Flexible and Semi-Transparent Silicon Solar Cells as a Power Supply to Smart Contact Lenses.

Supplying electric power to wearable IoT devices, particularly smart contact lenses (SCLs), is one of the main obstacles to widespread adoption and commercialization. In the present study, we have successfully designed, fabricated, and characterized semi-transparent, self-supported, and flexible single crystalline silicon solar cells using a single-sided micromachining procedure. Optical, mechanical, and electrical simulations, together with the practical measurements, verify the application of our developed solar cells to be mounted on a limited-footprint and flexible SCL. The 15 µm-thick silicon solar cells conformally fit on a dome-shaped contact lens (ROC = 8 mm) without any mechanical and electrical degradation. This homojunction photovoltaic device containing an array of micro-holes exhibits a V oc, J sc, and maximum power density of 504 mV, 6.48 mA cm-2, and 1.67 mW cm-2, respectively, at 25% visible light transparency under an AM1.5 one sun condition. Furthermore, the measurements were conducted under low-intensity indoor light conditions and resulted in a maximum power output of 25 and 42 µW cm-2 for the 50 and 25% transparent solar cells, respectively.

Research Participants' Attitudes towards Receiving Information on Genetic Susceptibility to Arsenic Toxicity in Rural Bangladesh.

BACKGROUND: In human genetics research, it has become common practice for researchers to consider returning genetic information to participants who wish to receive it. Research participants in lower-resource settings may have barriers or competing interests that reduce the benefit or relevance of such information. Thus, the decision to return genetic information in these settings may involve special considerations of participants' interests and preferences. In this project, our goal was to assess Bangladeshi research participants' attitudes towards receiving information regarding genetic susceptibility to the effects of consuming arsenic-contaminated drinking water, a serious environmental health concern in Bangladesh and other countries. METHODS: We administered a short questionnaire to 200 individuals participating in the Health Effects of Arsenic Longitudinal Study. Associations between survey responses and participant characteristics were estimated using logistic regression. RESULTS: Overall, 100% of our participants were interested in receiving information regarding their genetic susceptibility to arsenic toxicities, and 91% indicated that being at increased genetic risk would motivate them to make efforts to reduce their exposure. Lower levels of education showed evidence of association with less concern regarding the health effects of arsenic and lower levels of motivation to reduce exposure in response to genetic information. CONCLUSIONS: Research participants in this low-resource setting appeared interested in receiving information on their genetic susceptibility to arsenic toxicity and motivated to reduce exposure in response to such information. Additional research is needed to understand how best to communicate genetic information in this population and to assess the impact of such information on individuals' behaviors and health.

Association between number of children and carotid intima-media thickness in Bangladesh.

Previous studies on the association between number of children and carotid intima-media thickness (cIMT) were limited to Western populations. Pregnancy in women is associated with physiologic changes that may influence the risk of cardiovascular disease. Comparing the association between number of children and cIMT in men and women can provide insights on whether the association may be due to pregnancy. We investigated the association between number of children and cIMT among 718 female (mean age 37.5 years) and 417 male participants (mean age 41.3 years), randomly selected from the Health Effect of Arsenic Longitudinal Study (HEALS), a population-based cohort study in Bangladesh. Multivariate linear regression was used to assess the association and to control for education attainment, history of diabetes, age, smoking, betel use, BMI, systolic blood pressure, and diastolic blood pressure. The average number of children was 4.43 for women and 3.74 for men. There were no nulliparous women. We observed a positive association between number of children and cIMT in women. Mean cIMT increased by 4.5 µm (95% CI, 0.8-8.1) per increment of one birth (P = 0.02). Compared to women with two children, cIMT in women with 4 children and ≥5 children was 23.6µm (95%CI, 2.6-44.7; P = 0.03) and 25.1 µm (95%CI, 3.5-46.6; P = 0.02) greater, respectively. The association was not modified by BMI, SBP, betel use or age. Data in men showed no evidence of association (P = 0.4). The finding suggests a role of high parity in atherosclerosis in women of a low-income, high parity population.

A study of telomere length, arsenic exposure, and arsenic toxicity in a Bangladeshi cohort.

BACKGROUND: Chronic arsenic exposure is associated with increased risk for arsenical skin lesions, cancer, and other adverse health outcomes. One potential mechanism of arsenic toxicity is telomere dysfunction. However, prior epidemiological studies of arsenic exposure, telomere length (TL), and skin lesion are small and cross-sectional. We investigated the associations between arsenic exposure and TL and between baseline TL and incident skin lesion risk among individuals participating in the Health Effects of Arsenic Longitudinal Study in Bangladesh (2000-2009). METHODS: Quantitative PCR was used to measure the average TL of peripheral blood DNA collected at baseline. The association between baseline arsenic exposure (well water and urine) and TL was estimated in a randomly-selected subcohort (n = 1469). A nested case-control study (466 cases and 464 age- and sex-matched controls) was used to estimate the association between baseline TL and incident skin lesion risk (diagnosed < 8 years after baseline). RESULTS: No association was observed between arsenic exposure (water or urine) and TL. Among incident skin lesion cases and matched controls, we observed higher skin lesion risk among individuals with shorter TL (Ptrend = 1.5 × 10-5) with odds ratios of 2.60, 1.59, and 1.10 for the first (shortest), second, and third TL quartiles compared to the fourth (longest). CONCLUSIONS: Arsenic exposure was not associated with TL among Bangladeshi adults, suggesting that leukocyte TL may not reflect a primary mode of action for arsenic's toxicity. However, short TL was associated with increased skin lesion risk, and may be a biomarker of arsenic susceptibility modifying arsenic's effect on skin lesion risk.

Arsenic Exposure from Drinking Water and Urinary Metabolomics: Associations and Long-Term Reproducibility in Bangladesh Adults.

BACKGROUND: Chronic exposure to inorganic arsenic from drinking water has been associated with a host of cancer and noncancer diseases. The application of metabolomics in epidemiologic studies may allow researchers to identify biomarkers associated with arsenic exposure and its health effects. OBJECTIVE: Our goal was to evaluate the long-term reproducibility of urinary metabolites and associations between reproducible metabolites and arsenic exposure. METHODS: We studied samples and data from 112 nonsmoking participants (58 men and 54 women) who were free of any major chronic diseases and who were enrolled in the Health Effects of Arsenic Longitudinal Study (HEALS), a large prospective cohort study in Bangladesh. Using a global gas chromatography-mass spectrometry platform, we measured metabolites in their urine samples, which were collected at baseline and again 2 y apart, and estimated intraclass correlation coefficients (ICCs). Linear regression was used to assess the association between arsenic exposure at baseline and metabolite levels in baseline urine samples. RESULTS: We identified 2,519 molecular features that were present in all 224 urine samples from the 112 participants, of which 301 had an ICC of ≥0.60. Of the 301 molecular features, water arsenic was significantly related to 31 molecular features and urinary arsenic was significantly related to 74 molecular features after adjusting for multiple comparisons. Six metabolites with a confirmed identity were identified from the 82 molecular features that were significantly associated with either water arsenic or urinary arsenic after adjustment for multiple comparisons. CONCLUSIONS: Our study identified urinary metabolites with long-term reproducibility that were associated with arsenic exposure. The data established the feasibility of using metabolomics in future larger studies. https://doi.org/10.1289/EHP1992.

The association between socioeconomic status and subclinical atherosclerosis in a rural Bangladesh population.

BACKGROUND: In Bangladesh, CVD accounts for the majority of non-communicable mortality. The purpose of this study was to determine the role of socioeconomic status (SES) on subclinical atherosclerosis measured as carotid intima-media thickness (IMT) in a rural Bangladesh population. METHODS: Carotid IMT was measured between 2010 and 2011 in 1022 participants (average age 46, 40% male) randomly selected from the Health Effects of Arsenic Longitudinal Study (HEALS), a population-based prospective cohort study based in rural Bangladesh. SES was measured as occupation type, land ownership, educational attainment, and television ownership. RESULTS: Half of the participants received formal education (53%) and under half owned land (48%) and a television (44%). Women were primarily homemakers (95%) and men worked as factory workers (24%), laborers (18%), or in business (55%). In univariate analysis, those owning greater than one acre of land (p=0.03), owning a television (p=0.02), or laborers and business owners compared to factory workers had higher levels of carotid IMT (p<0.01). In multivariate analysis after adjustment for confounders, only men employed in the business sector had elevated carotid IMT compared to factory workers. The association was strongest in older men (58.7µm, 95% CI 17.2-100.0, ≥50years old) compared to younger men (13.7µm, 95% CI -7.8-35.2, <50years old). CONCLUSION: Business sector employment was positively associated with subclinical atherosclerosis after adjustment for confounders. This finding is consistent with evidence from other developing nations suggesting that certain SES factors are independent predictors of CVD.

Dyspnoea as a predictor of cause-specific heart/lung disease mortality in Bangladesh: a prospective cohort study.

BACKGROUND: The spectrum of mortality outcomes by cause in populations with/without dyspnoea has not been determined. The study aimed to evaluate whether dyspnoea, a symptom, predicts cause-specific mortality differences between groups. The hypothesis was that diseases that result in chronic dyspnoea, those originating from the heart and lungs, would preferentially result in heart and lung disease mortality in those with baseline dyspnoea (relative to no dyspnoea) when followed over time. METHODS: A population-based sample of 11 533 Bangladeshis was recruited and followed for 11-12 years and cause-specific mortality evaluated in those with and without baseline dyspnoea. Dyspnoea was ascertained by trained physicians. The cause of death was determined by verbal autopsy. Kaplan-Meier survival curves, the Fine-Gray competing risk hazards model and logistic regression models were used to determine group differences in cause-specific mortality. RESULTS: Compared to those not reporting dyspnoea at baseline, the adjusted HRs were 6.4 (3.8 to 10.7), 9.3 (3.9 to 22.3), 1.8 (1.2 to 2.8), 2.2 (1.0 to 5.1) and 2.8 (1.3 to 6.2) for greater risk of dying from chronic obstructive pulmonary disease (COPD), asthma, heart disease, tuberculosis and lung cancer, respectively. In contrast, there was a similar risk of dying from stroke, cancer (excluding lung), liver disease, accidents and other (miscellaneous causes) between the dyspnoeic and non-dyspnoeic groups. In addition, the HR was 2.1 (1.7 to 2.5) for greater all-cause mortality in those with baseline dyspnoea versus no dyspnoea. CONCLUSIONS: Dyspnoea, ascertained by a single question with binary response, predicts heart and lung disease mortality. Individuals reporting dyspnoea were twofold to ninefold more likely to die of diseases that involve the heart and/or lungs relative to the non-dyspnoeic individuals. Therefore, in those with chronic dyspnoea, workup to look for the five common dyspnoeic diseases resulting in increased mortality (COPD, asthma, heart disease, tuberculosis and lung cancer), all treatable, should reduce mortality and improve the public health.

Betel quid use and mortality in Bangladesh: a cohort study.

OBJECTIVE: 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). METHODS: Prospective data were available on 20 033 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. FINDINGS: 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. CONCLUSION: Betel quid use was associated with mortality from all causes and from cancer in this cohort.

Dipstick proteinuria as a predictor of all-cause and cardiovascular disease mortality in Bangladesh: A prospective cohort study.

OBJECTIVE: Baseline, persistent, incident, and remittent dipstick proteinuria have never been tested as predictors of mortality in an undeveloped country. The goal of this study was to determine which of these four types of proteinuria (if any) predict mortality. METHODS: Baseline data was collected from 2000 to 2002 in Bangladesh from 11,121 adults. Vital status was ascertained over 11-12years. Cox models were used to evaluate proteinuria in relation to all-cause and cardiovascular disease (CVD) mortality. CVD mortality was evaluated only in those with baseline proteinuria. Persistent, remittent, and incident proteinuria were determined at the 2-year exam. RESULTS: Baseline proteinuria of 1+ or greater was significantly associated with all-cause (hazard ratio (HR) 2.87; 95% C.I., 1.71-4.80) and CVD mortality (HR: 3.55; 95% C.I., 1.81-6.95) compared to no proteinuria, adjusted for age, gender, arsenic well water concentration, education, hypertension, BMI, smoking, and diabetes mellitus. Persistent 1+ proteinuria had a stronger risk of death, 3.49 (1.64-7.41)-fold greater, than no proteinuria. Incident 1+ proteinuria had a 1.87 (0.92-3.78)-fold greater mortality over 9-10years. Remittent proteinuria revealed no increased mortality. CONCLUSIONS: Baseline, persistent, and incident dipstick proteinuria were predictors of all-cause mortality with persistent proteinuria having the greatest risk. In developing countries, those with 1+ dipstick proteinuria, particularly if persistent, should be targeted for definitive diagnosis and treatment. The two most common causes of proteinuria to search for are diabetes mellitus and hypertension.

Gene-arsenic interaction in longitudinal changes of blood pressure: Findings from the Health Effects of Arsenic Longitudinal Study (HEALS) in Bangladesh.

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide and mounting evidence indicates that toxicant exposures can profoundly impact on CVD risk. Epidemiologic studies have suggested that arsenic (As) exposure is positively related to increases in blood pressure (BP), a primary CVD risk factor. However, evidence of whether genetic susceptibility can modify the association between As and BP is lacking. In this study, we used mixed effect models adjusted for potential confounders to examine the interaction between As exposure from well water and potential genetic modifiers on longitudinal change in BP over approximately 7years of follow-up in 1137 subjects selected from the Health Effects of Arsenic Longitudinal Study (HEALS) cohort in Bangladesh. Genotyping was conducted for 235 SNPs in 18 genes related to As metabolism, oxidative stress and endothelial function. We observed interactions between 44 SNPs with well water As for one or more BP outcome measures (systolic, diastolic, or pulse pressure (PP)) over the course of follow-up. The interaction between CYBA rs3794624 and well water As on annual PP remained statistically significant after correction for multiple comparisons (FDR-adjusted p for interaction=0.05). Among individuals with the rs3794624 variant genotype, well water As was associated with a 2.23mmHg (95% CI: 1.14-3.32) greater annual increase in PP, while among those with the wild type, well water As was associated with a 0.13mmHg (95% CI: 0.02-0.23) greater annual increase in PP. Our results suggest that genetic variability may contribute to As-associated increases in BP over time.

Association between Arsenic Exposure from Drinking Water and Longitudinal Change in Blood Pressure among HEALS Cohort Participants.

BACKGROUND: Cross-sectional studies have shown associations between arsenic exposure and prevalence of high blood pressure; however, studies examining the relationship of arsenic exposure with longitudinal changes in blood pressure are lacking. METHOD: We evaluated associations of arsenic exposure in relation to longitudinal change in blood pressure in 10,853 participants in the Health Effects of Arsenic Longitudinal Study (HEALS). Arsenic was measured in well water and in urine samples at baseline and in urine samples every 2 years after baseline. Mixed-effect models were used to estimate the association of baseline well and urinary creatinine-adjusted arsenic with annual change in blood pressure during follow-up (median, 6.7 years). RESULT: In the HEALS population, the median water arsenic concentration at baseline was 62 µg/L. Individuals in the highest quartile of baseline water arsenic or urinary creatinine-adjusted arsenic had a greater annual increase in systolic blood pressure compared with those in the reference group (ß = 0.48 mmHg/year; 95% CI: 0.35, 0.61, and ß = 0.43 mmHg/year; 95% CI: 0.29, 0.56 for water arsenic and urinary creatinine-adjusted arsenic, respectively) in fully adjusted models. Likewise, individuals in the highest quartile of baseline arsenic exposure had a greater annual increase in diastolic blood pressure for water arsenic and urinary creatinine-adjusted arsenic, (ß = 0.39 mmHg/year; 95% CI: 0.30, 0.49, and ß = 0.45 mmHg/year; 95% CI: 0.36, 0.55, respectively) compared with those in the lowest quartile. CONCLUSION: Our findings suggest that long-term arsenic exposure may accelerate age-related increases in blood pressure. These findings may help explain associations between arsenic exposure and cardiovascular disease.

Association of major dietary patterns and blood pressure longitudinal change in Bangladesh.

BACKGROUND: Observational studies and clinical trials have shown associations of diet and high blood pressure (BP). However, prospective studies on the association between dietary patterns and longitudinal BP change are lacking, especially in low-income populations. METHOD: We evaluated the association of dietary patterns and food groups with longitudinal change of BP in 10 389 participants in the Health Effects of Arsenic Longitudinal Study, with a median of 6.7 years of follow-up. Dietary information was obtained through a previously validated food-frequency questionnaire. BP was measured at baseline and at each biennial follow-up using the same method. RESULT: Each standard deviation (SD) increase for the 'gourd vegetable' dietary pattern score was related to a slower annual change of 0.08, 0.04, and 0.05 mmHg in SBP, DBP, or pulse pressure, respectively. Each SD increase in the 'balanced' dietary pattern score was related to a decreasing annual change of 0.06 mmHg (P = 0.012) and 0.08 mmHg in SBP and pulse pressure (P < 0.001). On the contrary, one SD increase in 'western' dietary pattern score was related to a greater annual increase of 0.07 (P = 0.005) and 0.05 mmHg in SBP and pulse pressure (P = 0.013). Higher intake of fruits and vegetables was associated with a slower rate of change in annual SBP and pulse pressure, whereas higher meat intake was related to a more rapid increase in annual pulse pressure. CONCLUSION: The findings suggest that dietary patterns play a significant role in the rate of BP change over time in a low-income population.

A prospective study of arm circumference and risk of death in Bangladesh.

BACKGROUND: Epidemiological studies have observed protective effects of mid-upper arm circumference (MUAC) against all-cause mortality mostly in Western populations. However, evidence on cause-specific mortality is limited. METHODS: The sample included 19 575 adults from a population-based cohort study in rural Bangladesh, who were followed up for an average of 7.9 years for mortality. Cox proportional hazards regression was used to evaluate the effect of MUAC, as well as the joint effect of body mass index (BMI) and MUAC, on the risk of death from any cause, cancer and cardiovascular disease (CVD). RESULTS: During 154 664 person-years of follow-up, 744 deaths including 312 deaths due to CVD and 125 deaths due to cancer were observed. There was a linear inverse relationship of MUAC with total and CVD mortality. Each 1-cm increase in MUAC was associated a reduced risk of death from any cause [hazard ratio (HR) = 0.85; 95% confidence interval (C), 0.81-0.89) and CVD (HR = 0.87; 95% CI, 0.80-0.94), after controlling for potential confounders. No apparent relationship between MUAC and the risk of death from cancer was observed. Among individuals with a low BMI (<18.5 kg/m(2)), a MUAC less than 24 cm was associated with increased risk for all-cause (HR = 1.81; 95% CI, 1.52-2.17) and CVD mortality (HR = 1.45; 95% CI, 1.11-1.91). CONCLUSIONS: MUAC may play a critical role on all-cause and CVD mortality in lean Asians.

Association between arsenic exposure from drinking water and hematuria: results from the Health Effects of Arsenic Longitudinal Study.

Arsenic (As) exposure has been associated with both urologic malignancy and renal dysfunction; however, its association with hematuria is unknown. We evaluated the association between drinking water As exposure and hematuria in 7843 men enrolled in the Health Effects of Arsenic Longitudinal Study (HEALS). Cross-sectional analysis of baseline data was conducted with As exposure assessed in both well water and urinary As measurements, while hematuria was measured using urine dipstick. Prospective analyses with Cox proportional regression models were based on urinary As and dipstick measurements obtained biannually since baseline up to six years. At baseline, urinary As was significantly related to prevalence of hematuria (P-trend<0.01), with increasing quintiles of exposure corresponding with respective prevalence odds ratios of 1.00 (reference), 1.29 (95% CI: 1.04-1.59), 1.41 (95% CI: 1.15-1.74), 1.46 (95% CI: 1.19-1.79), and 1.56 (95% CI: 1.27-1.91). Compared to those with relatively little absolute urinary As change during follow-up (-10.40 to 41.17 µg/l), hazard ratios for hematuria were 0.99 (95% CI: 0.80-1.22) and 0.80 (95% CI: 0.65-0.99) for those whose urinary As decreased by >47.49 µg/l and 10.87 to 47.49 µg/l since last visit, respectively, and 1.17 (95% CI: 0.94-1.45) and 1.36 (95% CI: 1.10-1.66) for those with between-visit increases of 10.40 to 41.17 µg/l and >41.17 µg/l, respectively. These data indicate a positive association of As exposure with both prevalence and incidence of dipstick hematuria. This exposure effect appears modifiable by relatively short-term changes in drinking water As.

A prospective study of variability in systolic blood pressure and mortality in a rural Bangladeshi population cohort.

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.

Arsenic exposure and impaired lung function. Findings from a large population-based prospective cohort study.

RATIONALE: Exposure to arsenic through drinking water has been linked to respiratory symptoms, obstructive lung diseases, and mortality from respiratory diseases. Limited evidence for the deleterious effects on lung function exists among individuals exposed to a high dose of arsenic. OBJECTIVES: To determine the deleterious effects on lung function that exist among individuals exposed to a high dose of arsenic. METHODS: In 950 individuals who presented with any respiratory symptom among a population-based cohort of 20,033 adults, we evaluated the association between arsenic exposure, measured by well water and urinary arsenic concentrations measured at baseline, and post-bronchodilator-administered pulmonary function assessed during follow-up. MEASUREMENTS AND MAIN RESULTS: For every one SD increase in baseline water arsenic exposure, we observed a lower level of FEV1 (-46.5 ml; P < 0.0005) and FVC (-53.1 ml; P < 0.01) in regression models adjusted for age, sex, body mass index, smoking, socioeconomic status, betel nut use, and arsenical skin lesions status. Similar inverse relationships were observed between baseline urinary arsenic and FEV1 (-48.3 ml; P < 0.005) and FVC (-55.2 ml; P < 0.01) in adjusted models. Our analyses also demonstrated a dose-related decrease in lung function with increasing levels of baseline water and urinary arsenic. This association remained significant in never-smokers and individuals without skin lesions, and was stronger in male smokers. Among male smokers and individuals with skin lesions, every one SD increase in water arsenic was related to a significant reduction of FEV1 (-74.4 ml, P < 0.01; and -116.1 ml, P < 0.05) and FVC (-72.8 ml, P = 0.02; and -146.9 ml, P = 0.004), respectively. CONCLUSIONS: This large population-based study confirms that arsenic exposure is associated with impaired lung function and the deleterious effect is evident at low- to moderate-dose range.

A prospective study of arsenic exposure, arsenic methylation capacity, and risk of cardiovascular disease in Bangladesh.

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% CI: 1.04, 1.38), and 1.08 (95% CI: 0.90, 1.30), respectively. aHRs for the second and third tertiles of percentage urinary monomethylarsonic acid (MMA%) relative to the lowest tertile, respectively, were 1.27 (95% CI: 0.85, 1.90) and 1.55 (95% CI: 1.08, 2.23) for all CVD, and 1.65 (95% CI: 1.05, 2.60) and 1.61 (95% CI: 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% CI: 0.34, 0.85) and heart disease (aHR = 0.54; 95% CI: 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.

A prospective study of tobacco smoking and mortality in Bangladesh.

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.

Arsenic exposure from drinking water and QT-interval prolongation: results from the Health Effects of Arsenic Longitudinal Study.

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.