UChicago Research Bangladesh Ltd

Dhaka, Bangladesh

UChicago Research Bangladesh Ltd

Dhaka, Bangladesh
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Chen Y.,New York University | Wu F.,New York University | Liu M.,New York University | Parvez F.,Columbia University | And 10 more authors.
Environmental Health Perspectives | Year: 2013

Background: Few prospective studies have evaluated the influence of arsenic methylation capacity on cardiovascular disease (CVD) risk. Objective: We evaluated the association of arsenic exposure from drinking water and arsenic methylation capacity with CVD risk. Method: We conducted a case-cohort study of 369 incident fatal and nonfatal cases of CVD, including 211 cases of heart disease and 148 cases of stroke, and a subcohort of 1,109 subjects randomly selected from the 11,224 participants in the Health Effects of Arsenic Longitudinal Study (HEALS). Results: The adjusted hazard ratios (aHRs) for all CVD, heart disease, and stroke in association with a 1-SD increase in baseline well-water arsenic (112 μg/L) were 1.15 (95% CI: 1.01, 1.30), 1.20 (95%1.04, 1.38), and 1.08 (95%0.90,respectively. aHRs for the second and third tertiles of percentage urinary monomethylarsonic acid (MMA%) relative to the lowest tertile, respectively, were 1.27 (95%0.85, 1.90) and 1.55 (95%1.08, 2.23) for all CVD, and 1.65 (95%1.05, 2.60) and 1.61 (95%1.04, 2.49) for heart disease specifically. The highest versus lowest ratio of urinary dimethylarsinic acid (DMA) to MMA was associated with a significantly decreased risk of CVD (aHR = 0.54; 95%0.34, 0.85) and heart disease (aHR =95%0.33, 0.88). There was no significant association between arsenic metabolite indices and stroke risk. The effects of incomplete arsenic methylation capacity-indicated by higher urinary MMA% or lower urinary DMA%-with higher levels of well-water arsenic on heart disease risk were additive. There was some evidence of a synergy of incomplete methylation capacity with older age and cigarette smoking. Conclusions: Arsenic exposure from drinking water and the incomplete methylation capacity of arsenic were adversely associated with heart disease risk.


Chen Y.,New York University | Wu F.,New York University | Parvez F.,Columbia University | Ahmed A.,U Chicago Research Bangladesh Ltd | And 13 more authors.
Environmental Health Perspectives | Year: 2013

Background: Arsenic exposure from drinking water has been associated with heart disease; however, underlying mechanisms are uncertain. Objective: We evaluated the association between a history of arsenic exposure from drinking water and the prolongation of heart rate-corrected QT (QTc), PR, and QRS intervals. Method: We conducted a study of 1,715 participants enrolled at baseline from the Health Effects of Arsenic Longitudinal Study. We assessed the relationship of arsenic exposure in well water and urine samples at baseline with parameters of electrocardiogram (ECG) performed during 2005-2010, 5.9 years on average since baseline. Results: The adjusted odds ratio (OR) for QTc prolongation, defined as a QTc ≥ 450 msec in men and ≥ 460 msec in women, was 1.17 (95% CI: 1.01, 1.35) for a 1-SD increase in well-water arsenic (108.7 μg/L). The positive association appeared to be limited to women, with adjusted ORs of 1.24 (95% CI: 1.05, 1.47) and 1.24 (95% CI: 1.01, 1.53) for a 1-SD increase in baseline well-water and urinary arsenic, respectively, compared with 0.99 (95% CI: 0.73, 1.33) and 0.86 (95% CI: 0.49, 1.51) in men. There were no apparent associations of baseline well-water arsenic or urinary arsenic with PR or QRS prolongation in women or men. Conclusions: Long-term arsenic exposure from drinking water (average 95 μg/L; range, 0.1-790 μg/L) was associated with subsequent QT-interval prolongation in women. Future longitudinal studies with repeated ECG measurements would be valuable in assessing the influence of changes in exposure.


Yinon L.,New York University | Chen Y.,New York University | Parvez F.,Columbia University | Bangalore S.,New York University | And 6 more authors.
Preventive Medicine | Year: 2013

Objective: Limited studies suggest that blood pressure variability over time is a risk factor of long-term cardiovascular outcomes. However, most of these were in populations with pre-existing cardiovascular diseases (CVD) and studies in general population are lacking. Methods: The study included 11,153 participants in a population-based, prospective cohort study in Araihazar, Bangladesh. Resting blood pressure was measured at baseline and every two years thereafter. Participants were followed up for an average of 6.5. years (2002-2009). Results: Male gender, older age, baseline systolic blood pressure (SBP), and absence of betel leaf use were independently positively associated with greater SBP variability over time. There was a significant association between SBP variability and the risk of death from overall CVD, especially from major CVD events. The positive association with the risk of death from any cause and stroke in age- and sex-adjusted models was attenuated in fully-adjusted models. In addition, the hazard ratio (HR) of stroke mortality was greater for individuals with both high baseline and high SBP variability. Similar patterns of HRs were observed for all-cause and CVD mortalities. Conclusion: In this rural Bangladeshi population, variability in SBP contributes to the risk of death from CVD and may further potentiate the increased mortality risk associated with high SBP. © 2013 Elsevier Inc.


Melkonian S.,University of Chicago | Argos M.,University of Chicago | Chen Y.,New York University | Parvez F.,Columbia University | And 4 more authors.
Journal of Nutrition | Year: 2012

Risk of skin lesions due to chronic arsenic exposure can be further affected by nutrient intake. We prospectively evaluated the association of nutrient intake and gender with incident skin lesions using data from the Health Effects of Arsenic Longitudinal Study (HEALS) in Araihazar, Bangladesh. Discrete time hazard models were used to estimate these effects in stratified analyses based on skin lesion severity. Overall, we observed significant associations between low intakes of various nutrients (retinol, calcium, fiber, folate, iron, riboflavin, thiamin, and vitamins A, C, and E) and skin lesion incidence, particularly for keratotic skin lesions. Associations for vitamins C and E showed significant linear trends. Gender-specific analyses revealed an inverse association between the lowest quartile of nutrient intake and keratotic skin lesion incidence for retinol equivalents, calcium, folate, iron, and fiber among women. Interactions by gender were observed for retinol equivalents (P-interaction = 0.03), calcium (P-interaction = 0.04), vitamin A (P-interaction = 0.03), and riboflavin (P-interaction = 0.04) with the incidence of keratotic skin lesions. Understanding differential susceptibility to skin lesion incidence based on nutrient intake will help researchers develop targeted interventions to prevent health consequences of arsenic poisoning in Bangladesh and beyond. © 2012 American Society for Nutrition.


Melkonian S.,University of Chicago | Argos M.,University of Chicago | Hall M.N.,Columbia University | Chen Y.,New York University | And 11 more authors.
PLoS ONE | Year: 2013

Background: We utilized data from the Health Effects of Arsenic Longitudinal Study (HEALS) in Araihazar, Bangladesh, to evaluate the association of steamed rice consumption with urinary total arsenic concentration and arsenical skin lesions in the overall study cohort (N=18,470) and in a subset with available urinary arsenic metabolite data (N=4,517). Methods: General linear models with standardized beta coefficients were used to estimate associations between steamed rice consumption and urinary total arsenic concentration and urinary arsenic metabolites. Logistic regression models were used to estimate prevalence odds ratios (ORs) and their 95% confidence intervals (CIs) for the associations between rice intake and prevalent skin lesions at baseline. Discrete time hazard models were used to estimate discrete time (HRs) ratios and their 95% CIs for the associations between rice intake and incident skin lesions. Results: Steamed rice consumption was positively associated with creatinine-adjusted urinary total arsenic (β=0.041, 95% CI: 0.032-0.051) and urinary total arsenic with statistical adjustment for creatinine in the model (β=0.043, 95% CI: 0.032-0.053). Additionally, we observed a significant trend in skin lesion prevalence (P-trend=0.007) and a moderate trend in skin lesion incidence (P-trend=0.07) associated with increased intake of steamed rice. Conclusions: This study suggests that rice intake may be a source of arsenic exposure beyond drinking water. © 2013 Melkonian et al.


Wu F.,New York University | Chen Y.,New York University | Parvez F.,Columbia University | Segers S.,New York University | And 7 more authors.
PLoS ONE | Year: 2013

Background: Limited data are available on smoking-related mortality in low-income countries, where both chronic disease burden and prevalence of smoking are increasing. Methods: Using data on 20, 033 individuals in the Health Effects of Arsenic Longitudinal Study (HEALS) in Bangladesh, we prospectively evaluated the association between tobacco smoking and all-cause, cancer, and cardiovascular disease mortality during ~7.6 years of follow-up. Cox proportional hazards models were used to estimate hazard ratios (HRs) and their 95% confidence intervals (CIs) for deaths from all-cause, cancer, CVD, ischemic heart disease (IHD), and stroke, in relation to status, duration, and intensity of cigarette/bidi and hookah smoking. Results: Among men, cigarette/bidi smoking was positively associated with all-cause (HR 1.40, 95% CI 1.06 1.86) and cancer mortality (HR 2.91, 1.24 6.80), and there was a dose-response relationship between increasing intensity of cigarette/bidi consumption and increasing mortality. An elevated risk of death from ischemic heart disease (HR 1.87, 1.08 3.24) was associated with current cigarette/bidi smoking. Among women, the corresponding HRs were 1.65 (95% CI 1.16 2.36) for all-cause mortality and 2.69 (95% CI 1.20 6.01) for ischemic heart disease mortality. Similar associations were observed for hookah smoking. There was a trend towards reduced risk for the mortality outcomes with older age at onset of cigarette/bidi smoking and increasing years since quitting cigarette/bibi smoking among men. We estimated that cigarette/bidi smoking accounted for about 25.0% of deaths in men and 7.6% in women. Conclusions: Tobacco smoking was responsible for substantial proportion of premature deaths in the Bangladeshi population, especially among men. Stringent measures of tobacco control and cessation are needed to reduce tobacco-related deaths in Bangladesh. © 2013 Wu et al.


Chen Y.,New York University | Wu F.,New York University | Graziano J.H.,Columbia University | Parvez F.,Columbia University | And 13 more authors.
American Journal of Epidemiology | Year: 2013

We conducted a cross-sectional study to evaluate the interrelationships between past arsenic exposure, biomarkers specific for susceptibility to arsenic exposure, and carotid intima-media thickness (cIMT) in 959 subjects from the Health Effects of Arsenic Longitudinal Study in Bangladesh. We measured cIMT levels on average 7.2 years after baseline during 2010-2011. Arsenic exposure was measured in well water at baseline and in urine samples collected at baseline and during follow-up. Every 1-standard-deviation increase in urinary arsenic (357.9 μg/g creatinine) and well-water arsenic (102.0 μg/L) concentration was related to a 11.7-μm (95% confidence interval (CI): 1.8, 21.6) and 5.1-μm (95% CI:-0.2, 10.3) increase in cIMT, respectively. For every 10% increase in monomethylarsonic acid (MMA) percentage, there was an increase of 12.1 μm (95% CI: 0.4, 23.8) in cIMT. Among participants with a higher urinary MMA percentage, a higher ratio of urinary MMA to inorganic arsenic, and a lower ratio of dimethylarsinic acid to MMA, the association between well-water arsenic and cIMT was stronger. The findings indicate an effect of past long-term arsenic exposure on cIMT, which may be potentiated by suboptimal or incomplete arsenic methylation capacity. Future prospective studies are needed to confirm the association between arsenic methylation capacity and atherosclerosis-related outcomes. © 2013 The Author.


Chen Y.,New York University | McClintock T.R.,New York University | Segers S.,New York University | Parvez F.,Columbia University | And 6 more authors.
International Journal of Cardiology | Year: 2013

Background: Dietary pattern analysis is emerging as a practical, effective tool for relating comprehensive dietary intake to risk of cardiovascular disease mortality. However, no studies have applied this technique to a population outside of the developed world. Methods: We conducted prospective cohort analyses in 11,116 participants enrolled in the Health Effects of Arsenic Study in Araihazar, Bangladesh, measuring deaths attributable to disease of circulatory system, heart disease, and cerebrovascular disease. Participants were enrolled in 2000 and followed up for an average of 6.6 years. Dietary information was obtained through a previously validated food-frequency questionnaire at baseline. Results: Principal component analysis based on our comprehensive, 39 item FFQ yielded 3 dietary patterns: (i) a balanced pattern, comprised of steamed rice, red meat, fish, fruit and vegetables; (ii) an animal protein diet, which was more heavily weighted towards eggs, milk, red meat, poultry, bread, and vegetables; and (iii) a gourd and root vegetable diet that heavily relied on a variety of gourds, radishes, pumpkin, sweet potato, and spinach. We observed a positive association between increasing adherence to the animal protein diet and risk of death from both disease of the circulatory system and heart disease; the hazard ratios were 1.13 (95% CI, 1.00-1.28, p = 0.05) and 1.17 (95% CI, 0.99-1.38, p = 0.07), respectively, in relation to one standard deviation increase in the factor scores for the animal protein diet pattern, after controlling for age, sex, body mass index, smoking status, and energy intake. The positive association was more significant among ever smokers; the hazard ratios (95% CI) for deaths from disease of the circulatory system and heart disease were 1.17 (1.02-1.34) and 1.20 (1.00-1.45), respectively, in relation to one standard deviation increase in the factor scores for the animal protein diet pattern. Conclusions: An animal protein-rich diet in rural Bangladesh may increase risk of heart disease mortality, especially among smokers. This emphasizes the need to further explore and address the impact of dietary patterns on cardiovascular disease in populations undergoing epidemiologic transition. © 2012 Elsevier Ireland Ltd.


PubMed | U Chicago Research Bangladesh Ltd., University of Chicago, New York University and Columbia University
Type: Journal Article | Journal: Bulletin of the World Health Organization | Year: 2015

To evaluate the potential effects of betel quid chewing on mortality. (A quid consists of betel nut, wrapped in betel leaves; tobacco is added to the quid by some users).Prospective data were available on 20033 individuals aged 18-75 years, living in Araihazar, Bangladesh. Demographic and exposure data were collected at baseline using a standardized questionnaire. Cause of death was defined by verbal autopsy questionnaires administered to next of kin. We estimated hazard ratios (HR) and their 95% confidence intervals (CI) for associations between betel use and mortality from all causes and from specific causes, using Cox proportional hazards models. We adjusted for age, sex, body mass index, educational attainment and tobacco smoking history.There were 1072 deaths during an average of 10 years of follow-up. Participants who had ever used betel were significantly more likely to die from all causes (HR: 1.26; 95% CI: 1.09-1.44) and cancer (HR: 1.55; 95% CI: 1.09-2.22); but not cardiovascular disease (HR: 1.16; 95% CI: 0.93-1.43). These findings were robust to adjustment for potential confounders. There was a dose-response relationship between mortality from all causes and both the duration and the intensity of betel use. The population attributable fraction for betel use was 14.1% for deaths from all causes and 24.2% for cancer.Betel quid use was associated with mortality from all causes and from cancer in this cohort.


PubMed | UChicago Research Bangladesh Ltd., University of Illinois at Chicago, University of Chicago and Columbia University
Type: Journal Article | Journal: PloS one | Year: 2015

Human fertility is a complex trait determined by gene-environment interactions in which genetic factors represent a significant component. To better understand inter-individual variability in fertility, we performed one of the first genome-wide association studies (GWAS) of common fertility phenotypes, lifetime number of pregnancies and number of children in a developing country population. The fertility phenotype data and DNA samples were obtained at baseline recruitment from individuals participating in a large prospective cohort study in Bangladesh. GWAS analyses of fertility phenotypes were conducted among 1,686 married women. One SNP on chromosome 4 was non-significantly associated with number of children at P <10(-7) and number of pregnancies at P <10(-6). This SNP is located in a region without a gene within 1 Mb. One SNP on chromosome 6 was non-significantly associated with extreme number of children at P <10(-6). The closest gene to this SNP is HDGFL1, a hepatoma-derived growth factor. When we excluded hormonal contraceptive users, a SNP on chromosome 5 was non-significantly associated at P <10(-5) for number of children and number of pregnancies. This SNP is located near C5orf64, an open reading frame, and ZSWIM6, a zinc ion binding gene. We also estimated the heritability of these phenotypes from our genotype data using GCTA (Genome-wide Complex Trait Analysis) for number of children (hg2 = 0.149, SE = 0.24, p-value = 0.265) and number of pregnancies (hg2 = 0.007, SE = 0.22, p-value = 0.487). Our genome-wide association study and heritability estimates of number of pregnancies and number of children in Bangladesh did not confer strong evidence of common variants for parity variation. However, our results suggest that future studies may want to consider the role of 3 notable SNPs in their analysis.

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