Perfluoroalkyl substances and lipid concentrations in the blood: A systematic review of epidemiological studies

Association between PFAS exposure and metabolic-related biomarkers in Spanish adolescents

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) exert endocrine disruptive effects on the endocrine-metabolic axis. Emerging knowledge suggests that kisspeptin may play a key role in these effects.

OBJECTIVE

To assess the cross-sectional association of blood PFAS concentrations with kisspeptin levels, KISS1 gene DNA methylation, and metabolic-related biomarkers in adolescent males from the Spanish INMA-Granada cohort.

METHODS

Seven PFAS and twelve biomarkers (glucose-GLU, total cholesterol-TC, triglycerides, LDL, HDL, ALP, AST, ALT, GGT, total bilirubin-BILT, direct bilirubin-BILD, and urea) were measured in plasma and serum, respectively, from 129 adolescent males (15-17 yrs). Systolic and diastolic blood pressure (SBP, DBP), pulse, z-scored body mass index, kisspeptin protein levels (n = 104) and whole blood KISS1 DNA methylation (n = 117) were determined. Linear regression models, weighted quantile sum (WQS), and Bayesian kernel machine (BKMR) were fit.

RESULTS

PFHpA was associated with lower GLU levels [% change per log-unit increase in plasma concentrations (95%CI) = -4.73 (-8.98;-0.28)], and PFUnDA with higher GLU, TC, and HDL levels. In models adjusted by kisspeptin level, PFOS was associated with higher SBP [3.42 (-0.12; 7.09)]. Additionally, PFNA and total PFAS concentrations were associated with higher kisspeptin levels [3.91 (0.55; 7.37) and 6.14 (0.47; 12.13), respectively]. Mixture models showed that combined PFAS exposure was associated with higher HDL, lower hepatic biomarkers (ALT, BILD) and higher kisspeptin levels.

CONCLUSION

Certain PFAS (e.g. PFUnDA) and their mixture were associated with metabolic-related biomarkers, mainly GLU, HDL, and SBP. These associations may be influenced by kisspeptin levels. More studies are needed to verify these observations.

Legacy, alternative, and precursor PFAS and associations with lipids and liver function biomarkers: results from a cross-sectional analysis of adult females in the MIREC-ENDO study

BACKGROUND

Legacy per- and polyfluoroalkyl substances (PFAS) can promote dyslipidemia; however, evidence is lacking for alternative and precursor PFAS. We investigated associations between serum concentrations of 31 PFAS and concurrently measured lipids and liver function biomarkers.

METHODS

PFAS, lipids, and liver function biomarkers were analyzed in serum samples provided by 282 adult females participating in a 2018-2021 follow-up study of a Canadian pregnancy cohort. We examined percent differences in outcomes continuously for 17 PFAS with >50% detection and as detected vs. not detected for 14 PFAS with 10-50% detection. We also examined associations with the sum of 7 PFAS recommended by the National Academies of Sciences, Engineering, and Medicine guidance report on PFAS testing and 17 PFAS. We used weighted quantile sum (WQS) and quantile g-computation models to estimate joint associations.

RESULTS

Each two-fold increase in concentrations of PFHxS, PFOS, PFNA, PFDA, PFHpS, and Σ7PFAS were associated with up to 7% higher total and LDL cholesterol and the TC:HDL ratio. Individuals with detectable concentrations of N-EtFOSA, N-MeFOSA, PFBS, and 9Cl-PF3ONS had up to 17% higher total and LDL cholesterol and TC:HDL. Each one-quartile increase in the mixture of 7 PFAS was associated with up to 10% higher total and LDL cholesterol. Adding additional PFAS to the mixture (17 PFAS) made estimates less precise in WQS models and attenuated associations to the null in quantile g-computation models.

CONCLUSION

Alternative and precursor PFAS, including replacements for legacy PFAS, are associated with higher cholesterol levels; prospective studies are required to confirm these findings.

Polystyrene nanoplastics amplify the toxic effects of PFOA on the Chinese mitten crab (Eriocheir sinensis)

Nanoplastics (NPs), the final form of degraded microplastics in the environment, can adsorb PFOA (an emerging organic pollutant in recent years) in several ways. Current research on these has focused on bony fishes and mollusks, however, the combined toxicity of PFOA and NPs remains unknown in Eriocheir sinensis. Therefore, the effects of single or combined exposure to PFOA and NPs were investigated. The results showed that NPs aggravated PFOA exposure-induced oxidative stress, serum lipid disorders, immune responses, and morphological damage. DEGs altered by NPs-PFOA exposure were predominantly enriched in GO terms for cell lumen, and organelle structure, and KEGG terms for spliceosome and endocrine disorders-related diseases. Notably, the apoptotic pathway plays a central role enriched under different exposure modes. PFOA or NPs-PFOA exposure disrupted the levels of lipids molecules-related metabolites by mediating the glycerophospholipid pathway, and the NPs mediated the ferroptosis pathway to exacerbate PFOA-induced metabolic toxicity. In addition, NPs exacerbated the inflammatory response and metabolic imbalance by mediating Fusobacterium ulcerans in the intestinal. In conclusion, this study provides a valuable reference for the characterization of NPs-PFOA combined pollution and a scientific basis for the development of environmental protection policies and pollution management strategies.

PFC/PFAS concentrations in human milk and infant exposure through lactation: a comprehensive review of the scientific literature

Per- and polyfluoroalkyl substances (PFAS), previously known as perfluorinated compounds (PFC), are a group of synthetic chemicals widely used over the past decades. Their extensive application, combined with their environmental persistence, has contributed to their ubiquitous presence in the environment and the associated toxicological risks. Regarding humans, blood serum testing remains the primary method for biomonitoring PFAS exposure, while breast milk has also been used due to the transfer of these substances from mothers to infants during lactation. This paper aims to review the scientific literature (using PubMed and Scopus databases) on PFAS concentrations in the breast milk of non-occupationally exposed women. Where available, the estimated daily intake of these compounds by breastfeeding infants is also examined. The reviewed studies are categorized by continent and country/region, revealing a significant lack of data for many countries, including both developed and developing nations. The findings indicate substantial variability in PFAS concentrations, influenced by factors such as geographic location, sampling year, and the specific PFAS analyzed. Among the identified compounds, perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are most commonly detected, along with perfluorohexanesulfonic acid (PFHxS) and perfluorononanoic acid (PFNA), being the only PFAS with regulated maximum levels in certain foodstuffs. Most studies were conducted before the implementation of the current (updated) tolerable weekly intake (TWI) values for these substances. Consequently, the majority reported a low health risk for breastfeeding infants, even in high-intake scenarios. Nevertheless, biomonitoring studies are urgently needed in countries with limited or no data, and new investigations should assess whether current estimated intakes exceed the updated TWI. Special focus should be given to rural and industrial areas where exposure levels remain poorly understood.

Risk of serum circulating environmental chemical residues to esophageal squamous cell carcinoma: a nested case-control metabolome-wide association study

Esophageal squamous cell carcinoma (ESCC) is the primary histological subtype of esophageal carcinoma, yet research on environmental exposure risks and associated metabolic alterations preceding ESCC is limited. In a nested case-control cohort of 396 adults (199 diagnosed with ESCC and 197 healthy controls (HC)), we combined exposomics and metabolomics to assess circulating chemical residues and early serum metabolic changes linked to ESCC risk. A cell experiment further evaluated the proliferative impact of 1H,1H,2H,2H-perfluorooctanesulfonic acid (6:2 FTS), identifying it as a risk factor for ESCC, primarily through lipid metabolism-related chronic inflammation. Significant metabolic disruptions were observed in ESCC cases, characterized by increased carnitines, phosphatidylcholines (PCs), and triglycerides (TGs) alongside reduced lysophosphatidylcholines (LPCs) and ether lysophosphatidylcholines (LPC-Os). An early-warning biomarker panel, including glutamic acid, methionine, choline, LPC-O 18:0, TG (14:0_18:2_20:5), and PC (18:0_20:4)/LPC 18:0, showed improved predictive capacity when combined with 6:2 FTS. Metabolome-exposome-wide association studies largely confirmed 6:2 FTS as a potential ESCC risk factor through lipid mediation. This study offers novel insights for ESCC prevention and early diagnosis through a combined biomarker panel integrating metabolic and environmental risk indicators.

Temporal and cross-sectional associations of serum per- and polyfluoroalkyl substances (PFAS) and lipids from 1986 to 2016 - The Tromsø study

INTRODUCTION

Per- and polyfluoroalkyl substances (PFAS) have been linked to effects on human lipid profiles, with several epidemiological studies reporting associations between specific PFAS and blood lipid concentrations. However, these associations have been inconsistent, and most studies have focused on cross-sectional analyses with limited repeated measurements.

OBJECTIVE

In this study, we investigated associations between serum PFAS concentrations and major blood lipid classes over a 30-year period (1986-2016) and up to five time points. Lipids analyzed included total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG).

METHODS

This study included 145 participants from The Tromsø Study, Norway, who donated plasma samples three to five times over the study period. Linear mixed-effects (LME) models assessed longitudinal associations between PFAS and lipid classes, while multiple linear regression (MLR) models were used for cross-sectional associations.

RESULTS

LME models demonstrated positive longitudinal associations between perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorododecanoic acid (PFDoDA), and perfluorotridecanoic acid (PFTrDA) with TC. Additionally, PFOA, PFDA, PFUnDA, PFDoDA, and PFTrDA were associated with LDL-C, and PFUnDA and summed perfluorooctane sulfonate isomers (∑PFOS) with HDL-C. Cross-sectional analyses corroborated positive associations between the six PFAS compounds and TC at least three times, but the LDL-C and HDL-C associations were not confirmed. Summed perfluorooctane sulfonamide isomers (∑PFOSA) showed a negative association with LDL-C longitudinally, but this was not confirmed cross-sectionally. No associations were observed between PFAS and TG, longitudinally or cross-sectionally.

CONCLUSION

Concentrations of multiple PFAS were positively associated with blood lipids in longitudinal analyses, with the most consistent associations observed between six PFCA compounds and TC. These findings highlight the need for further investigation into these complex associations.

Individual and mixtures of PFAS during pregnancy are associated with maternal cardiometabolic outcomes during pregnancy

INTRODUCTION

Per- and polyfluoroalkyl substances (PFAS) are endocrine-disrupting chemicals and widespread environmental contaminants. PFAS cross the placental barrier and reach the developing fetus with potential impacts on many organ systems. There are no studies of PFAS in residents of central Arkansas despite reports of environmental contamination in the region. We aimed to quantify PFAS concentrations in repeated serum samples from participants living in central Arkansas and to investigate relationships with maternal cardiometabolic health during pregnancy.

METHODS

Participants were enrolled during early pregnancy in a longitudinal study (NCT01131117) from 2010 to 2014. PFAS concentrations were measured in serum from each trimester (first trimester n = 282, second trimester n = 217, and third trimester n = 195). PFAS were compared across pregnancy. Linear and linear-mixed effects models were used to investigate relationships between trimester-specific PFAS levels, as single exposures, and maternal outcomes. Effects of PFAS as an exposure mixture were estimated using quantile g-computation.

RESULTS

Six PFAS were detected in more than 70% of the maternal serum samples: PFOS, PFOA, PFBS, PFHxS, PFNA, and PFHxA. In adjusted linear-mixed models and quantile g-computation models, maternal serum PFAS levels were significantly negatively associated with triglycerides [effect estimates (β)= -16.29; 95% confidence interval (CI)= -24.95, -7.63], total cholesterol (β= -12.77; 95%CI= -19.80, -5.74), low-density lipoproteins (β= -10.83; 95%CI = -16.72, -4.93), high-density lipoproteins (β= -4.10; 95%CI= -6.23, -1.96), and pulse (β= -1.60; 95%CI= -2.85, -0.35). Maternal serum PFAS, as a mixture, was not associated with maternal diastolic blood pressure, but separately, PFASsum, PFOS, PFOA and PFNA had significant positive associations.

CONCLUSION

This study evaluated PFAS exposures during pregnancy in central Arkansas. We show that PFAS exposure during pregnancy influences maternal cardiometabolic outcomes and a case in point that future studies are needed to determine the impact on maternal health and to investigate potential interventions to limit the effects of PFAS exposure during pregnancy.

Serum PFAS and lipid concentrations in Ecuadorian adolescents

There is growing evidence that per- and polyfluoroalkyl substances (PFAS) may alter serum lipid concentrations; however, this topic is understudied in adolescents and Latin American populations. We aimed to characterize these associations among adolescents in Ecuador's main floricultural region. This cross-sectional study included 97 adolescents ages 11-17 years from Pedro Moncayo County, Ecuador. Generalized estimating equation models were applied to estimate the associations of serum perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorononanoic acid (PFNA) concentrations with serum lipids. Models were adjusted for age, gender, height, body mass index (BMI), acetylcholinesterase (AChE) activity, and hemoglobin concentrations. Significant inverse relationships between PFAS and triglycerides were observed in females (% lipid difference per 50% increase in: PFOS= -15.0% [95%CI: -24.72, -4.06], PFNA= -25.49% [-36.93, -12.00], and PFOA= -16.55% [-28.16, -3.07]) but not in males. No associations were observed between total cholesterol, high-density lipoprotein (HDL), or low-density lipoprotein (LDL) cholesterol and any PFAS. PFOS, PFOA, and PFNA were inversely associated with triglycerides in adolescent females but not males. Further characterization of gender-specific associations of PFAS and blood lipids in adolescents is warranted.

Health Impacts of Per- and Polyfluoroalkyl Substances (PFASs): A Comprehensive Review

Per- and polyfluoroalkyl substances (PFASs) are among the persistent organic pollutants characterized by their persistence in the environment, high mobility, and adverse impact not only on the ecosystem but also on human health. The biggest challenges in human biomonitoring are the low concentrations of PFASs in biological matrices and the presence of matrix interferents in samples. The combination of liquid chromatography with tandem mass spectrometry (LC-MS/MS) and solid-phase extraction (SPE) as a sample preparation technique appears to be the most suitable solution for achieving the desired selectivity and sensitivity in PFAS determination. The aim of this review is to describe possible sources of PFASs, their presence in various human matrices, analytical methods for determining PFASs in different biological matrices using various pretreatment techniques for complex samples, as well as adverse health risks associated with PFAS exposure. The most studied PFASs include PFOA and PFOS, which are most frequently detected in matrices such as plasma, serum, and breast milk. The average concentrations of PFOA range from 1.0 to 2.6 ng.mL-1 in plasma, 1.9 to 2.4 ng.mL-1 in serum, and 0.4 to 3.1 ng.mL-1 in breast milk. For PFOS, the average concentrations were 2.0-4.0 ng.mL-1, 3.7-4.6 ng.mL-1, and 3.6-4.8 ng.mL-1 for plasma, serum, and breast milk, respectively. The most significant health effects associated with exposure to long-chain PFASs (such as PFOA and PFOS) include lipid disorders, hypertension, diabetes mellitus, thyroid disorders, infertility, cancer, obesity, autism, neurodevelopmental issues, cardiovascular diseases, and kidney and liver disorders. It is of utmost importance to monitor PFAS exposure, predict their toxicity, and develop effective strategies to mitigate their potential effects on human health.

Associations of endocrine-disrupting chemicals mixtures with serum lipid and glucose metabolism among overweight/obese and normal-weight children: A panel study

BACKGROUND

Endocrine-disrupting chemicals (EDCs) can disturb lipid and glucose metabolism, but few studies have explored the effects of EDC mixtures and underlying inflammation mechanisms in weight-specific children.

METHODS

We conducted a panel study with 3 repeated visits among 144 children aged 4-12 years. For each visit, participants provided morning urine samples for 4 consecutive days and fasting blood samples on day 4. A total of 36 EDCs were measured, including 10 per- and polyfluoroalkyl substances (PFAS), 3 phenols, 3 parabens, 10 phthalates, and 10 polycyclic aromatic hydrocarbons. We used quantile g-computation, grouped weighted quantile sum (GWQS) regression, and linear mixed-effect models to evaluate and validate the associations of the mixture and individual effects of EDCs on lipid and fasting blood glucose (FBG). Further, mediation models were applied to explore the potential role of cytokines in the relationships of EDCs and outcomes.

RESULTS

A quantile increase in EDC mixtures was associated with elevated triglyceride (TG) (β = 0.18, 95 % CI: 0.04, 0.33) and FBG (β = 0.02, 95 % CI: 0.01, 0.04). Also, GWQS regression revealed that PFAS contributed the most to the overall effects for TG and FBG, followed by phenols. These associations were more pronounced in overweight/obese children. Regarding individual pollutants, we observed positive relationships of several PFAS with TG and FBG. Furthermore, chemokine ligand 2 mediated the associations of PFAS with TG among overweight/obese children.

CONCLUSIONS

The present study suggested that the EDC mixtures were associated with elevated lipid and glucose levels among children, particularly for those with overweight/obesity.

The Environmental Impact of Medical Imaging Agents and the Roadmap to Sustainable Medical Imaging

Medical imaging agents, i.e., contrast agents for magnetic resonance imaging (MRI) and radiopharmaceuticals, play a vital role in the diagnosis of diseases. Yet, they mostly contain harmful and non-biodegradable substances, such as per- and polyfluoroalkyl substances (PFAS), heavy metals or radionuclides. As a result of their increasing clinical use, these agents are entering various water bodies and soil, posing risks to environment and human health. Here, the environmental effects of the application of imaging agents are outlined for the major imaging modalities, and the respective chemistry of the contrast agents with environmental implications is linked. Recommendations are introduced for the design and application of contrast agents: the 3Cs of imaging agents: control, change, and combine; and recent approaches for more sustainable imaging strategies are highlighted. This combination of measures should engage an open discussion, inspire solutions to reduce pollution by imaging agents, and increase awareness for the impact of toxic waste related to imaging agents.

Non-Invasive Matrices for the Human Biomonitoring of PFAS: An Updated Review of the Scientific Literature

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals widely used in consumer and industrial products due to their unique physicochemical properties. However, their persistence and bioaccumulative potential pose significant environmental and human health risks. This review focuses on the use of non-invasive matrices-urine, hair, and nails-for the human biomonitoring of PFAS, highlighting key findings from scientific studies. While urine offers a non-invasive and practical option, its limited sensitivity for long-chain PFAS requires further analytical advances. Hair and nails have demonstrated potential for use in biomonitoring, with higher detection frequencies and concentrations for certain PFAS compared to urine. The variability in PFAS levels across studies reflects differences in population characteristics, exposure sources, and geographic regions. This review emphasizes the need for standardized analytical methods, expanded population studies, and the use of complementary matrices to enhance the accuracy and reliability of PFAS exposure assessment.

Per- and Polyfluoroalkyl Substances and Outcomes Related to Metabolic Syndrome: A Review of the Literature and Current Recommendations for Clinicians

Per- and polyfluoroalkyl substances (PFAS) are a class of toxic, ubiquitous, anthropogenic chemicals known to bioaccumulate in humans. Substantial concern exists regarding the human health effects of PFAS, particularly metabolic syndrome (MetS), a precursor to cardiovascular disease, the leading cause of mortality worldwide. This narrative review provides an overview of the PFAS literature on 4 specific components of MetS: insulin resistance/glucose dysregulation, central adiposity, dyslipidemia, and blood pressure. We focus on prospective cohort studies as these provide the best body of evidence compared to other study designs. Available evidence suggests potential associations between some PFAS and type-2 diabetes in adults, dyslipidemia in children and adults, and blood pressure in adults. Additionally, some studies found that sex and physical activity may modify these relationships. Future studies should consider modification by sex and lifestyle factors (e.g., diet and physical activity), as well quantifying the impact of PFAS mixtures on MetS features and related clinical disease. Finally, clinicians can follow recently developed clinical guidance to screen for PFAS exposure in patients, measure PFAS levels, conduct additional clinical care based on PFAS levels, and advise on PFAS exposure reduction.

Triglycerides mediate the relationships of per- and poly-fluoroalkyl substance (PFAS) exposure with nonalcoholic fatty liver disease (NAFLD) risk in US participants

Nonalcoholic fatty liver disease (NAFLD) is recognized as a significant public health problem worldwide. Several clinical studies have investigated the associations between Per- and poly-fluoroalkyl substances (PFAS) compounds with the risk of NAFLD in general adults, but the mediating effect of triglycerides (TG) was remained unexplored. In this study, 6990 individuals from the National Health and Nutrition Examination Survey (NHANES, 2003-2018) database were enrolled. Firstly, the results of generalized linear models (GLM) and restricted cubic splines (RCS) revealed positive associations of PFAS compounds with NAFLD risk score and liver function, and nearly linear E-R curves indicated no safe threshold. Meanwhile, weighted quantile sum (WQS) regression demonstrated the relationships between PFAS mixtures with NAFLD risk score and liver function, as well as perfluorooctanoic acid (PFOA) was identified as the main contributor to the increased NAFLD risk. Then, mediation analysis was conducted to explore whether serum lipids mediate the relationships. It further highlighted significant mediation effects of TG, with the mediated proportion ranging from 10.4 % to 42.9 %. Finally, sensitivity and stratified analyses were performed, confirming the reliability of these findings. Notably, significant associations were observed in individuals with a BMI ≥ 28, highlighting that these relationships were particularly evident in obese participants. In conclusion, our study suggested that PFAS mixtures exposure may influence NAFLD risk score by mediating TG in human metabolism. This result could provide more comprehensive epidemiological evidence and guide clinical applications.

Serum per- and polyfluoroalkyl substance (PFAS) levels and health-related biomarkers in a pilot study of skiers in New England

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS), synthetic chemicals with adverse health effects, are used extensively in consumer products. Ski waxes, applied to the base of skis, contain up to 100% PFAS by mass, but exposure and health effects are poorly characterized.

OBJECTIVES

Our objectives were to quantify serum PFAS concentrations among skiers and explore associations with reported ski wax use and biomarkers of cardiometabolic, thyroid, and immune health.

METHODS

We recruited 30 active adult skiers to provide non-fasting blood samples and complete questionnaires. We quantified 18 PFAS using mass spectrometry, and measured serum lipids, thyroid hormones, and immunoglobulins. We explored associations of individual and aggregate measures of serum PFAS with wax use indicators and health biomarkers using multivariable regression models, adjusted for age and gender identity.

RESULTS

Nine PFAS (PFBS, PFHpS, PFHxS, Sm-PFOS, n-PFOS, PFDA, PFNA, PFUnDA, n-PFOA) were detected in 100% of participants, and MeFOSAA in 93%. Compared to NHANES, median serum concentrations (ng/ml) were similar, but higher in coaches (e.g., PFOAall: 1.1, PFOAcoaches: 2.7, PFOANHANES: 1.2; PFNAall: 0.5, PFNAcoaches: 1.7, PFNANHANES: 0.4). Factors reflecting wax exposure were positively associated with PFAS: e.g., >10 years as a snow sport athlete, compared to ≤10 years, was associated with 3.2 (95% CI: 0.7, 5.6) ng/ml higher aggregate PFAS, as defined by National Academies of Science, Engineering, and Medicine (NASEM). An IQR (6.3 ng/ml) increase in NASEM PFAS was associated with 32.1 (95% CI: 7.0, 57.2), 35.5 (13.5, 57.5), and 12.8 (0.6, 25.1) mg/dl higher total cholesterol, LDL-C, and sdLDL-C, respectively.

DISCUSSION

Our study provides early evidence that recreational skiers, particularly coaches, are exposed to PFAS through ski wax. Several PFAS were associated with higher serum lipids among these physically active adults. Interventions to remove PFAS from fluorinated wax could decrease direct exposure to skiers and reduce PFAS release into the environment.

Associations between maternal per- and polyfluoroalkyl substances exposure and lipid levels in maternal and cord blood: The Japan environment and Children's study

Despite numerous studies, the associations between per- and polyfluoroalkyl substances (PFAS) exposure and various lipid levels in pregnant women remain ambiguous, especially concerning the association with cord blood lipids. This analysis included 20,960 pregnant women enrolled in the Japan Environment and Children's Study, recruited between 2011 and 2014. Non-fasting plasma samples collected before 22 weeks of gestation were examined for PFAS concentrations. Additionally, non-fasting serum samples collected before, at and after 22 weeks of gestation, at birth, and from cord blood were used to measure total cholesterol (TC) and triglycerides (TG). Linear regression models were applied to quantify the association between each PFAS and various lipid metrics. Among the 28 PFAS analyzed, 7 were quantifiable in more than 80% of participants. Of these, 6 PFAS showed positive associations with TC in maternal blood before 22 weeks of gestation, a trend that remained mostly consistent for maternal blood samples in later stages. However, no associations were found with TC levels in cord blood. Regarding TG, 3 PFAS demonstrated a negative association with TG levels in maternal blood before 22 weeks of gestation, with these relationships generally persisting in later stages, while 4 PFAS were positively associated with TG in cord blood. In summary, this study identified associations between PFAS concentrations in maternal blood and lipid levels in both maternal and cord blood, with differing patterns observed between the two.

Effects of per- and polyfluoroalkyl substances on the liver: Human-relevant mechanisms of toxicity

Per- and polyfluoroalkyl substances (PFAS) are abundantly used in a plethora of products with applications in daily life. As a result, PFAS are widely distributed in the environment, thus providing a source of exposure to humans. The majority of human exposure to PFAS is attributed to the human diet, which encompasses drinking water. Their chemical nature grants persistent, accumulative and toxic properties, which are currently raising concerns. Over the past few years, adverse effects of PFAS on different organs have been repeatedly documented. Numerous epidemiological studies established a clear link between PFAS exposure and liver toxicity. Likewise, effects of PFAS on liver homeostasis, lipid metabolism, bile acid metabolism and hepatocarcinogenesis have been reported in various in vitro and in vivo studies. This review discusses the role of PFAS in liver toxicity with special attention paid to human relevance as well as to the mechanisms underlying the hepatotoxic effects of PFAS. Future perspectives and remaining knowledge gaps were identified to enhance future PFAS risk assessment.

Fish consumption benefits and PFAS risks: Epidemiology and public health recommendations

Finfish and shellfish intake (collectively referred to as fish) has been associated with health benefits, although fish often have chemical contaminants that are separately associated with health risks. The presence of chemical contaminants, however, does not inherently pose a health risk and optimizing the benefits is desirable for individual and population health. Reference doses (RfDs) and other comparison values that estimate contaminant or pollutant safety thresholds typically do not account for the benefits of the foods that carry them (e.g., fish, eggs, fruit, vegetables). Rather, these numbers are typically applied uniformly for various media such as food, soil, and water. This paper summarizes principal epidemiology studies on per- and polyfluoroalkyl substances (PFAS)-associated noncancer health indicators used by the United States Environmental Protection Agency (EPA) to develop RfDs for PFAS and compares these with the same health outcomes associated with seafood intake. Moreover, it frames these findings in relation to varying human PFAS exposures, fish intake amount, and fish type when the information is available. Further, it presents brief overviews of both general population temporal PFAS exposure trends and PFAS fish contaminant data in the United States. Finally, it discusses approaches that risk assessors and policy makers can consider in developing their fish consumption recommendations in relation to PFAS. In brief, epidemiology studies show that the benefits of fish intake generally counter the risks of PFAS exposure based on four noncancer health endpoints that EPA identified as having the greatest strength of evidence for PFAS health effects.

PFAS exposure is associated with an unfavourable metabolic profile in infants six months of age

Exposure to perfluoroalkyl substances (PFAS) are reported to have numerous negative health effects and children are especially vulnerable. The aim of this study was to investigate whether maternal and infant PFAS burden have any impact on prenatal and postnatal growth, liver and lipid parameters in infants at age six months. Data on diet and growth parameters, as well as blood samples were collected from healthy pregnant women in week 18 and in the women and their infants at six months postpartum. The blood samples were analysed for liver enzymes, blood lipids and PFAS. Maternal perfluoroalkyl carboxylic acids (PFCA) and fish for dinner ≥ 3 days per week in pregnancy week 18 were associated with reduced birth weight and increased percent weight gain the first six months of life. Infant PFCA concentrations were positively associated with serum alanine aminotransferase and total- and LDL-cholesterol concentrations at six months of age. Our data demonstrate that prenatal and postnatal PFAS exposure are associated with an unfavourable metabolic profile at a very young age. This pattern is concerning as it may be linked to early conditioning of later metabolic disease. It is vital to reduce PFAS exposure in women of fertile age in order to prevent development of metabolic disease in the next generation.

Association of co-exposure to organophosphate esters and per- and polyfluoroalkyl substances and mixture with cardiovascular-kidney-liver-metabolic biomarkers among Chinese adults

BACKGROUND

Organophosphate esters (OPEs) and Per- and polyfluoroalkyl substances (PFAS) are ubiquitous environmental contaminants with common exposure sources, leading to their widespread presence in human body. However, evidence on co-exposure to OPEs and PFAS and its impact on cardiovascular-kidney-liver-metabolic biomarkers remains limited.

METHODS

In this cross-sectional study, 467 adults were enrolled from January to May 2022 during physical visits in Shijiazhuang, Hebei province. Eleven types of OPEs and twelves types of PFAS were detected, among which eight OPEs and six PFAS contaminants were detected in more than 60% of plasma samples. Seventeen biomarkers were assessed to comprehensively evaluate the cardiovascular-kidney-liver-metabolic function. Multiple linear regression, multipollutant models with sparse partial least squares, and Bayesian kernel machine regression (BKMR) models were applied to examine the associations of individual OPEs and PFAS and their mixtures with organ function and metabolism, respectively.

RESULTS

Of the over 400 exposure-outcome associations tested when modelling, we observed robust results across three models that perfluorohexanoic acid (PFHxS) was significantly positively associated with alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), and indirect bilirubin (IBIL). Perfluorononanoic acid was significantly associated with decreased AST/ALT and increased very-low-density lipoprotein cholesterol levels. Besides, perfluorodecanoic acid was correlated with increased high lipoprotein cholesterol and perfluoroundecanoic acid was consistently associated with lower glucose level. BKMR analysis showed that OPEs and PFAS mixtures were positively associated with IBIL and TBIL, among which PFHxS was the main toxic chemicals.

CONCLUSIONS

Our findings suggest that exposure to OPEs and PFAS, especially PFHxS and PFNA, may disrupt organ function and metabolism in the general population, providing insight into the potential pathophysiological mechanisms of OPEs and PFAS co-exposure and chronic diseases.

Per- and polyfluoroalkyl substances and human health outcomes: An umbrella review of systematic reviews with meta-analyses of observational studies

BACKGROUND

Although evidence on the association between per- and polyfluoroalkyl substances (PFASs) and human health outcomes has grown exponentially, specific health outcomes and their potential associations with PFASs have not been conclusively evaluated.

METHODS

We conducted a comprehensive search through the databases of PubMed, Embase, and Web of Science from inception to February 29, 2024, to identify systematic reviews with meta-analyses of observational studies examining the associations between the PFASs and multiple health outcomes. The quality of included studies was evaluated using the A Measurement Tool to Assess Systematic Reviews (AMSTAR) tool, and credibility of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) criteria. The protocol of this umbrella review (UR) had been registered in PROSPERO (CRD 42023480817).

RESULTS

The UR identified 157 meta-analyses from 29 articles. Using the AMSTAR measurement tool, all articles were categorized as of moderate-to-high quality. Based on the GRADE assessment, significant associations between specific types of PFASs and low birth weight, tetanus vaccine response, and triglyceride levels showed high certainty of evidence. Moreover, moderate certainty of evidence with statistical significance was observed between PFASs and health outcomes including lower BMI z-score in infancy, poor sperm progressive motility, and decreased risk of preterm birth as well as preeclampsia. Fifty-two (33%) associations (e.g., PFASs and gestational hypertension, cardiovascular disease, etc) presented low certainty evidence. Additionally, eighty-five (55%) associations (e.g., PFASs with infertility, lipid metabolism, etc) presented very low certainty evidence.

CONCLUSION

High certainty of evidence supported that certain PFASs were associated with the incidence of low birth weight, low efficiency of the tetanus vaccine, and low triglyceride levels.

Paradoxes: Cholesterol and Hypoxia in Preeclampsia

Preeclampsia, a hypertensive disease of pregnancy of unknown etiology, is intensely studied as a model of cardiovascular disease (CVD) not only due to multiple shared pathologic elements but also because changes that develop over decades in CVD appear and resolve within days in preeclampsia. Those affected by preeclampsia and their offspring experience increased lifetime risks of CVD. At the systemic level, preeclampsia is characterized by increased cellular, membrane, and blood levels of cholesterol; however, cholesterol-dependent signaling, such as canonical Wnt/βcatenin, Hedgehog, and endothelial nitric oxide synthase, is downregulated indicating a cholesterol deficit with the upregulation of cholesterol synthesis and efflux. Hypoxia-related signaling in preeclampsia also appears to be paradoxical with increased Hypoxia-Inducible Factors in the placenta but measurably increased oxygen in maternal blood in placental villous spaces. This review addresses the molecular mechanisms by which excessive systemic cholesterol and deficient cholesterol-dependent signaling may arise from the effects of dietary lipid variance and environmental membrane modifiers causing the cellular hypoxia that characterizes preeclampsia.

Serum concentrations of legacy, alternative, and precursor per- and polyfluoroalkyl substances: a descriptive analysis of adult female participants in the MIREC-ENDO study

BACKGROUND

Several legacy and emerging per- and polyfluoroalkyl substances (PFAS) have been regulated around the world. There is growing concern over the proliferation of alternative PFAS, as well as PFAS precursors. Biomonitoring data for PFAS are critical for assessing exposure and human health risk.

METHODS

We collected serum samples from 289 adult female participants in a 2018-2021 follow-up study of the Maternal-Infant Research on Environmental Chemicals (MIREC) Canadian pregnancy cohort. Samples were analyzed for 40 PFAS using ultra-performance liquid chromatography-tandem mass spectrometry. For those compounds with > 50% detection, as well as the sum of these compounds, we describe serum concentrations and patterns of exposure according to sociodemographic and obstetrical history characteristics.

RESULTS

17 out of 40 PFAS were detected in > 50% of samples with 7 of these detected in > 97% of samples. Median [95th percentile] concentrations (µg/L) were highest for PFOS (1.62 [4.56]), PFOA (0.69 [1.52]), PFNA (0.38 [0.81]), and PFHxS (0.33 [0.92]). Geometric mean concentrations of PFOA and PFHxS were approximately 2-fold lower among those with more children (≥ 3 vs. 1), greater number of children breastfed (≥ 3 vs. ≤ 1), longer lifetime duration of breastfeeding (> 4 years vs. ≤ 9 months), and shorter time since last pregnancy (≤ 4 years vs. > 8 years). We observed similar patterns for PFOS, PFHpS, and the sum of 17 PFAS, though the differences between groups were smaller. Concentrations of PFOA were higher among "White" participants, while concentrations of N-MeFOSE, N-EtFOSE, 7:3 FTCA, and 4:2 FTS were slightly higher among participants reporting a race or ethnicity other than "White". Concentrations of legacy, alternative, and precursor PFAS were generally similar across levels of age, education, household income, body mass index, and menopausal status.

CONCLUSIONS

We report the first Canadian biomonitoring data for several alternative and precursor PFAS. Our findings suggest that exposure to PFAS, including several emerging alternatives, may be widespread. Our results are consistent with previous studies showing that pregnancy and breastfeeding are excretion pathways for PFAS.

Environmental Exposures and Pediatric Cardiology: A Scientific Statement From the American Heart Association

Environmental toxicants and pollutants are causes of adverse health consequences, including well-established associations between environmental exposures and cardiovascular diseases. Environmental degradation is widely prevalent and has a long latency period between exposure and health outcome, potentially placing a large number of individuals at risk of these health consequences. Emerging evidence suggests that environmental exposures in early life may be key risk factors for cardiovascular conditions across the life span. Children are a particularly sensitive population for the detrimental effects of environmental toxicants and pollutants given the long-term cumulative effects of early-life exposures on health outcomes, including congenital heart disease, acquired cardiac diseases, and accumulation of cardiovascular disease risk factors. This scientific statement highlights representative examples for each of these cardiovascular disease subtypes and their determinants, focusing specifically on the associations between climate change and congenital heart disease, airborne particulate matter and Kawasaki disease, blood lead levels and blood pressure, and endocrine-disrupting chemicals with cardiometabolic risk factors. Because children are particularly dependent on their caregivers to address their health concerns, this scientific statement highlights the need for clinicians, research scientists, and policymakers to focus more on the linkages of environmental exposures with cardiovascular conditions in children and adolescents.

Integrating high-throughput phenotypic profiling and transcriptomic analyses to predict the hepatosteatosis effects induced by per- and polyfluoroalkyl substances

Per- and polyfluoroalkyl substances (PFAS) is a large compound class (n > 12,000) that is extensively present in food, drinking water, and aquatic environments. Reduced serum triglycerides and hepatosteatosis appear to be the common phenotypes for different PFAS chemicals. However, the hepatosteatosis potential of most PFAS chemicals remains largely unknown. This study aims to investigate PFAS-induced hepatosteatosis using in vitro high-throughput phenotype profiling (HTPP) and high-throughput transcriptomic (HTTr) data. We quantified the in vitro hepatosteatosis effects and mitochondrial damage using high-content imaging, curated the transcriptomic data from the Gene Expression Omnibus (GEO) database, and then calculated the point of departure (POD) values for HTPP phenotypes or HTTr transcripts, using the Bayesian benchmark dose modeling approach. Our results indicated that PFAS compounds with fully saturated C-F bonds, sulfur- and nitrogen-containing functional groups, and a fluorinated carbon chain length greater than 8 have the potential to produce biological effects consistent with hepatosteatosis. PFAS primarily induced hepatosteatosis via disturbance in lipid transport and storage. The potency rankings of PFAS compounds are highly concordant among in vitro HTPP, HTTr, and in vivo hepatosteatosis phenotypes (ρ = 0.60-0.73). In conclusion, integrating the information from in vitro HTPP and HTTr analyses can accurately project in vivo hepatosteatosis effects induced by PFAS compounds.

Perfluoroalkyl/Polyfluoroalkyl Substances: Links to Cardiovascular Disease Risk

Conservative estimates by the World Health Organization suggest that at least a quarter of global cardiovascular diseases are attributable to environmental exposures. Associations between air pollution and cardiovascular risk have garnered the most headlines and are strong, but less attention has been paid to other omnipresent toxicants in our ecosystem. Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are man-made chemicals that are extensively used in industrial and consumer products worldwide and in aqueous film-forming foam utilized in firefighting. As such, our exposure to PFAS is essentially ubiquitous. Given the long half-lives of these degradation-resistant chemicals, virtually, all people are carrying a body burden of PFAS. Health concerns related to PFAS are growing such that the National Academies of Sciences, Engineering and Medicine has recommended standards for clinical follow-up of individuals with high PFAS blood levels, including prioritizing screening for dyslipidemia. The link between PFAS and dyslipidemia has been extensively investigated, and evidence for associations is compelling. However, dyslipidemia is not the only cardiovascular risk factor with which PFAS is associated. Here, we review the epidemiological evidence for links between PFAS of concern identified by the National Academies of Sciences, Engineering and Medicine and risk factors for cardiovascular disease, including overweight/obesity, glucose intolerance, hypertension, dyslipidemia, and hyperuricemia. Moreover, we review the potential connections of PFAS with vascular disease and atherosclerosis. While observational data support associations between the National Academies of Sciences, Engineering and Medicine PFAS and selected cardiac risk factors, additional research is needed to establish causation and better understand how exposure to PFAS leads to the development of these conditions.

Comparing the effects of developmental exposure to alpha lipoic acid (ALA) and perfluorooctanesulfonic acid (PFOS) in zebrafish (Danio rerio)

Alpha lipoic acid (ALA) is a dietary supplement that has been used to treat a wide range of diseases, including obesity and diabetes, and have lipid-lowering effects, making it a potential candidate for mitigating dyslipidemia resulting from exposures to the per- and polyfluoroalkyl substance (PFAS) family member perfluorooctanesulfonic acid (PFOS). ALA can be considered a non-fluorinated structural analog to PFOS due to their similar 8-carbon chain and amphipathic structure, but, unlike PFOS, is rapidly metabolized. PFOS has been shown to reduce pancreatic islet area and induce β-cell lipotoxicity, indicating that changes in β-cell lipid microenvironment is a mechanism contributing to hypomorphic islets. Due to structural similarities, we hypothesized that ALA may compete with PFOS for binding to proteins and distribution throughout the body to mitigate the effects of PFOS exposure. However, ALA alone reduced islet area and fish length, with several morphological endpoints indicating additive toxicity in the co-exposures. Individually, ALA and PFOS increased fatty acid uptake from the yolk. ALA alone increased liver lipid accumulation, altered fatty acid profiling and modulated PPARɣ pathway signaling. Together, this work demonstrates that ALA and PFOS have similar effects on lipid uptake and metabolism during embryonic development in zebrafish.

The effect of PFAS exposure on glucolipid metabolism in children and adolescents: a meta-analysis

Background

Previous studies showed that per- and polyfluoroalkyl substances (PFAS), which are widely found in the environment, can disrupt endocrine homeostasis when they enter the human body. This meta-analysis aimed to evaluate current human epidemiological evidence on the relationship between PFAS exposure and glucolipid metabolism in childhood and adolescence.

Methods

We searched PubMed, Web of Science, Embase, and Cochrane Library databases, and identified population-based epidemiological studies related to PFAS and glucolipid metabolism indexes that were published before 30 December 2022. The heterogeneity of the included literature was assessed using the I-square (I2) test and statistics Q. Random-effects and fixed-effects models were used to combine the effect size. Subgroup analysis based on age and sex of the study participants was performed. A sensitivity analysis was used to evaluate the robustness and reliability of the combined results. Egger's and Begg's tests were used to analyze publication bias.

Results

A total of 12 studies were included in this analysis. There was a positive association between PFAS and TC (β = 1.110, 95% CI: 0.601, 1.610) and LDL (β = 1.900, 95% CI: 1.030, 2.770), and a negative association between PFAS and HOMA-IR in children and adolescents (β = -0.130, 95% CI: -0. 200, -0.059). PFOS was significant positive associated with TC (β = 8.22, 95% CI: 3.93, 12.51), LDL (β = (12.04, 95% CI: 5.08, 18.99), and HOMA-IR (β = -0.165, 95% CI: -0.292, -0.038). Subgroup analysis showed that exposure to PFAS in the adolescent group was positively associated with TC and LDL levels, and the relationship was stronger in females.

Conclusion

PFAS exposure is associated with glucolipid metabolism in children and adolescents. Among them, PFOS may play an important role. Recognition of environmental PFAS exposure is critical for stabilizing the glycolipid metabolism relationship during the growth and development of children and adolescents.

Assessing the performance of a targeted absolute quantification isotope dilution liquid chromatograhy tandem mass spectrometry assay versus a commercial nontargeted relative quantification assay for detection of three major perfluoroalkyls in human blood

Isotope dilution ultrahigh-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) is commonly used for trace analysis of polyfluoroalkyl and perfluoroalkyl substances (PFAS) in difficult matrices. Commercial nontargeted analysis of major PFAS where relative concentrations are obtained cost effectively is rapidly emerging and is claimed to provide comparable results to that of absolute quantification using matrix matched calibration and isotope dilution UHPLC-MS/MS. However, this remains to be demonstrated on a large scale. We aimed to assess the performance of a targeted absolute quantification isotope dilution LC-MS/MS assay versus a commercial nontargeted relative quantification assay for detection of three major PFAS in human blood. We evaluated a population-based cohort of 503 individuals. Correlations were assessed using Spearman's rank correlation coefficients (rho). Precision and bias were assessed using Bland-Altman plots. For perfluorooctane sulfonic acid, the median concentrations were 5.10 ng/mL (interquartile range [IQR] 3.50-7.24 ng/mL), the two assays correlated with rho 0.83. For perfluorooctanoic acid, the median concentrations were 2.14 ng/mL (IQR 1.60-3.0 ng/mL), the two assays correlated with rho 0.92. For perfluorohexanesulfonate, the median concentrations were 5.5 ng/mL (IQR 2.50-11.61 ng/mL), the two assays correlated with rho 0.96. The Bland-Altman statistical test showed agreement of the mean difference for the majority of samples (97-98%) between the two assays. Absolute plasma concentrations of PFAS obtained using matrix matched calibration and isotope dilution UHPLC-MS/MS show agreement with relative plasma concentrations from a nontargeted commercial platform by Metabolon. We observed striking consistency between the two assays when examining the associations of the three PFAS with cholesterol, offering additional confidence in the validity of utilizing the nontargeted approach for correlations with various health phenotypes.

Per- and polyfluoroalkyl substances and cardiometabolic diseases: A review

Per- and polyfluoroalkyl substances (PFAS) are a group of persistent and widespread environmental pollutants that represent a high concern for human health. They have been shown to be associated with several important physiological processes such as lipid metabolism and the immune system. Consequently, PFAS are suspected to play a role in cardiometabolic disease development. However, the evidence regarding associations between PFAS and overt cardiovascular disease and type 2 diabetes remains limited and inconsistent. To address this, we conducted a review of the epidemiological evidence. A deeper understanding of potential underlying molecular mechanisms may help to explain inconsistencies in epidemiological findings. Thus, to gain more mechanistic insight, we also summarized evidence from omics and laboratory studies into an adverse outcome pathway framework. Our observations indicate the potential for associations of PFAS with multiple molecular pathways that could have opposite associations with disease risk, which could be further modified by mixture composition, lifestyle factors or genetic polymorphisms. This identifies the need for exposome studies considering mixture effects, the use of multi-omics data to gain insight in relevant pathways and the integration of epidemiological and laboratory studies to enhance mechanistic understanding and causal inference. Improved comprehension is essential for environmental health risk assessments.

A co-twin control study of in utero exposure to poly- and perfluoroalkyl substances and associations with neonatal thyroid-stimulating hormone

Research quantifying associations between early-life exposure to poly- and perfluoroalkyl substances (PFAS) and neonatal thyroid hormone levels is limited and reports inconsistent results. This study aimed to examine the associations of in utero PFAS exposure with neonatal thyroid-stimulating hormone (TSH), and to verify whether genetic and familial factors contribute to these associations. Within Wuhan Twin Birth Cohort study, we included 148 mother-twin pairs recruited between March 2016 and January 2018. Maternal plasma PFAS concentrations were measured at three different trimesters and averaged. Additionally, we measured cord plasma PFAS concentrations for twin newborns and retrieved their TSH levels from the medical system. Multivariable linear regression, generalized estimation equation, and linear mixed models were used to examine the covariate-adjusted associations. For maternal PFAS analyses, a 2-fold increment of average maternal perfluorooctanoic acid (PFOA) and perfluorodecanoic acid (PFDA) concentrations was linked with a 15% (95% CI: 2.5%, 28%) and 14% (95% CI: 2.4%, 28%) increase in neonatal TSH, respectively. For twin newborns discordant for PFAS exposure, a 2-fold increment of cord plasma PFOA, PFDA, perfluoroundecanoic acid (PFUdA), and perfluorohexanesulfonic acid (PFHxS) concentrations was related to a 7.1% (95% CI: 0.31%, 14%), 12% (95% CI: 4.8%, 20%), 7.5% (95% CI: 0.30%, 15%), and 8.5% (95% CI: 3.0%, 14%) increase in TSH among twins as individuals, respectively. Although these associations were mainly observed between twin pairs, certain PFAS exposure might have an independent association with increased TSH. Our present study suggests that higher maternal and cord plasma PFAS concentrations are associated with increased neonatal TSH, and genetic and familial factors contribute to these associations.

Cardiometabolic health and per and polyfluoroalkyl substances in an Inuit population

INTRODUCTION

The cardiometabolic health status of Inuit in Nunavik has worsened in the last thirty years. The high concentrations of perfluoroalkyl acids (PFAAs) may be contributing to this since PFAAs have been linked with hypercholesterolemia, diabetes, and high blood pressure. The aim of this study was to examine the association between a PFAAs mixture and lipid profiles, Type II diabetes, prediabetes, and high blood pressure in this Inuit population.

METHODS

We included 1212 participants of the Qanuilirpitaa? 2017 survey aged 16-80 years. Two mixture models (quantile g-computation and Bayesian Kernel Machine Regression (BKMR)) were used to investigate the associations between six PFAAs (PFHxS, PFOS, PFOA and three long-chain PFAAs (PFNA, PFDA and PFUnDA)) with five lipid profiles and three cardiometabolic outcomes. Non-linearity and interaction between PFAAs were further assessed.

RESULTS

An IQR increase in all PFAAs congeners resulted in an increase in total cholesterol (β 0.15, 95% confidence interval (CI) 0.06, 0.24), low-density lipoprotein cholesterol (LDL) (β 0.08, 95% CI 0.01, 0.16), high-density lipoprotein cholesterol (HDL) (β 0.04, 95% CI 0.002, 0.08), apolipoprotein B-100 (β 0.03, 95% CI 0.004, 0.05), and prediabetes (OR 1.80, 95% CI 1.11, 2.91). There was no association between PFAAs and triglycerides, diabetes, or high blood pressure. Long-chain PFAAs congeners were the main contributors driving the associations. Associations were largely linear, and there was no evidence of interaction between the PFAAs congeners.

CONCLUSIONS

Our study provides further evidence of increasing circulating lipids with increased exposure to PFAAs. The increased risk of prediabetes points to the influence of PFAAs on potential clinical outcomes. International regulation of PFAAs is essential to curb PFAAs exposure and related health effects in Arctic communities.

Plasma levels of per- and polyfluoroalkyl substances (PFAS) and cardiovascular disease - Results from two independent population-based cohorts and a meta-analysis

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are persistent chemicals that have been linked to increased cholesterol levels and thus may have a role in the development of cardiovascular disease (CVD).

OBJECTIVES

To investigate associations between PFAS exposure and incident CVD (a combined CVD end-point consisting of myocardial infarction, ischemic stroke, or heart failure) in two independent population-based cohorts in Sweden. In addition, we performed a meta-analysis also including results from previous studies.

METHODS

In 2,278 subjects aged 45-75 years from the EpiHealth study, the risk of incident CVD in relation to relative plasma levels of perfluorohexanesulfonic acid (PFHxS), perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) was investigated. Associations between plasma levels of six PFAS and incident CVD were also examined in the PIVUS-study (n = 1,016, all aged 70 years). In addition, a meta-analysis was performed including three previous prospective studies, together with the results from the present study.

RESULTS

There were no overall statistically significant associations between levels of the different PFAS and incident CVD, neither in EpiHealth nor in PIVUS. However, there was a significant sex interaction for PFOS in EpiHealth (p = 0.008), and an inverse association could be seen only in men (Men, HR: 0.68, 95 % CI: 0.52, 0.89) (Women, HR: 1.13, 95 % CI: 0.82, 1.55). A meta-analysis of five independent studies regarding PFOA and incident CVD showed a risk ratio (RR) of 0.80 (CI: 0.66, 0.94) when high levels were compared to low levels.

CONCLUSIONS

This longitudinal study using data from two population-based cohort studies in Sweden did not indicate any increased risk of incident CVD for moderately elevated PFAS levels. A meta-analysis of five independent cohort studies rather indicated a modest inverse association between PFOA levels and incident CVD, further supporting that increasing PFAS levels are not linked to an increased risk of CVD.

Decreased levels of perfluoroalkyl substances in patients receiving hemodialysis treatment

Perfluoroalkyl substances (PFAS) have been reported to be harmful to multiple organs in the human body. Based on a previous study suggesting that hemodialysis (HD) may be a means of eliminating PFAS from the human body, we aimed to compare the serum PFAS concentrations of patients undergoing regular HD, patients with chronic kidney disease (CKD) and controls. Additionally, we also investigated the correlation between PFAS and biochemical data, as well as concurrent comorbidities. We recruited 301 participants who had been on maintenance dialysis for >90 days, 20 participants with stage 5 non-dialysis CKD, and 55 control participants who did not have a diagnosis of kidney disease, with a mean creatinine level of 0.77 mg/dl. Eight different PFAS, namely perfluorooctanoic acid (PFOA), total and linear perfluorooctanesulfonic acid (PFOS), perfluoroheptanoic acid (PFHpA), perfluorohexanesulfonic acid (PFHxS), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), and perfluoroundecanoic acid (PFUnDA), were measured using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Spearman correlation and multivariable linear regression with 5 % false discovery rate were used to evaluate the relationships between PFAS and clinical parameters in HD patients and controls. Circulating concentrations of seven PFAS, including total and linear PFOS (T-PFOS and L-PFOS) PFDA, PFNA, PFHxS, PFOA, and PFUnDA, were significantly lower in the HD group compared to the CKD and control group. For the interplay between biochemical data and PFAS, all of the studied PFAS were positively correlated with aspartate aminotransferase, alanine aminotransferase, glucose, blood urea nitrogen, ferritin, and vitamin D in the controls, while in HD patients, the PFAS were all positively correlated with albumin, uric acid, iron, and vitamin D. These findings may offer valuable insights for future studies seeking to eliminate PFAS.

Association of per- and polyfluoroalkyl substances with hepatic steatosis and metabolic dysfunction-associated fatty liver disease among patients with acute coronary syndrome

Etiology of hepatic steatosis and metabolic dysfunction-associated fatty liver disease (MAFLD) among acute coronary syndrome (ACS) remains unclear. Existing studies suggested the potential role of per- and polyfluoroalkyl substances (PFAS) in comorbidity of hepatic steatosis among ACS patients. Therefore, we conducted a cross-sectional study based on the ACS inpatients to assess the associations of plasma PFAS congeners and mixtures with hepatic steatosis and MAFLD. This study included 546 newly diagnosed ACS patients. Twelve PFAS were quantified using ultra-high-performance liquid chromatography-tandem mass spectrometry. Hepatic steatosis was defined by hepatic steatosis index (HSI). MAFLD was defined as the combination of hepatic steatosis based on the risk factor calculation with metabolic abnormalities. Generalized linear model was used to examine the associations of PFAS congeners with HSI and MAFLD. Adaptive elastic net (AENET) was further used for PFAS congeners selection. Mixture effects were also assessed with Bayesian kernel machine regression model (BKMR). Congeners analysis observed significant greater percent change of HSI for each doubling in PFOS (1.82%, 95% CI: 0.87%, 2.77%), PFHxS (1.17%, 95% CI: 0.46%, 1.89%) and total PFAS (1.84%, 95% CI: 0.56%, 3.14%). Moreover, each doubling in PFOS (OR=1.42, 95% CI: 1.13, 1.81), PFHxS (OR=1.31, 95% CI: 1.09, 1.59) and total PFAS (OR=1.43, 95% CI: 1.06, 1.94) was associated with increased risk of MAFLD. In AENET regression, only PFOS presented significant positive associations with HSI. Mixture analysis indicated significant positive associations between PFAS mixtures and HSI. This is the first study to demonstrate associations of PFAS congeners and mixtures with hepatic steatosis and MAFLD among ACS patients, which provides hypothesis into the mechanisms behind comorbidity of hepatic steatosis among ACS patients, as well as tertiary prevention of ACS.

Firefighters and the liver: Exposure to PFAS and PAHs in relation to liver function and serum lipids (CELSPAC-FIREexpo study)

INTRODUCTION

Firefighting is one of the most hazardous occupations due to exposure to per- and polyfluoroalkyl substances (PFAS) and polycyclic aromatic hydrocarbons (PAHs). Such exposure is suspected to affect the cardiometabolic profile, e.g., liver function and serum lipids. However, only a few studies have investigated the impact of this specific exposure among firefighters.

METHODS

Men included in the CELSPAC-FIREexpo study were professional firefighters (n = 52), newly recruited firefighters in training (n = 58), and controls (n = 54). They completed exposure questionnaires and provided 1-3 samples of urine and blood during the 11-week study period to allow assessment of their exposure to PFAS (6 compounds) and PAHs (6 compounds), and to determine biomarkers of liver function (alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and total bilirubin (BIL)) and levels of serum lipids (total cholesterol (CHOL), low-density lipoprotein cholesterol (LDL) and triglycerides (TG)). The associations between biomarkers were investigated both cross-sectionally using multiple linear regression (MLR) and Bayesian weighted quantile sum (BWQS) regression and prospectively using MLR. The models were adjusted for potential confounders and false discovery rate correction was applied to account for multiplicity.

RESULTS

A positive association between exposure to PFAS and PAH mixture and BIL (β = 28.6%, 95% CrI = 14.6-45.7%) was observed by the BWQS model. When the study population was stratified, in professional firefighters and controls the mixture showed a positive association with CHOL (β = 29.5%, CrI = 10.3-53.6%) and LDL (β = 26.7%, CrI = 8.3-48.5%). No statistically significant associations with individual compounds were detected using MLR.

CONCLUSIONS

This study investigated the associations between exposure to PFAS and PAHs and biomarkers of cardiometabolic health in the Czech men, including firefighters. The results suggest that higher exposure to a mixture of these compounds is associated with an increase in BIL and the alteration of serum lipids, which can result in an unfavourable cardiometabolic profile.

Perfluorooctanoic Acid (PFOA) Exposure and Abnormal Alanine Aminotransferase: Using Clinical Consensus Cutoffs Compared to Statistical Cutoffs for Abnormal Values

BACKGROUND

Per- and polyfluoroalkyl substances (PFASs) including perfluorooctanoic acid (PFOA) are ubiquitous environmental contaminants. Prior analysis in the large "C8 Health Project" population defined abnormal alanine aminotransferase (ALT) with statistically derived cutoffs (>45 IU/L in men, >34 IU/L in women).

OBJECTIVE

To explore the degree to which PFOA was associated with modern, clinically predictive ALT biomarker cutoffs in obese and nonobese participants, excluding those with diagnosed liver disease.

METHODS

We reevaluated the relationship of serum PFOA to abnormal ALT using predictive cutoff recommendations including those of the American College of Gastroenterology (ACG). Evaluations modeled lifetime cumulative exposure and measured internal PFOA exposure.

RESULTS

ACG cutoff values (≥34 IU/L for males, ≥25 IU/L for females) classified 30% of males (3815/12,672) and 21% of females (3359/15,788) above ALT cutoff values. Odds ratios (OR) for above cutoff values were consistently associated with modeled cumulative and measured serum PFOA. Linear trends were highly significant. ORs by quintile showed near monotonic increases. Trends were stronger for the overweight and obese. However, all weight classes were affected.

CONCLUSION

Predictive cutoffs increase the OR for abnormal ALT results. Obesity increases ORs, yet association with abnormal ALT pertains to all weight classes. The results are discussed in context of current knowledge about the health implications of PFOA hepatotoxicity.

Association of per- and polyfluoroalkyl substance exposure with fatty liver disease risk in US adults

BACKGROUND & AIMS

Per- and polyfluoroalkyl substances (PFAS) are widespread pollutants with demonstrated hepatotoxicity. Few studies have examined the association between PFAS and fatty liver disease (FLD) risk in an adult population.

METHODS

In this cross-sectional study of participants from the 2017-2018 National Health and Nutrition Examination Survey, serum PFAS were measured, and FLD cases were ascertained by vibration-controlled transient elastography. Logistic regression models were used to examine the association between circulating PFAS levels and FLD risk. Analyses were stratified into non-alcoholic FLD and alcoholic FLD risk groups by alcohol intake status, as well as controlling for other risk factors, including personal demographics, lifestyle factors, and related health factors.

RESULTS

Among 1,135 eligible participants, 446 had FLD. For FLD risk, the multivariable-adjusted odds ratio per log-transformed SD increase (ORSD) in perfluorohexane sulfonate (PFHxS) was 1.13 (95% CI 1.01-1.26). The association between PFHxS and FLD appeared stronger among individuals with obesity or high-fat diets (both p interaction <0.05). When limiting the analysis to 212 heavy drinkers (≥2 drinks/day for women and ≥3 drinks/day for men), significantly higher risk of alcoholic FLD was found for higher levels of perfluorooctanoic acid (ORSD 1.79; 95% CI 1.07-2.99), PFHxS (ORSD 2.06; 95% CI 1.17-3.65), and perfluoroheptane sulfonic acid (ORSD 1.44; 95% CI 1.00-2.07), and marginally significant higher risk for total PFAS (ORSD 2.12; 95% CI 0.99-4.54). In never or light drinkers, we did not observe any significant association between PFAS and non-alcoholic FLD. Significant positive associations were found for PFAS with aspartate aminotransferase, gamma-glutamyl transaminase, total bilirubin, and albumin (β ranged from 0.008 to 0.101, all p <0.05).

CONCLUSIONS

Higher serum PFAS was moderately associated with FLD risk and worse liver function in the general population, and among those with independent risk factors, including heavy alcohol intake, obesity, or high-fat diets, PFAS increased the risk. These results suggest synergistic effects on hepatic steatosis between PFAS exposures as measured through biomonitoring data and lifestyle risk factors in a nationally representative US population.

IMPACT AND IMPLICATIONS

The per- and polyfluoroalkyl substances (PFAS) may convey higher risk for chronic liver disease in humans. Among 1,135 US adults in the 2017-2018 National Health and Nutrition Examination Survey, we found that higher serum PFAS was associated with higher fatty liver disease risk and worse liver function, especially among those with liver disease risk factors, including heavy alcohol intake, obesity, or high-fat diets. Continuously monitoring PFAS in the population and examining how they potentiate risk to the liver are essential.

Metabolic perturbations in pregnant rats exposed to low-dose perfluorooctanesulfonic acid: An integrated multi-omics analysis

Emerging epidemiological evidence has linked per- and polyfluoroalkyl substances (PFAS) exposure could be linked to the disturbance of gestational glucolipid metabolism, but the toxicological mechanism is unclear, especially when the exposure is at a low level. This study examined the glucolipid metabolic changes in pregnant rats treated with relatively low dose perfluorooctanesulfonic acid (PFOS) through oral gavage during pregnancy [gestational day (GD): 1-18]. We explored the molecular mechanisms underlying the metabolic perturbation. Oral glucose tolerance test (OGTT) and biochemical tests were performed to assess the glucose homeostasis and serum lipid profiles in pregnant Sprague-Dawley (SD) rats randomly assigned to starch, 0.03 and 0.3 mg/kg·bw·d groups. Transcriptome sequencing combined with non-targeted metabolomic assays were further performed to identify differentially altered genes and metabolites in the liver of maternal rats, and to determine their correlation with the maternal metabolic phenotypes. Results of transcriptome showed that differentially expressed genes at 0.03 and 0.3 mg/kg·bw·d PFOS exposure were related to several metabolic pathways, such as peroxisome proliferator-activated receptors (PPARs) signaling, ovarian steroid synthesis, arachidonic acid metabolism, insulin resistance, cholesterol metabolism, unsaturated fatty acid synthesis, bile acid secretion. The untargeted metabolomics identified 164 and 158 differential metabolites in 0.03 and 0.3 mg/kg·bw·d exposure groups, respectively under negative ion mode of Electrospray Ionization (ESI-), which could be enriched in metabolic pathways such as α-linolenic acid metabolism, glycolysis/gluconeogenesis, glycerolipid metabolism, glucagon signaling pathway, glycine, serine and threonine metabolism. Co-enrichment analysis indicated that PFOS exposure may disturb the metabolism pathways of glycerolipid, glycolysis/gluconeogenesis, linoleic acid, steroid biosynthesis, glycine, serine and threonine. The key involved genes included down-regulated Ppp1r3c and Abcd2, and up-regulated Ogdhland Ppp1r3g, and the key metabolites such as increased glycerol 3-phosphate and lactosylceramide were further identified. Both of them were significantly associated with maternal fasting blood glucose (FBG) level. Our findings may provide mechanistic clues for clarifying metabolic toxicity of PFOS in human, especially for susceptible population such as pregnant women.

Serum per- and polyfluoroalkyl substances and abnormal lipid metabolism: A nationally representative cross-sectional study

BACKGROUND

The associations of legacy per- and polyfluoroalkyl substances (PFAS) with lipid metabolism are controversial, and there is little information about the impact of emerging PFAS (6:2 Cl-PFESA) on lipid metabolism in China.

OBJECTIVES

We aimed to explore the associations of legacy and emerging PFAS with lipid profiles and dyslipidemia in Chinese adults.

METHODS

We included 10,855 Chinese participants aged 18 years and above in the China National Human Biomonitoring. The associations of 8 PFAS with 5 lipid profiles and 4 dyslipidemia were investigated using weighted multiple linear regression or weighted logistic regression, and the dose-response associations were investigated using restricted cubic spline model.

RESULTS

Among the 8 PFAS, the concentration of PFOS was the highest, with a geometric mean of 5.15 ng/mL, followed by PFOA and 6:2 Cl-PFESA, which were 4.26 and 1.63 ng/mL, respectively. Legacy (PFOA, PFOS, PFUnDA) or emerging (6:2 Cl-PFESA) PFAS were associated with lipid profiles (TC, LDL-C, HDL-C, non HDL-C) and dyslipidemia (high LDL-C, high TC, low HDL-C), and their effects on TC were most obvious. TC concentration increased by 0.595 mmol/L in the highest quartile (Q4) of PFOS when compared with the lowest quartile (Q1), (95 % CI:0.396, 0.794). Restricted cubic spline models showed that PFAS are nonlinearly associated with TC, non HDL-C, LDL-C and HDL-C, and that the lipid concentrations tend to be stable when PFOS and PFOA were > 20 ng/mL well as when the 6:2 Cl-PFESA level was > 10 ng/mL. The positive associations between PFAS mixtures and lipid profiles were also significant.

CONCLUSIONS

Single and mixed exposure to PFAS were positively associated with lipid profiles, and China's unique legacy PFAS substitutes (6:2 Cl-PFESA) contributed less to lipid profiles than legacy PFAS. In the future, cohort studies will be needed to confirm our findings.