Asymptomatic Enteric Virus Infections and Association with the Gut Microbiome in Rural Residents of Northern Laos.

Viral gastrointestinal infections are an important public health concern, and the occurrence of asymptomatic enteric virus infections makes it difficult to prevent and control their spread. This study aimed to determine the prevalence of and factors associated with asymptomatic enteric virus infection in adults in northern Laos. Fecal samples were collected from apparently healthy participants who did not report diarrhea or high fever at the time of the survey in northern Laos, and enteric viruses were detected using polymerase chain reaction (PCR) and reverse transcription (RT)-PCR. Individual characteristics, including the gut microbiome, were compared between asymptomatic carriers and noncarriers of each enteric virus. Of the participants (N = 255), 12 (4.7%) were positive for norovirus genogroup I (GI), 8 (3.1%) for human adenovirus, and 1 (0.4%) for norovirus GII; prevalence tended to be higher in less-modernized villages. Gut microbial diversity (evaluated by the number of operational taxonomic units) was higher in asymptomatic carriers of norovirus GI or human adenovirus than in their noncarriers. Gut microbiome compositions differed significantly between asymptomatic carriers and noncarriers of norovirus GI or human adenovirus (permutational analysis of variance, P <0.05). These findings imply an association between asymptomatic enteric virus infection and modernization and/or the gut microbiome in northern Laos.

Transition to a market economy and chronic psychosocial stress in northern Laos: An exploratory study of urinary free cortisol in rural residents.

OBJECTIVES: The indigenous population in northern Laos has experienced a transition from self-sufficiency to a market-oriented economy, which may have brought about unprecedented chronic psychosocial stress. This study examined the association between the transition to a market economy and urinary free cortisol (UFC) concentration as a stress biomarker among rural residents of three villages with different degrees of integration into the market economy. METHODS: An interview survey and urine sample collection were conducted in August 2018 and March 2019. We measured the UFC concentration in spot urine samples collected in the morning from participants aged 20-60 years (n = 168) using an enzyme-linked immunosorbent assay. Multiple linear regression analysis was performed to examine differences in UFC concentrations among villages by sex, with time of arrival for the survey, age, and body mass index included as covariates. RESULTS: The UFC concentration was higher in men living in the village with the highest degree of integration into the market economy than in those in the two villages with a lower dependence on cash, possibly linking increased stress levels with a change in employment type. This trend was not observed in women. CONCLUSION: Socioeconomic changes incidental to a transition to a market economy may increase the stress levels of men in northern Laos.

Corrigendum: Handwashing among caregivers of young children in a protracted and complex refugee and immigration context: a mixed methods study on the Thai-Myanmar border.

[This corrects the article DOI: 10.3389/fpubh.2023.1099831.].

Handwashing among caregivers of young children in a protracted and complex refugee and immigration context: a mixed methods study on the Thai-Myanmar border.

Introduction: Protracted refugee situations create complex contexts that present significant health risks for young children. Effective hand hygiene practices by caregivers can reduce respiratory infections and diarrhoeal disease, the two largest contributors to mortality among children between 1 month and 5 years of age. This study documented handwashing patterns and access to water, sanitation and hygiene (WASH) infrastructure among caregivers of young children living along the Thai-Myanmar border, one of the world's most protracted and complex refugee and immigration contexts. It also examined the association between handwashing and socio-demographic variables and captured participants' explanations for when and how hands are washed. The study broadened the scope of previous research by also including the large number of caregivers living outside formal camps. Methods: Caregivers of children attending 11 preschools in Tak province, Thailand participated in a mixed-methods cross-sectional study. Quantitative questionnaire data (n = 384) were supplemented by a thematic analysis of data from in-depth interviews (n = 9). Results: Fewer than half the caregivers reported routinely washing their hands before preparing meals or after using the latrine/toilet. Fewer than one-in-five routinely used soap in these situations. Interviewees explained that handwashing was only necessary when a substance could be felt or seen, in which case wiping with a cloth or a rinsing with water were sufficient to clean hands. However, their explanations also suggested some potential avenues for culturally appropriate and feasible interventions to improve hand hygiene. Conclusion: The results confirmed previous research on the multi-dimensional barriers to good hand hygiene in protracted refugee situations and other low-resource settings. Additional investment to overcome shortages in the infrastructure necessary to support good hand hygiene and creative means of drawing on and developing human capital will be necessary to realize the potential hand hygiene holds for reducing ill-health and mortality among young children living in these contexts.

Impact of modernization on oxidative stress among indigenous populations in northern Laos.

OBJECTIVES: To explore the impact of modernization on oxidative stress during a momentous health transition process, we investigated differences in oxidative stress among the indigenous populations of villages in northern Laos with different levels of modernization. METHODS: We conducted a cross-sectional study of 380 adults in three villages with different levels of modernization. Three biomarkers related to oxidative stress were measured: urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-isoprostane concentrations (both measured by liquid chromatography-tandem mass spectrometry), and blood telomere length (measured with qPCR). We examined associations between village-level modernization and oxidative stress-related biomarkers in a multilevel analysis including a random effect and covariates. RESULTS: The geometric means of urinary 8-OHdG and 8-isoprostane concentrations were 2.92 and 0.700 µg/g creatinine, respectively, in our study population. Higher urinary 8-OHdG concentrations and shorter telomeres were observed in participants from the more modernized villages, whereas urinary 8-isoprostane concentrations did not differ significantly among villages. CONCLUSIONS: Our findings imply that modernization-induced changes in lifestyle may increase oxidative DNA damage. Baseline levels of oxidative lipid damage are expected to be high in the indigenous populations of northern Laos. Assessments of oxidative stress may provide valuable insights into the mechanisms of health transition in specific populations.

Determinants of oxidative stress among indigenous populations in Northern Laos: Trace element exposures and dietary patterns.

OBJECTIVES: To investigate determinants of oxidative stress in an indigenous population, we examined associations of trace element exposures and dietary patterns with three oxidative stress-related biomarkers among indigenous populations in Northern Laos. METHODS: This cross-sectional study included 341 adults from three villages with different levels of modernization. We used three oxidative stress-related biomarkers: urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-isoprostane concentrations, which were measured using liquid chromatography-tandem mass spectrometry, and blood telomere lengths, which were measured using a quantitative polymerase chain reaction method. We used multilevel analysis to examine associations of urinary arsenic, cadmium, and selenium concentrations, their interaction terms, and wild-plant-food scores (principal component scores calculated from food consumption frequencies) with oxidative stress-related biomarkers. RESULTS: Urinary arsenic and cadmium concentrations were positively associated with urinary 8-isoprostane concentrations. Urinary selenium concentrations were positively associated with urinary 8-OHdG concentrations. Interaction terms ([arsenic or cadmium] × selenium) showed negative associations with urinary 8-OHdG and 8-isoprostane concentrations, respectively. Urinary cadmium concentrations were negatively associated with telomere lengths. Wild-plant-food scores did not exhibit associations with oxidative stress-related biomarkers. CONCLUSION: Our findings imply that exposure to arsenic and cadmium is associated with greater oxidative lipid damage, whereas selenium may attenuate arsenic-induced oxidative DNA damage and cadmium-induced oxidative lipid damage. Cadmium exposure may accelerate telomere attrition. Trace element exposure may be a determinant of oxidative stress among indigenous populations in Northern Laos.

Factors associated with failure to undergo health check-ups in Nagasaki Prefecture, Japan.

Objective: Municipal National Health Insurance (NHI) in Nagasaki Prefecture in Japan struggles with poor attendance of health check-ups, which was only 39.6% in 2018. This study aimed to evaluate factors that encourage healthy behaviors, including opting for health check-ups, and the characteristics of middle-aged and older individuals who did not undergo health check-ups. Materials and Methods: This cross-sectional study, using a self-administered questionnaire, was conducted in August 2020 in three municipalities of Nagasaki Prefecture. In addition to questions regarding sociodemographic information, such as sex, age, educational status, self-rated economic status, and family structure, the questionnaire included questions on daily lifestyle habits such as alcohol intake and exercise, current medical treatment, self-rated health, and information related to health check-ups. Of the 18,710 questionnaires distributed in the three municipalities, 8,756 (46.8%) were collected by the end of December 2020, of which 7,840 were valid for analysis. The compliance rate for health check-ups was obtained from the Public Health and Welfare Bureau of Nagasaki Prefecture. Statistical analyses were performed according to two age groups: 40-59 and 60-74 years. Results: Among the respondents who did not undergo health check-ups in the year prior to this study, "lack of time" and being "too bothersome" were the most popular reasons for not attending health check-ups. "Living alone" and "low self-rated economic status" were negative factors for receiving health check-ups regardless of age group. Conclusions: Vulnerable middle-aged and older persons, such as those living alone and with low economic status, were less likely to undergo health check-ups. Emphasis on home visits by public health nurses may also be needed to increase awareness of individual health conditions, especially for people living alone and those who are socioeconomically disadvantaged.

Association between the dietary inflammatory index and disability in Japanese older people.

OBJECTIVES: To examine the demographic and lifestyle characteristics related to the dietary inflammatory index (DII™) score and to evaluate the association between DII score and disability among older people in Japan. DESIGN: Cross-sectional design. The DII score was calculated from nutrient intake information obtained from a FFQ. Disability was assessed using the Tokyo Metropolitan Institute of Gerontology Index of Competence questionnaire. Overall disability and disability in each component of everyday competence, that is, instrumental activities of daily living (IADL), intellectual activities and social participation, were assessed. Those with a deficit in one or more activities were defined as disabled. SETTING: Five non-urban areas in Japan. PARTICIPANTS: A total of 1642 Japanese older people aged 65 years or older. RESULTS: Women, residents of Oga-shi, and those with a higher education and greater frequency of shopping followed a more anti-inflammatory diet, while those living alone and residents of Minamiawaji-shi had higher dietary inflammation. A pro-inflammatory diet was associated with higher odds of overall disability and disability in each component of competence: overall disability, OR (95 % CI) = 1·26 (1·16, 1·36); IADL disability, OR (95 % CI) = 1·16 (1·07, 1·26); disability in intellectual activities, OR (95 % CI): 1·30 (1·20, 1·40); and disability in social participation, OR (95 % CI) = 1·20 (1·11, 1·29). CONCLUSIONS: Sex, living alone, education, frequency of shopping and area of residence were shown to be determinants of DII score in Japanese older people. DII score was positively associated with disability.

Food store accessibility affects nutritional intake through shopping frequency and food intake in middle-aged to older adults in rural Nagasaki, Japan.

OBJECTIVES: The food environment is an important determinant of dietary and nutritional intake, but studies thus far have reported mixed results. We examined associations between food store accessibility and nutritional intake among middle-aged to older adults in rural Japan using data from a questionnaire survey of national health insurance enrollees. METHODS: The survey was conducted in Nagasaki, Japan, for individuals aged 40-74 years. Direct distances from home and food store density were estimated using a geographic information system (GIS). We focused on protein, vitamin D, and calcium intake for their preventive effects on frailty and sarcopenia. To examine the effects of food store accessibility on nutritional intake, we hypothesized a model with a chain of associations of food store accessibility, shopping frequency, food intake frequency, and nutritional intake. We performed a path analyses to explore the food items to be included in the models, associations between the variables, and fitness of the models. RESULTS: We obtained final models with satisfactory fit indices. The resultant models included significant associations between: 1) accessibility indicators and shopping frequency, 2) shopping frequency and intake frequency for two or four categories of food, and 3) intake frequency and nutritional intake. CONCLUSIONS: The results demonstrated that accessibility to food stores, assessed in terms of direct distance from home and food store density, can affect the intake of protein, vitamin D, and calcium through the effect on shopping frequency and intake frequency of some categories of food items, among middle-aged to older adults in Nagasaki, Japan.

Impact of modernization on urinary concentrations of arsenic, cadmium, lead, and selenium in rural residents of Northern Laos.

OBJECTIVES: The impacts of modernization on toxic heavy metal exposure and essential trace element intake in indigenous populations of subsistence societies are unknown. We assessed urinary trace element concentrations in rural residents of Northern Laos and examined associations with levels of modernization. METHODS: A cross-sectional study was conducted comprising 380 residents of three villages in Northern Laos with different levels of modernization. We surveyed general characteristics and measured the weight and height of 341 participants. Arsenic, cadmium, lead, and selenium concentrations were measured in spot urine samples by inductively coupled plasma mass spectrometry. We examined associations between urinary trace element concentrations and variables related to modernization (village, roofing material, possessions index [total number of possessions], and body mass index [BMI]) using multilevel analyses with household as a random effect, after adjusting for sex, age, and smoking status. RESULTS: Urinary concentrations of arsenic and cadmium were high, while those of lead and selenium were low in comparison to previous reports of populations in non-contaminated regions or without excess/deficiency. We observed associations between urinary trace element concentrations and village-level modernization: lead and selenium concentrations were higher in more modernized villages and cadmium concentration was highest in the least modernized village. Urinary arsenic concentration was not predicted by the modernization level of a village, although we observed significant differences among villages. In addition, urinary selenium concentration was higher in participants inhabiting more modernized houses. CONCLUSION: Modernization of villages may impact toxic heavy metal exposure and selenium intake in rural residents of Northern Laos.

The search for aliens within us: a review of evidence and theory regarding the foetal microbiome.

The microbiome is believed to be established during the birthing process through exposure to the maternal microbiome and immediate external environment. The absence of a microbiome prior to birth is based on the sterile womb hypothesis, which was formulated at the beginning of the 20th century and is supported primarily by the culture-based approach in microbiological studies.Findings of bacterial presence in products of fertilization such as the placenta, amniotic fluid, foetal membranes, and umbilical cord blood in studies using next-generation DNA sequencing technologies began to challenge the sterile nature of the intrauterine environment during gestation. These studies have been mainly criticized by their approach to contamination and inconclusive evidence of viability. The implications of bacterial presence in utero are far reaching in medicine and basic sciences. If commensal bacteria exist in the foetus, antibiotic therapies in pregnancy particularly for asymptomatic cases will need to be re-evaluated. Experimental studies utilizing gnotobiology may also be impacted by a realignment of theory.This review of existing literature aims to provide insight into the existence of bacteria in utero, specifically the foetal microbiome through analysis of experimental evidence and theoretical concepts, and to suggest approaches that may further provide clarity into this inquiry.

Associations between urinary heavy metal concentrations and blood pressure in residents of Asian countries.

BACKGROUND: Previous studies have suggested that exposures to heavy metals (arsenic, cadmium, lead, and selenium) may be associated with differences in blood pressure. However, the findings of these studies have been inconsistent. This study was performed to examine the associations between urinary heavy metal concentrations and blood pressure among residents of four Asian countries (Bangladesh, Indonesia, Nepal, and Vietnam). METHODS: This cross-sectional study examined 1899 adults in four Asian countries. Urinary concentrations of heavy metals were measured by inductively coupled plasma mass spectrometry. A questionnaire survey was administered regarding individual characteristics. Anthropometric measurements (height and weight) were performed. Systolic and diastolic blood pressures were measured after a short rest. Multiple linear regression models were applied to investigate associations between urinary heavy metal concentrations and blood pressure after adjustments for age, sex, and body mass index. RESULTS: The geometric means of the urinary concentrations of arsenic, cadmium, lead, and selenium were 84.6, 0.885, 2.09, and 16.5 µg/g creatinine, respectively. The urinary arsenic concentrations were slightly higher than those typically reported in non-polluted populations, while urinary cadmium, lead, and selenium concentrations were equivalent or slightly lower. The urinary lead concentrations were positively associated with both systolic and diastolic blood pressure, but urinary selenium concentrations were negatively associated with them. CONCLUSIONS: Variations in the urinary concentrations of lead and selenium were associated with blood pressure at low levels of exposure/intake.

Factors Affecting Undernutrition among School Children in Cebu, Philippines.

School children in vulnerable areas continue to be at risk for undernutrition. This study investigated the factors associated with the nutritional status of school children in a rural municipality in Cebu, Philippines. Children aged 6-12 years (n = 327) and their parents were asked to participate. Children's anthropometric measurements were taken in schools, while interviews and measurements of parents were conducted at home. Children's nutritional status was assessed using height-for-age (HAZ) and weight-for-age (WAZ) z scores, while body mass index (BMI) was used for parents. Children's dietary patterns and physical activity, and household characteristics, such as food insecurity, eating practices, water/sanitation/hand washing facilities, and sociodemographic status, were collected. Of 327 school children, 37.3% were stunted, while 35.1% were underweight in this rural community. HAZ and WAZ were negatively associated with household size, and positively associated with household income and parental BMI in multivariate least-squares regression models. Severe food insecurity was negatively associated with WAZ, which suggested that the experiences of severe food insecurity (i.e., not eating for a day) had a significant impact on nutritional status of children.

The influences of low protein diet on the intestinal microbiota of mice.

Recent research suggests that protein deficiency symptoms are influenced by the intestinal microbiota. We investigated the influence of low protein diet on composition of the intestinal microbiota through animal experiments. Specific pathogen-free (SPF) mice were fed one of four diets (3, 6, 9, or 12% protein) for 4 weeks (n = 5 per diet). Mice fed the 3% protein diet showed protein deficiency symptoms such as weight loss and low level of blood urea nitrogen concentration in their serum. The intestinal microbiota of mice in the 3% and 12% protein diet groups at day 0, 7, 14, 21 and 28 were investigated by 16S rRNA gene sequencing, which revealed differences in the microbiota. In the 3% protein diet group, a greater abundance of urease producing bacterial species was detected across the duration of the study. In the 12% diet protein group, increases of abundance of Streptococcaceae and Clostridiales families was detected. These results suggest that protein deficiency may be associated with shifts in intestinal microbiota.

Gut microbiota composition in obese and non-obese adult relatives from the highlands of Papua New Guinea.

Obesity is a condition that results from an imbalance between energy intake and expenditure. Recently, obesity has been linked to differences in the composition of gut microbiota. To examine this association in Papua New Guinea (PNG) highlanders, fecal samples were collected from 18 adults; nine obese participants were paired with their non-obese relative. Amplification of the 16S rRNA gene targeting the V1-V2 region was performed on DNA extracts for each participant, with high-quality sequences selected and used for operational taxonomic unit clustering. The data showed Firmicutes and Bacteroidetes were the two dominant phyla, while at genus level Prevotella was the most dominant genus in all of the samples. Nonetheless, statistical evaluation of potential association between nutritional status and bacterial abundance at both phyla and genus levels showed no significant difference. Further studies, ideally in both rural and urban areas, are needed to evaluate the role of the gut microbiome in the occurrence of obesity in PNG and other resource-limited settings.

Protective role of selenium in the shortening of telomere length in newborns induced by in utero heavy metal exposure.

The effects of toxic heavy metals, such as arsenic (As), cadmium (Cd), and lead (Pb), on telomere length (TL) have been reported previously. Although selenium (Se) is considered as an anti-oxidant which may detoxify the effects, there are no data on whether Se could protect against the TL-shortening effects of heavy metals. Thus, the aim of this study was to evaluate the protective role of Se against heavy metal-induced TL shortening. A birth cohort study was conducted in Myanmar in 2016, including 408 mother-infant pairs. First, pregnant women in the third trimester were interviewed concerning their socioeconomic, and pregnancy and birth characteristics using a pre-validated questionnaire. Maternal spot urine samples were collected after the interview. During the follow-up period (1-3 months), blood samples were collected from the umbilical cord at birth by local health workers. Metal concentrations were measured using inductively coupled plasma mass spectrometry (ICP-MS). TL was measured by quantitative real-time polymerase chain reaction (PCR). Relative TL was calculated as the ratio of telomere genes to single-copy genes. To evaluate the effect of Se on TL shortening, molar ratios were calculated. Linear regression analyses were performed to examine the associations between heavy metals and TL, individually and after adjustment for Se level. The effects of As, Cd, and Pb exposure on TL were smaller after adjustment for the Se level, especially for Pb (unadjusted ß = -0.10; 95% CI: 0.18, -0.01; adjusted ß = -0.03; 95% CI: 0.13, 0.05). On stratifying the data by Se concentration, there was no significant association between Cd or Pb exposure and TL in the high-Se group. Our study indicated a protective effect of Se against the TL shortening induced by heavy metal exposure, where the effect sizes were smaller after adjusting for the Se level, compared to individual metal exposure.

In-utero arsenic exposure and growth of infants from birth to 6 months of age: a prospective cohort study in rural Bangladesh.

Arsenic exposure in postnatal life impacts the growth of children, but little is known about the effect of in-utero arsenic exposure on growth very early in childhood. The aim of this study was to examine the associations between in-utero arsenic exposure and the growth of infants from birth to 6 months of age using monthly follow-up data. A prospective cohort study was conducted in rural areas of Bangladesh with 108 mother-infant pairs. This study identified a negative association between in-utero arsenic exposure and head circumference of infants 1-6 months of age (coefficient = -1.20, 95% confidence interval [CI]: -1.97, -0.42), and the effect was more pronounced in the earlier ages of 1-3 months (coefficient = -0.88, 95% CI: -1.70, -0.05). Because head circumference is considered as a surrogate of brain size, our findings suggest that in-utero arsenic exposure influences brain growth during an important developmental period.

Health Challenges of the Pacific Region: Insights From History, Geography, Social Determinants, Genetics, and the Microbiome.

The Pacific region, also referred to as Oceania, is a geographically widespread region populated by people of diverse cultures and ethnicities. Indigenous people in the region (Melanesians, Polynesians, Micronesians, Papuans, and Indigenous Australians) are over-represented on national, regional, and global scales for the burden of infectious and non-communicable diseases. Although social and environmental factors such as poverty, education, and access to health-care are assumed to be major drivers of this disease burden, there is also developing evidence that genetic and microbiotic factors should also be considered. To date, studies investigating genetic and/or microbiotic links with vulnerabilities to infectious and non-communicable diseases have mostly focused on populations in Europe, Asia, and USA, with uncertain associations for other populations such as indigenous communities in Oceania. Recent developments in personalized medicine have shown that identifying ethnicity-linked genetic vulnerabilities can be important for medical management. Although our understanding of the impacts of the gut microbiome on health is still in the early stages, it is likely that equivalent vulnerabilities will also be identified through the interaction between gut microbiome composition and function with pathogens and the host immune system. As rapid economic, dietary, and cultural changes occur throughout Oceania it becomes increasingly important that further research is conducted within indigenous populations to address the double burden of high rates of infectious diseases and rapidly rising non-communicable diseases so that comprehensive development goals can be planned. In this article, we review the current knowledge on the impact of nutrition, genetics, and the gut microbiome on infectious diseases in indigenous people of the Pacific region.

Arsenic exposure through drinking Water and oxidative stress Status: A cross-sectional study in the Ayeyarwady region, Myanmar.

Arsenic is a well-known toxic heavy metal that is naturally dispersed in groundwater. Whereas arsenic is widely accepted to be involved in oxidative stress damage, little is known about arsenic-induced oxidative damage in relationship to contaminated drinking water as a source. The aim of this study was to determine the association between arsenic exposure through drinking water and oxidative stress status by measuring levels of urinary 8-hydroxydeoxyguanosine (8-OHdG) as a biomarker of oxidative stress damage in a Myanmar population. A questionnaire-based survey and drinking water and urine sampling (n = 198) were performed to assess the association between arsenic exposure and urinary 8-OHdG concentration in the Ayeyarwady Region, Myanmar. Urinary arsenic concentrations were significantly correlated with drinking water arsenic concentrations (Spearman's rho = 0.32, p < 0.001). Multivariate linear regression analysis showed that higher urinary arsenic concentrations were significantly associated with higher 8-OHdG concentrations (coefficient = 0.09, 95% confidence interval, 0.03 - 0.15; p = 0.002). The present study identified that exposure to arsenic through drinking water could induce an increase in the urinary 8-OHdG concentration, reflecting increased oxidative DNA damage. These findings provide evidence that may explain the role of arsenic-induced oxidative stress in the pathophysiology of arsenic-induced diseases including cancers.

Association between short-term exposure to fine particulate matter and daily emergency room visits at a cardiovascular hospital in Dhaka, Bangladesh.

BACKGROUND: It has been suggested that exposure to fine particulate matter (PM2.5) adversely affects cardiovascular health. However, the effect modifications by individual characteristics and season have been less studied in developing countries where PM2.5 levels are high. OBJECTIVES: To estimate the risks of cardiovascular emergency room visits in relation to daily concentrations of PM2.5 and to assess how these associations can be modified by age, sex, and nutritional status of patients and by season. METHODS: The analytic sample was 6774 adults who visited the emergency room at a cardiovascular disease (CVD) hospital in Dhaka throughout one year (n = 364 days). A time-stratified case-crossover design with conditional Poisson regression analysis was used to estimate the relative risks (RRs) and 95% confidence intervals (CIs) of visits while adjusting for temperature. Stratification was performed by gender, age (<65 and ≥65 years), BMI (underweight, normal weight, overweight), and season (dry summer: February to April; wet summer: May to October; dry winter: November to January). RESULTS: The mean concentration of PM2.5 was 86.1 µg/m3. An IQR increase (103 µg/m3) in PM2.5 at lag 3 was significantly associated with a 12% (RR: 1.12; 95% CI: 1.01-1.23) increase in CVD emergency room visits. No evidence of association was found for the other lags. Underweight and overweight patients showed evidence of increased risk at lag 2 (RR: 1.31; 95% CI: 1.02-1.67) and lag 4 (RR: 1.20; 95% CI: 1.04-1.39), respectively. CONCLUSION: Increases in the daily concentrations of PM2.5 may lead to more cardiovascular emergency room visits in Dhaka, Bangladesh. Response times from ambient exposure to CVD emergency visits may differ by season and the nutritional status of susceptible individuals, necessitating further research.