Blood manganese and nonalcoholic fatty liver disease: A cohort-based case-control study

Impact of blood lead and manganese levels on metabolic dysfunction-associated steatotic liver disease prevalence: insights from NHANES (2017-2020)

BACKGROUND

The metabolic dysfunction-associated steatotic liver disease (MASLD) paradigm represents a significant departure from the previous nonalcoholic fatty liver disease (NAFLD) framework, offering a non-stigmatizing approach that enhances awareness and accelerates patient understanding. Our primary aim was to investigate the potential relationship between blood lead and manganese exposure and the onset of MASLD.

METHODS

Using data from the National Health and Nutrition Examination Survey (NHANES) database spanning from 2017 to 2020, a cross-sectional study included 4,475 participants was performed to assess the relationship. The statistical analysis used throughout the study included multivariable linear regression and multiple logistic regression models, adjusted for potential confounders to ensure robust and reliable results. We applied a thorough multivariable analysis, examining various factors including age, sex, and ethnicity to enhance the robustness of our findings.

RESULTS

Employing linear regression models in our study, we observed a clear positive correlation between elevated levels of blood lead and manganese and Controlled attenuation parameter (CAP). Additionally, employing multiple logistic regression models for detailed analysis, we noted a significant increase in the likelihood of MASLD with higher levels of blood lead and manganese.

CONCLUSION

The findings of this study strongly suggest a notable correlation between increased levels of blood lead and manganese with both CAP and the presence of MASLD. This study represents a population-based approach, enhancing the generalizability of the findings to the broader U.S.

POPULATION

Association of blood manganese and selenium levels with hepatic steatosis among adolescents: a nationwide cross-sectional analysis

Objective

This study aimed to investigate the association between blood manganese and selenium levels and hepatic steatosis among adolescents, using data from the National Health and Nutrition Examination Survey (NHANES) 2017-2023.

Methods

A cross-sectional analysis was conducted using data from 2,459 adolescents (aged 12-19 years) with complete data on liver ultrasound transient elastography, blood manganese, and selenium levels. Hepatic steatosis was defined as a controlled attenuation parameter (CAP) score of ≥248 dB/m, a measure of liver steatosis, which is a primary characteristic and a less severe stage of hepatic steatosis, assessed by vibration-controlled transient elastography (VCTE). Multivariate logistic regression models were used to assess the associations between blood manganese and selenium levels and hepatic steatosis, while restricted cubic splines (RCS) were employed to examine the dose-response relationships.

Results

The mean age of the participants was 15.37 years, with 52.22% boy. Higher blood manganese and selenium levels were significantly associated with an increased prevalence of hepatic steatosis. In the fully adjusted model, adolescents in the highest quartile of blood manganese had more than twice the odds of hepatic steatosis compared to those in the lowest quartile (OR = 2.41, 95% CI: 1.55-3.75, P < 0.01). Similarly, the highest quartile of blood selenium was associated with a 57% increase in hepatic steatosis prevalence compared to the lowest quartile (OR = 1.57, 95% CI: 1.19-2.08, P < 0.01). RCS analysis confirmed a linear association between both blood manganese and selenium levels and hepatic steatosis prevalence. Subgroup analyses did not reveal statistically significant interactions by age, sex, or obesity status, although associations appeared stronger in younger adolescents.

Conclusion

Elevated blood manganese and selenium levels are associated with a higher prevalence of hepatic steatosis in adolescents. These findings suggest a potential role of trace elements in the development of hepatic steatosis, highlighting the need for further research to better understand the underlying mechanisms involved in liver fat accumulation in this population.

Role of ginsenoside Rg1 as a PPAR-γ activator in protecting against manganese-induced hepatotoxicity: Insights into the TLR4/MyD88/MAPK signaling pathway

This study investigates the protective effect of ginsenoside Rg1 against manganese (Mn)-induced hepatotoxicity, highlighting its role as a PPAR-γ activator and its impact on TLR4/MyD88/MAPK pathway. Manganese induces liver damage through mechanisms involving oxidative stress and inflammation. Rg1, a principal bioactive compound of ginseng, significantly alleviates Mn-induced liver injury. Rg1 markedly enhances the activities of SOD, GSH, and CAT, while reducing levels of MDA and ROS, indicating an improvement in antioxidant defense capacity. Furthermore, Rg1 decreases inflammatory markers iNOS, TNF-α, IL-6, IL-12 and NO levels, underscoring its strong anti-inflammatory effects. Importantly, as a PPAR-γ activator, Rg1 upregulates PPAR-γ expression, subsequently inhibiting TLR4/MyD88/MAPK pathway. Additionally, silencing of PPAR-γ diminishes the protective effects of Rg1, while overexpression of PPAR-γ enhances them. The findings conclude that Rg1 exerts significant hepatoprotective effects against manganese-induced damage by activating PPAR-γ and modulating TLR4/MyD88/MAPK pathway, positioning it as a promising candidate for the treatment of Mn-induced hepatotoxicity.

Association between multiple metals exposure and metabolic dysfunction-associated fatty liver disease among Chinese adults

BACKGROUND

Previous research has investigated the hepatotoxicity of single metal exposure. However, there is limited evidence about metal mixture and their association with metabolic dysfunction-associated fatty liver disease (MAFLD), particularly in the Chinese population.

OBJECTIVE

To investigate the individual and combine effects of 20 metals on MAFLD in a large population in China.

METHODS

This study included 3651 participants from the Medical Physical Examination Center of Tongji Hospital, Wuhan, China. MAFLD was identified based on ultrasonic graphic evidence of hepatic steatosis and the presence of overweight/obese, diabetes mellitus, or metabolic dysregulation. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine urinary concentrations of 20 metals. Logistic regression was used to assess the relationship between individual metal and MAFLD, with results presented as odds ratios (ORs) and 95 % confidence intervals (CIs). Weighted quantile sum (WQS) regression was performed to evaluate the combine effect of metals.

RESULTS

The prevalence of MAFLD among the participants was 32.1 % (1173/3651). In singe-metal analysis, high exposure to zinc (OR =1.42; 95 % CI = 1.27, 1.59) and selenium (OR = 1.23; 95 % CI = 1.10, 1.39) were positively associated with MAFLD. No significant association was found for other metals. WQS regression analysis showed that urinary metal mixture was positively associated with MAFLD (OR = 1.32, 95 % CI: 1.15, 1.51), with zinc (50.4 %) being the largest contributor, followed by barium (10.8 %).

CONCLUSIONS

In conclusion, our finding suggested that exposure to the mixture of metals was positively correlated with MAFLD, with zinc being the major contributor.

Machine learning uncovers manganese as a key nutrient associated with reduced risk of steatotic liver disease

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) affects approximately 20%-30% of the general population and is linked to high-caloric western style diet. However, there are little data that specific nutrients might help to prevent steatosis.

METHODS

We analysed the UK Biobank (ID 71300) 24 h-nutritional assessments and investigated the association between nutrient intake calculated from food questionnaires and hepatic steatosis indicated by imaging or ICD10-coding. The effect of manganese (Mn) on subgroups with risk single nucleotide polymorphism carriage as well as the effect on metabolomics was investigated. All analyses are corrected for age, sex, body mass index, Townsend index for socioeconomic status, kcal, alcohol, protein intake, fat intake, carbohydrate intake, energy from beverages, diabetes, physical activity and for multiple testing.

RESULTS

We used a random forest classifier to analyse the feature importance of 63 nutrients and imaging-proven steatosis in a cohort of over 25 000 UK Biobank participants. Increased dietary Mn intake was associated with a lower likelihood of MRI-diagnosed steatosis. Subsequently, we conducted a cohort study in over 200 000 UK Biobank participants to explore the relationship between Mn intake and hepatic or cardiometabolic outcomes and found that higher Mn intake was associated with a lower risk of ICD-10 coded steatosis (OR = .889 [.838-.943], p < .001), independent of other potential confounders.

CONCLUSION

Our study provides evidence that higher Mn intake may be associated with lower odds of steatosis in a large population-based sample. These findings underline the potential role of Mn in the prevention of steatosis, but further research is needed to confirm these findings and to elucidate the underlying mechanisms.

Serum macroelements and microelements levels in periparturient dairy cows in relation to fatty liver diseases

BACKGROUND

Fatty liver in dairy cows is a common metabolic disease defined by triglyceride (TG) buildup in the hepatocyte. Clinical diagnosis of fatty liver is usually done by liver biopsy, causing considerable economic losses in the dairy industry owing to the lack of more effective diagnostic methods. Therefore, this study aimed to investigate the potential utility of blood biomarkers for the diagnosis and early warning of fatty liver in dairy cows.

RESULTS

A total of twenty-four lactating cows within 28 days after parturition were randomly selected as experimental animals and divided into healthy cows (liver biopsy tested, n = 12) and cows with fatty liver (liver biopsy tested, n = 12). Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the macroelements and microelements in the serum of two groups of cows. Compared to healthy cows (C), concentrations of calcium (Ca), potassium (K), magnesium (Mg), strontium (Sr), selenium (Se), manganese (Mn), boron (B) and molybdenum (Mo) were lower and copper (Cu) was higher in fatty liver cows (F). Meanwhile, the observed differences in macroelements and microelements were related to delivery time, with the greatest major disparity between C and F occurring 7 days after delivery. Multivariable analysis was used to test the correlation between nine serum macroelements, microelements and fatty liver. Based on variable importance projection and receiver operating characteristic (ROC) curve analysis, minerals Ca, Se, K, B and Mo were screened as the best diagnostic indicators of fatty liver in postpartum cows.

CONCLUSIONS

Our data suggested that serum levels of Ca, K, Mg, Se, B, Mo, Mn, and Sr were lower in F than in C. The most suitable period for an early-warning identification of fatty liver in cows was 7 days after delivery, and Ca, Se, K, B and Mo were the best diagnostic indicators of fatty liver in postpartum cows.

Joint and interactive effects of metal mixtures on liver damage: Epidemiological evidence from repeated-measures study

BACKGROUND

The impact of heavy metals on liver function has been examined in numerous epidemiological studies. However, these findings lack consistency and longitudinal validation.

METHODS

In this study, we conducted three follow-up surveys with 426 participants from Northeast China. Blood and urine samples were collected, along with questionnaire information. Urine samples were analyzed for concentrations of four metals (chromium [Cr], cadmium [Cd], lead [Pb], and manganese [Mn]), while blood samples were used to measure five liver function indicators (alanine aminotransferase [ALT], aspartate aminotransferase [AST], albumin [ALB], globulin [GLB], and total protein [TP]). We utilized a linear mixed-effects model (LME) to explore the association between individual heavy metal exposure and liver function. Joint effects of metal mixtures were investigated using quantile g-computation and Bayesian kernel machine regression (BKMR). Furthermore, we employed BKMR and Marginal Effect models to examine the interaction effects between metals on liver function.

RESULTS

The LME results demonstrated a significant association between urinary heavy metals (Cr, Cd, Pb, and Mn) and liver function markers. BKMR results indicated positive associations between heavy metal mixtures and ALT, AST, and GLB, and negative associations with ALB and TP, which were consistent with the g-comp results. Synergistic effects were observed between Cd-Cr on ALT, Mn-Cr and Cr-Pb on ALB, while an antagonistic effect was found between Mn-Pb and Mn-Cd on ALB. Additionally, synergistic effects were observed between Mn-Cr on GLB and Cd-Cr on TP. Furthermore, a three-way antagonistic effect of Mn-Pb-Cr on ALB was identified.

CONCLUSION

Exposure to heavy metals (Cr, Cd, Mn, Pb) is associated with liver function markers, potentially leading to liver damage. Moreover, there are joint and interaction effects among these metals, which warrant further investigation at both the population and mechanistic levels.

Association between blood heavy metal exposure levels and risk of metabolic dysfunction associated fatty liver disease in adults: 2015-2020 NHANES large cross-sectional study

Background

The relationships between heavy metals and fatty liver, especially the threshold values, have not been fully elucidated. The objective of this research was to further investigate the correlation between blood heavy metal exposures and the risk of Metabolic dysfunction Associated Fatty Liver Disease (MAFLD) in adults.

Methods

Laboratory data on blood metal exposure levels were obtained from National Health and Nutrition Examination Survey (NHANES) data for the period 2015 to 2020 for a cross-sectional study in adults. Associations between blood levels of common heavy metals and the risk of MAFLD in adults were analyzed using multifactorial logistic regression and ranked for heavy metal importance using a random forest model. Finally, thresholds for important heavy metals were calculated using piecewise linear regression model.

Results

In a multifactorial logistic regression model, we found that elevated levels of selenium (Se) and manganese (Mn) blood exposure were strongly associated with the risk of MAFLD in adults. The random forest model importance ranking also found that Se and Mn blood exposure levels were in the top two positions of importance for the risk of disease in adults. The restricted cubic spline suggested a non-linear relationship between Se and Mn blood exposure and adult risk of disease. The OR (95% CI) for MAFLD prevalence was 3.936 (2.631-5.887) for every 1 unit increase in Log Mn until serum Mn levels rose to the turning point (Log Mn = 1.10, Mn = 12.61 μg/L). This correlation was not significant (p > 0.05) after serum Mn levels rose to the turning point. A similar phenomenon was observed for serum Se levels, with a turning point of (Log Se = 2.30, Se = 199.55 μg/L).

Conclusion

Blood heavy metals, especially Se and Mn, are significantly associated with MAFLD in adults. They have a non-linear relationship with a clear threshold.

Blood manganese and non-alcoholic fatty liver disease in a high manganese exposure area in China

BACKGROUND AND AIMS

Manganese (Mn) deficiency and intoxication may affect nonalcoholic fatty liver disease (NAFLD) risk differently. We aimed to explore the association between blood Mn and NAFLD in an area with high Mn exposure in drinking water.

METHODS

We conducted a case-control study among 1407 patients with NAFLD and 1774 sex- and age-matched healthy controls in a physical examination population in Zhoushan hospital, Zhejiang province in China. We used the restricted cubic splines method to investigate the dose-response relationship. Logistic regression models were applied to determine the risk of NAFLD, and severity of NAFLD.

RESULTS

The blood Mn concentration was higher in the NAFLD group than in the control group in women (16.1 ± 6.2 μg/L vs. 14.7 ± 6.4 μg/L, P = 0.022) and men (14.5 ± 6.3 μg/L vs. 13.6 ± 6.8 μg/L, P < 0.001). We found an inverted L shape relationship between blood Mn and NAFLD in both women and men. Compared to the lowest quartile, the adjusted odds ratio (OR) and 95% confidence interval (CI) of NAFLD for the highest quartile group was 1.646(1.222,2.217), 1.494(1.082,2.061), and 3.146(1.285,7.701) for the total population, men, and women. The positive relationship was only observed in those with fibrosis-4 score < 1.30 and normal alanine transaminase. Stratified analysis showed an interaction between smoking (P = 0.073), alcohol drinking (P = 0.013), and Mn, with a more prominent effect on the NAFLD in the never-smokers (OR = 2.153, 95% CI 1.408-3.290) and drinkers (OR = 2.596, 95% CI 1.608-4.191).

CONCLUSION

Higher blood Mn is associated with an elevated NAFLD risk in the high Mn exposure areas, especially in nonsmokers and drinkers. Further studies are needed to verify this result in the areas with high Mn exposure.

Essential metal mixtures exposure and NAFLD: A cohort-based case-control study in northern Chinese male adults

Epidemiologic evidence on metal mixtures and non-alcoholic fatty liver disease (NAFLD) is limited. We aimed to assess the relationship between multiple metal co-exposure and NAFLD among male adults in Northern China. We conducted a cohort-based case-control study with 648 NAFLD and 648 non-NAFLD males. Seven metal concentrations (calcium, copper, iron, magnesium, manganese, selenium, and zinc) were determined in the blood. We used logistic regression and restricted cubic splines (RCS) to estimate the associations between the single metal and NAFLD. The impact of metal mixtures was quantified by the environmental risk score (ERS) in the adaptive elastic-net regression, and the association with NAFLD was estimated by logistic regression. Age-adjusted RCS showed linear relationships between blood calcium, selenium, and NAFLD. Blood copper, iron, magnesium, and manganese were non-linearly associated with NAFLD. Single metal analysis observed significant relationships between calcium, copper, manganese, and NAFLD, with the adjusted odds ratio (95% confidence interval) for quartile 1 vs. quartile 4 of 1.99 (1.30, 3.05), 2.36 (1.52, 3.64), and 1.77 (1.22, 2.55), respectively. However, metal mixtures analysis revealed one squared term (copper [β = -0.146]) and five metal-metal interactions (calcium × copper [β = 0.200], copper × magnesium [β = 0.188], copper × selenium [β = 0.188], iron × magnesium [β = 0.143], magnesium × selenium [β = -0.297]) except the three main effects. Higher ERS indicated a higher risk for NAFLD when exposed to metal mixtures, with an adjusted odds ratio = 6.50 (95% confidence interval: 4.36-9.69) for quartile 4 vs. quartile 1. Mediation analysis suggested that 11.66% of the effect of ERS on NAFLD was suppressed by fasting blood glucose. Our results show that exposure to metal mixtures is associated with a higher risk for NAFLD than the single metal. Interactions between metals suggest the importance of balancing the various metals for health benefits. Prospective cohorts and mechanism studies need to confirm the findings.

Association of blood manganese concentrations with 24-h based brachial and central blood pressure, and pulse-wave velocity

Potential environmental determinants of BP and hypertension in older adults are far less known than their lifestyle risk factors. Manganese (Mn) is an essential element for life that may induce changes in blood pressure (BP), but the direction of the association is unclear. We aimed to examine the association of blood manganese (bMn) with 24-h-based brachial, central BP (cBP), and pulse-wave velocity (PWV). With this purpose, we analyzed data from 1009 community-living adults aged >65 years without BP medication. bMn was measured using inductively-coupled plasma-mass spectrometry and 24-h BP with validated devices. The association of bMn (median: 6.77 μg/L; IQR: 5.59-8.27) with daytime brachial and central systolic (SBP) and with diastolic BP (DBP) was non-linear, with BP increases up to around the median of Mn and then stabilization or slight rightward decrease. Mean BP differences (95% confidence interval) comparing Mn Q2 to Q5 (vs Q1 quintile) for brachial daytime SBP were 2.56 (0.22; 4.90), 3.59 (1.22; 5.96), 3.14 (0.77; 5.51) and 1.72 (-0.68; 4.11) mmHg, respectively; and 2.22 (0.70, 3.73), 2.55 (1.01, 4.08), 2.45 (0.91; 3.98), and 1.68 (0.13; 3.24), respectively, for DBP. Daytime central-pressures showed a similar dose-response relationship with bMn as daytime brachial-pressures. The association with nighttime BP was linearly positive for brachial BPs, and only increasing for Q5 for cBP. Regarding PWV, a tendency to significant linear increase along bMn levels was observed (p-trend = 0.042). The present findings extend the scarce evidence on the association between Mn and brachial BP to 2 other vascular parameters, suggesting Mn levels as a candidate risk factor for increasing levels of both brachial and cBPs in older adults, yet further research is needed with larger cohort studies in adults at all age ranges.

Associations of metals and metals mixture with lipid profiles: A repeated-measures study of older adults in Beijing

Metals inevitably and easily enter into human bodies and can induce a series of pathophysiological changes, such as oxidative stress damage and lipid peroxidation, which then may further induce dyslipidemia. However, the effects of metals and metals mixture on the lipid profiles are still unclear, especially in older adults. A three-visits repeated measurement of 201 older adults in Beijing was conducted from November 2016 to January 2018. Linear Mixed Effects models and Bayesian kernel machine regression models were used to estimate associations of eight blood metals and metals mixture with lipid profiles, including total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), Castelli risk indexes I (CRI-1), Castelli risk indexes II (CRI-2), atherogenic coefficient (AC), and non-HDL cholesterol (NHC). Cesium (Cs) was positively associated with TG (β_Cs = 0.14; 95% CI: 0.02, 0.26) whereas copper (Cu) was inversely related to TG (β_Cu = -0.65; 95%CI: -1.14, -0.17) in adjusted models. Manganese (Mn) was mainly related to higher HDL-C (β_Mn = 0.14; 95% CI: 0.07, 0.21) whereas molybdenum showed opposite association. Metals mixture was marginally positive associated with HDL-C, among which Mn played a crucial role. Our findings suggest that the effects of single metal on lipid profiles may be counteracted in mixtures in the context of multiple metal exposures; however, future studies with large sample size are still needed to focus on the detrimental effects of single metals on lipid profiles as well as to identify key components.

Blood and urine manganese exposure in non-alcoholic fatty liver disease and advanced liver fibrosis: an observational study

Manganese was the key activator of biological enzymes-mediated metabolic diseases (Mets)-associated pathophysiological process. Non-alcoholic fatty liver disease (NAFLD), which was the hepatic manifestation of Mets, development remained a mystery. We aimed to explore the association between blood/urine manganese exposure and NAFLD and liver fibrosis diagnosed by vibration-controlled transient elastography (VCTE). All data were extracted from National Health and Nutrition Examination Survey database (2017-2018). A total of 3580 participants with blood manganese data were enrolled and divided into four groups according to the quartile of blood manganese exposure level. In multiple logistic regression models, the higher blood manganese exposure level (groups 2, 3, and 4) had a significant positive association with NAFLD (β = 1.58, 1.30, and 1.69). In subgroup analysis, the main inversely correlation between blood manganese and NAFLD was found in participants with normal/high body mass index and high blood manganese exposure level. Moreover, in 1179 participants with urine manganese data, urine manganese exposure level presented as significantly associated with advanced liver fibrosis in models 1 and 2 (β = 2.00 and 2.02). This study showed that manganese exposure level was positively associated with NAFLD and advanced liver fibrosis among the US population. We suggested that manganese exposure level was a biomarker of the development of NAFLD.

Recent advances in the application of ionomics in metabolic diseases

Trace elements and minerals play a significant role in human health and diseases. In recent years, ionomics has been rapidly and widely applied to explore the distribution, regulation, and crosstalk of different elements in various physiological and pathological processes. On the basis of multi-elemental analytical techniques and bioinformatics methods, it is possible to elucidate the relationship between the metabolism and homeostasis of diverse elements and common diseases. The current review aims to provide an overview of recent advances in the application of ionomics in metabolic disease research. We mainly focuses on the studies about ionomic or multi-elemental profiling of different biological samples for several major types of metabolic diseases, such as diabetes mellitus, obesity, and metabolic syndrome, which reveal distinct and dynamic patterns of ion contents and their potential benefits in the detection and prognosis of these illnesses. Accumulation of copper, selenium, and environmental toxic metals as well as deficiency of zinc and magnesium appear to be the most significant risk factors for the majority of metabolic diseases, suggesting that imbalance of these elements may be involved in the pathogenesis of these diseases. Moreover, each type of metabolic diseases has shown a relatively unique distribution of ions in biofluids and hair/nails from patients, which might serve as potential indicators for the respective disease. Overall, ionomics not only improves our understanding of the association between elemental dyshomeostasis and the development of metabolic disease but also assists in the identification of new potential diagnostic and prognostic markers in translational medicine.

Association between urine metals and liver function biomarkers in Northeast China: A cross-sectional study

BACKGROUND

After heavy metals enter the body, they affect a variety of organs, particularly the main metabolic organ, the liver. Moreover, people are more likely to be exposed to multiple metals than to a single metal. We explored the associations between exposure to a heavy metal mixture and liver function biomarkers.

METHODS

This study involved 1171 residents living in areas with or without heavy metal exposure in northeast China. Urine concentrations of chromium (Cr), cadmium (Cd), lead (Pb), and manganese (Mn) were measured. Total protein (TP), albumin (ALB), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were used as biomarkers of liver function. A generalized linear model (GLM), quantile g-computation, and Bayesian kernel machine regression (BKMR) were used to explore the associations between the four metals and liver function.

RESULTS

GLM analysis revealed that Cr level was negatively associated with TP (β = - 0.57; 95% CI: - 0.89, - 0.26) and ALB (β = - 0.27; 95% CI: - 0.47, - 0.07) levels, and Cd level was positively associated with AST (β = 1.04; 95% CI: 0.43, 1.65) and ALT (β = 0.94; 95% CI: 0.08, 1.79) levels. ALB (β = 0.26; 95% CI: 0.10, 0.41) and ALT (β = 0.52; 95% CI: 0.02, 1.02) levels were positively associated with urine Mn concentration. The quantile g-computation indicated that exposure to a mixture of the four metals was significantly associated with TP (β = - 0.56; 95% CI: - 0.94, - 0.18) and ALT (β = 0.84; 95% CI: 0.04, 1.63) levels. Among the metals, Cr had the strongest effect on TP and Cd had that on AST. The BKMR model indicated that mixed metal exposure was negatively associated with TP and ALB levels and positively associated with ALT and AST levels.

CONCLUSION

Exposure to mixtures of heavy metals may influence liver function. Cr and Cd may be the largest contributors.