Association between hyperuricemia and chronic kidney disease: a cross-sectional study in Bangladeshi adults.

BACKGROUND AND AIMS: Chronic kidney disease (CKD) is a public health concern worldwide and has been recognized as a significant risk factor for cardiovascular disease. The elevated level of uric acid (hyperuricemia) has been suggested to be associated with obesity, hypertension, cardiovascular disease and diabetes. However, there is limited information on the relationship between hyperuricemia and CKD. Therefore, this study aimed to estimate the prevalence of CKD and assess its relationship with hyperuricemia in Bangladeshi adults. METHODS: In this study, blood samples were collected from 545 participants (398 males and 147 females) aged ≥ 18 years. Biochemical parameters such as serum uric acid (SUA), lipid profile markers, glucose, creatinine and urea were measured by colorimetric methods. The estimated glomerular filtration rate (eGFR) and CKD were determined based on serum creatinine levels with existed formula. Multivariate logistic regression analysis was performed to evaluate the association between SUA and CKD. RESULTS: The overall prevalence of CKD was 5.9% with 6.1% in males and 5.2% in females. Hyperuricemia was prevalent in 18.7% of participants with 23.2% in males and 14.6% in females. An increasing trend of CKD prevalence was observed with increasing age in the groups. The mean eGFR level was significantly lower in male (95.1 ± 31.8 ml/min/1.73m2) than in female (109.3 ± 77.4 ml/min/1.73m2) subjects (p < 0.01). The mean level of SUA was significantly higher (p < 0.01) in participants having CKD (7.1 ± 1.9 mg/dL) than in participants without CKD (5.7 ± 1.6 mg/dL). A decreasing trend for eGFR concentration and an increasing trend for CKD prevalence was observed across the SUA quartiles (p < 0.001). In regression analysis, a significant positive association was found between hyperuricemia and CKD. CONCLUSION: This study showed an independent association between hyperuricemia and CKD in Bangladeshi adults. Further mechanistic studies are needed to explore the potential link between hyperuricemia and CKD.

Prevalence of dyslipidemia and its associated factors among university academic staff and students in Bangladesh.

BACKGROUND: Dyslipidemia is one of the important contributors to cardiovascular disease and type 2 diabetes. There is little or no information on dyslipidemia among academic staff and students in Bangladesh. Therefore, this study aimed to investigate the prevalence and factors related to dyslipidemia among university academic staff and students in Bangladesh. METHODS: A total of 533 participants (302 academic staff and 231 students) were enrolled in this cross-sectional study. A simple random sampling technique was used to enrol the participants. Fasting blood samples were obtained from the participants, and serum levels of triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were measured using the standard methods. Dyslipidemia was defined according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP-III) model guideline. Multivariable logistic regression was conducted to identify the factors related to lipid marker abnormalities. RESULTS: Overall, the prevalence of dyslipidemia was 81.5%, of which 85% was in staff and 76.5% in students. A significant difference was found in the prevalence of dyslipidemia between males and females only in the student group (p < 0.01). Among staff, hypertriglyceridemia prevalence was 49.7%, hypercholesterolemia 23%, high LDL-C 24.7% and low HDL-C 77.3%. On the other hand, hypertriglyceridemia prevalence was 39%, hypercholesterolemia 25.6%, high LDL-C 26.5% and low HDL-C 69.3% among students. The most common lipid abnormality was low HDL-C in both groups. The prevalence of mixed dyslipidemia was 14.2% and 14.1% in staff and students, respectively. According to the regression analysis, increased age, obesity, diabetes, and inadequate physical activity were significantly associated with dyslipidemia. CONCLUSIONS: Dyslipidemia was prevalent among the majority of the study participants. Increased age, obesity, diabetes, and inadequate physical activity were significantly associated with dyslipidemia. The study's results highlight the importance of implementing interventions to address the associated risk factors of dyslipidemia among academic staff and students in Bangladesh.

Maternal exposure to multiple mycotoxins and adverse pregnancy outcomes: a prospective cohort study in rural Bangladesh.

There is limited and inconsistent evidence, primarily from cross-sectional studies, linking mycotoxins to adverse birth outcomes. This study investigates the potential role of maternal dietary exposure to multiple mycotoxins in the development of several adverse pregnancy and birth outcomes. We analyzed data from 436 singleton pregnancies enrolled in a prospective cohort study in the rural Habiganj district, Bangladesh, between July 2018 and November 2019. Thirty-five urinary mycotoxin biomarkers were quantified using liquid chromatography coupled with tandem mass spectrometry and used to estimate dietary mycotoxin exposure. Multivariable regression models, adjusted for potential confounding and clustering, were fitted to assess the associations between maternal exposure to frequently occurring mycotoxins (ochratoxin A-OTA, citrinin- CIT, and Deoxynivalenol- DON) and pregnancy loss, preterm birth (PTB), low birth weight (LBW), born small-for-gestational-age (SGA) and small-vulnerable newborn. The results indicate that only in 16 of 436 pregnancies (4%) were urine samples free from all investigated mycotoxins. Biomarkers for six major mycotoxins were detected in the urine samples. OTA (95%), CIT (61%), and DON (6%) were most frequently detected, with at least two mycotoxins co-occurring in the majority of women (63%). There was evidence that maternal dietary intake of OTA was associated with higher odds of having an LBW baby, with the odds increasing in a dose-dependent manner. We found no evidence of associations between pregnancy loss, PTB, SGA, small-vulnerable newborns, and maternal dietary exposure to OTA, CIT, and DON, albeit with large confidence intervals, so findings are consistent with protective as well as large harmful effects. Exposure to multiple mycotoxins during pregnancy is widespread in this rural community and represents a health risk for mothers and babies. Tailored public health policies and interventions must be implemented to reduce mycotoxin exposure to the lowest possible level.

Assessment of multiple mycotoxin exposure and its association with food consumption: a human biomonitoring study in a pregnant cohort in rural Bangladesh.

Aflatoxins (AFs), ochratoxin A (OTA), citrinin (CIT), fumonisin B1 (FB1), zearalenone (ZEN), and deoxynivalenol (DON) are mycotoxins that may contaminate diets, especially in low-income settings, with potentially severe health consequences. This study investigates the exposure of 439 pregnant women in rural Bangladesh to 35 mycotoxins and their corresponding health risks and links their exposure to certain foods and local stimulants. Overall, 447 first-morning urine samples were collected from pregnant women between July 2018 and November 2019. Mycotoxin biomarkers were quantified by DaS-HPLC-MS/MS. Urinary concentration of frequently occurring mycotoxins was used to estimate dietary mycotoxin exposure. Median regression analyses were performed to investigate the association between the consumption of certain foods and local stimulants, and urinary concentration of frequently occurring mycotoxins. Only in 17 of 447 urine samples (4%) were none of the investigated mycotoxins detected. Biomarkers for six major mycotoxins (AFs, CIT, DON, FB1, OTA, and ZEN) were detected in the urine samples. OTA (95%), CIT (61%), and DON (6%) were most frequently detected, with multiple mycotoxins co-occurring in 281/447 (63%) of urine samples. Under the lowest exposure scenario, dietary exposure to OTA, CIT, and DON was of public health concern in 95%, 16%, and 1% of the pregnant women, respectively. Consumption of specific foods and local stimulants-betel nut, betel leaf, and chewing tobacco-were associated with OTA, CIT, and DON urine levels. In conclusion, exposure to multiple mycotoxins during early pregnancy is widespread in this rural community and represents a potential health risk for mothers and their offspring.

Prevalence and risk factors of general and abdominal obesity and hypertension in rural and urban residents in Bangladesh: a cross-sectional study.

BACKGROUND: Obesity and hypertension are global health concerns. Both are linked with increased risks of all-cause and cardiovascular mortality. Several early studies reported the prevalence of obesity and hypertension in Bangladeshi adults, but the associated factors in this country population are not clear yet. We aimed to estimate the prevalence and related risk factors of general and abdominal obesity and hypertension in rural and urban adults in Bangladesh. METHODS: In this cross-sectional study, data (n = 1410) was collected on rural (n = 626) and urban (n = 784) adults from eight divisional regions of Bangladesh. Both anthropometric and socio-demographic measurements were recorded in a standardized questionnaire form. General and abdominal obesity were defined based on WHO proposed cut-off values and hypertension was defined by SBP ≥ 140 mmHg and/or, DBP ≥ 90 mmHg and/or, intake of anti-hypertensive drugs at the time of data collection. Multivariable logistic regression analyses were performed to assess the relationship of general and abdominal obesity and hypertension with various factors. RESULTS: The overall prevalence of general obesity, abdominal obesity and hypertension was 18.2, 41.9 and 30.9%, respectively. The women had a higher prevalence of general obesity (25.2%), abdominal obesity (56.1%) and hypertension (32.3%) compared to the men (12.2, 29.0, and 29.7%, respectively). The prevalence of both general and abdominal obesity was higher in urban participants (21.7 and 46.6%, respectively) than in the rural participants (13.8 and 35.1%, respectively), whereas, the rural participants had a higher prevalence of hypertension (35.1%) compared to the urban participants (27.5%). In geographical region comparison, the prevalence of general and abdominal obesity and hypertension were higher in participants enrolled from Dhaka (30.8%), Khulna (63.6%) and Mymensingh (43.5%) regions, respectively compared to other regions. In regression analysis, increased age, place of residence and less physical activity were positively associated with the increased risk of both types of obesity and hypertension. The analysis also showed a significant positive association between high BMI and an increased risk of hypertension. CONCLUSION: This study shows a high prevalence of obesity and hypertension in rural and urban adults. Increased age, inadequate physical activity and place of residence were significant determinants of general and abdominal obesity and hypertension. A comprehensive intervention program focusing on modifiable risk factors such as lifestyles and food habits is needed to increase awareness and prevent the burden of obesity and hypertension in the Bangladeshi population.

Assessment of the role of zinc in the prevention of COVID-19 infections and mortality: A retrospective study in the Asian and European population.

Several studies have demonstrated an association between individual zinc status and viral respiratory infections; however, evidence regarding COVID-19 is still missing or insufficient. This study aimed to evaluate the correlation between the prevalence of zinc deficiency and COVID-19 cases and deaths per million population in the Asian and European countries. The COVID-19 data from two different time points, that is, May 30 and June 30, 2020 for the Asian population and May 15 and June 15, 2020 for the European population, were analyzed to determine the correlation with the estimated zinc deficiency for these two continents. The prevalence of zinc deficiency was about two times higher in the Asian population (mean 17.5%) than in the European population (mean 8.9%). A significant positive correlation (p < .05) was observed between the prevalence of zinc deficiency and COVID-19 cases at both time periods for the Asian population. However, the correlation between zinc deficiency prevalence and COVID-19 deaths was not significant in the Asian population. In contrast, a significant but negative correlation (p < .05 for all cases) was observed for zinc deficiency with both COVID-19 cases and deaths per million population at both time periods in the European countries. Considering the direct antiviral properties of zinc, it can be suggested that zinc supplementation may be beneficial for most of the population, especially older people and those who are at risk of COVID-19 infections. In conclusion, there is not enough evidence on the association between individual zinc status and COVID-19 infections and mortality. Therefore, cohort studies and randomized controlled trials are required to test this hypothesis.

Association of microalbuminuria with metabolic syndrome: a cross-sectional study in Bangladesh.

BACKGROUND AND AIMS: The objectives of this study were to estimate the prevalence of microalbuminuria and examine the association of microalbuminuria with metabolic syndrome (MetS) and its component in a Bangladeshi adult cohort. METHODS: This cross-sectional study included 175 subjects (84 males and 91 females; aged 19-59 years), recruited from the outdoor Department of Medicine and Endocrinology of a medical college hospital in Dhaka, Bangladesh. Lipid profile and fasting blood glucose (FBG) were measured in serum and albumin and creatinine were determined in urine samples. Microalbuminuria was defined as the urinary albumin-to-creatinine ratio (ACR) of 30 to 300 mg/g. The MetS was defined according to the criteria of the National Cholesterol Education Program (NECP). The association of microalbuminuria with MetS and its components was evaluated by multivariate logistic regression analysis. RESULTS: Among the study subjects, 66.3% were hypertensive and 70.3% were diabetic individuals. Overall, the prevalence of microalbuminuria was 29.7% with 31% in males and 28.6% in females. Microalbuminuria was 2.6 fold higher in hypertensive and diabetic adults than in the non-hypertensive or non-diabetic adults. The prevalence of microalbuminuria was much more frequent in persons with the MetS (36.0%) than the persons without the MetS (5.4%). The levels of FBG, systolic blood pressure (SBP), diastolic blood pressure (DBP) and triglycerides were significantly higher (p < 0.01 for all cases) in subjects with microalbuminuria. In regression analysis, after adjusting for sex, age, and body mass index, microalbuminuria was strongly correlated with MetS followed by elevated BP and FBG (p < 0.01 for all cases). CONCLUSIONS: Microalbuminuria was strongly associated with MetS in Bangladeshi adults. Elevated BP and FBG were the most predominant components of MetS among the study subjects. Comprehensive management of MetS at its early stage can be effective to prevent and reduce the progression of kidney injury and cardiovascular complications.

Association between serum liver enzymes and hypertension: a cross-sectional study in Bangladeshi adults.

BACKGROUND: Hypertension is a major contributing factor to cardiovascular disease and is a leading cause of death in the world. The association between hepatic enzymes and hypertension has been reported in limited studies and the findings are inconsistent; data from Bangladeshi adults are not available yet. This study was conducted to estimate the prevalence of elevated liver enzymes and evaluate the association of elevated liver enzymes with hypertension in Bangladeshi adults. METHODS: In this cross-sectional study, 302 blood samples were collected from adult participants and analyzed the serum concentrations of alanine and aspartate aminotransferase (ALT, AST), alkaline phosphatase (ALP), and γ-glutamyltransferase (GGT) and other markers related to hypertension. Hypertension was defined as resting SBP ≥ 140 mmHg and/or DBP ≥ 90 mmHg. Associations between elevated liver enzymes and hypertension were evaluated by multinomial logistic regression. RESULTS: The mean concentrations of serum ALT, AST and GGT were significantly higher in the hypertensive group compared to the normotensive group (p < 0.01, p < 0.01 and p < 0.001, respectively). Overall, 49.2% of subjects in the hypertensive group and 38.1% of individuals in the normotensive group had at least one or more elevated liver enzymes. The prevalence of elevated ALT, AST, and GGT was significantly higher among participants in the hypertensive group compared to the normotensive group (p < 0.01, p < 0.01 and p < 0.001, respectively). An increasing trend for elevated liver enzymes was observed with increasing blood pressure. Serum ALT and GGT showed an independent relationship with hypertension. CONCLUSIONS: The prevalence of elevated liver enzymes was higher in hypertensive individuals. Increased serum ALT and GGT activities were positively associated with hypertension in Bangladeshi adults.

Determination of aflatoxin M1 and deoxynivalenol biomarkers in infants and children urines from Bangladesh.

The mycotoxins aflatoxin B1 (AFB1) and deoxynivalenol (DON) are found worldwide in crops and dietary staples. The prevalence and levels of these contaminants can vary greatly, and data in Bangladeshi food commodities are scarce. To characterize human exposure, we have conducted biomonitoring, analyzing AFM1 (a metabolite of AFB1) and DON levels in urines of adult cohorts in Bangladesh. Yet, AFM1 and DON occurrence has not been studied in the very young population of this country. Thus, the same methods, HPLC-FD for AFM1 and LC-MS/MS for DON analysis, were now applied to determine these biomarkers in urines of infants (n = 49) and young children (n = 105) in Rajshahi and Dhaka district. Overall, AFM1 and DON detection frequency was 43.5% and 33.4%, with 34.7% and 11.5% in infant and 47.6% and 39.4% in children urines, respectively. The mean AFM1 levels in all infants (9.1 ± 14.3, max 55.6 pg/mL) and children (8.8 ± 12.9, max 75.3 pg/mL) were not significantly different. The AFM1 mean level was slightly higher in Dhaka (9.4 ± 12.4) compared to Rajshahi (8.5 ± 13.9 pg/mL) district. The average DON level was about 2-fold higher in infant (3.8 ± 2.9, max 6.8 ng/mL) than children urines (1.6 ± 1.8, max 8.6 ng/mL), and higher in Rajshahi (2.1 ± 2.3 ng/mL) than Dhaka (1.4 ± 1.6 ng/mL) district. The biomarker-based estimated average daily DON intake (29.6 ± 108.3 ng/kg bw in infants and 36.4 ± 81.8 ng/kg bw in children) or the maximum exposure (560 ng/kg bw) do not exceed the current maximum provisional tolerable daily intake value of 1 µg/kg bw for DON, although DON exposure in infants and children is higher than that of Bangladeshi adults. The AFM1 urine levels in young children are somewhat lower than those found previously in adult cohorts in Bangladesh, but the frequent detection of this biomarker for AFB1 exposure raises further concerns, also for this vulnerable part of the population. Therefore, continuous surveillance for aflatoxins in Bangladeshi food commodities is clearly required, first to identify major sources of intake and then to reduce exposure.

The relationship between serum uric acid and lipid profile in Bangladeshi adults.

BACKGROUND: Although the link between elevated uric acid and metabolic syndrome has been reported in some studies; the relationship of serum uric acid (SUA) with lipid profile has not well studied or little is known so far. This study was conducted to assess the relationship between SUA and lipid profile among the general adults in Bangladesh. METHODS: In total, 280 blood samples were collected from general adult participants (male, n = 150 and female, n = 130) and analyzed for serum lipid profile (TC, TG, HDL and LDL) and SUA levels. The study subjects were divided by quartiles based on SUA levels (Q1: ≤225 µmol/L, Q2: 226-285 µmol/L, Q3: 286-340 µmol/L and Q4: > 340 µmol/L). Linear regression modeling was used to evaluate the relationship between SUA and lipid levels. RESULTS: The prevalence of hyperuricemia was 9.2% in males and 10.4% in females. The mean level of SUA was significantly higher in male (317 ± 90 µmol/L) than in the female (255 ± 65 µmol/L) subjects (p < 0.001). An increasing trend for elevated lipid profile was observed in both gender with increasing levels of SUA in the quartiles (p < 0.05). In regression analysis, a significant positive correlation was found between SUA and TG, TC and LDL (p < 0.01) while an inverse correlation was observed between SUA and HDL (p < 0.01). After adjusting for potential confounders, lipid profile was linearly associated with SUA levels (p < 0.01 for trend). CONCLUSIONS: Present study showed a significant positive relationship for SUA with TG, TC and LDL levels, and an inverse relationship for SUA with HDL. Early prevention of hyperuricemia and dyslipidemia may be helpful to reduce the incidence of associated cardiovascular diseases.

Citrinin biomarkers: a review of recent data and application to human exposure assessment.

The mycotoxin citrinin (CIT) deserves attention due to its known toxic effects in mammalian species and a widespread occurrence in food commodities, often along with ochratoxin A, another nephrotoxic mycotoxin. Human exposure, a key element in assessing risks related to these food contaminants, depends upon mycotoxin levels in food and on food consumption. Yet, data available for CIT levels in food are insufficient for reliable intake estimates. Now biomonitoring, i.e., analysis of parent compound and/or metabolites in human specimen (blood, urine, breast milk), is increasingly used to investigate mycotoxin exposure. Biomonitoring requires sensitive methods for determining biomarkers of exposure, combined with kinetic data to conclude on the absorbed internal dose in an individual. Recent advances in LC-MS/MS-based analytical techniques have facilitated biomonitoring studies on the occurrence of CIT biomarkers in body fluids, mainly in urine samples. This review compiles evidence on human exposure to CIT in different countries, on CIT kinetics in humans, and on biomarker-based CIT intake estimates. Human CIT exposures are discussed in light of an intake value defined as 'level of no concern for nephrotoxicity' by the European Food Safety Agency, and some uncertainties in the toxicological data base. Further studies on CIT, including biomarker-based studies are warranted along with regular food surveys for this mycotoxin to protect consumers against undesirable health effects.

Urinary biomarkers of exposure to the mycoestrogen zearalenone and its modified forms in German adults.

Zearalenone (ZEN), a mycotoxin with estrogenic activity, can exert adverse endocrine effects in mammals and is thus of concern for humans. ZEN is found in cereal crops and grain-based foods, often along with modified ('masked') forms usually not detected in routine contaminant analysis, e.g., ZEN-O-ß-glucosides and ZEN-14-sulfate. These contribute to mycoestrogen exposure, as they are cleaved in the gastrointestinal tract to ZEN, and further metabolized in animals and humans to α- and ß-zearalenol (α-ZEL and ß-ZEL). ZEN and its metabolites are mainly excreted as conjugates in urine, allowing to monitor human exposure by a biomarker-based approach. Here, we report on a new study in German adults (n = 60) where ZEN, α-ZEL, and ß-ZEL were determined by LC-MS/MS analysis after enzymatic hydrolysis and immunoaffinity column clean-up of the aglycones in urines. Biomarkers were detected in all samples: ZEN ranges 0.04-0.28 (mean 0.10 ± 0.05; median 0.07) ng/mL; α-ZEL ranges 0.06-0.45 (mean 0.16 ± 0.07; median 0.13) ng/mL, and ß-ZEL ranges 0.01-0.20 (mean 0.05 ± 0.04; median 0.03) ng/mL. Notably, average urinary levels of α-ZEL, the more potent estrogenic metabolite, are higher than those of ZEN, while ß-ZEL (less estrogenic than ZEN) is found at lower levels than the parent mycotoxin. Similar results were found in ten persons who collected multiple urine samples to gain more insight into temporal fluctuations in ZEN biomarker levels; here some urines had higher maximal concentrations of total ZEN (the sum of ZEN, α-ZEL, and ß-ZEL) with 1.6 and 1.01 ng/mL, i.e., more than those found in the majority of other urines. A preliminary approach to translate the new urinary biomarker data into dietary mycotoxin intake suggests that exposure of most individuals in our cohort is probably below the tolerable daily intake (TDI) of 0.25 µg/kg b.w. set by EFSA as group value for ZEN and its modified forms while that of some individuals exceed it. In conclusion, biomonitoring can help to assess consumer exposure to the estrogenic mycotoxin ZEN and its modified forms and to identify persons at higher risk.

Co-occurrence of citrinin and ochratoxin A in rice in Asia and its implications for human health.

Citrinin (CIT) and ochratoxin A (OTA) are nephrotoxic mycotoxins, produced by several Aspergillus and Penicillium species and their co-occurrence in rice may cause health effects in humans. Rice is an important food crop worldwide and is a major staple food in Asia which may be invaded by CIT and OTA producing fungal spores in the field, during harvest and storage. Humans are exposed to these mycotoxins through ingestion of contaminated rice and other food commodities. Yet, data on the combined presence to these food contaminants are still insufficient to estimate human exposure in Asia. This review describes the prevalence of CIT and OTA in rice in Asia and its implications on human health, which may help in establishing and carrying out proper management strategies against mould development on rice. From the health point of view, combined exposition of CIT and OTA should be a public concern as both are nephrotoxic and long-term exposure can pose detrimental health effects. Thus, it is necessary for local farmers and food factories to implement strict measures and to improve methods for rice preservation during the distribution to consumers, particularly in the markets. Moreover, regular surveys for CIT and OTA occurrence in rice and human biomonitoring are recommended to reduce the health effects in Asian population. © 2017 Society of Chemical Industry.

Hypertension prevalence and influence of basal metabolic rate on blood pressure among adult students in Bangladesh.

BACKGROUND: Hypertension is a global health issue and is currently increasing at rapid pace in South Asian countries including Bangladesh. Although, some studies on hypertension have been conducted in Bangladesh, there is a lack of scientific evidence in the adult student population that was missing from the previous and recent national cross-sectional studies. Moreover, the specific risk factors of hypertension in the Bangladeshi adults still need to be investigated. This study was conducted to estimate hypertension prevalence among adult students in Bangladesh and to test the hypothesis of Luke et al. (Hypertension 43:555-560, 2004) that basal metabolic rate (BMR) and blood pressure are positively associated independent of body size. METHOD: The data was collected on 184 adult university students (118 female and 66 male) in Dhaka, Bangladesh. Anthropometric, BMR details and an average of at least two blood pressure measurements were obtained. Hypertension was defined by a systolic blood pressure (SBP) ≥ 140 mmHg and/or, diastolic blood pressure (DBP) ≥ 90 mmHg. RESULTS: Overall, 6.5% of participants had hypertension with significantly (p < 0.001) higher prevalence in male (12.1%) than in the female (3.4%) students. Age and BMI showed positive and significant correlation with hypertension among the students. When adjusted for body mass index (BMI), as well as other potentially confounding variables such as age, sex, smoking status and degree of urbanization, BMR was positively correlated with SBP and DBP (p < 0.001). Thus, higher BMR is associated with SBP and DBP; this is opposite the well documented inverse relationship between physical activity and blood pressure. If the influence of BMR on blood pressure is confirmed, the systematically elevated BMR might be an important predictor that can explain relatively high blood pressure and hypertension in humans. CONCLUSION: This study reports the prevalence and associated risk factors of hypertension in the Bangladeshi adult students. The study also showed a positive association between BMR and blood pressure among the participants. A large scale longitudinal study across the country is needed to find out the underlying causes of hypertension in the Bangladeshi adults. In addition, comprehensive and integrated intervention programs focusing on modifiable risk factors are recommended to make awareness and prevent hypertension.

Urinary biomarkers of ochratoxin A and citrinin exposure in two Bangladeshi cohorts: follow-up study on regional and seasonal influences.

Biomonitoring studies can provide valuable insights into human mycotoxin exposure, especially when food contaminant data are scarce or unavailable as in Bangladesh. First biomonitoring data in Bangladeshi adults indicated exposure to the nephrotoxic mycotoxins ochratoxin A (OTA) and citrinin (CIT). This led us to conduct a follow-up study with analysis of urinary biomarkers for both CIT and OTA to investigate regional and seasonal influences on mycotoxin exposure in two Bangladeshi cohorts. In total, 164 urines were collected (n = 69 in summer, n = 95 in winter) from residents of a rural and an urban area, among which there were 62 participants enrolled in both sampling periods. Most urines had detectable biomarker levels (OTA, CIT and its metabolite dihydrocitrinone, HO-CIT), with more or less pronounced differences with regard to season and region. In both cohorts, OTA was found at a mean level of 0.06 ± 0.10 ng/mL urine (range 0.01-0.55 ng/mL) in summer and a mean of 0.19 ± 0.38 ng/mL (range 0.01-1.75 ng/mL) in winter season. A season difference was significant in the rural cohort, but not in the urban cohort, and slightly higher mean OTA levels in the rural compared to the urban cohort were only observed in winter urines. CIT biomarkers showed more pronounced variations, with a CIT mean of 0.10 ± 0.17 ng/mL (range 0.02-1.22 ng/mL) and HO-CIT mean of 0.42 ± 0.98 ng/mL (range 0.02-5.39 ng/mL) in summer, and CIT mean of 0.59 ± 0.98 ng/mL (range 0.05-5.03 ng/mL) and HO-CIT mean of 3.18 ± 8.49 ng/mL (range 0.02-46.44 ng/mL) in winter urines of both cohorts. In both seasons, total CIT biomarker concentrations were significantly higher in the rural cohort than in the urban cohort. A provisional daily intake for CIT was calculated and exceeded a preliminary value set by EFSA (0.2 µg/kg/d) in 10 and 24 % of participants in summer and winter, respectively. No significant correlations were found between urinary biomarker levels and intake of certain types of food, except for a positive trend for higher rice consumption. Our results in the Bangladeshi population indicate frequent co-exposure to nephrotoxic mycotoxin food contaminants that vary by season and region.

Occurrence of aflatoxin M1 in urines from rural and urban adult cohorts in Bangladesh.

Aflatoxins are important mycotoxins produced by Aspergillus flavus and A. parasiticus, moulds which contaminate mainly grains and nuts, especially in hot and humid climate. Presence of aflatoxin B1 (AFB1), the most toxic one and a potent hepatocarcinogen, has been reported in food and feed in Bangladesh and raised concerns about mycotoxin exposure in the population. Biomonitoring provides the best approach to assess human exposure from various sources and by all routes. Part of the ingested AFB1 is converted in the body to aflatoxin M1 (AFM1), a metabolite that has served as biomarker of AFB1 exposure, as it is excreted in urine, and thus enables non-invasive sampling, a relevant aspect in field studies. This investigation measured the AFM1 concentration in urines collected from adult residents of a rural (n = 52) and an urban (n = 43) area in the Rajshahi district of Bangladesh. The urinary levels of AFM1 were determined by enzyme-linked immunosorbent assay. AFM1 was detected in 46 % of all urine samples at a range of 31-348 pg/mL. The median and mean concentration of AFM1 in urine was 61 and 80 ± 60 pg/mL, respectively. A significant difference (p < 0.05) was found at the mean level of AFM1 between the rural (99 ± 71 pg/mL) and urban (54 ± 15 pg/mL) cohort. Urinary AFM1 levels did not show significant correlations with food frequency data or age, gender and body mass index of the participants. Among them, the highest mean AFM1 level (101 ± 71 pg/mL) was observed in the 50-60 years age group. In conclusion, detection frequency and urinary AFM1 levels in the Bangladeshi adults support concerns regarding their dietary exposure to AFB1. These first data warrant further biomarker-based studies in children and in cohorts of other parts of the country.

Biomonitoring of Mycotoxins in Urine: Pilot Study in Mill Workers.

Contamination of grains with mycotoxins results in a dietary background exposure of the general population. In occupational settings such as during processing of raw materials as in milling, an additional mycotoxin exposure by inhalation is possible. Biomonitoring is an integrative approach to assess human exposure from various sources and by all routes. To investigate possible workplace exposure to mycotoxins, a pilot study was conducted that compared levels of urinary biomarkers in mill workers to those in a control group with dietary mycotoxin intake alone. Workers (n = 17) from three grain mills in North Rhine Westphalia, Germany, provided spot urines during shift; volunteers (n = 13, IfADo staff) with matched age structure served as control group. The mycotoxins selected for biomarker analysis were citrinin (CIT) deoxynivalenol (DON), ochratoxin A (OTA), and zearalenone (ZEN). Immunoaffinity columns (CIT, DON, ZEN) or liquid-liquid extraction (OTA) was employed for urine sample cleanup prior to targeted analysis by liquid chromatography with tandem mass spectrometry (LC-MS/MS) or by high-performance liquid chromatography (HPLC). In addition, mycotoxin metabolites that may be formed in the organism were analyzed, including deepoxy-deoxynivalenol (DOM-1), ochratoxin alpha (OTα), dihydrocitrinone (DH-CIT), and α- and ß-zearalenol (α- and ß-ZEL), as well as phase II metabolites that were hydrolyzed with ß-glucuronidase/arylsulfatase prior to sample cleanup. All analyte concentrations were adjusted for creatinine (crea) content in the spot urine samples. Citrinin, DON, OTA, and ZEN were detected in nearly all urine samples from mill workers and controls. Interestingly, DH-CIT was found at higher mean levels than the parent compound (~0.14 and 0.045 µg/g crea, respectively), suggesting an effective metabolism of CIT in humans. Other metabolites DOM-1, OTα, and α- and ß-ZEL were detected less frequently in urine. Deoxynivalenol was detected at the highest concentrations (mean ~6 µg/g crea), followed by OTA (mean ~0.08 µg/g crea); ZEN (mean ~0.03 µg/g crea) and its metabolites appeared in urine at lower levels. Mycotoxin biomarker levels in urine from mill workers and controls were not significantly different. From these results it is concluded that biomarker levels measured in urine samples from the two cohorts reflect mainly dietary mycotoxin exposure. An additional occupational (inhalational) exposure of mill workers, if any, is apparently low at the investigated workplaces.

Occurrence of the mycotoxin citrinin and its metabolite dihydrocitrinone in urines of German adults.

As data on food contamination with the mycotoxin citrinin (CIT) are scarce, a recently developed method for biomarker analysis (Blaszkewicz et al. in Arch Toxicol 87:1087-1094, 2013) was applied to investigate CIT exposure of German adults. CIT and its human metabolite dihydrocitrinone (HO-CIT) were determined in urine samples from a group of 50 healthy adults (n = 27 females and n = 23 males). After cleanup by immunoaffinity (CitriTest®) columns, extracts were analyzed by LC-MS/MS. The mycotoxin and its major metabolite HO-CIT were detected in 82 and 84 % of all urine samples, at concentrations ranging from 0.02 (limit of detection, LOD) to 0.08 ng/mL for CIT, and 0.05 (LOD) to 0.51 ng/mL for HO-CIT. Median urine analyte levels in the cohort were 0.03 (CIT) and 0.06 ng/mL (OH-CIT) or adjusted to creatinine 20.2 ng/g crea (CIT) and 60.9 ng/g crea (HO-CIT), respectively. Except for higher urinary CIT levels in males, differences between subgroups were not significant. This first biomarker analysis indicates widespread and variable exposure to CIT in German adults, and conversion of ingested mycotoxin to its less toxic metabolite HO-CIT, which may serve as biomarker of exposure in addition to the parent compound.

Elevated levels of plasma uric acid and its relation to hypertension in arsenic-endemic human individuals in Bangladesh.

Blood uric acid has been recognized as a putative marker for cardiovascular diseases (CVDs). CVDs are the major causes of arsenic-related morbidity and mortality. However, the association of arsenic exposure with plasma uric acid (PUA) levels in relation to CVDs has not yet been explored. This study for the first time demonstrated the associations of arsenic exposure with PUA levels and its relationship with hypertension. A total of 483 subjects, 322 from arsenic-endemic and 161 from non-endemic areas in Bangladesh were recruited as study subjects. Arsenic concentrations in the drinking water, hair and nails of the study subjects were measured by inductively coupled plasma mass spectroscopy. PUA levels were measured using a colorimetric method. We found that PUA levels were significantly (p<0.001) higher in males and females living in arsenic-endemic areas than those in non-endemic area. Arsenic exposure (water, hair and nail arsenic) levels showed significant positive correlations with PUA levels. In multiple regression analyses, arsenic exposure levels were found to be the most significant contributors on PUA levels among the other variables that included age, body mass index, blood urea nitrogen, and smoking. There were dose-response relationships between arsenic exposure and PUA levels. Furthermore, diastolic and systolic blood pressure showed significant positive correlations with PUA levels. Finally, the average PUA levels were significantly higher in the hypertensive group than those in the normotensive group in both males and females living in arsenic-endemic areas. These results suggest that arsenic exposure-related elevation of PUA levels may be implicated in arsenic-induced CVDs.