Associations between urinary phthalate metabolite concentrations and rheumatoid arthritis in the U.S. adult population

Associations between phthalate metabolites and two novel systemic inflammatory indexes: a cross-sectional analysis of NHANES data

BACKGROUND

The potentially risky effects of metabolites of phthalates (mPAEs) on inflammation and immune function have attracted much attention in recent years. However, direct studies on the relationship between these metabolites and the systemic immune inflammatory index (SII) and systemic inflammatory response index (SIRI) are limited.

METHODS

This cross-sectional study used generalized linear regression models (GLM), restricted cubic splines (RCS), weighted quantile sum (WQS), and Bayesian kernel-machine regression (BKMR) to analyze data from 2,763 U.S. adults aged between 20 and 80 years, obtained from the U.S. National Health and Nutrition Examination Survey (NHANES) conducted between 2013 and 2018. The study aimed to investigate the relationship between urine samples of nine mPAEs and levels of SII/SIRI in a single, nonlinear, and mixed relationship and explored the robustness of the findings under single and mixed effects using two sensitivity analyses for completeness. In addition, the effects of six variables (age, sex, BMI, the percentage of total daily energy intake from ultra-processed foods (UPFs), total vegetable intake, and dietary supplements) on the association results were explored through subgroup analyses to identify potentially important confounders.

RESULTS

In single exposure analyses, mono-n-butyl phthalate (MnBP), mono-ethyl phthalate (MEP), and monobenzyl phthalate (MBzP) were positively associated with SII/SIRI. The findings from the two mixed exposure models demonstrated a positive association between the collective concentrations of mPAEs and levels of SII/SIRI, with MBzP being identified as a significant contributor to the urinary levels of mPAEs. The subgroup analysis results of the effects of single and mixed exposures show that the association between mPAEs and SII/SIRI is more significant in females, overweight/obese populations, young/middle-aged populations, and populations with high levels of intake of UPFs.

CONCLUSION

Positive associations were identified between mPAEs and SII/SIRI. MBzP was determined to have the most significant impact. The association between mPAEs and SII/SIRI is significantly influenced by female groups, young and middle-aged populations, overweight and obese individuals, as well as those with a higher intake of UPFs.

Association of urinary perchlorate, nitrate and thiocyanate with pregnancy loss risk among reproductive-aged women

Environmental pollution is recognized as a critical contributor to pregnancy loss. However, there is currently a paucity of evidence concerning the potential impact of perchlorate, thiocyanate and nitrate, which are known as sodium iodine symporter inhibitors. This study was therefore designed to investigate the potential association between urinary perchlorate, thiocyanate and nitrate concentration and the risk of pregnancy loss. Based on the National Health and Nutrition Examination Survey 2001-2002 and 2005-2020 cycles, a total of 3249 reproductive-aged women were enrolled, of whom 1729 (53.22 %) had a history of pregnancy loss encompassing miscarriages, stillbirths, ectopic pregnancies, or abortions. Logistic regression analyses revealed that urinary perchlorate levels were significantly associated with increased pregnancy loss prevalence. In the weighted quantile sum and Bayesian kernel machine regression models, co-exposure to three anions were also significantly associated with higher pregnancy loss odds, with perchlorate identified as the primary contributor. Additionally, the mediation analysis suggested that insulin resistance, represented by the triglyceride-glucose index, accounted for 6.08 % of the perchlorate-associated risk. In summary, our study revealed a potential role of perchlorate exposure in pregnancy loss. Further prospective studies are needed to confirm our findings and elucidate the underlying causative mechanistic links.

Monocarboxyoctyl phthalate is associated with platelet count: evidence from a large cross-sectional study

Introduction

Phthalates are environmental pollutants that are harmful to human health. However, the impact of phthalate on platelet count remains unclear. This study aimed to examine the correlation between five phthalate metabolites in urine and platelet count, as well as the impact of phthalate metabolite exposure on platelet count in adults.

Methods

This cross-sectional study included 11,409 non-pregnant participants aged >20 years using data available from the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2018. Weighted logistic regression, restricted cubic spline (RCS) modeling, and weighted quantile sum (WQS) were employed to investigate the effects of mono-(carboxyisononyl) phthalate (MCNP), mono-(carboxyoctyl) phthalate (MCOP), mono-(3-carboxypropyl) phthalate (MCPP), mono-isobutyl phthalate (MiBP) and mono-isononyl phthalate (MNP) on platelet count.

Results

Logistic regression analysis suggested that MCOP [odds ratio (OR) (95% confidence interval CI) = 0.009 (0.002-0.036)] was significantly associated with the platelet count. Subgroup analysis showed negative correlations between MCOP and platelet count across all age and sex groups, and MCNP [OR (95% CI) = 0.083(0.013-0.552)] displayed a negative association with platelet count in females. MCOP had a nonlinear relationship with the platelet count in the RCS model. WQS also revealed that MCOP was related to platelet count.

Conclusion

Higher urinary MCOP level was associated with lower platelet count. Further investigation is necessary to substantiate these findings, considering the shortcomings of the NHANES study.

Toxic Effects of Exposure to Phthalates on Cardiac Injury Biomarkers: Evidence from NHANES 1999-2004

Background: Humans are consistently and increasingly exposed to phthalate products, but the effect of the combined exposure to phthalates on myocardial injury remains largely unexplored. The present study aimed to explore the effect of the combined exposure to phthalates on myocardial injury. Methods: A total of 1237 male adults (aged ≥20) without coronary artery disease (CAD) from the National Health and Nutrition Examination Survey (NHANES) in 1999-2004 were included in the current study. Multiple linear regression, Bayesian kernel machine regression (BKMR), and a weighted quantile sum (WQS) model were employed to examine the associations of urinary phthalate metabolites with two cardiac injury biomarkers, including troponin T (TNT) and troponin I, using four highly sensitive assays (Abbott, Chicago, IL, USA; Siemens, Erlangen, Germany; and Ortho, Raritan, NJ, USA) (TNIA, TNIS, TNIO). Results: According to the linear regression analysis, mono-(3-carboxypropyl) phthalate (MCPP, a metabolite of di-n-octyl phthalate) was found to be positively associated with serum TNT; a positive association was found between mono-isobutyl phthalate (MiBP, a metabolite of di-isobutyl phthalate) and TNIA, as well as MiBP and TNIS. Mono-benzyl phthalate (MBzP, a metabolite of butyl benzyl phthalate) and MCPP were positively associated with serum TNIO. The BKMR analyses showed a positive overall relationship of serum TNT, TNIA, TNIS, and TNIO with increased concentrations of phthalate metabolites. The WQS model showed MCPP and MBzP were the top two contributors to being an increased risk for elevated TNT levels. MCPP and mono-ethyl phthalate (MEP, a metabolite of diethyl phthalate) were identified as the leading contributors to increased TNIA and TNIS. MCPP and MBzP were the dominant contributors to elevated TNIO. Conclusions: As a combined mixture, phthalate metabolites were positively associated with serum TNT and TNI among adults without CAD, indicating the potential toxic effect of phthalate exposure on cardiac injury.

Association between exposure to per- and polyfluoroalkyl substances (PFAS) and chronic cough in American adults: Results from NHANES 2003-2012

Chronic cough, which affects approximately 10 % of the global population, is recognized as a significant health issue, especially among females. Recent research suggests that chronic cough may be an independent disease rather than merely a symptom of other conditions. This study focuses on the potential role of exposure to perfluoroalkyl and polyfluoroalkyl substances (PFAS) in the development of chronic cough, noting that PFAS exposure has been linked to various adverse health outcomes. We aimed to explore the association between PFAS exposure and the risk of chronic cough in the U.S. population, analyzing data from the National Health and Nutrition Examination Survey (NHANES) from 2003 to 2012 and examining potential sex-based differences. Our findings reveal several factors independently associated with an increased incidence of chronic cough, including elevated levels of serum perfluorobutane sulfonic acid (PFBS) and perfluoroheptanoic acid (PFHP). The multi-pollutant models consistently demonstrated a significant positive correlation between PFAS exposure and a higher risk of chronic cough in adult males, with PFBS and PFHP as the primary contributors. However, due to the cross-sectional design of the NHANES study, further research is necessary to elucidate the precise mechanisms by which PFAS contribute to chronic cough.

Association between urinary volatile organic compounds metabolites and rheumatoid arthritis among the adults from NHANES 2011-2018

Rheumatoid arthritis (RA) is closely associated with environmental factors. Volatile organic compounds (VOCs) are a common environment pollutant which can induce autoimmune diseases. However, studies on the relationship between VOCs and RA are still unclear. This study aimed to evaluate the potential associations between exposure to urinary VOCs and RA risk among adults. Data was analyzed from the National Health and Nutrition Examination Survey (NHANES) 2011-2018. We used logistics regression, restricted cubic splines (RCS) model, (Weighted Quantile Sum) WQS, qgcomp and (Bayesian Kernel Machine Regression) BKMR models to assess single and mixed relationships between VOCs and RA. A total of 3390 participants and 15 urinary VOCs included in this study. The results showed that AMCC, CEMC, DHBC, MB3C, PHGA, and PMMC were significantly higher than in RA compare to the participants without RA. Logistic regression model reveals that AAMC, AMCC, CEMC, CYMC, DHBC, HPMC, and MB3C were positive correlation with RA which age between 20 and 50. Then the WQS, qgcomp, and BKMR model suggest a positive association between mixed urinary VOCs and RA, with WQS and qgcomp model highlighting CYMC and CEMC as the major contributors in age 20-59 group. In BKMR analysis, the overall effects of co-exposure displayed CYMC, CEMC, and AMCC has significant positive with RA in age 20-59. Furthermore, RCS regression proved the positive linear relationship between CYMC, AMCC, and CEMC with RA. According to our study results, we demonstrated that exposure to certain urinary VOCs (CYMC, CEMC, and AMCC) is associated with an increased prevalence of RA among adults that age 20-59.

Associations of exposure to blood heavy metal mixtures with Toxoplasma infection among U.S. adults: a cross-sectional study

Introduction

Research increasingly links environmental exposure to toxic metals with health risks, yet the effect of combined metal exposure on Toxoplasma infection remains underexplored. This study investigates the relationship between concurrent heavy metal exposure and Toxoplasma infection in adults.

Methods

We analyzed data from 10,746 adults aged 20-80 from NHANES, with 1,869 positive for Toxoplasma gondii IgG. The study assessed associations between lead (Pb), cadmium (Cd), and mercury (Hg) with Toxoplasma infection risk using single-metal logistic regression, RCS analysis, WQS regression, and qgcomp models.

Results

Each metal showed an independent association with Toxoplasma infection risk. Pb had a non-linear association, while Hg had a linear one. Analysis of multiple metals indicated a positive correlation between heavy metal exposure and infection risk, particularly in younger and middle-aged adults, with Pb showing the strongest link.

Discussion

Our findings reveal a significant association between heavy metal exposure and Toxoplasma infection risk, especially in younger demographics, with lead being a key factor. This highlights the importance of understanding environmental metal exposure's impact on public health and informs the development of prevention strategies.

Relationship between mixed exposure to phenyl hydroxides, polycyclic aromatic hydrocarbons, and phthalates and the risk of arthritis

BACKGROUND

To determine the relationship between mixed exposure to three types of endocrine-disrupting chemicals (EDCs), namely phenyl hydroxides, polycyclic aromatic hydrocarbons (PAHs), and phthalates (PAEs), and risk of arthritis.

METHODS

Participants were selected from National Health and Nutrition Examination Survey (NHANES). The relationships between the urinary concentrations of phenyl hydroxides, PAHs, and PAEs and the risk of arthritis were analyzed by generalized linear regression model. The mixed exposure to these EDCs and the risk of arthritis was analyzed by weighted quantile sums (WQSs) and Bayesian kernel machine regression (BKMR) model.

RESULTS

Our analysis showed that participants with urinary benzophenone-3 and methylparaben concentrations in the highest quartile (Q4) had an increased risk of arthritis compared with those in Q1. For each one-unit increase in the natural logarithm-converted urinary concentrations of 1-hydroxynapthalene and 2-hydroxynapthalene, the risk of arthritis increased by 5% and 8%, respectively. Chemical mixing index coefficients were significantly associated with risk of arthritis in both WQS positive- and negative-constraint models. In the BKMR model, there was a significant positive correlation between mixed exposure and the risk of arthritis.

CONCLUSION

Mixed exposure to phenyl hydroxides, PAHs, and PAEs increased the risk of arthritis, with exposure to PAHs being the key factor.

Associations of phthalates with accelerated aging and the mitigating role of physical activity

Phthalates are positioned as potential risk factors for health-related diseases. However, the effects of exposure to phthalates on accelerated aging and the potential modifications of physical activity remain unclear. A total of 2317 participants containing complete study-related information from the National Health and Nutrition Examination Survey 2007-2010 were included in the current study. We used two indicators, the Klemera-Doubal method biological age acceleration (BioAgeAccel) and phenotypic age acceleration (PhenoAgeAccel), to assess the accelerated aging status of the subjects. Multiple linear regression (single pollutant models), weighted quantile sum (WQS) regression, Quantile g-computation, and Bayesian kernel machine regression (BKMR) models were utilized to explore the associations between urinary phthalate metabolites and accelerated aging. Three groups of physical activity with different intensities were used to evaluate the modifying effects on the above associations. Results indicated that most phthalate metabolites were significantly associated with BioAgeAccel and PhenoAgeAccel, with effect values (β) ranging from 0.16 to 0.21 and 0.16-0.37, respectively. The WQS indices were positively associated with BioAgeAccel (0.33, 95% CI: 0.11, 0.54) and PhenoAgeAccel (0.50, 95% CI: 0.19, 0.82). Quantile g-computation indicated that phthalate mixtures were associated with accelerated aging, with effect values of 0.15 (95% CI: 0.02, 0.28) for BioAgeAccel and 0.39 (95% CI: 0.12, 0.67) for PhenoAgeAccel respectively. The BKMR models indicated a significant positive association between the concentrations of urinary phthalate mixtures with the two indicators. In addition, we found that most phthalate metabolites showed the strongest effects on accelerated aging in the no physical activity group and that the effects decreased gradually with increasing levels of physical activity (P < 0.05 for trend). Similar results were also observed in the mixed exposure models (WQS and Quantile g-computation). This study indicates that phthalates exposure is associated with accelerated aging, while physical activity may be a crucial barrier against phthalates exposure-related aging.

Sexual dimorphism association of combined exposure to volatile organic compounds (VOC) with kidney damage

BACKGROUND

Epidemiological evidence emphasizes air pollutants' role in chronic kidney disease (CKD). Volatile organic compounds (VOCs) contribute to air pollution, yet research on VOCs and kidney damage, especially gender disparities, is limited.

METHODS

This study analyzed NHANES data to explore associations between urinary VOC metabolite mixtures (VOCMs) and key kidney-related parameters: estimated glomerular filtration rate (eGFR), albumin-to-creatinine ratio (ACR), chronic kidney disease (CKD), and albuminuria. Mediation analyses assessed the potential mediating roles of biological aging (BA) and serum albumin in VOCM mixtures' effects on kidney damage. Sensitivity analyses were also conducted.

RESULTS

The mixture analysis unveiled a noteworthy positive association between VOCM mixtures and the risk of developing CKD, coupled with a significant negative correlation with eGFR within the overall participant cohort. These findings remained consistent when examining the female subgroup. However, among male participants, no significant link emerged between VOCM mixtures and CKD or eGFR. Furthermore, in both the overall and female participant groups, there was an absence of a significant correlation between VOCM mixtures and either ACR or albuminuria. On the other hand, in male participants, while no significant correlation was detected with albuminuria, a significant positive correlation was observed with ACR. Pollutant analysis identified potential links between kidney damage and 1,3-butadiene, toluene, ethylbenzene, styrene, xylene, acrolein, crotonaldehyde and propylene oxide. Mediation analyses suggested that BA might partially mediate the relationship between VOCM mixtures and kidney damage.

CONCLUSION

The current findings highlight the widespread exposure to VOCs among the general U.S. adult population and indicate a potential correlation between exposure to VOC mixtures and compromised renal function parameters, with notable gender disparities. Females appear to exhibit greater sensitivity to impaired renal function resulting from VOCs exposure. Anti-aging treatments may offer some mitigation against kidney damage due to VOCs exposure.

Bifenthrin induces changes in clinical poisoning symptoms, oxidative stress, DNA damage, histological characteristics, and transcriptome in Chinese giant salamander (Andrias davidianus) larvae

Bifenthrin (BF) is a broad-spectrum insecticide that has gained widespread use due to its high effectiveness. However, there is limited research on the potential toxic effects of bifenthrin pollution on amphibians. This study aimed to investigate the 50 % lethal concentration (LC50) and safety concentration of Chinese giant salamanders (CGS) exposed to BF (at 0, 6.25,12.5,25 and 50 μg/L BF) for 96 h. Subsequently, CGS were exposed to BF (at 0, 0.04, and 4 μg/L BF) for one week to investigate its toxic effects. Clinical poisoning symptoms, liver pathology, oxidative stress factors, DNA damage, and transcriptome differences were observed and analyzed. The results indicate that exposure to BF at 4 μg/L significantly decreased the adenosine-triphosphate (ATP), superoxide dismutase (SOD), glutathione (GSH), and catalase (CAT) contents in the brain, liver, and kidney of CGS. Additionally, the study found that the malondialdehyde (MDA), reactive oxygen species (ROS), and 8-hydroxydeoxyguanosine (8-OHdG) contents were increased. The liver tissue exhibited significant inflammatory reactions and structural malformations. RNA-seq analysis of the liver showed that BF caused abnormal antioxidant indices of CGS. This affected molecular function genes such as catalytic activity, ATP-dependent activity, metabolic processes, signaling and immune system processes, behavior, and detoxification, which were significantly upregulated, resulting in the differential genes significantly enriched in the calcium signaling pathway, PPARα signaling pathway and NF-kB signaling pathway. The results suggest that BF induces the abnormal production of free radicals, which overwhelms the body's self-defense system, leading to varying degrees of oxidative stress. This can result in oxidative damage, DNA damage, abnormal lipid metabolism, autoimmune diseases, clinical poisoning symptoms, and tissue inflammation. This work provides a theoretical basis for the rational application of bifenthrin and environmental risk assessment, as well as scientific guidance for the conservation of amphibian populations.

Associations of per- and polyfluoroalkyl substances (PFAS) and their mixture with risk of rheumatoid arthritis in the U.S. adult population

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are known environmental contaminants with immunosuppressive properties. Their connection to rheumatoid arthritis (RA), a condition influenced by the immune system, is not well studied. This research explores the association between PFAS exposure and RA prevalence.

METHODS

This research utilized data from the NHANES, encompassing a sample of 10,496 adults from the 2003-2018 cycles, focusing on serum levels of several PFAS. The presence of RA was determined based on self-reports. This study used multivariable logistic regression to assess the relationship between individual PFAS and RA risk, adjusting for covariates to calculate odds ratios (ORs). The combined effects of PFAS mixtures were evaluated using BKMR, WQS regression, and quantile g-computation. Additionally, sex-specific associations were explored through stratified analysis.

RESULTS

Higher serum PFOA (OR = 0.88, 95% CI: 0.79, 0.98), PFHxS (OR = 0.91, 95% CI: 0.83, 1.00), PFNA (OR = 0.87, 95% CI: 0.77, 0.98), and PFDA (OR = 0.89, 95% CI: 0.81, 0.99) concentration was related to lower odds of RA. Sex-specific analysis in single chemical models indicated the significant inverse associations were only evident in females. BKMR did not show an obvious pattern of RA estimates across PFAS mixture. The outcomes of sex-stratified quantile g-computation demonstrated that an increase in PFAS mixture was associated with a decreased odds of RA in females (OR: 0.76, 95% CI: 0.62, 0.92). We identified a significant interaction term of the WQS*sex in the 100 repeated hold out WQS analysis. Notably, a higher concentration of the PFAS mixture was significantly associated with reduced odds of RA in females (mean OR = 0.93, 95% CI: 0.88, 0.98).

CONCLUSIONS

This study indicates potential sex-specific associations of exposure to various individual PFAS and their mixtures with RA. Notably, the observed inverse relationships were statistically significant in females but not in males. These findings contribute to the growing body of evidence indicating that PFAS may have immunosuppressive effects.

Associations of perchlorate, nitrate, and thiocyanate exposure with arthritis and inflammation indicators in young and middle-aged adults, NHANES 2005-2016

Background

Perchlorates, nitrates, and thiocyanates are prevalent environmental chemicals. Their potential association with arthritis remains unexplored. This study aimed to investigate the link between perchlorate, nitrate, and thiocyanate exposure and arthritis, as well as the potential role of inflammation in this context.

Methods

Utilizing the National Health and Nutrition Examination Survey (NHANES) data spanning from 2005 to 2016, the study enrolled 6597 participants aged 20-59 (young and middle-aged), of which 1045 had arthritis. Employing multivariate logistic regression modeling, multiple linear regression models, restricted cubic spline analysis, Bayesian kernel machine regression (BKMR) modeling, and mediation analysis, we assessed these relationships.

Results

There was a significant positive association between elevated urinary thiocyanate levels and arthritis risk [1.19 (1.11, 1.28)]. This association held true across subgroups of osteoarthritis (OA) [1.24 (1.10, 1.40)] and rheumatoid arthritis (RA) [1.33 (1.15, 1.55)]. Thiocyanate levels displayed a dose-dependent relationship with arthritis risk, showing a linear trend (nonlinear P > 0.05). Conversely, perchlorate and nitrate did not exhibit associations with arthritis risk. BKMR outcomes highlighted a positive correlation between a mixture of perchlorate, nitrate, and thiocyanate and arthritis risk, with thiocyanate being the predominant predictors. Moreover, BKMR and generalized linear model analyses unveiled no significant synergistic effect of urinary perchlorate, nitrate, and thiocyanate on arthritis risk. Furthermore, thiocyanate exposure has been linked to elevated levels of inflammatory indicators (white blood cell, neutrophils, lymphocytes, and systemic immune-inflammatory index (SII)).

Conclusion

Heightened thiocyanate exposure may be linked to elevated arthritis risk, either single or in combined effects. Additionally, thiocyanate exposure is associated with heightened inflammation levels.