Nonlinear Association Research Articles

Testing the validity of feminization U-shape hypothesis for female labor force participation and economic development in Pakistan: a reexamination

Purpose The participation of females in economic activity remains a challenge, and received a lot of attention for a better labor policy discourse. The empirical research focused widely on the relationship between female labor force participation (FLFP) and economic development, called the feminization U-shape hypothesis. However, the linear/nonlinear relationship has been questioned due to empirical and methodological anomalies. Hence, this study aims to extend the previous work by reexamining this relationship in Pakistan. Design/methodology/approach The annual data from 1980 to 2021, the unit root tests augmented Dickey–Fuller and Phillips and Perron, the conventional autoregressive distributed lag bound test approach by including the quadratic-term of GDP per capita and the novel Sasabuchi–Lind–Mehlum (SLM) U test (2010) used for empirical estimation. Findings The findings revealed the prospects of a long-run nonlinear association between FLFP and economic development in Pakistan. However, an inverse U-shape exists between the female labor force participation rate (FLFPR) and GDP per capita, predicting that FLFP may decline in the future. Research limitations/implications The traditional feminization U-shape hypothesis has little empirical support in the case of Pakistan. Therefore, the Government of Pakistan should enhance the enabling environment for females through the provision of better job opportunities, technical skills, on-the-job training and social security benefits during all phases of economic development. Originality/value The conventional approach of testing U-shape is insufficient. To the best of the authors’ knowledge, therefore, this study incorporated a wider data set in a time series that is less evident, an advanced methodology SLM U test (2010), to validate the feminization U-shape hypothesis in Pakistan for the first time.

Preoperative fasting glucose value can predict acute kidney injury in non-cardiac surgical patients without diabetes but not in patients with diabetes

BackgroundPostoperative acute kidney injury (AKI) is a common and costly complication after non-cardiac surgery. Patients with or without diabetes could develop hyperglycemia before surgery, and preoperative hyperglycemia was closely associated with postoperative poor outcomes, but the association between preoperative fasting blood glucose level and postoperative AKI is still unclear.MethodsData from patients undergoing non-cardiac surgery in Chongqing University Cancer Hospital from January 1, 2017, to May 31, 2023, were collected, preoperative glucose value and perioperative variables were extracted, the primary exposure of interest was preoperative glucose value, and the outcome was postoperative AKI.ResultsData from 39,986 patients were included in the final analysis, 741(1.9%) patients developed AKI, 134(5.6%) in the cohort with DM, and 607(1.6%) in the cohort without DM(OR 1.312, 95% CI 1.028–1.675, P = 0.029). A significant non-linear association between preoperative glucose and AKI exists in the cohort without DM after covariable adjustment (P = 0.000), and every 1 mmol/L increment of preoperative glucose level increased OR by 15% (adjusted OR 1.150, 95% CI 1.078–1.227, P = 0.000), the optimal cut-point of preoperative fasting glucose level to predict AKI was 5.39 mmol/L (adjusted OR 1.802, 95%CI 1.513–2.146, P = 0.000). However, in the cohort with DM, the relation between preoperative glucose and postoperative AKI was not significant after adjusting by covariables (P = 0.437). No significance exists between both cohorts in the risk of AKI over the range of preoperative glucose values.ConclusionA preoperative fasting glucose value of 5.39 mmol/L can predict postoperative acute kidney injury after non-cardiac surgery in patients without diagnosed diabetes, but it is not related to AKI in patients with the diagnosis.

Association between pulse pressure and carotid plaques in old adults with uncontrolled hypertension: results from a community-based screening in Hangzhou, China

BackgroundThere is a broad pulse pressure (PP) and a high prevalence of carotid plaques in old adults. Previous studies have indicated that PP is strongly associated with carotid plaque formation. This study aimed to explore this association in old adults with uncontrolled hypertension.Methods1371 hypertensive patients aged ≥ 60 years with uncontrolled hypertension were enrolled in a community-based screening in Hangzhou, China. Carotid plaques were assessed using ultrasonography. Logistic regression models were used to estimate the association between PP and carotid plaques by odds ratios (ORs) and 95% confidence intervals (CIs).ResultsCarotid plaques were detected in 639 (46.6%) of subjects. Multiple plaques were found in 408 (63.8%) and soft plaques in 218 (34.1%). Elevated PP was associated with a high prevalence of carotid plaques. After adjusting for traditional risk factors, compared to patients within the lowest tertile of PP, those within the highest tertiles had an increased risk of carotid plaques (OR 2.061, CI 1.547–2.745). For each 1-SD increase, the risk increased by 40.1% (OR 1.401, CI 1.237–1.587). There was a nonlinear association between PP and carotid plaques (P nonlinearity = 0.039). The risk increased rapidly after the predicted PP level reached around 60 mmHg. The associations were stronger among participants with multiple and soft plaques.ConclusionsOur findings suggested that PP was independently associated with carotid plaques in old adults with uncontrolled hypertension who have an increased risk of atherosclerosis.

Serum urate levels and neurodegenerative outcomes: a prospective cohort study and mendelian randomization analysis of the UK Biobank

BackgroundPrevious studies on the associations between serum urate levels and neurodegenerative outcomes have yielded inconclusive results, and the causality remains unclear. This study aimed to investigate whether urate levels are associated with the risks of Alzheimer’s disease and related dementias (ADRD), Parkinson’s disease (PD), and neurodegenerative deaths.MethodsThis prospective study included 382,182 participants (45.7% men) from the UK Biobank cohort. Cox proportional hazards models were used to assess the associations between urate levels and risk of neurodegenerative outcomes. In the Mendelian randomization (MR) analysis, urate-related single-nucleotide polymorphisms were identified through a genome-wide association study. Both linear and non-linear MR approaches were utilized to investigate the potential causal associations.ResultsDuring a median follow-up period of 12 years, we documented 5,400 ADRD cases, 2,553 PD cases, and 1,531 neurodegenerative deaths. Observational data revealed that a higher urate level was associated with a decreased risk of ADRD (hazard ratio [HR]: 0.93, 95% confidence interval [CI]: 0.90, 0.96), PD (HR: 0.87, 95% CI: 0.82, 0.91), and neurodegenerative death (HR: 0.88, 95% CI: 0.83, 0.94). Negative linear associations between urate levels and neurodegenerative events were observed (all P-values for overall < 0.001 and all P-values for non-linearity > 0.05). However, MR analyses yielded no evidence of either linear or non-linear associations between genetically predicted urate levels and the risk of the aforementioned neurodegenerative events.ConclusionAlthough the prospective cohort study demonstrated that elevated urate levels were associated with a reduced risk of neurodegenerative outcomes, MR analyses found no evidence of causality.

Relationship between remnant cholesterol and risk of kidney stones in U.S. Adults: a 2007–2016 NHANES analysis

Purpose Remnant cholesterol (RC) is the cholesterol content of triglyceride-rich lipoproteins. This study aimed to investigate the association between RC levels and kidney stones in U.S. adults. Methods Data were obtained from the 2007 to 2016 National Health and Nutrition Examination Survey (NHANES). A total of 10,551 participants with complete data were included and analyzed in this study. Univariate and multivariate logistic regression analysis, restricted cubic spline function, subgroup analysis and mediation analysis were preformed to estimate the independent relationship between RC levels and kidney stones. Results Participants with stone formation had higher levels of RC than those with without stone formation (25.78 ± 13.83 vs 23.27 ± 13.04, p< 0.001). The results of logistic regression analysis and dose-response risk curves revealed a positive nonlinear association between RC levels and risk of kidney stones [univariate: adjusted odds ratio (aOR) =2.388, 95% CI: 1.797–3.173, p< 0.001; multivariate: aOR = 1.424, 95% CI: 1.050–1.929, p = 0.023]. Compared with the discordantly low RC group, the discordantly high RC group was associated with increased risk of kidney stones (aOR = 1.185, 95% CI: 1.013–1.386, p= 0.034). Similar results were demonstrated according to the discordance of different clinical cut points. And metabolic syndrome parameters and vitamin D levels parallelly mediated the association between RC and kidney stone risk. Conclusions Higher RC levels were independently associated with an increased risk of kidney stone incidence.

Non-Linear Association of Exercise with Animal Protein Consumption among U.S. Adults

Supply chain disruptions, human and animal health concerns, and environmental impacts of livestock production have spurred renewed attention to animal protein consumption in the U.S. Prior research has sought to better understand animal protein consumption by assessing demographic and socioeconomic determinants. However, physical exercise represents a behavioral determinant of consumption that is societally important and, thus far, has not been considered in empirical assessments. Our objective was to quantify the association of exercise with the consumption of total protein, beef, pork, poultry, seafood, eggs, and dairy among U.S. adults. We analyzed 24 h dietary recall and physical activity data from adults in the 2007–2018 National Health and Nutrition Examination Survey (NHANES). The association of exercise with protein consumption (total and disaggregated animal protein) was assessed using ordinary least squares and multivariate Tobit regression. Non-linear associations of exercise with total protein consumption were found, with the magnitude of association highest at 121–180 min per day of exercise. Non-linear associations were also found with animal protein consumption, which differed in sign and magnitude across protein sources. The magnitudes of association, paired with a sizable share of the study sample engaged in exercise, suggest a substantial influence of exercise on protein consumption habits in the U.S.

The relationship between dietary intake of ω-3 and ω-6 fatty acids and frailty risk in middle-aged and elderly individuals: a cross-sectional study from NHANES

BackgroundFrailty is a complex clinical syndrome characterized by a decline in the functioning of multiple body systems and reduced adaptability to external stressors. Dietary ω-3 fatty acids are considered beneficial dietary nutrients for preventing frailty due to their anti-inflammatory and immune-regulating properties. However, previous research has yielded conflicting results, and the association between ω-6 fatty acids, the ω-6: ω-3 ratio, and frailty remains unclear. This study aims to explore the relationship between these factors using the National Health and Nutrition Examination Survey (NHANES) database.Materials and methodsSpecialized weighted complex survey design analysis software was employed to analyze data from the 2005–2014 NHANES, which included 12,315 participants. Multivariate logistic regression models and restricted cubic splines (RCS) were utilized to assess the relationship between omega intake and frailty risk in all participants. Additionally, a nomogram model for predicting frailty risk was developed based on risk factors. The reliability of the clinical model was determined by the area under the receiver operating characteristic (ROC) curve, calibration curves, and decision curve analysis (DCA).ResultsIn dietary ω-3 intake, compared to the T1 group (≤1.175 g/d), the T3 group’s intake level (&amp;gt;2.050 g/d) was associated with approximately 17% reduction in frailty risk in model 3, after rigorous covariate adjustments (odds ratio (OR) = 0.83, 95% confidence interval (CI): (0.70, 0.99)). In dietary ω-6 intake, the T2 group’s intake level (&amp;gt;11.423, ≤19.160 g/d) was associated with a 14% reduction in frailty risk compared to the T1 group (≤11.423 g/d) (OR: 0.86, 95% CI: 0.75, 1.00, p = 0.044). RCS results indicated a non-linear association between ω-3 and ω-6 intake and frailty risk. Both ROC and DCA curves demonstrated the stability of the constructed model and the effectiveness of an omega-rich diet in reducing frailty risk. However, we did not find a significant association between the ω-6: ω-3 ratio and frailty.ConclusionThis study provides support for the notion that a high intake of ω-3 and a moderate intake of ω-6 may contribute to reducing frailty risk in middle-aged and elderly individuals.

Association between triglyceride glucose-body mass index and long-term adverse outcomes of heart failure patients with coronary heart disease

BackgroundThe triglyceride glucose-body mass index (TyG-BMI) is recognized as a reliable surrogate for evaluating insulin resistance and an effective predictor of cardiovascular disease. However, the link between TyG-BMI index and adverse outcomes in heart failure (HF) patients remains unclear. This study examines the correlation of the TyG-BMI index with long-term adverse outcomes in HF patients with coronary heart disease (CHD).MethodsThis single-center, prospective cohort study included 823 HF patients with CHD. The TyG-BMI index was calculated as follows: ln [fasting triglyceride (mg/dL) × fasting blood glucose (mg/dL)/2] × BMI. To explore the association between the TyG-BMI index and the occurrences of all-cause mortality and HF rehospitalization, we utilized multivariate Cox regression models and restricted cubic splines with threshold analysis.ResultsOver a follow-up period of 9.4 years, 425 patients died, and 484 were rehospitalized due to HF. Threshold analysis revealed a significant reverse “J”-shaped relationship between the TyG-BMI index and all-cause mortality, indicating a decreased risk of all-cause mortality with higher TyG-BMI index values below 240.0 (adjusted model: HR 0.90, 95% CI 0.86–0.93; Log-likelihood ratio p = 0.003). A distinct “U”-shaped nonlinear relationship was observed with HF rehospitalization, with the inflection point at 228.56 (adjusted model: below: HR 0.95, 95% CI 0.91–0.98; above: HR 1.08, 95% CI 1.03–1.13; Log-likelihood ratio p < 0.001).ConclusionsThis study reveals a nonlinear association between the TyG-BMI index and both all-cause mortality and HF rehospitalization in HF patients with CHD, positioning the TyG-BMI index as a significant prognostic marker in this population.

Association between ambient temperature and risk of notifiable infectious diseases in China from 2011 to 2019

ABSTRACT Previous studies on temperature and infectious diseases primarily focused on individual disease types, yielding inconsistent conclusions. This study collected monthly data on notifiable infectious disease cases and meteorological variables across 7 provinces in China from 2011 to 2019. A distributed lag nonlinear model was used to evaluate the association between ambient temperature and infectious diseases within each province, and random meta-analysis was applied to evaluate the pooled effect. Extreme hot temperature (the 97.5th percentile) was positively associated with the risk of respiratory infectious diseases with the relative risk (RR) of 1.45 (95%CI: 1.01–2.08). Conversely, extreme cold temperature (the 2.5th percentile) was negatively associated with intestinal infectious diseases and zoonotic diseases and vector-borne diseases, reporting RRs of 0.43 (95%CI: 0.30–0.60) and 0.46 (95%CI: 0.38–0.57), respectively. This study described the nonlinear association between ambient temperature and infectious diseases with different transmission routes, informing comprehensive prevention and control strategies for temperature-related infectious diseases.

Association between sleep disorders and physical activity in middle-aged Americans: a cross-sectional study from NHANES

BackgroundAmong the numerous studies on physical activity and sleep disorders, few have focused on physical activity and sleep disorders in middle-aged people who are particularly stressed. A restricted cubic web (RCS) technique was applied to determine whether physical activity and the self-rated prevalence of sleep disorders exhibit a dose-response relationship in middle-aged adults.MethodsThis study analyzed 8880 middle-aged adults aged 40–65 years who participated in the National Health and Nutrition Examination Survey (NHANES) 2007–2018. Logistic regression was performed to estimate the odds ratio (OR) and 95% confidence interval (CI) between physical activity and sleep disorders in middle-aged adults. Thereafter, the dose-response connection was examined using RCS.ResultsAfter adjusting for potential confounders, subjects with MET values in the first quartile (Q1) had odds ratios (OR) for sleep disturbance of 0.851 (95% CI = 0.745–0.973), 0.800 (95% CI = 0.698–0.917), and 0.780 (95% CI = 0.680–0.895) compared to subjects with MET values in the second, third, and fourth quartiles respectively. RCS regression showed a non-linear association between physical activity and sleep disorders in middle-aged adults (non-linearity P = 0.0382). Furthermore, the prevalence of sleep disorders in middle-aged adults decreased with increasing physical activity, reaching a minimum when weekly physical activity was around 166.27MET*h (OR = 0.885, 95% CI = 0.799–0.981).ConclusionOur research demonstrates that physical activity was negatively associated with sleep disorders.

Association of calciprotein particles with serum phosphorus among patients undergoing conventional and extended-hours haemodialysis

Abstract Background and hypothesis Extended-hours haemodialysis (HD) is associated with better clinical outcomes than conventional HD. We investigated whether extended-hours HD and conventional HD have varying effects on blood levels of calciprotein particles (CPP) and phosphorus, which have been identified as major pathogenic molecules for vascular calcification. Methods Patients who underwent conventional or extended in-centre daytime HD between January and March 2020 were included. Plasma CPP levels, representing only secondary CPP (CPP-Ⅱ), were measured in pre-dialysis samples. Linear and non-linear associations between CPP and serum phosphorus levels were examined across dialysis modalities. Results A total of 382 participants (185 undergoing extended-hours HD and 197 undergoing conventional HD) were included in the analysis. The median age of participants was 71 years, 65% of the patients were men, and the mean phosphorus level was 5.4 mg/dL. Plasma CPP (CPP-Ⅱ) levels were lower in the extended-hours HD group than in the conventional HD group (40 018 AU vs. 75 728 AU, p &amp;lt; 0.01). Multivariable linear regression analysis showed that extended-hours HD was associated with lower natural logarithmic plasma CPP (CPP-Ⅱ) levels: -0.64 (95% CI: -0.74 to -0.55). Restricted cubic spline function indicated that extended-hours HD was associated with lower plasma CPP (CPP-Ⅱ) levels across levels of serum phosphorus, with significant differences observed between groups, especially in hyperphosphatemic conditions (P for interaction &amp;lt; 0.01). Conclusions The extended-hours HD group had lower CPP levels than the conventional HD group despite no significant differences in serum phosphorus levels, which may contribute to better clinical outcomes in patients on extended-hours HD.

Dietary choline intake and health outcomes in U.S. adults: exploring the impact on cardiovascular disease, cancer prevalence, and all-cause mortality

BackgroundCholine, an indispensable nutrient, plays a pivotal role in various physiological processes. The available evidence regarding the nexus between dietary choline intake and health outcomes, encompassing cardiovascular disease (CVD), cancer, and all-cause mortality, is limited and inconclusive. This study aimed to comprehensively explore the relationship between dietary choline intake and the aforementioned health outcomes in adults aged > 20 years in the U.S.MethodsThis study utilized data from the National Health and Nutrition Examination Survey between 2011 and 2018. Dietary choline intake was evaluated using two 24-h dietary recall interviews. CVD and cancer status were determined through a combination of standardized medical status questionnaires and self-reported physician diagnoses. Mortality data were gathered from publicly available longitudinal Medicare and mortality records. The study utilized survey-weighted logistic and Cox regression analyses to explore the associations between choline consumption and health outcomes. Restricted cubic spline (RCS) analysis was used for dose‒response estimation and for testing for nonlinear associations.ResultsIn our study of 14,289 participants (mean age 48.08 years, 47.71% male), compared with those in the lowest quintile (Q1), the adjusted odds ratios (ORs) of CVD risk in the fourth (Q4) and fifth (Q5) quintiles of choline intake were 0.70 (95% CI 0.52, 0.95) and 0.65 (95% CI 0.47, 0.90), respectively (p for trend = 0.017). Each 100 mg increase in choline intake was associated with a 9% reduced risk of CVD. RCS analysis revealed a linear correlation between choline intake and CVD risk. Moderate choline intake (Q3) was associated with a reduced risk of mortality, with an HR of 0.75 (95% CI 0.60–0.94) compared with Q1. RCS analysis demonstrated a significant nonlinear association between choline intake and all-cause mortality (P for nonlinearity = 0.025). The overall cancer prevalence association was nonsignificant, except for colon cancer, where each 100 mg increase in choline intake indicated a 23% reduced risk.ConclusionElevated choline intake demonstrates an inverse association with CVD and colon cancer, while moderate consumption exhibits a correlated reduction in mortality. Additional comprehensive investigations are warranted to elucidate the broader health implications of choline.

Nonlinear relationship between oxidative balance score and hyperuricemia: analyses of NHANES 2007–2018

BackgroundLimited data regarding the correlation between oxidative balance score (OBS) and hyperuricemia highlights the necessity for thorough investigations. This study aims to examine the link between OBS, which incorporates dietary and lifestyle factors, and the occurrence of hyperuricemia.MethodsWe conducted a cross-sectional study involving 13,636 participants from the 2007–2018 National Health and Nutrition Examination Survey (NHANES). The oxidative balance score (OBS) was determined based on four lifestyle factors and sixteen dietary nutrients. We assessed the levels of serum uric acid (SUA) and the occurrence of hyperuricemia as outcomes. Weighted logistic regression and linear models were used for statistical analysis, using Restricted Cubic Splines (RCS) to examine potential nonlinear associations. Subgroup analysis and sensitivity assessments were performed to identify any variations and ensure the robustness of the findings.ResultsHigher OBS was consistently correlated with decreased SUA levels and a reduced prevalence of hyperuricemia. RCS highlighted a significant negative nonlinear association, particularly in females. Subgroup analysis revealed gender-based differences and interactive correlation, providing additional insights regarding OBS and hyperuricemia relationship.ConclusionThis study underscores a robust negative correlation between OBS and SUA levels as well as the incidence of hyperuricemia, emphasizing the importance of dietary and lifestyle factors. Incorporating RCS, subgroup analysis, and sensitivity assessments enhances the depth of our findings, providing valuable insights for further research.

Self-reported caffeine consumption miss-matched consumption measured by plasma levels of caffeine and its metabolites: results from two population-based studies.

Self-reported caffeine consumption has been widely used in research while it may be subject to bias. We sought to investigate the associations between self-reported caffeine consumption and plasma levels of caffeine and its two main metabolites (paraxanthine and theophylline) in the community. Data from two population-based studies (SKIPOGH1 and 2 (N = 1246) and CoLaus|PsyCoLaus (N = 4461)) conducted in Switzerland were used. Self-reported caffeine consumption was assessed using questionnaires. Plasma levels of caffeine and its metabolites were quantified by ultra-high performance liquid chromatography coupled to a tandem quadrupole mass spectrometer. In both studies, mean log plasma levels of caffeine and its two metabolites were over 6.48 (plasma levels = 652 ng/ml) when no caffeine consumption was reported. Subsequently, nonlinear associations between log plasma levels and self-reported caffeine consumption were observed in SKIPOGH, with a change of the slope at 3-5 cups of espresso per day in SKIPOGH1 but not SKIPOGH2. In CoLaus|PsyCoLaus, increased daily consumption of caffeinated beverages was associated with increased log plasma levels with a change of the slope at 3 cups. In both studies, declared caffeine consumption higher than 3-5 cups per day was not associated with higher plasma levels of caffeine and its metabolites. Self-reports of no or low caffeine consumption and consumption of more than 3-5 cups of coffee should be interpreted with caution, with possible under- or over-estimation. Quantifying plasma levels of caffeine and its metabolites may contribute to a better estimation of caffeine intake.

Environmental perchlorate, thiocyanate, and nitrate exposures and bone mineral density: a national cross-sectional study in the US adults.

Associations of perchlorate, thiocyanate, and nitrate exposures with bone mineral density (BMD) in adults have not previously been studied. This study aimed to estimate the associations of individual and concurrent exposure of the three chemicals with adult BMD. Based on National Health and Nutrition Examination Survey (NHANES, 2011-2018), 1618 non-pregnant adults (age ≥ 20years and 47.0% female) were included in this study. Survey-weighted linear regression models were used to estimate individual urinary perchlorate, thiocyanate, and nitrate concentrations with lumbar spine BMD and total BMD in adults. Then, weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) models were conducted to evaluate associations of co-occurrence of the three chemicals with adult BMD. In all participants, nitrate exposure was inversely associated with lumbar spine BMD (β =  - 0.054, 95%CI: - 0.097, - 0.010). In stratification analyses, significant inverse associations were observed in female and participants older than 40years old. In WQS regressions, significant negative associations of the weighted sum of the three chemicals with total and lumbar spine BMD (β =  - 0.014, 95%CI: - 0.021, - 0.007; β =  - 0.011, 95%CI: - 0.019, - 0.004, respectively) were found, and the dominant contributor was nitrate. In the BKMR models, non-linear dose-response associations of nitrate exposure with lumbar spine and total BMD were observed. These findings suggested that environmental perchlorate, thiocyanate, and nitrate exposure may reduce adult BMD and nitrate is the main contributor.

Sex and adrenal hormones in association with insecticide biomarkers among adolescents living in ecuadorian agricultural communities

BackgroundOrganophosphate, pyrethroid, and neonicotinoid insecticides have resulted in adrenal and gonadal hormone disruption in animal and in vitro studies; limited epidemiologic evidence exists in humans. We assessed relationships of urinary insecticide metabolite concentrations with adrenal and gonadal hormones in adolescents living in Ecuadorean agricultural communities. MethodsIn 2016, we examined 522 Ecuadorian adolescents (11-17y, 50.7% female, 22% Indigenous; ESPINA study). We measured urinary insecticide metabolites, blood acetylcholinesterase activity (AChE), and salivary testosterone, dehydroepiandrosterone (DHEA), 17β-estradiol, and cortisol. We used general linear models to assess linear (β = % hormone difference per 50% increase of metabolite concentration) and curvilinear relationships (β2 = hormone difference per unit increase in squared ln-metabolite) between ln-metabolite or AChE and ln-hormone concentrations, stratified by sex, adjusting for anthropometric, demographic, and awakening response variables. Bayesian Kernel Machine Regression was used to assess non-linear associations and interactions. ResultsThe organophosphate metabolite malathion dicarboxylic acid (MDA) had positive associations with testosterone (βboys = 5.88% [1.21%, 10.78%], βgirls = 4.10% [-0.02%, 8.39%]), and cortisol (βboys = 6.06 [-0.23%, 12.75%]. Para-nitrophenol (organophosphate) had negatively-trending curvilinear associations, with testosterone (β2boys = −0.17 (−0.33, −0.003), p = 0.04) and DHEA (β2boys = −0.49 (−0.80, −0.19), p = 0.001) in boys. The neonicotinoid summary score (βboys = 5.60% [0.14%, 11.36%]) and the neonicotinoid acetamiprid-N-desmethyl (βboys = 3.90% [1.28%, 6.58%]) were positively associated with 17β-estradiol, measured in boys only. No associations between the pyrethroid 3-phenoxybenzoic acid and hormones were observed. In girls, bivariate response associations identified interactions of MDA, Para-nitrophenol, and 3,5,6-trichloro-2-pyridinol (organophosphates) with testosterone and DHEA concentrations. In boys, we observed an interaction of MDA and Para-nitrophenol with DHEA. No associations were identified for AChE. ConclusionsWe observed evidence of endocrine disruption for specific organophosphate and neonicotinoid metabolite exposures in adolescents. Urinary organophosphate metabolites were associated with testosterone and DHEA concentrations, with stronger associations in boys than girls. Urinary neonicotinoids were positively associated with 17β-estradiol. Longitudinal repeat-measures analyses would be beneficial for causal inference.

The association between triglyceride-glucose index and the likelihood of cardiovascular disease in the U.S. population of older adults aged ≥ 60 years: a population-based study

BackgroundThe association between the triglyceride-glucose (TyG) index and the likelihood of developing cardiovascular disease (CVD) in the general elderly population in the United States aged 60 and above is not well understood. The objective of our study was to examine the relationship between the TyG index and CVD likelihood in the general elderly population over 60 years of age in the United States.MethodsData for this cross-sectional study were sourced from the 2003–2018 National Health and Nutrition Examination Survey. Weighted multivariable regression analysis and subgroup analysis were conducted to estimate the independent relationship between the TyG index and the likelihood of CVD. Non-linear correlations were explored using restricted cubic splines.ResultsA total of 6502 participants were included, with a mean TyG index of 8.75 ± 0.01. The average prevalence of CVD was 24.31% overall. Participants in the higher TyG quartiles showed high rates of CVD (Quartile 1: 19.91%; Quartile 2: 21.65%; Quartile 3: 23.82%; Quartile 4: 32.43%). For CVD, a possible association between the TyG index and the odds of CVD was observed. Our findings suggest a nonlinear association between the TyG index and the odds of CVD. The threshold of 8.73 for the likelihood of CVD. Interaction terms were employed to assess heterogeneities among each subgroup, revealing a significant difference specifically in alcohol consumption. This suggests that the positive association between the TyG index and the likelihood of CVD is dependent on the drinking status of the participants.ConclusionA higher TyG index is linked to an increased likelihood of CVD in US adults aged ≥ 60 years. TyG index is anticipated to emerge as a more effective metric for identifying populations at early likelihood of CVD.

Relationship among Falls, Fear of Falling, and Physical Activity Level in Patients on Hemodialysis.

Patients on hemodialysis are highly susceptible to falls and fractures. Amplified apprehension regarding the fear of falling (FOF) constitutes a risk factor that restricts physical activity and escalates the probability of falls among the elderly population. This study aimed to elucidate the association between falls and FOF and physical activity in patients on hemodialysis. A prospective cohort study was conducted across 9 centers. FOF was assessed using the Falls Efficacy Scale-International (FES-I). Physical activity was assessed using the Japanese version of the International Physical Activity Questionnaire short form. Subsequently, falls were monitored over a duration of 1year. Logistic regression analysis was performed to evaluate the relationship between falls and FOF and physical activity. In addition, in the receiver operating characteristic analysis, the cutoff value of FES-I that predicts falls was determined using the Youden Index. A restricted cubic spline curve was utilized to analyze the nonlinear association between falls and the FES-I. A total of 253 patients on hemodialysis (70.0 [59.0-77.0] years old; 105 female [41.5%]) were included in the analysis. During the 1-year observation period, 90 (35.6%) patients experienced accidental falls. The median FES-I score was 36.0 (24.0-47.0) points, and patients with higher FES-I scores had more falls. Following adjusted logistic regression analysis, FES-I exhibited an independent association with falls (OR = 1.04; 95% CI = 1.01-1.06), but physical activity was not. The area under the receiver operating characteristic curve was 0.70 (95% CI = 0.64-0.77), and the FES-I threshold value for distinguishing fallers from non-fallers was determined as 37.5 points (sensitivity 65.6%, specificity 35.0%). A nonlinear relationship between falls and FES-I was observed. FOF was associated with the incidence of falls in patients on hemodialysis. The evaluation and implementation of interventions targeting the FOF may mitigate the risk of falls.

The non-linear associations between blood manganese level and sarcopenia in patients undergoing maintenance hemodialysis: A multicenter cross-sectional study

Background & AimsManganese (Mn), a vital element in energy metabolism, is predominantly stored in skeletal muscles and plays a crucial role in muscle function and strength. Patients on maintenance hemodialysis (MHD) often experience muscle wasting due to metabolic disruption and inflammation. This study aimed to explore the relationship between blood Mn levels and sarcopenia in a patient population. MethodsIn this multicenter cross-sectional study, conducted from March 2021 to March 2022, 386 patients on MHD from three medical centers were included. Blood Mn levels were measured using inductively coupled plasma mass spectrometry, and body composition was assessed post-dialysis using bioelectrical impedance analysis. Grip strength was measured using a digital dynamometer. The patients were categorized into groups with and without sarcopenia. Using a generalized additive model to fit a smooth curve, we employed a generalized linear model to identify the optimal inflection point and explore the threshold effect after discovering a segmented relationship. Subsequently, a binary logistic regression analysis was conducted to investigate the relationship between blood manganese levels and the risk of sarcopenia, with adjustments made for potential confounding factors. ResultsA negative correlation was observed between blood Mn levels and sarcopenia-related parameters (Appendicular Skeletal Muscle Mass Index and grip strength) in Spearman’s correlation analysis (both P<0.05). After adjusting for confounding factors, a nonlinear association was identified. When blood Mn was ≤10.6μg/L, the increase in sarcopenia was not statistically significant (P>0.05). Conversely, when blood Mn exceeded 10.6μg/L, each 1μg/L increase raised the risk of sarcopenia by 0.1 times. Considering confounders, multivariate binary logistic regression confirmed an independent association between elevated blood Mn levels and sarcopenia. ConclusionThis study revealed an independent association between elevated blood Mn levels (>10.6μg/L) and sarcopenia in patients undergoing MHD. These findings emphasize the importance of understanding the Mn metabolism in the context of muscle health in this patient population. Further research is warranted to explore the underlying mechanisms and potential interventions for mitigating sarcopenia in patients with elevated blood Mn levels undergoing MHD.

Are There Meaningful Prestige Metrics of Kinesiology-Related Journals?

ABSTRACT This study documented the associations and variability of four prestige metrics for kinesiology-related journals. Four prestige metrics for the year 2022 were collected from three database services for 334 kinesiology-related journals. The prestige measures were highly skewed and had large variability, with medical journals having the highest values. There were strong nonlinear and heteroscedastic associations between all four prestige indicators, however rankings of top 10% journals based on these metrics had considerable disagreement between metrics. The substantial variability of journal prestige metrics was larger than the variation previously reported for scholar subjective perceptions of journal prestige. The prestige metrics provided inconsistent and unrealistically precise estimates of kinesiology journal prestige. Great care should be exercised in interpreting prestige metrics and scholar perceptions of journal prestige in diverse disciplines like kinesiology.