Association between urinary phthalate metabolites and nephrolithiasis in adults: A cross-sectional analysis with NHANES 2007-2018

Phthalate exposure increases oxidative stress, early renal injury, and the risk of calcium urolithiasis: A case-control study

BACKGROUND

Phthalates, ubiquitous in plastics and softening agents, are pervasive in our daily environment. Growing concerns have emerged regarding their potential impact on renal health, particularly due to their propensity to induce oxidative stress. However, the relationship between phthalate exposure and urolithiasis remains poorly understood. This research seeks to explore the connection between phthalate exposure, oxidative stress, and the risk of urolithiasis.

METHODS

A case-control study involving 285 patients diagnosed with calcium urolithiasis and 594 healthy controls was conducted. Participants completed structured questionnaires and provided urine samples for measuring 10 phthalate metabolites, biomarkers of oxidative stress (malondialdehyde [MDA]) and early renal injury (N-acetyl-beta-D-glucosaminidase [NAG] and albumin/creatinine ratio [ACR]). For subsequent analyses, we utilized distinct categories: the sum of high-molecular-weight phthalate metabolites (∑HMWm), the sum of low-molecular-weight phthalate metabolites (∑LMWm), and the daily intake of di-2-ethylhexyl phthalate (DEHP)(DI_DEHP_5).

RESULTS

Stone patients exhibited significantly elevated urinary biomarkers of oxidative stress (MDA) and early renal injury (NAG and ACR), along with higher levels of 9 out of 10 assessed phthalate metabolites compared to normal controls. Within the study population, significant positive associations were found between almost all individual phthalate metabolites and urinary biomarkers of oxidative stress (MDA) as well as early renal injury (NAG and ACR). Logistic regression further confirmed that elevated phthalate levels, including ∑HMWm, ∑LMWm, and DI_DEHP_5, were uniformly associated with an increased risk of oxidative stress, early renal injury, and urolithiasis after adjusting for confounding factors.

CONCLUSIONS

Our study uncovers a novel association between phthalate exposure and the risk of urolithiasis, underscoring the heightened risk of kidney injury posed by such exposure. Considering the widespread presence of phthalates, regulatory measures and public health interventions are crucial to mitigate phthalate-related nephrotoxicity, while further large-scale longitudinal research is imperative to validate our initial findings and elucidate the underlying mechanisms.

Association of non-high-density lipoprotein cholesterol-to-high-density lipoprotein cholesterol ratio (NHHR) with gout prevalence: a cross-sectional study

Background

The non-high-density lipoprotein cholesterol (non-HDL-C)-to-high-density lipoprotein cholesterol (HDL-C) ratio (NHHR) is a strong lipid marker that has been associated with atherogenic features. This study aimed to investigate the potential association between the NHHR and gout prevalence.

Methods

This study investigated the relationship between the NHHR and gout by analyzing data gathered from the National Health and Nutrition Examination Survey (NHANES), a research study conducted in the United States from 2007 to 2018. All participants in NHANES provided written informed consent prior to participation. The NHHR was calculated as the ratio of non-HDL-C to HDL-C. Total cholesterol (TC) and HDL-C levels were sourced from NHANES laboratory data. Gout was assessed using a questionnaire. Weighted logistic regression analysis, subgroup analysis, and smoothed curve fitting were performed.

Results

This study included 30,482 participants. The fully adjusted models showed that for each unit increase in NHHR in continuous variables, there was a 10% higher likelihood of gout prevalence (OR: 1.10, 95% CI: 1.05, 1.16). Analysis of the NHHR quartiles revealed that patients in the highest quartile had a notably greater probability of developing gout than those in the lowest quartile. (Q4 vs. Q1, OR: 1.34, 95% CI: 1.05, 1.71). Subgroup analyses yielded consistent results across categories, indicating a significant positive association between the NHHR and gout. E-value analysis suggested robustness to unmeasured confounding. Interaction tests showed that the race, education level, marital relationship, poverty-income ratio (PIR), hypertension, smoking habits, estimated glomerular filtration rate (eGFR), lipid-lowering therapy, and diabetes had no discernible effects on this association. The p-values for all the interactions were > 0.05. Nevertheless, the relationship between the NHHR and gout was significantly affected by the age and sex of the participants (interaction p < 0.05).

Conclusion

Among adults in the United States, elevated NHHR levels are correlated with increased odds of gout prevalence.

Association between advanced lung cancer inflammation index and chronic kidney disease: a cross-sectional study

Background

Chronic kidney disease (CKD) is one of the common chronic diseases, and malnutrition and inflammation play a key role in the development of CKD. The advanced lung cancer inflammation index (ALI) is a novel index of nutrition and inflammation, and its association with CKD has not yet been clarified. The aim of this study was to explore the potential association between ALI and CKD.

Methods

We conducted a cross-sectional survey using data extracted from the National Health and Nutrition Examination Survey (NHANES, 2003-2018). Weighted multivariate logistic regression was used to assess the association between ALI and CKD, and smoothed curve fitting and threshold effect analyses were used to describe the nonlinear association between ALI and CKD. Subgroup analyses were performed to further assess the influence of other covariates on the relationship between ALI and CKD.

Results

A total of 39,469 adult participants were included in the study, of whom 7,204 (18.25%) were diagnosed with CKD. After adjusting for multiple confounders, we found a significant negative correlation between ALI and CKD (OR = 0.93; 95%CI, 0.91-0.95; p < 0.0001). The risk of CKD tended to decrease with increasing quartiles of ALI. Smoothed curve fitting showed an L-shaped negative correlation between ALI and CKD. Threshold analysis showed a saturation effect of ALI at the inflection point of 55.09. Subgroup analyses and interaction tests showed that this negative association was maintained across age, sex, race, BMI, diabetes, hypertension, cardiovascular disease, and cancer subgroups (P for interaction >0.05).

Conclusion

Our findings suggest a significant correlation between ALI and CKD in the US adult population. However, more large-scale prospective studies are still needed to further confirm our findings.

Association between urinary phthalate metabolites and Anemia in US adults

Initial research indicates a possible connection between exposure to phthalates and the development of anemia. To fill the gap in epidemiological data, our study utilized data from across the United States, representative on a national scale, to evaluate the association between the concentration of phthalate metabolites in urine and both anemia and iron levels. We gathered data on 11,406 individuals from the National Health and Nutrition Examination Survey (NHANES) database, spanning 2003-2018. We conducted logistic and linear regression analyses, adjusted for potential confounding factors, to evaluate the correlations between different phthalate metabolites and anemia, as well as serum iron levels, including gender-stratified analysis. Most urinary phthalate metabolites were positively correlated with an increased risk of anemia, and the majority were negatively correlated with serum iron levels. The study revealed that for every unit increase in ln-transformed metabolite concentrations, the odds ratios (ORs) for anemia increased to varying degrees, depending on the phthalate: Monobutyl phthalate (MBP) at 1.08 (95% CI 1.01-1.17, P = 0.0314), mono(3-carboxypropyl) phthalate (MCPP) at 1.17 (95% CI 1.10-1.24, P < 0.0001), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) at 1.08 (95% CI 1.02-1.15, P = 0.0153), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) at 1.14 (95% CI 1.07-1.21, P < 0.0001), mono(2-ethyl-5-carboxypentyl) phthalate (MECPP) at 1.11 (95% CI 1.03-1.18, P = 0.0030), monocarboxynonyl phthalate (MCNP) at 1.11 (95% CI 1.03-1.19, p = 0.0050), and monocarboxyoctyl phthalate (MCOP) at 1.13 (95% CI 1.07-1.19, P < 0.0001). Increased levels of MBP, MEHP, MBzP, MCPP, MEHHP, MEOHP, MIBP, MECPP, MCNP, and MCOP were linked with changes in serum iron levels, ranging from - 0.99 µg/dL (95% CI - 1.69 to - 0.29) to - 3.72 µg/dL (95% CI - 4.32 to - 3.11). Mixed-exposure analysis shows consistency with single-exposure model. Further mediation analysis showed that the association between single urinary phthalates and the risk of anemia was mediated by serum iron with a mediation ratio of 24.34-95.48% (P < 0.05). The presence of phthalate metabolites in urine shows a positive correlation with the prevalence of anemia, which was possibly and partly mediated by iron metabolism. Nonetheless, to confirm a definitive causal link and comprehend the underlying mechanisms of how phthalate exposure influences anemia, additional longitudinal and experimental research is required.

Association between waist triglyceride index, body mass index, dietary inflammatory index, and triglyceride- glucose index with chronic kidney disease: the 1999-2018 cohort study from NHANES

Purpose

To compare the dietary inflammatory index (DII), triglyceride glucose index (TyG), waist triglyceride index (WTI), and body mass index (BMI) in predicting the survival of chronic kidney disease (CKD).

Methodology

Inclusion of 23,099 participants from the NHANES database who met specific criteria. Baseline was established using quartiles of DII index. The relationship between DII index, WTI index, TyG index, and BMI index with mortality rate in CKD patients was evaluated using Kaplan-Meier curves. Univariate and multivariate COX regression risk models were used to study the relationship between DII index, WTI index, and TyG index with mortality risk in CKD patients. Stratification of eGFR by age and gender was conducted to investigate the association between DII index, WTI index, and TyG index with mortality risk in CKD patients. Restricted cubic spline analysis was used to study the correlation between DII index, WTI index, and TyG index with mortality risk in CKD patients.

Results

The incidence of CKD increased with the increase of DII index, WTI index and TyG index. After multivariable adjustment, the fourth quartile of DII index, TyG index and WTI index showed the highest risk for CKD [DII: hazard ratio (HR) 1.36, 95% confidential interval (CI) (1.23-1.51); TyG: HR 1.21; 95% CI (1.07-1.37); WTI: HR 1.29; 95% CI (1.13-1.46)]. There was no difference in the risk of developing CKD between the obese group (BMI ≥24 kg/m2) and the normal weight group (P>0.05).

Conclusion

This study has identified a significant association between elevated DII index, WTI index, and TyG index with the risk of CKD. Furthermore, the DII index demonstrated superior prognostic capability in predicting CKD compared to other indicators.

Phthalate metabolites and sex steroid hormones in relation to obesity in US adults: NHANES 2013-2016

Background

Obesity and metabolic syndrome pose significant health challenges in the United States (US), with connections to disruptions in sex hormone regulation. The increasing prevalence of obesity and metabolic syndrome might be associated with exposure to phthalates (PAEs). Further exploration of the impact of PAEs on obesity is crucial, particularly from a sex hormone perspective.

Methods

A total of 7780 adult participants in the National Health and Nutrition Examination Survey (NHANES) from 2013 to 2016 were included in the study. Principal component analysis (PCA) coupled with multinomial logistic regression was employed to elucidate the association between urinary PAEs metabolite concentrations and the likelihood of obesity. Weighted quartiles sum (WQS) regression was utilized to consolidate the impact of mixed PAEs exposure on sex hormone levels (total testosterone (TT), estradiol and sex hormone-binding globulin (SHBG)). We also delved into machine learning models to accurately discern obesity status and identify the key variables contributing most to these models.

Results

Principal Component 1 (PC1), characterized by mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), and mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) as major contributors, exhibited a negative association with obesity. Conversely, PC2, with monocarboxyononyl phthalate (MCNP), monocarboxyoctyl phthalate (MCOP), and mono(3-carboxypropyl) phthalate (MCPP) as major contributors, showed a positive association with obesity. Mixed exposure to PAEs was associated with decreased TT levels and increased estradiol and SHBG. During the exploration of the interrelations among obesity, sex hormones, and PAEs, models based on Random Forest (RF) and eXtreme Gradient Boosting (XGBoost) algorithms demonstrated the best classification efficacy. In both models, sex hormones exhibited the highest variable importance, and certain phthalate metabolites made significant contributions to the model's performance.

Conclusions

Individuals with obesity exhibit lower levels of TT and SHBG, accompanied by elevated estradiol levels. Exposure to PAEs disrupts sex hormone levels, contributing to an increased risk of obesity in US adults. In the exploration of the interrelationships among these three factors, the RF and XGBoost algorithm models demonstrated superior performance, with sex hormones displaying higher variable importance.

Associations between the platelet/high-density lipoprotein cholesterol ratio and likelihood of nephrolithiasis: a cross-sectional analysis in United States adults

Aims

The primary objective of this study was to investigate the relationship between the platelet/high-density lipoprotein cholesterol ratio (PHR) and the prevalence of nephrolithiasis within the adult population of the United States.

Methods

The data used in this study were obtained from the National Health and Nutrition Examination Survey (NHANES) conducted between 2007 and 2018. The analysis included a non-pregnant population aged 20 years or older, providing proper PHR index and nephrolithiasis data. The research utilized subgroup analyses and weighted univariate and multivariable logistic regression to evaluate the independent association between the PHR and the susceptibility to nephrolithiasis.

Results

The study comprised 30,899 participants with an average PHR value of 19.30 ± 0.11. The overall prevalence rate of nephrolithiasis was estimated at 9.98% with an increase in the higher PHR tertiles (T1, 8.49%; T2, 10.11%; T3, 11.38%, P < 0.0001). An elevated PHR level was closely linked with a higher susceptibility to nephrolithiasis. Compared with patients in T1, and after adjusting for potential confounders in model 2, the corresponding odds ratio for nephrolithiasis in T3 was 1.48 (95% CI: 1.06 to 2.08), with a P-value = 0.02. The results of the interaction tests revealed a significant impact of chronic kidney disease on the relationship between PHR and nephrolithiasis. Furthermore, the restricted cubic spline analyses exhibited a positive, non-linear correlation between PHR and the risk of nephrolithiasis.

Conclusion

A convenient biomarker, the PHR, was independently associated with nephrolithiasis and could be a novel biomarker in predicting occurrence in clinical decision.

Systemic immune-inflammation Index is associated with chronic kidney disease in the U.S. population: insights from NHANES 2007-2018

Objectives

The systemic immune-inflammation index (SII), a novel and systematic inflammatory biomarker that is associated with chronic kidney disease (CKD), has not received much attention. This study aimed to investigate the relationship between SII and CKD in the United States (U.S.) population.

Methods

Our study ultimately included a nationally representative sample of 10,787 adults who participated in the 2007-2018 National Health and Nutrition Examination Survey. Weighted multivariate logistic regression was used to assess the correlation between SII and CKD, and a restricted cubic spline (RCS) model was subsequently used to explore the non-linear relationship between SII and CKD. Subgroup analyses were performed to further the effects of other covariates on the relationship between SII and CKD.

Results

Following confounder adjustment, a higher SII was related to the incidence of CKD (OR =1.36; 95% CI, 1.07-1.73; p =0.01), as validated by multivariable logistic regression. The RCS curve revealed a non-linear positive correlation between SII/1000 and CKD incidence (p for non-linear =0.0206). Additionally, subgroup analysis confirmed a stronger correlation for male participants (OR =2.628; 95% CI, 1.829-3.776) than for female participants (OR =1.733; 95% CI, 1.379-2.178) (p for interaction =0.046).

Conclusions

SII is positively associated with the incidence of CKD among U.S. adults, especially in males. However, further studies are needed to confirm our findings and explore the causal factors that can contribute to the prevention and treatment of CKD.