|Year : 2020 | Volume
| Issue : 2 | Page : 29-34
Heart Assessment and Monitoring in Rajaie Hospital (HAMRAH): A population-based cohort study
Hooman Bakhshandeh1, Majid Maleki2, Feridoun Noohi2, Shabnam Boudagh3, Yasaman Khalili2, Azin Alizadehasl3, Nasim Naderi2, Bahram Mohebbi4, Yousef Moghaddam2, Majid Haghjoo5, Maedeh Arabian2, Mohammad Javad Alemzadeh-Ansari4, Mohammadreza Baay2, Hamidreza Pouraliakbar2, Zahra Ghaemmaghami2, Shiva Khaleghparast2, Behshid Ghadrdoost2, Hamidreza Pasha2, Zahra Hosseini4, Reza Golpira2, Nejat Mahdieh6, Akbar Nikpajouh2, Parham Sadeghipour4
1 Rajaie Cardiovascular Medical and Research Center; Research Center for Prevention of Cardiovascular Disease, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, Tehran, Iran
2 Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
3 Echocardiography Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
4 Cardiovascular Intervention Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
5 Cardiac Electrophysiology Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
6 Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
|Date of Submission||26-May-2020|
|Date of Acceptance||03-Jun-2020|
|Date of Web Publication||27-Jul-2020|
Dr. Parham Sadeghipour
Cardiovascular Intervention Research Center, Rajaie Cardiovascular Medical and Research Center, Hashemi.Rafsanjani Vali.e.asr Intersection, Adjacent to Mellat Park, P O Box: 1995614331, Tehran
Source of Support: None, Conflict of Interest: None
Background and Objectives: Cardiovascular diseases (CVDs) impose great burden on the health systems worldwide. The prevention of CVDs depends on the correct information about the perveance/incidence of them and their determinants in the community and population-based studies are the most accurate ways for obtaining these data. The objective of this study is to determine the prevalence of the classic risk factors of CVDs among healthy adult residents of Tehran and their changes through a 10-year follow-up in Tehran, the capital of Iran. This article presents the study protocol. Methods: Heart Assessment and Monitoring in RAjaie Hospital, is a population-based study conducted in Rajaie Cardiovascular Medical and Research Center, the largest tertiary care hospital for CVDs in Tehran. It consists two phases: A survey and a prospective cohort. People between 30 and 75 years of age, without known CVDs, invite through a multistage random sampling process. They will assess for the CVD risk factors, laboratory indices, electrocardiography and echocardiography features, diet, physical activity levels, psychological aspects, and peripheral vascular diseases. All the participants will be followed for 10 years and the changes in the above-mentioned factors and incidence of CVDs assessed. Discussion: It is expected that through obtaining valid, population-specific data, the information for policy making and efficient management of CVDs in Iranian people be provided.
Keywords: Cardiovascular diseases, cohort studies, Iran, risk factors
|How to cite this article:|
Bakhshandeh H, Maleki M, Noohi F, Boudagh S, Khalili Y, Alizadehasl A, Naderi N, Mohebbi B, Moghaddam Y, Haghjoo M, Arabian M, Alemzadeh-Ansari MJ, Baay M, Pouraliakbar H, Ghaemmaghami Z, Khaleghparast S, Ghadrdoost B, Pasha H, Hosseini Z, Golpira R, Mahdieh N, Nikpajouh A, Sadeghipour P. Heart Assessment and Monitoring in Rajaie Hospital (HAMRAH): A population-based cohort study. Res Cardiovasc Med 2020;9:29-34
|How to cite this URL:|
Bakhshandeh H, Maleki M, Noohi F, Boudagh S, Khalili Y, Alizadehasl A, Naderi N, Mohebbi B, Moghaddam Y, Haghjoo M, Arabian M, Alemzadeh-Ansari MJ, Baay M, Pouraliakbar H, Ghaemmaghami Z, Khaleghparast S, Ghadrdoost B, Pasha H, Hosseini Z, Golpira R, Mahdieh N, Nikpajouh A, Sadeghipour P. Heart Assessment and Monitoring in Rajaie Hospital (HAMRAH): A population-based cohort study. Res Cardiovasc Med [serial online] 2020 [cited 2020 Dec 1];9:29-34. Available from: https://www.rcvmonline.com/text.asp?2020/9/2/29/290867
| Background and Significance|| |
According to a report by the World Health Organization (WHO), cardiovascular diseases (CVDs) are the leading cause of mortality the world over.,, Indeed, it was estimated that CVDs claimed in excess of 17.9 million lives in the years 2015 and 2016, representing 31% of all deaths. Over 75% of these deaths occurred in low- and middle-income countries. Recent estimates show that the global death toll taken by CVDs has risen by 12.5% in the past decade, with the bulk of the fatalities reported from South and East Asia. CVDs denote a wide spectrum of diseases involving the heart and the vascular structures that supply the heart, brain, and peripheral tissues. Meanwhile, heart attacks and strokes account for up to 85% of CVD deaths. Previous reports from Iran, as a developing country, have portrayed CVDs as the chief culprit for deaths.,, A case in point is the statistic indicating that up to 50% of annual mortalities  and up to 79% of deaths caused by chronic diseases are due to CVDs. The role of CVDs assumes even a greater significance when the available reports show that these diseases are responsible for a considerable portion of premature deaths happening in the productive age. The occurrence of CVDs is greatly dependent on risk factors, the most important of which are smoking, increased blood pressure, hyperlipidemia, diabetes mellitus, obesity, inadequate physical activity, alcohol consumption, and unhealthy diet. The good news, however, is that CVDs are among the most preventable diseases, and in fact, most of them (up to 80%) are avoidable in the early stages.,,,,
Given the remarkable share of CVDs in universal disease burden and death, it would not be a gross exaggeration to claim that global health is greatly dependent on the control of CVD risk factors. Fortunately, these risk factors, together with their side effects, can be modified and modulated, which is once again why CVDs are deemed the most important preventable causes of death among noncommunicable diseases. In point of fact, CVDs are the main focus of the Global Burden of Disease project, which aims to lower the global death toll exacted by these diseases., What comes to the fore in this international collaboration is information on CVD risk factors in order for health systems to prioritize their objectives and formulate plans accordingly for the prevention at primary and secondary levels.
However, not all CVD risk factors are ranked equally in terms of significance. It is generally acknowledged that diabetes mellitus, hypertension, smoking, hyperlipidemia, and family history constitute the risk factors meriting greater heed. The Framingham Heart Study, a significant cohort investigation, was the first to elucidate the relationships between the majority of these risk factors and CVDs.
Turning our focus on Iran, it is regrettable that the prevalence of some CVD risk factors – including insufficient physical activity, unhealthy diet, and smoking – was reported to have been on the rise in the time periods between the late 20th and early 21st century. It is, therefore, vitally important to reassess and monitor the trends of major CVD risk factors in the country.,,, The modifiability of the majority of these risk factors is the cornerstone of many a population-based intervention seeking to decrease the global mortality of CVDs. To determine the distribution, prevalence, and severity of CVD risk factors, investigators first need to appropriately analyze the current status of these factors to project future trends. The data collected would serve as the basis for prioritization and resource allocation in population-based preventive measures. A considerable number of such interventions have been made by designing and implementing long-lasting population cohorts that confer a concurrent assessment and monitoring of the outstanding risk factors. Many population-based cohort studies are conducted on a global level; for instance, the Framingham Heart Study is the most famous project in the field of CVDs., In Iran, there have been several population-based cohorts, too. The Tehran Lipid and Glucose Study is one of the earliest of such endeavors, which was aimed at assessing the general risk factors of noncommunicable diseases. Projects such as the Persian Cohort Study, the Golestan Cohort Study, the Persian Guilan Cohort Study, and the Tehran Cohort Study have all covered a wide range of factors, including cardiovascular items, whereas the Isfahan Cohort Study and the KERCADR Study (Kerman Coronary Artery Disease Risk Study) are concentrated on CVDs.,
Tehran is the largest and most populated Iranian city. It should, thus, come as no surprise that Tehran shares the same problems as its fellow metropolises: on the one hand, air pollution and traffic congestion and on the other, the heterogeneity of inhabitants who lead an unhealthy modern lifestyle. These notable risk factors and their trends over time have been evaluated by the aforementioned Iranian studies; nonetheless, there is currently a paucity of information on specific cardiovascular assessments of peripheral vascular diseases and comorbidities. Accordingly, we have designed a population-based cohort study entitled “Heart Assessment and Monitoring in RAjaie Hospital (HAMRAH)” to be performed in the city of Tehran over a 10-year period.
| Study Aims|| |
The HAMRAH study aims to determine the prevalence of the classic risk factors of CVDs among healthy adult residents of Tehran and their changes through a 10-year follow-up. The investigation also seeks to determine the incidence rate of coronary artery disease and the risk stratification score of the Iranian community. The participants in the study will also be assessed concerning diet, physical activity levels, and psychological aspects. Furthermore, great significance will be accorded to peripheral vascular diseases. It is hoped that the findings will pave the way for future community health-related interventions and studies.
| Design and Methods|| |
The HAMRAH study will be conducted in two different methodological phases. The first phase will be a cross-sectional study in which participants are recruited and their baseline information is recorded. Subsequently, in a prospective observational study, all the participants will be followed from the viewpoints of changes in CVD risk factors and the occurrence of CVDs.
The HAMRAH study will be conducted in Rajaie Cardiovascular Medical and Research Center (RCMRC), the largest tertiary care center for CVDs in Tehran, Iran. The study protocol was approved by the Review Board and Ethics Committee of RCMRC (Ethics Committee Code: RHC.AC.IR.REC.1396.22), and the funding for the project was granted by the Vice-Chancellorship of Research of RCMRC. About 50 faculty and medical staff members will be participating in different aspects and stages of the project. Two faculty members, 1 epidemiologist, and 1 cardiologist (H.B. and P.S.) are the primary investigators that will coordinate three study committees: the Steering Committee, the Scientific Committee, and the Executive Committee. The project will benefit from the expertise and collaboration of faculty members with clinical and nonclinical specialties such as general cardiology, cardiovascular intervention, echocardiography, electrophysiology, heart failure, endocrinology, community medicine and prevention, physiology, nutrition, biostatistics, and genetics. In addition, the team will be ably aided by nurses, medical technicians, and secretaries.
Study setting and population
Tehran is the capital of Iran and also the province of Tehran. According to Iran's Population and Housing Census-2016, Tehran had a population of more than 8.7 million, spreading in 22 municipal districts with different spans and populations. The city covers an approximate area of 730 km 2.
The criteria for inclusion in the HAMRAH study consist of fully informed willingness to participate in the project, living in Tehran, age between 30 and 75 years, no known history of CVDs (e.g., coronary artery disease, valvular heart diseases, and congenital anomalies of the heart and vessels), no known history of any cardiac surgery and intervention, and no defect in communication skills (e.g., somatic and psychological problems) that might interfere with cooperation in the entirety of the project.
Sampling and sample size
Sampling during the design of the project was done through the multistage random sampling method. First, Tehran was divided into five main geographical regions (strata): north, South, East, West, and Center. From each region, two different districts were randomly selected: districts 1 and 3 from the North, districts 12 and 18 from the South, districts 2 and 5 from the West, districts 4 and 14 from the East, and districts 6 and 7 from the Center [Figure 1]. According to the study protocol, 60 clusters each incorporating 20 households (units) will be chosen through the proportional-to-size approach. Given that Tehran has a family dimension median of 3, an estimated 3600 adults are expected to participate in the study. Similar previous experiences have demonstrated a participation rate of 50%; consequently, between 1800 and 2000 adults should be enrolled in the study.
Sampling is to be commenced from the starting point of the project. The Statistical Center of Iran will be consulted for defining the starting point addresses within the selected districts. According to the PPI approach, districts with larger populations have a greater share of clusters/sample size. From each starting point, 20 house numbers will be considered sequentially. Of each house number, a single household/house floor will be chosen randomly. If the family is absent or does not consent to participate in the study, another family at that house number will be contacted. In the event that no cooperation can be elicited from that house number, the adjacent house number will be considered. This process is to be continued and repeated until a total of 1200 households have been enrolled.
Endpoints and measurements
The HAMRAH study will mainly focus on the prevalence of the classic risk factors of CVDs, the associations between them, and their incidence or changes over time, in conjunction with the occurrence of CVDs. Nevertheless, it will also seek to measure other relevant factors. The study variables are categorized as follows:
- Demographic and socioeconomic status
- Vital signs
- Anthropometric measures
- Medical history, including CVD risk factors (e.g., family history, diabetes, hypertension, hypercholesterolemia, hyperlipidemia, and smoking), noncardiac diseases, and drug history
- Physical activity levels, measured using the Global Physical Activity Questionnaire, developed by the World Health Organization (WHO) for the measurement of physical activity levels during work, travel, and recreational activities
- Nutritional status, assessed using a self-administered food-frequency questionnaire devised by the National Institute of Nutritional Research and Food Industry  for the estimation of the average intake of different foods and nutritional groups among a certain population
- Psychological profile, evaluated using the General Health Questionnaire-28 (GHQ-28) and the WHO Quality of Life Questionnaire (WHOQOL-BREF) (GHQ is a self-administered questionnaire used for screening minor psychiatric disorders in the general population or nonpsychiatric conditions such as primary care or general out-patients, and the WHOQOL-BREF is a 26-item tool developed by the WHO for assessing the general quality of life.
- Laboratory tests such as complete blood count, blood glucose, A1c hemoglobin, lipid profile, serum electrolytes, liver function, thyroid function, pro-BNP, highly sensitive C-reactive protein, and urine analysis
- Cardiovascular physical examinations, including the assessment of signs and symptoms relevant to cardiac and peripheral vascular (upper and lower limbs) diseases
- Classic CVD risk factors, the presence and severity of which will be determined through clinical assessments
- Electrocardiography (ECG)
- Ultrasonography of the abdominal aorta (only in participants aged >65 years)
- Noninvasive peripheral vascular studies, including the ankle-brachial index (ABI) and the toe brachial index (TBI) (only in participants aged >65 years with symptoms of vascular problems)
- Varicose vein assessment.
The findings of the clinical examinations and diagnostic tests should reveal undiagnosed risk factors and CVDs, and the newly diagnosed patients will be referred for more specific tests such as radionuclide scanning and coronary angiography.
Study phases and data collection
The HAMRAH study will be conducted in two sequential stages: a cross-sectional phase (a population-based survey) and a longitudinal phase (a population-based cohort) [Figure 2].
|Figure 2: Heart Assessment and Monitoring in Rajaie Hospital flow diagram|
Click here to view
In this phase, participants will be registered and their baseline data will be collected. It is to be conducted in two steps: enrolment and data collection.
Three-person teams, consisting of a team leader and two assistants (1 male and 1 female) will conduct sampling and invite individuals to participate in the HAMRAH study. The teams will undergo training beforehand by the center's Scientific Committee to perform the sampling process in keeping with the methods explained in section 3.4. The teams will select households and determine whether or not they fulfill the inclusion criteria. Households that grant informed consent for study participation will then be invited to refer to RCMRC according to a predefined schedule, which requires 12 hours' fasting for blood sampling.
According to the HAMRAH study protocol, a clinic will be established in RCMRC to receive the project participants for the acquisition of relevant data. This clinic will be active every Thursday, on which the other clinics in the hospital are inactive. A supervisor, 2 cardiologists, 1 research physician, 4 research nurses, 2 laboratory technicians, 2 ECG technicians, 2 echocardiography technicians, 3 secretaries, and 1 security guard will man the HAMRAH clinic.
All the participants will be asked to refer to the HAMRAH clinic in two consecutive weeks. At the first visit, the participants will register; sign a written informed consent form; help fill out a questionnaire about their personal and socioeconomic information; have their vital signs and anthropometric indices measured by the research nurses; give blood and urine samples for lab tests; undergo ECG testing; and receive information about the food-recall (to be filled in at home). The GHQ-28, and WHOQOL-BREF questionnaires will be given to participants and they should answer at the clinic. In the final stage of the first clinic visit, the team's research physician will interview the participants individually to obtain the information about their medical history and physical activity levels and then assess them for the risk of abdominal aortic aneurysms and peripheral vascular diseases. If need be, sonography and ABI-TBI tests will be performed at the discretion of the research physician. A healthy snack buffet will be laid on for the participants.
At the second visit in the following week, the participants will hand in their food-recall; undergo echocardiography; and then have the results of their laboratory, ECG, and echocardiography tests evaluated by the team's cardiologist. Different scenarios are defined based on the cardiologist's diagnosis. Participants with a diagnosed CVD will be excluded from the study and referred for specialist treatment, those with a suspected CVD will be given more specific diagnostic tests (positive tests will lead to the exclusion of the individual and referral for specialist treatment), and those with CVD risk factors will be offered consultations on risk-factor modifications and included in the follow-up phase of the project. All the other participants will also be included in the follow-up phase.
The steps of the survey phase are depicted in [Figure 1].
The entire study population will undergo the aforementioned assessments every 2 years for up to 10 years, and the data obtained will be methodically classified. Each follow-up visit will consist of the following items:
- Inquiries about the new changes in socioeconomic status
- Vital signs
- Anthropometric measures
- Medical history in the preceding 2 years, encompassing morbidities, hospitalization (for any reason including cardiovascular problems), cardiovascular events, and cardiovascular diagnostic and therapeutic procedures
- Laboratory tests such as complete blood count, blood glucose, A1c hemoglobin, lipid profile, and serum electrolytes
- Cardiovascular physical examinations, including the assessment of signs and symptoms relevant to cardiac and peripheral vascular (upper and lower limbs) diseases
- Inquiries about the management of cardiac risk factors and smoking status
- ECG assessment
- Echocardiographic assessment
- Varicose vein assessment.
Importantly, individuals with new cardiovascular manifestations in need of further assessments will be supported by the HAMRAH study and RCMRC facilities and will be followed in accordance with their presumed medical plan.
An appropriate, uninterrupted quality-controlling and monitoring of the project requires a well-thought-out program every step of the way. This vital task is within the remit of the Steering Committee, whose members will continuously oversee the administrative processes of field invitation and sampling, as well as the activities of the HAMRAH clinic. In tandem with the Steering Committee members, the supervisor of the clinic will separately observe the data-collection flow, data-collection quality, task performance, and management issues. In addition, the Scientific Committee will check 5% of the collected data with a view to detecting any faults in the processes of acquisition, recording, and registration.
Data management and statistical analysis plan
The HAMRAH study data forms, checklists, and questionnaires will be designed and handled through the hospital information system (HIS) of RCMRC. Every single piece of information will be fed into the HIS by the experts that design and run the system. The data will be exported as standard formats of databases or MS Excel data sheets for use with the aid of statistical software packages.
The statistical analyses in the HAMRAH study will be carried out in two stages. The first stage is the survey analysis, whereby the prevalence of the CVD risk factors will be computed and the study variables will be described through suitable statistics such as the mean (the standard deviation) for the interval data and frequencies (percentages) for the categorical data. For the statistics, 95% confidence intervals will be presented, and the design effect for multistage sampling will be computed in order that all estimations can be corrected accordingly. Subgroup analyses will be performed using appropriate statistical tests such as the t-test or the one-way analysis of variance (ANOVA) (or their nonparametric equivalents) for the comparison of the interval variables and the Pearson Chi-square test or the Fisher exact test for the comparison of the categorical variables between the groups. In addition, multivariable analyses will be carried out through appropriate methods such as regression models. In the second stage, analyses will be conducted on the follow-up data through suitable statistics. The incidence rate of the defined CVDs and changes in the risk factors will be computed. Methods that are generally drawn upon for repeated measurements (e.g., repeated measures ANOVA) will be applied. The data will also be subjected to multivariate analyses and modeling, and survival analyses will be performed through appropriate methods such as the Kaplan–Meier estimator and the Cox proportional hazard model. Reliable statistical packages such as Stata Statistical Software (StataCorp 2015, College Station, TX: StataCorp LP) and IBM SPSS Statistics (IBM Inc, Armonk, NY, USA) will be utilized.
| Discussion|| |
The HAMRAH study is a population-based cohort study aimed at investigating the prevalence of the classic risk factors of CVDs among healthy adult residents in the Iranian capital, Tehran, and their changes during a 10-year follow-up. This study will be conducted in two different methodological phases: recruiting the study population and recording their baseline characteristics will constitute the first stage, and a 10-year follow-up will comprise the second stage. While the main focus of the HAMRAH study is on the prevalence of the traditional CVD risk factors, the project has also be designed to investigate the prevalence of lower limb peripheral vascular diseases, abdominal aortic aneurysms, and varicose veins.
Several population-based studies have already been performed in Tehran, the most notable of which are the Tehran Lipid and Glucose Study and the Tehran Cohort Study., It is worthy of note that not only have we devised methodological approaches that differ from those applied in the previous studies but also, we have incorporated new dimensions into our project. We have selected the most up-to-date questionnaires and in several instances, (eg, nutrition) will use newly validated local questionnaires. Peripheral vascular diseases and varicose veins have been the focus of many a small cross-sectional study in Iran before. However, to the best of our knowledge, no population-based study has hitherto been undertaken on these issues in Iran. Another salient distinction between the previous investigations and the HAMRAH study is that we will benefit from some diagnostic modalities such as routine echocardiography, the ABI/TBI test, and abdominal aortic aneurysm screening by abdominal sonography that were not used previously.
To conclude, we firmly believe that the HAMRAH study enjoys the design and scope required for the assessment of the prevalence of CVD risk factors and indeed, the detection of latent CVDs in the modern urban population of the Iranian capital, Tehran.
We are thankful to Dr. Elahe Baghizadeh who provided the protocol document of HAMRAH study. We are also grateful to Dr. Majid Shakiba and Hamidreza Bakhshandeh for assistance with preparing the manuscript.
Financial support and sponsorship
This research is financially supported by RCMRC.
Conflicts of interest
There are no conflicts of interest.
| References|| |
Roth GA, Johnson C, Abajobir A, Abd-Allah F, Abera SF, Abyu G, et al
. Global, regional, and national burden of cardiovascular diseases for 10 causes, 1990 to 2015. J Am Coll Cardiol 2017;70:1-25.
Shafiq M, Fong AY, Tai ES, Nang EE, Wee HL, Adam J, et al
. Cohort profile: LIFE course study in CARdiovascular disease epidemiology (LIFECARE). Int J Epidemiol 2018;47:1399-1400g.
Forouzanfar MH, Sepanlou SG, Shahraz S, Dicker D, Naghavi P, Pourmalek F, et al
. Evaluating causes of death and morbidity in Iran, global burden of diseases, injuries, and risk factors study 2010. Arch Iran Med 2014;17:304-20.
Sadeghi M, Haghdoost AA, Bahrampour A, Dehghani M. Modeling the burden of cardiovascular diseases in Iran from 2005 to 2025: The impact of demographic changes. Iran J Public Health 2017;46:506-16.
Sarrafzadegan N, Mohammmadifard N. Cardiovascular disease in Iran in the last 40 years: Prevalence, mortality, morbidity, challenges and strategies for cardiovascular prevention. Arch Iran Med 2019;22:204-10.
Emamgholipour S, Akbari Sari A, Pakdaman M, Geravandi S. Economic Burden of Cardiovascular disease in South West of Iran, Int Cardio Res J 2018;12:e55067.
Sadeghi M, Talaei M, Oveisgharan S, Rabiei K, Dianatkhah M, Bahonar A, et al
. The cumulative incidence of conventional risk factors of cardiovascular disease and their population attributable risk in an Iranian population: The Isfahan Cohort Study. Adv Biomed Res 2014;3:242.
Emamian M, Hashemi H, Fotouhi A. Predicted 10-year risk of cardiovascular disease in shahroud, Islamic republic of Iran and the body mass index paradox. East Mediterr Health J 2020;26. Doi: 10.26719/emhj.20.012.
Ebrahimi M, Kazemi-Bajestani SM, Ghayour-Mobarhan M, Ferns GA. Coronary artery disease and its risk factors status in iran: A review. Iran Red Crescent Med J 2011;13:610-23.
Khalili D, Sheikholeslami FH, Bakhtiyari M, Azizi F, Momenan AA, Hadaegh F. The incidence of coronary heart disease and the population attributable fraction of its risk factors in Tehran: A 10-year population-based cohort study. PLoS One 2014;9:e105804.
Rabani S, Sardarinia M, Akbarpour S, Azizi F, Khalili D, Hadaegh F. 12-year trends in cardiovascular risk factors (2002-2005 through 2011-2014) in patients with cardiovascular diseases: Tehran lipid and glucose study. PLoS One 2018;13:e0195543.
Tsao CW, Vasan RS. Cohort profile: The framingham heart study (FHS): Overview of milestones in cardiovascular epidemiology. Int J Epidemiol 2015;44:1800-13.
Boston University & the National Heart, L., & Blood Institute. Framingham Heart Study; 2019. Available from: https://framinghamheartstudy.org/
. [Last accessed on 2020 Apr 05].
Kheradmand M, Enayati A, Rafiei A, Moosazadeh M. Population Based Cohort Studies in Iran: A Review Article. J Mazandaran Univ Med Sci 2015;25:171-85.
Karimi A, Zafarghandi M, Noorbala A, Sadeghian S, Saadat S, Alaedini F, et al
. Tehran Cohort Study; 2019. Available from: http://tehrancohort.ir/
. [Last accessed on 2020 Apr 05].
WHO, Global Physical Activity Surveillance; 2018.
The Institute of Nutritional Research and Food Industry. Official Website; 2019. Available from: http://nnftri.ac.ir
. [Last accessed on 2020 Apr 05].
[Figure 1], [Figure 2]