OBJECTIVE: To investigate the associations between eight serum per- and polyfluoroalkyl substances (PFASs) and regional fat depots, we analyzed the data from the National Health and Nutrition Examination Survey (NHANES) 2011-2018 cycles. METHODS: Multiple linear regression models were developed to explore the associations between serum PFAS concentrations and six fat compositions along with a fat distribution score created by summing the concentrations of the six fat compositions. The associations between structurally grouped PFASs and fat distribution were assessed, and a prediction model was developed to estimate the ability of PFAS exposure to predict obesity risk. RESULTS: Among females aged 39-59 years, trunk fat mass was positively associated with perfluorooctane sulfonate (PFOS). Higher concentrations of PFOS, perfluorohexane sulfonate (PFHxS), perfluorodecanoate (PFDeA), perfluorononanoate (PFNA), and n-perfluorooctanoate (n-PFOA) were linked to greater visceral adipose tissue in this group. In men, exposure to total perfluoroalkane sulfonates (PFSAs) and long-chain PFSAs was associated with reductions in abdominal fat, while higher abdominal fat in women aged 39-59 years was associated with short-chain PFSAs. The prediction model demonstrated high accuracy, with an area under the curve (AUC) of 0.9925 for predicting obesity risk. CONCLUSION PFAS exposure is associated with regional fat distribution, with varying effects based on age, sex, and PFAS structure. The findings highlight the potential role of PFAS exposure in influencing fat depots and obesity risk, with significant implications for public health. The prediction model provides a highly accurate tool for assessing obesity risk related to PFAS exposure.
Humans ; Fluorocarbons/blood* ; Female ; Adult ; Middle Aged ; Male ; Environmental Pollutants/blood* ; Abdominal Fat ; Nutrition Surveys ; Alkanesulfonic Acids/blood* ; Obesity ; Environmental Exposure

OBJECTIVE: The relationship between non-high-density lipoprotein (NHDL) cholesterol to high-density lipoprotein cholesterol (HDL-C) ratio (NHHR) and stoke remains unknown. This study aimed to evaluate the association between the adult NHHR and stroke occurrence in the United States of America (USA). METHODS: To clarify the relationship between the NHHR and stroke risk, this study used a multivariable logistic regression model and a restricted cubic spline (RCS) model to investigate the association between the NHHR and stroke, and data from the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2018. Subgroup and sensitivity analyses were conducted to test the robustness of the results. RESULTS: This study included 29,928 adult participants, of which 1,165 participants had a history of stroke. Logistic regression analysis of variables demonstrated a positive association between NHHR and stroke ( OR 1.24, 95% CI: 1.03-1.50, P = 0.026). Compared with the lowest reference group of NHHR, participants in the second, third, and fourth quartile had a significantly increased risk of stroke after full adjustments ( OR: 1.35, 95% CI: 1.08-1.69) ( OR: 1.83, 95% CI: 1.42-2.36) ( OR: 2.04, 95% CI: 1.50-2.79). In the total population, a nonlinear dose-response relationship was observed between the NHHR and stroke risk ( P non-linearity = 0.002). This association remained significant in several subgroup analyses. Further investigation of the NHHR may enhance our understanding of stroke prevention and treatment. CONCLUSION Our findings suggest a positive correlation between the NHHR and an increased prevalence of stroke, potentially serving as a novel predictive factor for stroke. Timely intervention and management of the NHHR may effectively mitigate stroke occurrence. Prospective studies are required to validate this association and further explore the underlying biological mechanisms.
Humans ; Stroke/blood* ; United States/epidemiology* ; Male ; Female ; Middle Aged ; Cross-Sectional Studies ; Nutrition Surveys ; Adult ; Aged ; Cholesterol, HDL/blood* ; Cholesterol/blood* ; Risk Factors

OBJECTIVE: Humans are exposed to complex mixtures of environmental chemicals and other factors that can affect their health. Analysis of these mixture exposures presents several key challenges for environmental epidemiology and risk assessment, including high dimensionality, correlated exposure, and subtle individual effects. METHODS: We proposed a novel statistical approach, the generalized functional linear model (GFLM), to analyze the health effects of exposure mixtures. GFLM treats the effect of mixture exposures as a smooth function by reordering exposures based on specific mechanisms and capturing internal correlations to provide a meaningful estimation and interpretation. The robustness and efficiency was evaluated under various scenarios through extensive simulation studies. RESULTS: We applied the GFLM to two datasets from the National Health and Nutrition Examination Survey (NHANES). In the first application, we examined the effects of 37 nutrients on BMI (2011-2016 cycles). The GFLM identified a significant mixture effect, with fiber and fat emerging as the nutrients with the greatest negative and positive effects on BMI, respectively. For the second application, we investigated the association between four pre- and perfluoroalkyl substances (PFAS) and gout risk (2007-2018 cycles). Unlike traditional methods, the GFLM indicated no significant association, demonstrating its robustness to multicollinearity. CONCLUSION GFLM framework is a powerful tool for mixture exposure analysis, offering improved handling of correlated exposures and interpretable results. It demonstrates robust performance across various scenarios and real-world applications, advancing our understanding of complex environmental exposures and their health impacts on environmental epidemiology and toxicology.
Humans ; Environmental Exposure/analysis* ; Linear Models ; Nutrition Surveys ; Environmental Pollutants ; Body Mass Index

BACKGROUND: Hypertension is a serious chronic disease that can significantly lead to various cardiovascular diseases, affecting vital organs such as the heart, brain, and kidneys. Our goal is to predict the risk of new onset hypertension using machine learning algorithms and identify the characteristics of patients with new onset hypertension. METHODS: We analyzed data from the 2011 China Health and Nutrition Survey cohort of individuals who were not hypertensive at baseline and had follow-up results available for prediction by 2015. We tested and evaluated the performance of four traditional machine learning algorithms commonly used in epidemiological studies: Logistic Regression, Support Vector Machine, XGBoost, LightGBM, and two deep learning algorithms: TabNet and AMFormer model. We modeled using 16 and 29 features, respectively. SHAP values were applied to select key features associated with new onset hypertension. RESULTS: A total of 4,982 participants were included in the analysis, of whom 1,017 developed hypertension during the 4-year follow-up. Among the 16-feature models, Logistic Regression had the highest AUC of 0.784(0.775∼0.806). In the 29-feature prediction models, AMFormer performed the best with an AUC of 0.802(0.795∼0.820), and also scored the highest in MCC (0.417, 95%CI: 0.400∼0.434) and F1 (0.503, 95%CI: 0.484∼0.505) metrics, demonstrating superior overall performance compared to the other models. Additionally, key features selected based on the AMFormer, such as age, province, waist circumference, urban or rural location, education level, employment status, weight, WHR, and BMI, played significant roles. CONCLUSION We used the AMFormer model for the first time in predicting new onset hypertension and achieved the best results among the six algorithms tested. Key features associated with new onset hypertension can be determined through this algorithm. The practice of machine learning algorithms can further enhance the predictive efficacy of diseases and identify risk factors for diseases.
Humans ; China/epidemiology* ; Hypertension/diagnosis* ; Machine Learning ; Male ; Female ; Middle Aged ; Adult ; Nutrition Surveys ; Algorithms ; Aged ; Risk Factors

BACKGROUND: Ethylene oxide (EO) is a widely utilized industrial compound known to pose health hazards. Although its carcinogenic characteristics have been thoroughly investigated, recent findings indicate possible links to respiratory disease. The correlation between EO exposure and the likelihood of developing obstructive sleep apnea (OSA) in individuals remains unclear. The study aimed to explore the association between EO exposure and OSA within the broader US population. METHODS: From 2015 to 2020, 4355 participants were analyzed cross-sectionally in the National Health and Nutrition Examination Survey (NHANES). As the primary indicator of EO exposure, hemoglobin adducts of EO (HbEO) were used in this study. The relationship between EO exposure and OSA prevalence was assessed using weighted multivariable regression analysis and smoothing curve fitting. Using subgroup analysis and interaction tests, we investigated whether this association remained consistent across populations. RESULTS: According to the study, higher HbEO level was positively correlated with a higher prevalence of OSA. Compared to the first HbEO quartile (Q1), participants within the highest quartile (Q4) presented a higher OSA prevalence in the fully model (OR = 1.32, 95% CI: 1.08-1.62, P = 0.01, P for trend = 0.001). This correlation was particularly evident among females and individuals who are insufficiently physically active. CONCLUSIONS This research found a positive relationship between the extent of exposure to EO and OSA prevalence among a representative sample of Americans.
Humans ; Sleep Apnea, Obstructive/chemically induced* ; Female ; Male ; Middle Aged ; Adult ; Cross-Sectional Studies ; Prevalence ; Ethylene Oxide/toxicity* ; United States/epidemiology* ; Nutrition Surveys ; Aged ; Environmental Exposure/adverse effects* ; Young Adult

BACKGROUND: Heavy metals are significant risk factors for kidney function. Numerous studies have shown that exposure to heavy metals negatively correlates with kidney function through oxidative stress pathways, and serum α-klotho is linked to oxidative stress. However, the role of α-klotho in the relationship between blood lead, mercury, and kidney function remains unclear. METHOD: This study evaluated the mediating role of alpha-klotho in the relationship between lead, mercury and renal function, using data from the 2007-2016 National Health and Nutrition Examination Survey (NHANES) in U.S. adults aged 40-79. The sample included 11,032 participants, with blood lead, mercury, α-klotho, and other relevant covariates measured. Inductively coupled plasma mass spectrometry was used to assess blood lead and mercury levels, and enzyme-linked immunosorbent assay (ELISA) was employed to measure serum α-klotho. Kidney function was evaluated using estimated glomerular filtration rate (eGFR) based on creatinine levels. Multivariable linear regression was conducted to analyze the relationships between blood lead, mercury, α-klotho, and eGFR. A mediation analysis model was used to assess whether α-klotho influenced these associations. RESULTS: We observed a significant association between blood lead and eGFR. Mediation analysis revealed that α-klotho accounted for 12.76% of the relationship between serum lead and eGFR in the NHANES population. Subgroup analysis showed that α-klotho mediated 12.43%, 6.87%, 21.50% and 5.44% of the relationship between blood lead and eGFR in women, middle-aged adults (40-59 years old), without cardiovascular disease and hypertension, respectively. However, α-klotho did not mediate the relationship between blood mercury and eGFR in terms of gender or age. This newly identified pathway may provide valuable insights for the prevention and treatment mechanisms related to kidney function impairment. CONCLUSION We found that blood lead was associated with renal function. According to the results of subgroup analysis, for blood lead, serum α-klotho mediated the association in females, middle aged 60-79 years. The relationship between blood mercury and renal function was not clinically significant, and serum α-Klotho mediated the relationship between blood mercury and renal function without significant clinical significance.
Humans ; Middle Aged ; Lead/blood* ; Female ; Klotho Proteins ; Male ; Aged ; Adult ; Mercury/blood* ; Glomerular Filtration Rate ; Nutrition Surveys ; United States ; Kidney/physiology* ; Glucuronidase/blood* ; Environmental Pollutants/blood*

BACKGROUND: Chronic kidney disease (CKD) poses a major global health challenge, often foreshadowing poor patient outcomes. The C-reactive protein to albumin ratio (CAR) serves as a pivotal biomarker, demonstrating a strong correlation with adverse outcomes in cardiovascular disease (CVD). This study sought to examine the correlation between CAR and the risk of all-cause and cardiovascular mortality in patients with CKD stages 3-5. METHODS: This study utilized data of CKD patients from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2010, with follow-up to December 31, 2019. The optimal CAR cutoff value was identified utilizing the method of maximally selected rank statistics. Multivariable Cox proportional hazards regression model, restricted cubic splines (RCS) model, and subgroup analysis were employed to assess the association between CAR and mortality among CKD patients. RESULTS: During a median (with interquartile range) follow-up period of 115 (112,117) months among 2,841 CKD individuals, 1,893 deaths were observed, including 692 deaths due to CVD events. Based on the RCS analysis, a non-linear correlation was observed between CAR and mortality. Using 0.3 as the optimal CAR cutoff value, the cohort was divided into high and low groups. In the fully adjusted model, CKD patients with high CAR values exhibited an elevated risk of all-cause mortality (hazard ratio [HR] 1.53, 95% confidence interval [CI] 1.28-1.83, P < 0.001) and cardiovascular mortality (HR 1.48, 95% CI 1.08-2.02, P = 0.014). Compared to the population aged >65 years (HR 1.32, 95% CI 0.99-1.76, P = 0.064), the risk of cardiovascular mortality was significantly higher in those aged ≤65 years (HR 2.19, 95% CI 1.18-4.09, P = 0.014) with elevated CAR levels. CONCLUSIONS A notable correlation exists between the elevation of CAR and increased all-cause and cardiovascular mortality, suggesting its potential as an independent indicator for evaluating the prognosis of patients with CKD stages 3-5.
Humans ; Renal Insufficiency, Chronic/epidemiology* ; Cardiovascular Diseases/blood* ; Male ; Female ; Middle Aged ; C-Reactive Protein/metabolism* ; Aged ; Biomarkers/blood* ; Nutrition Surveys ; Adult ; United States/epidemiology* ; Serum Albumin/analysis*

BACKGROUND: Post-stroke disability diminishes the physical activity (PA) level of survivors, potentially affecting their long-term prognosis. This study endeavors to explore the correlation between daily PA level and the all-cause mortality in patients with a history of stoke in the United States. METHODS: Data of stroke survivors were sourced from the National Health and Nutritional Examination Survey (NHANES) 2007-2018. The population was stratified into three groups based on their PA level. Kaplan-Meier method with log-rank tests for significance was used for survival analysis. Weighted Cox proportional hazards regression models were employed to estimate the hazard ratios (HRs) for all-cause mortality. Subgroup analysis was conducted to strengthen the results. RESULTS: A total of 1395 participants were recruited, comprising 679 males and 716 females, with a median age of 68 years. Based on their PA levels, 779 individuals were classified as inactive, 156 as insufficiently active, and 460 as sufficiently active. Following a median observation period of 59 months, there were 476 recorded deaths, with 349, 47, and 80 cases in the three respective groups. Compared to the inactive group, the HRs and 95% confidence intervals (CIs) for all-cause mortality in participants who were insufficiently active and sufficiently active were 0.58 (0.40, 0.84) and 0.47 (0.33, 0.67), respectively. The Kaplan-Meier curve revealed a significant difference in overall survival between the three groups, as confirmed by the log-rank test (P < 0.0001). Subgroup analysis further validated our results and demonstrated that the protective impact of PA on stroke prognosis varies according to distinct characteristics. CONCLUSIONS The results indicate that increased levels of PA are associated with a protective effect on long-term mortality among stroke survivors. Further prospective longitudinal studies are necessary to elucidate the optional PA level and special exercise guideline targeting this population.
Humans ; Male ; Female ; Aged ; Exercise ; Middle Aged ; Nutrition Surveys ; Stroke/mortality* ; United States/epidemiology* ; Survivors/statistics & numerical data* ; Aged, 80 and over ; Mortality

BACKGROUND: Premature menopause, defined as natural menopause before age 40, is associated with diminished ovarian reserve. Despite growing concerns regarding environmental pollutants, no large-scale population-based studies have systematically examined the association between urinary polycyclic aromatic hydrocarbon metabolites (UPAHMs) and premature menopause. METHODS: This cross-sectional study analyzed 2001-2020 NHANES data, including urinary levels of six PAH metabolites: 1-naphthol (1-NAP), 2-naphthol (2-NAP), 3-fluorene (3-FLU), 2-fluorene (2-FLU), 1-phenanthrene (1-PHE), and 1-pyrene (1-PYR). Premature menopause was self-reported as natural menopause occurring before age 40. Multivariable logistic regression assessed UPAHMs' association with premature menopause, with restricted cubic splines (RCS) evaluating nonlinear trends. Subgroup analyses examined demographic interactions. RESULTS: Among 2,565 participants, 662 reported premature menopause. Multivariable logistic regression showed significant associations between elevated urinary levels of 1-NAP (OR: 1.01, 95% CI: 1.00-1.02, P = 0.02), 2-NAP (OR: 1.01, 95% CI: 1.00-1.02, P = 0.02), and 3-FLU (OR: 1.03, 95% CI: 1.01-1.05, P = 0.01) and increased risk of premature menopause. RCS analysis revealed significant nonlinear relationships for 2-NAP, 3-FLU, 2-FLU, 1-PHE, and 1-PYR with premature menopause risk. White participants showed greater susceptibility to UPAHMs. CONCLUSION Elevated UPAHMs, particularly 1-NAP, 2-NAP, and 3-FLU, were linked to higher premature menopause risk, with nonlinear trends observed. White individuals demonstrated greater vulnerability, emphasizing the need for targeted interventions to reduce PAH exposure.
Humans ; Female ; Cross-Sectional Studies ; United States/epidemiology* ; Polycyclic Aromatic Hydrocarbons/urine* ; Adult ; Middle Aged ; Environmental Pollutants/urine* ; Nutrition Surveys ; Menopause, Premature/urine* ; Young Adult ; Environmental Exposure

BACKGROUND: Recent studies have provided compelling evidence that exposure to brominated flame retardants (BFRs) can adversely affect human health. We aim to explore the potential impact of BFRs on adiposity and central obesity. METHODS: Data from the National Health and Nutrition Examination Surveys (NHANES) cycles conducted between 2009 and 2014 was used to study the connections between variables. After filtering, we analyzed a sample of 4,110 adults aged 20 years and above. Our goal was to examine the potential association between BFRs and consequences and investigate the part played by oxidative stress and inflammatory markers as intermediaries. To achieve this, we used advanced statistical methods such as weighted quantile sum (WQS) regression, quantile-based g-computation (QGC), and the Bayesian kernel machine regression (BKMR). RESULTS: The findings showed that among the examined chemicals, exposure to PBDE85 (weight: 41%), PBDE100 (24%), and PBB153 (23%) may be the dominant contributors to general obesity risk. Upon controlling for all variables that could impact the results, it was found that the QGC outcomes indicated a positive correlation between exposure to mixtures of brominated flame retardants and the occurrence of abdominal obesity (OR = 1.187, 95% CI: 1.056-1.334, p = 0.004). Significant contributions were made by PBDE85 (52%), PBB153 (27%), and PBDE100 (21%). Mediation analysis shows that lymphatic cells (LC) and albumin (ALB) partially mediate the link between brominated flame retardants and obesity. The results of BKMR are generally consistent with those of WQS and QGC. CONCLUSION At a population level, our research has revealed a noteworthy correlation between BFRs and obesity. However, further investigation is required through prospective cohort studies and in-depth mechanistic exploratory studies.
Humans ; Flame Retardants/adverse effects* ; Oxidative Stress/drug effects* ; Adult ; Male ; Female ; Middle Aged ; Inflammation/epidemiology* ; Obesity/chemically induced* ; Biomarkers/blood* ; Nutrition Surveys ; Mediation Analysis ; Young Adult ; United States/epidemiology* ; Environmental Exposure/adverse effects* ; Aged ; Environmental Pollutants/adverse effects* ; Halogenated Diphenyl Ethers/adverse effects*