Perfluoroalkyl Substances and Abdominal Aortic Calcification

Associations between per- and polyfluoroalkyl chemicals and abdominal aortic calcification in middle-aged and older adults

INTRODUCTION

Per- and polyfluoroalkyl substances (PFAS) have infiltrated countless everyday products, raising concerns about potential effects on human health, specifically on the cardiovascular system and the development of abdominal aortic calcification (AAC). However, our understanding of this relationship is still limited.

OBJECTIVES

This study aims to investigate the effects of PFAS on AAC using machine learning algorithms.

METHODS

Leveraging the power of machine learning technique, extreme gradient boosting (XGBoost), we assessed the relationship between PFAS exposure and AAC risk. We focused on three PFAS compounds, perfluorodecanoic acid (PFDeA), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA) through multiple logistic regression, restricted cubic spline (RCS), and quantile g-computation (QGC) models. To get more insight into the underlying mechanisms, mediation analyses are used to investigate the potential mediating role of fatty acids and blood cell fractions in AAC.

RESULTS

Our findings indicate that elevated serum levels of PFHxS and PFDeA are associated with the increased risk of AAC. The QGC analyses underscore the overall positive association between the PFAS mixture and AAC risk, with PFHxS carrying the greatest weight, followed by PFDeA. The RCS analyses reveal a dose-dependent increase between serum PFHxS concentration and AAC risk in an inverted V-shape way. Moreover, age and PFHxS exposure are identified as the primary factors contributing to abdominal aortic calcification risk in SHapley Additive exPlanation (SHAP) summary plot combined with XGBoost technique. Although PFAS significantly change the profile of fatty acids, we do not find any mediating roles of them in AAC. Despite strong associations between PFAS exposure and hematological indicators, our analysis does not find evidence that these indicators mediate the development of AAC.

CONCLUSIONS

In summary, our study highlights the detrimental impact of PFAS on abdominal aortic health and emphasizes the need for further research to understand the underlying mechanisms involved.

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.

Exposure to perchlorate, nitrate, and thiocyanate and the prevalence of abdominal aortic calcification

Perchlorate, nitrate, and thiocyanate are reported to affect human health. However, it is unclear about the associations between exposure to these chemicals and abdominal aortic calcification (AAC). A total of 959 individuals were included in a large representative survey. Urinary levels of perchlorate, nitrate, and thiocyanate were measured by ion chromatography coupled with electrospray tandem mass spectrometry. AAC was diagnosed based on dual-energy X-ray absorptiometry (DXA). There were 276 (28.8%) cases of AAC among the participants. The level of urinary nitrate was significantly lower in AAC patients compared with non-AAC patients (36.4 mg/L [20.6, 59.5] vs. 42.4 [23.8, 68.3]; P = 0.013). In multivariable-adjusted logistic regression models, urinary nitrate was associated with the prevalence of AAC. Compared with the lowest quartile, the odds ratios (95% confidence intervals) across increasing quartiles were 1.06 (0.69-1.61; P = 0.799), 0.64 (0.41-1.00; P = 0.049) and 0.74 (0.47-1.15; P = 0.180). Restricted cubic splines suggested that urinary nitrate ranging between 43.7 and 115.4 mg/L was associated with a lower risk of AAC. Moderate exposure to nitrate was associated with a lower risk of AAC.