory infection (LRI) mortality in children and young people in Mexico. Material and methods: We estimated the percentage of total mortality attributable to COVID-19 (95% confidence intervals; 95%CI) and corresponding estimates for pre-pandemic LRI mortality. Results: In 2019, LRIs represen...

Background Previous studies have shown conflicting results regarding the influence of cardiovascular risk-factors on venous thromboembolism. This study aimed to determine if these risk-factors, i.e. physical activity, smoking, hypertension, dyslipidaemia, and diabetes, were associated with the risk of venous thromboembolism, and to determine if the...

Objective: To describe the burden of colorectal cancer (CRC) in Mexico and understand mortality patterns based on sex, geography, and insurance status. Materials and methods: Mortality data (1998-2018) from the Instituto Nacional de Estadística y Geografía was obtained. We included colon (C18.0, C18.2-18.9) and rectal cancer ICD-10 codes (C19, C...

Background While mammographic density is one of the strongest risk factors for breast cancer, little is known about its determinants, especially in young women. We applied targeted metabolomics to identify circulating metabolites specifically associated with mammographic density in premenopausal women. Then, we aimed to identify potential correlate...

Higher intake of ultra-processed foods (UPF), which have undergone multiple processes and have poor nutrient quality, is associated with higher incidence of non-communicable diseases. Yet, its association with hypertension has scarcly been studied, especially in low- and middle-income countries. We aimed to estimate the associations between consump...

Purpose: To present the use of administrative databases and registries to confirm and identify incident breast cancer (BC) cases in a prospective cancer cohort in Mexico where cancer registry coverage is limited. Methods: The Mexican Teacher's Cohort (MTC) was established in 2006-2008 when 115,314 female teachers residing in a 12-state area in Mexi...

p>Purpose: To determine 5-year survival for breast cancer among uninsured women treated under Mexico9s Seguro Popular landmark health reform according to clinical stage and identify factors associated to survival. Methods: We conducted a retrospective cohort study with data obtained from national reimbursement claims of patients treated under Segu...

The aim of the study was to measure survival of children with acute lymphoblastic leukemia (ALL) under Mexico’s public health insurance for the population treated under Seguro Popular. A retrospective cohort study using claims data from Mexico’s Seguro Popular program, covering cancer treatment from 2005 to 2015 was conducted. Overall 5-year nation...

Objectives To examine the relation between breakfast frequency and incidence of diabetes in middle-aged women. Methods The Mexican Teacher´s Cohort is a prospective study in women. We included 71,373 participants at baseline (2006–2008). Participants were classified according to breakfast frequency 0, 1–3, 4–6, or 7 d/wk; and meal frequency 1–2, 3...

Purpose We evaluated the relation between age at menarche and time to menstrual regularity with all-cause and cause specific mortality in a cohort of Mexican women. Methods We followed 113,540 women from the Mexican Teachers’ Cohort. After a mean follow-up time of 9.2 years, 1,355 deaths were identified. We estimated hazard ratios from Cox regress...

Background Previous studies have shown conflicting results regarding the influence of cardiovascular risk-factors on venous thromboembolism. This study aimed to determine if these risk-factors, i.e. physical activity, smoking, hypertension, dyslipidaemia, and diabetes, were associated with the risk of venous thromboembolism, and to determine if the...

Objective: To estimate temporary changes in the inciden-ce of SARS-CoV-2-confirmed hospitalizations (by date of symptom onset) by age group during and after the national lockdown. Materials and methods: For each age group g, we computed the proportion E(g) of individuals in that age group among all cases aged 10-59y during the early lock-down pe...

Objectives: To describe the prevalence and correlates of depressive symptoms, generalized anxiety disorder (GAD), and perceived negative mental health impact during the SARS-Cov-2 pandemic in Mexico City and evaluate their association with adherence to stay-at-home directives. Methods: Baseline data from a cohort study of 2,016 Mexico City governme...

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 mar...

Background Acute and agent-specific chronic infections have been associated with increased cardiovascular risk, however data on the burden of common recurrent infections on cardiovascular disease is limited. We hypothesized women with greater exposure to uncomplicated common infectious events had an increased risk of subclinical cardiovascular dise...

Background Food timing affects circadian rhythms involved in weight control. Regular consumption of breakfast may affect body weight. Objective We examined the relation between breakfast frequency with weight change in middle-age women over a 3-y period. Methods We used data from 65,099 nonpregnant women aged >20 y participating in the Mexican Te...

Background High body mass index (BMI) and low physical activity are associated with increased risk of hypertension. Few studies have assessed their joint impact or the relation of physical activity and hypertension among individuals within a healthy BMI range. The objective of this study was to investigate the associations between physical activity...

Colorectal cancer(CRC) is preventable and treatable by screening and early detection. Fecal immunochemical tests(FIT) for average risk individuals is an effective strategy for screening. Incidence and mortality in Mexico is increasing and large-scale screening programs do not yet exist. The aim was to evaluate the feasibility of FIT-based CRC scree...

Objectives. To measure survival of children with acute lymphoblastic leukaemia (ALL) under a public health insurance for the population without social security in Mexico, and explore patient groups that may be at risk for increased mortality. Design. Retrospective cohort study Setting. Claims data from Seguro Popular program, covering cancer treatm...

Background: Colorectal cancer (CRC) incidence and mortality are increasing in many low- and middle-income countries (LMICs), possibly due to a combination of changing lifestyles and improved healthcare infrastructure to facilitate diagnosis. Unfortunately, a large proportion of CRC cases in these countries remain undiagnosed or are diagnosed at ad...

PURPOSE Until 2005, most Mexican children did not have coverage for cancer treatment. In that year, Seguro Popular began funding the treatment of children with acute lymphoblastic leukemia (ALL). We aimed to estimate 5-year survival in children with ALL. We also sought to evaluate the relationship of hospital volume, out-of-state treatment, and tre...

PURPOSE One of the goals of Seguro Popular, Mexico’s landmark healthcare reform, was bridging the existing disparities in access to health care and health status. In 2007, this program began reimbursement of breast cancer treatment of previously uninsured Mexican women. We evaluated geographic disparities in breast cancer survival in women treated...

PURPOSE We undertook a formative qualitative research study to identify optimal participant recruitment, education, and follow-up strategies to facilitate colorectal cancer (CRC) screening in Mexico City. METHODS This study included semistructured individual and focus group interviews with different stakeholders: 36 average-risk laypeople, 16 publ...

Background Previous studies have evaluated how sun exposure affects cardiovascular health. In this sense, some evidence from ecological studies have found an inverse relationship between sun exposure and blood pressure or CVD. The aim of this study is to determine whether long-term sun exposure has a protective role in subclinical cardiovascular di...

Purpose: The relationship between egg and cholesterol intakes, and cardiovascular disease is controversial. Meta-analyses indicate that egg consumption is associated with increased cardiovascular disease and mortality, but reduced incidence of hypertension, a major risk factor for cardiovascular disease. This study aims to investigate the associati...

Multiple randomised controlled trials have shown high doses of cocoa to reduce blood pressure and improve endothelial function. However, evidence regarding long-term consumption of cocoa and its potential effect on hypertension is lacking. We aimed to prospectively evaluate if cocoa intake from various food sources was associated with incident hype...

Study objectives: To evaluate whether dietary patterns are associated with sleep quality in Mexican mid-life women. Methods: The study population included 4467 Mexican women from a longitudinal study of teachers. In 2008, a semi-quantitative food frequency questionnaire was administered. Principal components analysis identified three dietary pat...

One post‐partum behaviour that may be protective against post‐partum weight retention and long‐term weight gain among women of reproductive age is lactation because of its potential role in resetting maternal metabolism after pregnancy. However, most of the evidence focuses on weight retention at 6, 12, or 24 months post‐partum, and data beyond 2 y...

Background Colorectal cancer (CRC) incidence and mortality are increasing in many middle- and lower-income countries, possibly due to a combination of changing lifestyles and improved healthcare infrastructure that facilitates diagnosis. Unfortunately, a large proportion of cases may be diagnosed at advanced stages, resulting in poor outcomes. Decr...

Background. Colorectal cancer (CRC) incidence and mortality are increasing in many low- and middle-income countries (LMICs), possibly due to a combination of changing lifestyles and improved healthcare infrastructure to facilitate diagnosis. Unfortunately, a large proportion of CRC cases in these countries remain undiagnosed or are diagnosed at adv...

Objective: To compare cancer mortality rates in Mexico from two national death registries that independently code and attribute cause of death. Materials and methods: We compared 5-year age-standardized total cancer and sitespecific cancer mortality rates (2010-2014) from Mexico's official death registry with a death registry from a disease surv...

Background. Colorectal cancer (CRC) incidence and mortality are increasing in many middle- and lower-income countries, possibly due to a combination of changing lifestyles and improved healthcare infrastructure that facilitates diagnosis. Unfortunately, a large proportion of cases may be diagnosed at advanced stages, resulting in poor outcomes. Dec...

Background: Among potentially modifiable factors, dairy product consumption has been inconsistently associated with hypertension risk. The objective of this study was to investigate the relation between dairy product consumption and the risk of hypertension among middle-aged women. Methods: In a prospective cohort of 40,526 French women, there w...

Background: In middle-income countries, the burden of colorectal cancer (CRC) is increasing in parallel with resources for diagnosis and treatment. There is a potential benefit of CRC screening programs in Mexico. Objective: Since there are no organized screening programs in the country, we explored the willingness of individuals to complete a f...

Objectives. To examine the association between family member incarceration, psychological stress, and subclinical cardiovascular disease (CVD).Methods. Between 2012 and 2016, 1849 CVD-free women from the Mexican Teachers' Cohort responded to questions on family incarceration from the Life Stressor Checklist. Perceived stress and hair cortisol level...

This article explores the politics of passage of the SSB tax in Mexico, using published documents, media articles, and interviews with key stakeholders. The article examines first the period of agenda setting when the tax was included in the President’s fiscal reform package; and second, the period of legislative passage, when the bill was introduc...

Background: Childhood adversities are prevalent worldwide and might affect adult cardiovascular health. However, in middle-income countries such as Mexico, research on the impact of childhood adversities on cardiovascular disease (CVD) in adulthood is lacking. Objective: To evaluate the prevalence of adverse childhood experiences (ACEs) and thei...

Aims: In Mexico City, the mortality rate among patients with diabetes appears to be four times that of people without diabetes. Our study aimed to refine analyses of the impact of diabetes on mortality in a large cohort of women from different areas in Mexico with healthcare insurance. Methods: Our study followed 111,299 women with comprehensive...

Purpose Legume consumption has decreased in Mexico as part of a global nutrition transition that has shifted the intake of healthy traditional foods to more processed unhealthy foods. This study aims to assess preferences and patterns of legumes consumption, attitudes toward legumes and reasons to consume legumes among adults in Mexico City. Desig...

Household air pollution (HAP) is of public health concern, with ~3 billion people worldwide (including >15 million in the US) exposed. HAP from coal use is a human lung carcinogen, yet the epidemiological evidence on carcinogenicity of HAP from biomass use, primarily wood, is not conclusive. To robustly assess biomass’s carcinogenic potential, pros...

Prostate-specific antigen (PSA)-based early detection for prostate cancer is the subject of intense debate. Imple­mentation of organized prostate cancer screening has been challenging, in part because the PSA test is so amenable to opportunistic screening. To the extent that access to cancer screening tests increases in low- and middle-income count...

Background: Although there is evidence for a reduced risk of hypertension associated with fruit and vegetable consumption, the relationship between the total antioxidant capacity of the diet (TAC) and the risk of hypertension has not been previously examined. We aimed to evaluate that association in the large E3N French prospective cohort of women...

Objectives: To evaluate weight change between 2008 and 2011 in relation to the frequency of breakfast and meals. Methods: Data were obtained from 60,946 women from the Mexican Teacher's cohort. Lifestyle, diet, and anthropometric data were obtained by self-report. Frequency of breakfast and meals were categorized (0, 1-3, 4-6, or 7 day/week; 1-2...

Background: Epidemiological evidence supports an association between sugar-sweetened soda consumption and diabetes. However, evidence regarding this association is limited in countries that have recently undergone a nutritional transition. Objective: We estimated the association between sugar-sweetened soda consumption and incident diabetes. We als...

Introduction: Osteoarthritis is a growingly common joint disorder affecting older adults. It is characterized by chronic low-grade inflammation, a phenomenon by itself considered a cardiovascular risk factor. However, data on its potential impact on cardiovascular disease (CVD) is scarce. Assessing hand osteoarthritis (HOA) might be advantageous wh...

Objective: Although history of preeclampsia increases a woman′s risk of developing hypertension (HTN) in adulthood, it remains unclear whether a heart-healthy post-pregnancy diet could ameliorate some of this risk. Therefore, we evaluated whether adherence to dietary patterns is related with HTN among women with prior preeclampsia Methods: At basel...

Introduction: Sudden loss of income has been previously associated to all-cause mortality. Diminished financial resources may result in reduced access to healthcare. On the other hand, the psychological stress associated with economic loss may also affect cardiovascular health through a combination of negative physiological changes and unhealthy li...

Background: Sun exposure has been associated with reduced risk of stroke and all-cause mortality possibly due to a decreased vascular tone related to vitamin D production. However, previous studies have measured sun exposure based on geographical estimations of radiation, and have been mostly conducted in latitudes far from the Equator where UV rad...