Cohort Profile: The Maule Cohort (MAUCO)

The Maule Cohort (MAUCO) is the first prospective population-based cohort of cardiovascular disease (CVD) and cancer in central Chile. The rationale for this cohort is based on the social, environmental and health characteristics of an under-studied rural population at high risk for chronic diseases.1 Chile is regarded as a model for social and economic transition in Latin America. Nevertheless, Chile’s progress and economic growth hide persistent inequalities.2 Poverty rates have declined from 38.6% in 1990 to 20.7% in 2017, when a large proportion of the population was still living in poverty based on their education, health care, employment, social security and housing conditions.3,4 In Chile, as in other Latin American countries, obesity, CVD and cancer have reached epidemic levels, disproportionately affecting people with lower socioeconomic status and overshadowing the national progress.5,6 Chilean cross-sectional national health surveys held in 2003, 2009 and 2016 revealed high and increasing prevalences of diabetes (6.3%, 9.4%, 12.3%), metabolic syndrome (22.6%, 35.3%, 40.1%) and overweight/obesity (61.0%, 64.4%, 71.0%).7–10 In Chile, environmental risk factors for chronic diseases coexist with remnants of under-development, and health disparities are particularly aggravated in rural areas.5 The MAUCO Cohort is located in the agricultural Molina County in the Maule Region, 200 km south of the capital city of Santiago. In 2016, the Maule Region had among the highest Chilean all-cause mortality rates per 1000 (regional 6.3 vs 5.7 nationwide)11 and cause-specific mortality rates per 100 000 for gastric (17.3 vs 12.6 nationwide), colon (8.6 vs 7.2) and oesophageal (4.6 vs 2.5) cancers.12 Additionally, this population is vulnerable to several important environmental exposures, such as agrochemicals, wood combustion and chronic infections. Little is known about the natural history of CVD and of cancer in this particular socioenvironmental context. Launched in 2014, MAUCO is the core project of the Advanced Center for Chronic Diseases (ACCDiS), of the universities Pontificia Universidad Católica de Chile (PUC) and Universidad de Chile.1 The general objectives of MAUCO are: (i) to analyse the natural history of CVD and cancer, where outcomes of interest include CVD, cancer, mental health, ageing, quality of life and respiratory diseases among others, whereas risk factors of interest include socioeconomic, lifestyle, environmental, genetic and ethnic factors; and (ii) to build institutional capacity for advanced research on chronic diseases, including a biobank. Our initial hypothesis is that CVD and cancer share environmental exposures, as well as social and lifestyle risk factors, which lead to chronic inflammation and oxidative stress as the common underlying mechanisms for the development of chronic conditions.13–15 Examples of initial planned analyses include the association of CVD with pesticides and mycotoxins, social and psychosocial factors and inflammatory conditions such as gallstones. The cohort is drawn from Molina County’s adult residents. In 2015, Molina had 42 273 inhabitants of whom 50.1% were men,16 and 30.1% lived in rural areas;17 in 2011, 13.5% were living in poverty.18 This population has a low rate of migration and most residents are served by the national health insurance system and the local municipality.19 These two factors will facilitate follow-up and health demonstration projects at the local level, in the absence of a system to link participants with national databases. Beginning in July 2014, we conducted a household census of Molina County to identify potential participants and record household members, geographical coordinates (latitude-longitude format; World Geodetic System 1984) and basic housing conditions. Contact was established in 70% of visited households, and in 95% of those, a resident agreed to respond to the survey. All potential participants whom we were able to contact were invited to join the study. Inclusion criteria were: age 38 to 74 years, residency in Molina for at least 6 months in the past year and plans to remain there for the next 3 years. Exclusion criteria were: inability to provide informed consent autonomously and a diagnosis of a terminal illness. Age criteria were decided on the basis that the cohort was designed for a duration of 10 years. Thus, taking into account the natural history of chronic diseases, we required an age range that would be close enough to the event to allow us to observe it in this period. We expect to obtain new funds to extend the follow-up of the cohort for another 10 years and eventually enrol younger participants. Throughout March 2019, we identified 14 646 residents aged 38 to 74 years; we were able to contact 12 882, of whom 480 were ineligible. Of those who were eligible, 8970 (72.3%) were enrolled, 1215 (9.8%) refused to participate and 2217 (17.9%) were not reachable during the baseline period (Figure 1). Flow diagram of the MAUCO cohort. Compared with people who refused or were not reachable, participants were more likely to be women. Participants were slightly older and to have a rural place of residence than people who refused, and slightly younger and to have an urban place of residence than those who were not reachable (Table 1). Age, sex and residence of responders and non-responders in the MAUCO cohort P-values obtained from t test (continuous variable) and chi square test (categorical variables). SD, standard deviation. Age, sex and residence of responders and non-responders in the MAUCO cohort P-values obtained from t test (continuous variable) and chi square test (categorical variables). SD, standard deviation. Follow-up visits are planned at 2, 4 and 8 years after enrolment. Currently, we are conducting the first follow-up visit with 5748 visits completed (77.3% of target to date), 1286 (17.3%) pending contact, 114 (1.5%) withdrawals and 288 (3.9%) lost to follow-up (90 deaths, 106 not reachable, 92 moved to another region) (Figure 1). Participants who attended the year 2 visit were younger than people who withdrew or were lost to follow-up; they were also more likely to be married, have more schooling, be insured by the public health system and be currently employed (Table 2). Sociodemographic characteristics of participants who have completed the first follow-up visit, refusals and lost to follow-up in the MAUCO cohort Values are presented as percentages unless otherwise indicated; P-values obtained from t test (continuous variables) and chi square test (categorical variables). Year-2 follow-up is ongoing. Sociodemographic characteristics of participants who have completed the first follow-up visit, refusals and lost to follow-up in the MAUCO cohort Values are presented as percentages unless otherwise indicated; P-values obtained from t test (continuous variables) and chi square test (categorical variables). Year-2 follow-up is ongoing. To identify health events of interest, we established a surveillance system of admissions in all local hospitals by linking participants to the regional health system database. Also, we regularly obtain notification of participants’ deaths through the national death certificate registry. A detailed description of the measurements collected at each visit has been published previously.1 At baseline, participants answered health and risk factor surveys previously used in the Chilean population; these surveys included questions from the National Health Surveys as well as internationally validated instruments (detailed in Table 3) that had been adapted using vocabulary suitable for a low-schooling population. Participants underwent anthropometric and bioimpedance measurements, grip strength tests, electrocardiogram, hepatobiliary ultrasound and cognitive evaluation. They also provided urine, saliva and blood samples (for storage at −80°C, 30 aliquots from each participant); stool was obtained in a subgroup (n = 1000) (Table 3). In addition, we assessed environmental conditions in their households and neighbourhoods, and sampled air, water and soil from the Molina County area.1 Data collected at baseline and first follow-up visit in the MAUCO cohort Participants for whom the instrument was applied (missing values exist). Households identified by census of Molina County. SF-12 Health Survey. Encuestas Nacionales de Salud (National Health Surveys) [http://epi.minsal.cl/bases-de-datos/]. Minnesota Living with Heart Failure Questionnaire. Leighton F, Polic G, Strobel P et al. Health impact of Mediterranean diets in food at work. Public Health Nutrition 2009;12:1635–43. doi: 10.1017/S1368980009990486. PLCO Prostate Lung Colorectal and Ovarian Cancer Screening Trial. GPAQ- WHO Global Physical Activity Questionnaire. Encuesta Nacional de Empleo, Trabajo, Calidad de Vida y Salud de los Trabajadores y Trabajadoras de Chile 2009–2010 (National Survey of Employment, Labour, Quality of Life and Health of the Workers of Chile 2009–2010). PIPAH Prospective Investigation of Pesticide Applicators’ Health Study. PHQ-9Patient Health Questionnaire. Lanas F, Avezum A, Bautista LE et al. Risk factors for acute myocardial infarction in Latin America: the INTERHEART Latin American study. Circulation 2007;115:1067–74. Addenbrooke’s Cognitive Examination-Revised Spanish version. Reitan RM. Trail Making Test: Manual for Administration and Scoring. Tuscon, AZ: Reitan Neuropsychology Laboratory, 1992. Icaza et al.22 Sapag JC, Aracena M, Villarroel L et al. Social capital and self-rated health in urban low income neighbourhoods in Chile. J Epidemiol Community Health 2008;62:790–2. All participants with gallstones, history of cholecystectomy, agricultural workers, abnormal electrocardiogram, a subset of participants with high cardiovascular risk, and age-sex group-matched controls. Data collected at baseline and first follow-up visit in the MAUCO cohort Participants for whom the instrument was applied (missing values exist). Households identified by census of Molina County. SF-12 Health Survey. Encuestas Nacionales de Salud (National Health Surveys) [http://epi.minsal.cl/bases-de-datos/]. Minnesota Living with Heart Failure Questionnaire. Leighton F, Polic G, Strobel P et al. Health impact of Mediterranean diets in food at work. Public Health Nutrition 2009;12:1635–43. doi: 10.1017/S1368980009990486. PLCO Prostate Lung Colorectal and Ovarian Cancer Screening Trial. GPAQ- WHO Global Physical Activity Questionnaire. Encuesta Nacional de Empleo, Trabajo, Calidad de Vida y Salud de los Trabajadores y Trabajadoras de Chile 2009–2010 (National Survey of Employment, Labour, Quality of Life and Health of the Workers of Chile 2009–2010). PIPAH Prospective Investigation of Pesticide Applicators’ Health Study. PHQ-9Patient Health Questionnaire. Lanas F, Avezum A, Bautista LE et al. Risk factors for acute myocardial infarction in Latin America: the INTERHEART Latin American study. Circulation 2007;115:1067–74. Addenbrooke’s Cognitive Examination-Revised Spanish version. Reitan RM. Trail Making Test: Manual for Administration and Scoring. Tuscon, AZ: Reitan Neuropsychology Laboratory, 1992. Icaza et al.22 Sapag JC, Aracena M, Villarroel L et al. Social capital and self-rated health in urban low income neighbourhoods in Chile. J Epidemiol Community Health 2008;62:790–2. All participants with gallstones, history of cholecystectomy, agricultural workers, abnormal electrocardiogram, a subset of participants with high cardiovascular risk, and age-sex group-matched controls. At the year 2 follow-up, all participants completed a questionnaire to assess changes in exposures and health conditions and underwent blood pressure, weight and waist circumference and peak expiratory flow measurements. A subgroup of approximately 40% of the cohort underwent a complete examination similar to baseline (excluding electrocardiogram) and provided biological samples; this subgroup comprises all participants with gallstones, a history of cholecystectomy, abnormal electrocardiogram and a history of agricultural work, as well as a subset of participants at high risk for CVD and age-sex group-matched controls (Table 3). Of the 8970 participants, 56.3% were women; compared with males enrolled, women were somewhat younger, had slightly less schooling and were less likely to have ever worked in agriculture. Public health insurance was predominant among participants, with a higher prevalence than the national average (78%)19 (Table 4). Nearly all participants’ households had solid floors, indoor drinking water supply, sewage disposal and a refrigerator, and most used natural gas or electricity for cooking and wood or coal for heating; fewer households had a computer, car, domestic animals or farm animals (Supplementary Table 1, available as Supplementary data at IJE online). Sociodemographic characteristics of MAUCO cohort participants Values are presented as percentages unless otherwise indicated. Prevalence weighted to represent the sex distribution of Molina's population (49.9% women). Sociodemographic characteristics of MAUCO cohort participants Values are presented as percentages unless otherwise indicated. Prevalence weighted to represent the sex distribution of Molina's population (49.9% women). Women had a worse self-perception of health status than men, less hypertension, almost three times more history of cancer, a higher report of digestive symptoms (particularly biliary colic), more respiratory disease and three times more osteomuscular disease. Men reported consuming three times more alcohol per week than women, with a higher prevalence of risky alcohol intake (defined as ≥30 g for men or ≥20 g for women per week) and almost three times more binge drinking (≥4 drinks for men or ≥3 drinks for women per occasion).8 Also, more men had a high consumption of sugary drinks (defined as >2 times per day) and processed meat (>4 times per week), and low vegetable and fruit consumption (>1 time per day for each) compared with women. In addition, men were more likely to be current or former smokers (Table 5). Baseline health profile of MAUCO cohort participants Values are presented as percentages unless otherwise indicated; all prevalence and mean values are age-adjusted. SD, standard deviation; PHQ-2, Patient Health Questionnaire; ACE-R, Addenbrooke's Cognitive Examination Revised; MMSE, Mini Mental State Examination; AST (GOT), Aspartate aminotransferase (glutamic oxaloacetic transaminase). ALT (GPT), Alanine Aminotransferase (serum glutamic pyruvic transaminase); LDL, low-density lipoprotein cholesterol; HDL, high-density lipoprotein cholesterol. Prevalence weighted to represent the sex distribution of Molina's population (49.9% women) Self-report or glycaemia ≥126 mg/dL or use of hypoglycaemic drugs. Use of hypotensive drugs or measured systolic blood pressure ≥130 or blood pressure biliary and those who alcohol consumption at least a for women or ≥30 g for men per drinks for women or drinks for men per Encuesta Nacional de Salud (National Health of three for for blood pressure ≥130 or blood pressure for men or for women, measured by bioimpedance ≥3 of the obesity, high low high blood pressure and high systolic blood pressure, HDL, and for risk of a cardiovascular event in the next 10 years. systolic blood pressure, blood pressure, and for risk of a cardiovascular event in the next 10 Baseline health profile of MAUCO cohort participants Values are presented as percentages unless otherwise indicated; all prevalence and mean values are age-adjusted. SD, standard deviation; PHQ-2, Patient Health Questionnaire; ACE-R, Addenbrooke's Cognitive Examination Revised; MMSE, Mini Mental State Examination; AST (GOT), Aspartate aminotransferase (glutamic oxaloacetic transaminase). ALT (GPT), Alanine Aminotransferase (serum glutamic pyruvic transaminase); LDL, low-density lipoprotein cholesterol; HDL, high-density lipoprotein cholesterol. Prevalence weighted to represent the sex distribution of Molina's population (49.9% women) Self-report or glycaemia ≥126 mg/dL or use of hypoglycaemic drugs. Use of hypotensive drugs or measured systolic blood pressure ≥130 or blood pressure biliary and those who alcohol consumption at least a for women or ≥30 g for men per drinks for women or drinks for men per Encuesta Nacional de Salud (National Health of three for for blood pressure ≥130 or blood pressure for men or for women, measured by bioimpedance ≥3 of the obesity, high low high blood pressure and high systolic blood pressure, HDL, and for risk of a cardiovascular event in the next 10 years. systolic blood pressure, blood pressure, and for risk of a cardiovascular event in the next 10 of were as high among women. were similar in men and mean of the State and the Addenbrooke's Cognitive were the for (Table 5). Men had more measured hypertension, electrocardiogram and abnormal peak expiratory Women had more obesity, fewer and lower on hepatobiliary ultrasound women and men had a high prevalence of women had a higher prevalence of and gallstones, with a higher of Men had a higher prevalence of levels, high and abnormal (Table 2). the prevalence of metabolic syndrome was higher in women, men were times more likely to have a high CVD risk at 10 years based on the Risk times with the Chilean adapted (Table 5). A history of diabetes was reported by of participants with glycaemia and of those with glycaemia ≥126 of participants with diabetes were taking hypoglycaemic A history of was reported by of participants with measured blood pressure and of those with measured blood pressure of participants with were taking The prevalences of and are similar to those reported in the National Health Survey for the population of the age in the prevalence of diabetes is lower than the national prevalence In the first 4 years of follow-up, we identified admissions affecting cancer and CVD and of are available in Supplementary Table 2, available as Supplementary data at IJE online). To participants have the were CVD and cancer are available in Supplementary Table available as Supplementary data at IJE online). A diagnosis of diabetes at baseline was with a higher risk of and respiratory and death and respiratory The association of diabetes with cancer mortality has been previously and is to be in to a of oxidative stress and chronic The association of diabetes with respiratory disease mortality has also been and be by the in people with Additionally, and were with an risk of and and a low peak expiratory flow were with an risk of death (Table and deaths during follow-up through March and baseline health conditions of MAUCO cohort participants Values are and not include cancer in to AST (GOT), aminotransferase (glutamic oxaloacetic transaminase). from the their first for each myocardial and to or glycaemia ≥126 mg/dL or use of hypoglycaemic by sex and to use of hypotensive drugs or systolic blood pressure or blood pressure ≥3 of the obesity, high low high blood pressure or high and deaths during follow-up through March and baseline health conditions of MAUCO cohort participants Values are and not include cancer in to AST (GOT), aminotransferase (glutamic oxaloacetic transaminase). from the their first for each myocardial and to or glycaemia ≥126 mg/dL or use of hypoglycaemic by sex and to use of hypotensive drugs or systolic blood pressure or blood pressure ≥3 of the obesity, high low high blood pressure or high The death rate 95% is lower than the 2016 regional rate for population aged per 95% This lower risk in MAUCO be by the from the cohort of people with terminal who would have been more likely to in this period (Table of are in the MAUCO a of the risk of disease with and gallstones, including and and a risk of in a risk of in air, soil and a risk of processed meat and for gastric and genetic for chronic In addition, have been completed on from and to of for older participants. The of MAUCO from the among and from which Chilean This cohort is the first Latin American prospective including measurements from and genetic to environmental, and social a an and an of the of the Health health and of the who the use and of data and health and who in Molina County and are with the MAUCO and data by the MAUCO are for the quality and of the data and as well as the quality of the This has to with local and regional that are to the of the cohort. with the Molina as a in the is a for as an we to the about Community has been in a high rate and low to MAUCO is of the World Health of agricultural cohort with other from the and is of the 100 Cohort MAUCO an to the of research on the health of Chile’s population in the of which is also to other Latin American and to people in other The MAUCO at the of of the National Cancer Quality are in place to the quality of the MAUCO biological from to system of biological samples is used to identify the and available of each using The MAUCO system complete and data including data data and of databases. Data by the data is using Data for the MAUCO cohort currently on and has been for an initial period of 10 years from to and to Compared with population-based we in a research to a high for These conditions a for a prospective such as The of be this cohort an agricultural population from a city not be to residents of large urban to data and is by the in with the local institutional The system was the for and to the data and available to that and are All data and be by the and a be and research be in or Spanish and be available in Supplementary 1, available as Supplementary data at IJE online). be at MAUCO is the first prospective population-based cohort to a population with high rates of gastric cancer with a high of cardiovascular an health transition and to environmental exposures wood chronic All residents aged 38 to 74 years from the agricultural of Molina in Chile were invited in 2015, and 8970 participants the cohort. and is collected for all participants as well as anthropometric tests, electrocardiogram, hepatobiliary peak expiratory flow measurements, and and saliva samples collected for at is in place to identify and deaths enrolment. Additionally, we environmental quality of and soil and the of in To 5748 participants have completed the year 2 follow-up, which is ongoing. The rate of is to death of place of residence (1.5%) and not reachable participants are currently available for Data and are contact Supplementary data are available at IJE This is by two from Nacional de y a Chilean research de de de and Nacional de y We also from the of of Universidad Católica Maule the of of the Pontificia Universidad Católica de Chile the de Molina and the Molina and funds from the of the National of National Cancer of Cancer and and the of on Health of the National of the of of Pontificia Universidad Católica de Chile and the for We and for MAUCO J MAUCO of