Sumathy Rangarajan

McMaster University | McMaster · Department of Medicine

Background The pathogenesis of inflammatory bowel disease (IBD) which includes Crohn’s disease (CD) and ulcerative colitis (UC), is believed to involve activation of the intestinal immune system in response to the gut microbiome among genetically susceptible hosts. IBD has been historically regarded as a disease of developed nations, though in the...

Objectives: The dosing interval of a primary vaccination series can significantly impact on vaccine immunogenicity and efficacy. The current study compared 3 dosing intervals for the primary vaccination series of the BNT162b2 mRNA COVID-19 vaccine, on humoral immune response and durability against SARS-CoV-2 ancestral and Beta variants up to 9 mon...

Background: Evidence on whether an excess risk of incidence and mortality of cardiovascular disease (CVD) among people exposed to a high level of ambient PM2.5 in low- and middle-income countries (LMICs) is lacking. This study aimed to investigate the associations between long-term exposure to ambient fine particulate matter<2.5 µm (PM2.5) concent...

Background Several medications have been considered to contribute to the aetiology of inflammatory bowel disease (IBD). This study assessed the association between medication use and risk of developing IBD using the Prospective Urban Rural Epidemiology (PURE) cohort. Methods This was a prospective cohort study of 133,137 individuals between the ag...

Background Cardiovascular disease (CVD) incidence is higher in men with prostate cancer (PC) than without. Objectives We describe the rate and correlates of poor cardiovascular risk factor control among men with PC. Methods We prospectively characterized 2,811 consecutive men (mean age 68 ± 8 years) with PC from 24 sites in Canada, Israel, Brazil...

Background: Although several epidemiological studies have linked social isolation to increased risk of mortality, the magnitude of any effect is unclear, in part because of the use of different measures of social isolation. Objective: To examine the association between social isolation and all-cause mortality and investigate whether it differs i...

Research examining built environment (BE) characteristics and walking/cycling behaviors has been conducted primarily in high-income countries and conclusions cannot be applied directly to low- and middle-income countries. We evaluated perceived BE characteristics and walking/cycling behaviors across 355 urban communities in 21 low-, middle-, and hi...

This study aimed to identify the interaction of depression and diets on cardiovascular diseases (CVD) incident and death in China and key subpopulations. We included 40,925 participants from the Prospective Urban Rural Epidemiology (PURE)-China cohort which recruited participants aged 35–70 years from 45 urban and 70 rural communities. Depression w...

Background The triglyceride glucose (TyG) index is an easily accessible surrogate marker of insulin resistance, an important pathway in the development of type 2 diabetes and cardiovascular diseases. However, the association of the TyG index with cardiovascular diseases and mortality has mainly been investigated in Asia, with few data available fro...

Background: Several medications have been suspected to contribute to the etiology of inflammatory bowel disease (IBD). This study assessed the association between medication use and risk of developing IBD using the Prospective Urban Rural Epidemiology (PURE) cohort. Methods: This was a prospective cohort study of 133,137 individuals between the...

Background: Higher intake of ultra-processed foods (UPFs) has been associated with increased risk of CVD and mortality in observational studies from Western countries but data from non-Western countries are limited. Objectives: We aimed to assess the association between consumption of UPFs and risk of mortality and major CVD in a cohort from mul...

Objectives: To investigate whether lower hypertension prevalence or blood pressure was associated with cleaner household fuel usage for cooking and heating among Chinese adults. Methods: We enrolled 44,862 Chinese adults at the baseline of the prospective urban and rural epidemiology (PURE) study in China during 2005–2009, as a subset of the PURE-g...

Background and objectives: There is uncertainty about the association between alcohol consumption and stroke, particularly for low-moderate intake. We explored these associations in a large international study. Methods: INTERSTROKE, a case-control study, is the largest international study of risk factors for acute stroke. Alcohol consumption was...

Background: The large number of patients worldwide infected with the SARS-CoV-2 virus has overwhelmed health-care systems globally. The Anti-Coronavirus Therapies (ACT) outpatient trial aimed to evaluate anti-inflammatory therapy with colchicine and antithrombotic therapy with aspirin for prevention of disease progression in community patients wit...

Background: COVID-19 disease is accompanied by a dysregulated immune response and hypercoagulability. The Anti-Coronavirus Therapies (ACT) inpatient trial aimed to evaluate anti-inflammatory therapy with colchicine and antithrombotic therapy with the combination of rivaroxaban and aspirin for prevention of disease progression in patients hospitali...

Background There is a paucity of data on the prevalence of risk factors and their associations with incident cardiovascular disease in women compared with men, especially from low-income and middle-income countries. Methods In the Prospective Urban Rural Epidemiological (PURE) study, we enrolled participants from the general population from 21 hig...

Background and objective: The major contributing risk factors to airflow obstruction (AO) in China remain largely unknown. We examined the environmental and lifestyle risk factors of unrecognized AO in the baseline of a population-based cohort drawn from 115 urban and rural communities across 12 provinces in China. Methods: Amongst 46,285 adults...

Introduction: Measuring patient-reported information in stroke research is challenging. To overcome this, use of proxy respondents is often a necessary strategy. In this study, we report on use and effect of proxy respondents on patient case-mix in a large international epidemiologic stroke study (INTERSTROKE). Methods: This was a cross-sectiona...

Aims: To examine the incidence of cardiovascular disease (CVD) and mortality in China and in key subpopulations, and to estimate the population-level risks attributable to 12 common modifiable risk factors for each outcome. Methods and results: In this prospective cohort of 47 262 middle-aged participants from 115 urban and rural communities in...

Aim: To examine the incidence of cardiovascular disease (CVD), of death, and the comparative effects of 12 common modifiable risk factors for both outcomes in South Asia. Methods and results: Prospective study of 33 583 individuals 35-70 years of age from India, Bangladesh, or Pakistan. Mean follow-up period was 11 years. Age and sex adjusted in...

Importance: High amounts of sitting time are associated with increased risks of cardiovascular disease (CVD) and mortality in high-income countries, but it is unknown whether risks also increase in low- and middle-income countries. Objective: To investigate the association of sitting time with mortality and major CVD in countries at different ec...

Background and purpose: The association of dyslipidemia with stroke has been inconsistent, which may be due to differing associations within etiological stroke subtypes. We sought to determine the association of lipoproteins and apolipoproteins within stroke subtypes. Methods: Standardized incident case-control STROKE study in 32 countries. Case...

Aims: Elevated body mass index (BMI) is an important cause of cardiovascular disease (CVD). The population-level impact of pharmacologic strategies to mitigate the risk of CVD conferred by the metabolic consequences of an elevated BMI is not well described. Methods and results: We conducted an analysis of 145 986 participants (mean age 50 years,...

Background Household air pollution (HAP) from cooking with solid fuels has been associated with adverse respiratory effects, but most studies use surveys of fuel use to define HAP exposure, rather than on actual air pollution exposure measurements. Objective To examine associations between household and personal fine particulate matter (PM2.5) and...

Greenspace and socioeconomic status are known correlates of diabetes prevalence, but their combined effects at the sub-neighborhood scale are not yet known. This study derives, maps, and validates a combined socioeconomic/greenspace index of individual-level diabetes risk at the sub-neighborhood scale, without the need for clinical measurements. In...

BACKGROUND A higher prevalence of hypertension is reported among Afro-descendants compared to other ethnic groups in high-income countries, however there is a paucity of information in low- and medium-income countries. METHODS We evaluated 3745 adults from 3 ethnic groups (552 White, 2,746 Mestizos, 447 Afro-descendants) enrolled in the prospectiv...

Aims: In a multinational South American cohort, we examined variations in CVD incidence and mortality rates between subpopulations stratified by country, by sex and by urban or rural location. We also examined the contributions of 12 modifiable risk factors to CVD development and to death. Methods and results: This prospective cohort study inclu...

Background Effective treatments for COVID-19 are urgently needed but conducting randomized trials during the pandemic has been challenging. Methods The Anti-Coronavirus Therapy (ACT) trials are parallel factorial international trials that aimed to enroll 3,500 outpatients and 2,500 inpatients with symptomatic COVID-19. The outpatient trial is eval...

Background South Asian children's diets are considered unhealthy, yet the relationship with food parenting among South Asians is understudied. Methods In a cross-sectional study, questionnaires were administered to dyads of Canadian South Asian elementary and high school children and a parent. Relationships between parental factors (perceived resp...

Introduction Portable spirometers are commonly used in longitudinal epidemiological studies to measure and track the forced expiratory volume in first second (FEV 1 ) and forced vital capacity (FVC). During the course of the study, it may be necessary to replace spirometers with a different model. This raise questions regarding the comparability of...

Background COVID-19 has caused profound socio-economic changes worldwide. However, internationally comparative data regarding the financial impact on individuals is sparse. Therefore, we conducted a survey of the financial impact of the pandemic on individuals, using an international cohort that has been well-characterized prior to the pandemic. M...

Background: Separate studies suggest that the risks from smoking might vary between high-income (HICs), middle-income (MICs), and low-income (LICs) countries, but this has not yet been systematically examined within a single study using standardised approaches. We examined the variations in risks from smoking across different country income groups...

Introduction Use of polluting cooking fuels generates household air pollution (HAP) containing health-damaging levels of fine particulate matter (PM2.5). Many global epidemiological studies rely on categorical HAP exposure indicators, which are poor surrogates of measured PM2.5 levels. To quantitatively characterize HAP levels on a large scale, a m...

Background By 2050, the global population of adults 60 + will reach 2.1 billion, surging fastest in low- and middle-income countries (LMIC). In response, the World Health Organization (WHO) has developed indicators of age-friendly urban environments, but these criteria have been challenging to apply in rural areas and LMIC. This study fills this ga...

Purpose: Cardiovascular disease is a common cause of death in prostate cancer patients. Low testosterone is associated with increased cardiovascular risk in the general male population. We investigated the relationship between serum testosterone, cardiovascular disease and risk factors in androgen-deprivation therapy-naïve prostate cancer patients...

Background Final adult height is a useful proxy measure of childhood nutrition and disease burden. Tall stature has been previously associated with decreased risk of all-cause mortality, decreased risk of major cardiovascular events and an increased risk of cancer. However, these associations have primarily been derived from people of European and...

Importance Stress may increase the risk of cardiovascular disease (CVD). Most studies on stress and CVD have been conducted in high-income Western countries, but whether stress is associated with CVD in other settings has been less well studied. Objective To investigate the association of a composite measure of psychosocial stress and the developm...

Background In the Canadian Alliance for Healthy Hearts and Minds (CAHHM) cohort, participants underwent magnetic resonance imaging (MRI) of the brain, heart, and abdomen, that generated incidental findings (IFs). The approach to managing these unexpected results remain a complex issue. Our objectives were to describe the CAHHM policy for the manage...

Aims In INTERSTROKE, we explored the association of anger or emotional upset and heavy physical exertion with acute stroke, to determine the importance of triggers in a large, international population. Methods and results INTERSTROKE was a case–control study of first stroke in 32 countries. Using 13 462 cases of acute stroke we adopted a case-cr...

Black Carbon (BC) is an important component of household air pollution (HAP) in low- and middle-income countries (LMICs), but levels and drivers of exposure are poorly understood. As part of the Prospective Urban and Rural Epidemiological (PURE) study, we analyzed 48-hour BC measurements for 1187 individual and 2242 household samples from 88 commun...

Objective To determine whether cognitive reserve attenuates the association of vascular brain injury with cognition. Methods Cross-sectional data were analyzed from two harmonized studies: the Canadian Alliance for Healthy Hearts and Healthy Minds (CAHHM) and the Prospective Urban and Rural Epidemiology (PURE) study. Markers of cognitive reserve w...

Background There are few concise tools to evaluate dietary habits in men with prostate cancer in Canada. Objective To develop a short FFQ (SFFQ) in a cohort of prostate cancer patients. Methods A total of 130 men with prostate cancer completed the SFFQ and a validated comprehensive food frequency questionnaire (CFFQ). Both questionnaires were adm...

Metabolic syndrome (MetS) and type 2 diabetes (T2D) are metabolic alterations associated with high morbidity and mortality, particularly in low and middle-income countries. Diet has a significant impact on the risk to develop MetS and T2D; in this regard, consumption of fruits, vegetables, and protein rich foods (from plant and animals) are importa...

Objective To evaluate the relation between intake of ultra-processed food and risk of inflammatory bowel disease (IBD). Design Prospective cohort study. Setting 21 low, middle, and high income countries across seven geographical regions (Europe and North America, South America, Africa, Middle East, south Asia, South East Asia, and China). Partic...

The COVID-19 pandemic has caused an increase in anxiety and depression levels across broad populations. While anyone can be infected by the virus, the presence of certain chronic diseases has been shown to exacerbate the severity of the infection. There is a likelihood that knowledge of this information may lead to negative psychological impacts am...

Importance: Obesity is a growing public health threat leading to serious health consequences. Late bedtime and sleep loss are common in modern society, but their associations with specific obesity types are not well characterized. Objective: To assess whether sleep timing and napping behavior are associated with increased obesity, independent of...

Background Dietary factors may influence the risk of developing inflammatory bowel disease (IBD), but evidence from large, prospective studies is scarce. This study aimed to evaluate the relationship between ultra-processed food intake and the risk of developing IBD in the Prospective Urban Rural Epidemiology (PURE) cohort study. Methods This was...

Background To examine the association between dietary nutrients (protein, carbohydrates, total fats, saturated fatty acids [SFA], monounsaturated fatty acids [MUFA], polyunsaturated fatty acids [PUFA], and cholesterol) and various serum liquids in Chinese adults. Methods As a part of Prospective Urban and Rural Epidemiology (PURE) study, 46,285 Ch...

Background: Previous studies reported an association of renal impairment with stroke, but there are uncertainties underpinning this association. Aims: We explored if the association is explained by shared risk factors or is independent and whether there are regional or stroke subtype variations. Methods: INTERSTROKE is a case-control study and...

Background Dietary guidelines recommend limiting red meat intake because it is a major source of medium- and long-chain SFAs and is presumed to increase the risk of cardiovascular disease (CVD). Evidence of an association between unprocessed red meat intake and CVD is inconsistent. Objective The study aimed to assess the association of unprocessed...

Background Adiposity is a major component of the metabolic syndrome (MetS), low muscle strength has also been identified as a risk factor for MetS and for cardiovascular disease. We describe the prevalence of MetS and evaluate the relationship between muscle strength, anthropometric measures of adiposity, and associations with the cluster of the co...

Importance Cohort studies report inconsistent associations between fish consumption, a major source of long-chain ω-3 fatty acids, and risk of cardiovascular disease (CVD) and mortality. Whether the associations vary between those with and those without vascular disease is unknown. Objective To examine whether the associations of fish consumption...

Objective To examine the association between social isolation and mortality and incident diseases in middle-aged adults in urban and rural communities from high-income, middle-income and low-income countries. Design Population-based prospective observational study. Setting Urban and rural communities in 20 high income, middle income and low incom...

Background Most data regarding the association between the glycemic index and cardiovascular disease come from high-income Western populations, with little information from non-Western countries with low or middle incomes. To fill this gap, data are needed from a large, geographically diverse population. Methods This analysis includes 137,851 part...

Objective To evaluate the association between intakes of refined grains, whole grains, and white rice with cardiovascular disease, total mortality, blood lipids, and blood pressure in the Prospective Urban and Rural Epidemiology (PURE) study. Design Prospective cohort study. Setting PURE study in 21 countries. Participants 148 858 participants w...

Objectives This study aimed to examines the association of bedtime with mortality and major cardiovascular events. Methods Bedtime was recorded based on self-reported habitual time of going to bed in 112,198 participants from 21 countries in the Prospective Urban Rural Epidemiology (PURE) study. Participants were prospectively followed for 9.2 yea...

Background & aims Although fruits and vegetable consumption has been shown to be associated with lower risks of mortality, cancers, and cardiovascular disease (CVD), there are limited data from China on the shape of the association. This study aimed to quantify the relationship between levels of fruit, vegetable, and legume consumption with the ris...

Objective Hypertension is the most important modifiable risk factor for stroke globally. We hypothesised that country-income level variations in knowledge, detection and treatment of hypertension may contribute to variations in the association of blood pressure with stroke. Methods We undertook a standardised case-control study in 32 countries (IN...

Objective: We aimed to compare cardiovascular (CV) events, all-cause mortality, and CV mortality rates among adults with and without diabetes in countries with differing levels of income. Research design and methods: The Prospective Urban Rural Epidemiology (PURE) study enrolled 143,567 adults aged 35-70 years from 4 high-income countries (HIC),...

BACKGROUND Although low sodium intake (<2 g/day) and high potassium intake (>3.5 g/day) are proposed as public health interventions to reduce stroke risk, there is uncertainty about the benefit and feasibility of this combined recommendation on prevention of stroke. METHODS We obtained random urine samples from 9,275 cases of acute first stroke an...

Objective: The association between indoor air pollution resulting from household solid fuel use for heating and cooking with hypertension or blood pressure (BP) remains less clear. This study aims to rectify these knowledge gaps in a large Chinese population. Methods: During 2005-2009, 44 007 individuals aged 35-70 years with complete informatio...

Objectives: We aimed to examine the relationship between access to medicine for cardiovascular disease (CVD) and major adverse cardiovascular events (MACEs) among people at high risk of CVD in high- income countries (HICs), upper and lower middle- income countries (UMICs, LMICs) and low- income countries (LICs) participating in the Prospective Urba...

Background: Approximately 2·8 billion people are exposed to household air pollution from cooking with polluting fuels. Few monitoring studies have systematically measured health-damaging air pollutant (ie, fine particulate matter [PM2·5] and black carbon) concentrations from a wide range of cooking fuels across diverse populations. This multinatio...

Background: Angiotensin-converting enzyme 2 (ACE2) is an endogenous counter-regulator of the renin-angiotensin hormonal cascade. We assessed whether plasma ACE2 concentrations were associated with greater risk of death or cardiovascular disease events. Methods: We used data from the Prospective Urban Rural Epidemiology (PURE) prospective study t...

Background Both hypertension and grip strength (GS) are predictors of mortality and cardiovascular disease (CVD), but whether these risk factors interact to affect CVD and all-cause mortality is unknown. This study sought to investigate the associations of GS with the risk of major CVD incidence, CVD mortality, and all-cause mortality in patients w...

Objective: Previous prospective studies on the association of white rice intake with incident diabetes have shown contradictory results but were conducted in single countries and predominantly in Asia. We report on the association of white rice with risk of diabetes in the multinational Prospective Urban Rural Epidemiology (PURE) study. Research...