Causal mediation analysis in the context of clinical research

Visceral adipose tissue mediates the relationship between left ventricular global longitudinal strain and insulin resistance among adults living with type 2 diabetes

BACKGROUND

Adipose tissue distribution plays a crucial role in the development of cardiovascular complications. In particular, visceral adipose tissue (VAT) has been linked to insulin resistance (IR) and cardiovascular disease (CVD). However, the relationship between VAT, cardiac dysfunction and the meditation capacity of VAT related to IR has not been fully characterized.

METHODS

This cross-sectional study included adults living with type 2 diabetes (T2D). VAT was measured using electrical bioimpedance and also estimated with the Metabolic Score for Visceral Fat (METS-VF). LV function was assessed using left ventricular global longitudinal strain (LV-GLS) by speckle tracking echocardiography analysis. Spearman correlation coefficients, adjusted linear regression models guided by direct acyclic diagrams and causal mediation analysis were performed.

RESULTS

Among 195 adults living with T2D (median age: 57, IQR: 49-64, women: 63%), VAT showed a positive association with LV-GLS (β = 0.482, 95% CI: 0.060-0.904, p = 0.039) after adjusting for relevant confounders. The effect was strongly replicated using METS-VF as a surrogate for VAT. The mediation analysis revealed that VAT accounted for 60.9% (95% CI: 15.82-171) of the total effect between IR and LV-GLS.

CONCLUSION

This study demonstrated a positive association between VAT and LV-GLS. This relationship was consistently observed using the clinical surrogate METS-VF. Visceral adiposity was identified as a strong mediator in the relationship between IR and LV-GLS, underscoring its role in the pathophysiology of cardiovascular disease in patients with T2D.

Exploring the mediating role of depression in the relationship between sarcopenia and cardiovascular health in the middle-aged and elderly: A cross-sectional study

BACKGROUND

Cardiovascular health is influenced by various factors, including sarcopenia and depression. It has been demonstrated that sarcopenia has a negative impact on cardiovascular disease, with depression also being a contributing factor. However, the complex interplay between sarcopenia, depressive symptoms, and cardiovascular health in middle-aged and elderly populations is not fully explored.

METHODS

A total of 23,445 participants participated in China Health and Retirement Longitudinal Study and completed relevant measurements, including the Centre for Epidemiological Studies Depression Scale. The study also assessed sarcopenia and cardiovascular health score. The focus of the study was to test whether the association between sarcopenia and cardiovascular health scores was mediated by depression using PROCESS macros in R 4.3.2. Sensitivity analyses were conducted to affirm the robustness of our findings.

RESULT

The study revealed a partial mediation between sarcopenia and cardiovascular health score among the middle and elder adults, mediated by depression. Sarcopenia had a significant negative correlation with cardiovascular health score (B = -12.404, P < 0.05), and depression also showed a significant negative correlation (B = -1.515, P < 0.001).

CONCLUSION

The results support the notion that depression partially mediated the association between sarcopenia and cardiovascular health score. Therefore, interventions aimed at improving mood and addressing other cardiovascular risk factors may help alleviate the adverse effects of sarcopenia and potentially reduce the progression to cardiovascular disease.

Mediating Role of Platelet Count Increase in Unfractionated Heparin Treatment for Sepsis Patients: A Retrospective Cohort Analysis

Aims/Background The role of heparin in sepsis therapy has been widely debated. The controversy surrounding heparin's use as an anticoagulant in sepsis may stem from differences in sepsis definitions, study designs, timing and dosage of drug administration, treatment duration, complications, and patient severity. In this study, we aimed to determine the optimal timing and dosage of heparin in patients with sepsis, identify specific subgroups that could benefit from heparin therapy, and explore laboratory markers to assess its efficacy. Methods This retrospective cohort study was conducted using the Medical Information Mart for Intensive Care-IV dataset. Data from patients with sepsis were extracted based on the Sepsis 3.0 criteria. Patients were categorized according to heparin use. The effectiveness of early and appropriate heparin administration was assessed, and a subgroup analysis was performed to identify patients most likely to benefit from heparin therapy. Additionally, factors mediating the improvement in sepsis prognosis following heparin treatment were analyzed. Results We recruited 4149 participants who met the inclusion criteria, with an overall 28-day mortality rate of 19.5%. There were 2192 individuals in the heparin group and 1957 in the non-heparin group. After propensity score matching, heparin therapy demonstrated a significantly greater effect on reducing both 28-day and 90-day mortality compared to the non-heparin treatment (18.1% vs. 10.7%, p < 0.001; 18.8% vs. 12.6%, p < 0.001). However, the heparin group had a higher incidence of major bleeding (10.9% vs. 6.3%, p = 0.001), increased use of mechanical ventilation (54.3% vs. 45.1%, p < 0.001), and a longer intensive care unit stay (3.6 vs. 2.5 days, p < 0.001) compared to the non-heparin group. Early administration of high-dose heparin improved 28-day survival. Early and adequate heparin administration was more effective than late and insufficient dosing (p < 0.01), except in patients with sepsis who had low white blood cell counts, alkalosis, or reduced platelet counts. The increase in platelet count had a significant mediating effect on the entire cohort (p < 0.001 for the causal mediation effect), with a mediation proportion of 14%. Conclusion Early and adequate heparin administration can significantly improve the prognosis of sepsis. An increase in platelet count may serve as a potential indicator of the effectiveness of heparin therapy in sepsis.

Associations of malnutrition factors with dysphagia mediated by ADL among nursing home residents

OBJECTIVE

The potential link between malnutrition and dysphagia along with its underlying mechanisms remains unknown. This study aimed to investigate the association between malnutrition factors and dysphagia mediated by a decline in activities of daily living (ADL) among nursing home residents.

METHODS

This cross-sectional study used data from 705 nursing home residents. The primary factors were risk of malnutrition and dysphagia. A body mass index (BMI) of < 18.5 and insufficient energy and protein intakes were also collected as factors related to malnutrition. The causal mediation analysis was used with malnutrition factors as the exposure, dysphagia as the outcome, and ADL as the mediation factor.

RESULTS

In total, 391 residents (55.5%) were at risk of malnutrition and 451 residents (64.0%) had dysphagia. The average causal mediation effect (ACME) of risk of malnutrition on dysphagia was 0.07 (95% confidence interval, C, 0.07-0.08), and the ACME of BMI < 18.5 was 0.05 (95% CI 0.04-0.05, P < 0.001 for both). For insufficient nutritional intake, the ACME of low energy intake was 0.07 (95% CI 0.07-0.07), and the ACME of low protein intake was 0.03 (95% CI 0.02-0.04, P < 0.001 for both). The total effects of all these exposures on dysphagia were significant (P = 0.002 for low protein intake and P < 0.001 for the others).

CONCLUSION

Malnutrition factors were associated with dysphagia, mediated by a decline in ADL among nursing home residents. The results of this study suggest the importance of nutritional management along with approaches to ADL to prevent dysphagia.

Causal Mediation Analysis of Foodborne Salmonella Outbreaks in the United States: Serotypes and Food Vehicles

Various Salmonella serotypes have caused numerous foodborne outbreaks associated with food vehicles in different categories. This study provides evidence on the occurrence and inter-relations between Salmonella serotypes and the number of deaths mediated by the number of illnesses and hospitalizations. Confirmed foodborne outbreaks of Salmonella serotypes (n = 2868) that occurred between 1998 and 2021 were obtained from the Centers for Disease Control and Prevention National Outbreak Reporting System. Causal mediation analysis was performed based on 500 bootstrap samples. The serotypes and the Interagency Food Safety Analytics Collaboration (IFSAC) food categories as confounding effects were considered as categorical variables. A total of 106 single Salmonella serotypes were associated with foodborne outbreaks. Foodborne outbreaks caused by Salmonella serotypes resulted in 81,996 illnesses, 11,018 hospitalizations, and 115 deaths between 1998 and 2021 in the United States. The serotypes Enteritidis (815 outbreaks, 28.42%), Typhimurium (359 outbreaks, 12.52%), and Newport (220 outbreaks, 7.67%) accounted for almost half of Salmonella-linked outbreaks. Poultry products, "chickens", "eggs", and "turkey", were the leading IFSAC food categories, accounting for 14.02% of total outbreaks and 10.44% of total deaths. Certain serotypes had a significant effect on illness, hospitalization, and death counts. Two serotypes, Heidelberg and Saintpaul, and "fruits" as the food vehicle in IFSAC categories had a significant direct effect on the number of illnesses, hospitalizations, and deaths as outcomes of Salmonella outbreaks (p ≤ 0.05). There was strong evidence that illness and hospitalization counts played a key role in the pathway from serotype to death counts on foodborne outbreaks caused by Salmonella based on causal mediation analysis. The findings of this study can help outbreak investigations and lead to prevention and control measures by providing insightful information about the frequencies of Salmonella serotypes and the associated food vehicles causing foodborne diseases.

Role of human plasma metabolites in prediabetes and type 2 diabetes from the IMI-DIRECT study

AIMS/HYPOTHESIS

Type 2 diabetes is a chronic condition that is caused by hyperglycaemia. Our aim was to characterise the metabolomics to find their association with the glycaemic spectrum and find a causal relationship between metabolites and type 2 diabetes.

METHODS

As part of the Innovative Medicines Initiative - Diabetes Research on Patient Stratification (IMI-DIRECT) consortium, 3000 plasma samples were measured with the Biocrates AbsoluteIDQ p150 Kit and Metabolon analytics. A total of 911 metabolites (132 targeted metabolomics, 779 untargeted metabolomics) passed the quality control. Multivariable linear and logistic regression analysis estimates were calculated from the concentration/peak areas of each metabolite as an explanatory variable and the glycaemic status as a dependent variable. This analysis was adjusted for age, sex, BMI, study centre in the basic model, and additionally for alcohol, smoking, BP, fasting HDL-cholesterol and fasting triacylglycerol in the full model. Statistical significance was Bonferroni corrected throughout. Beyond associations, we investigated the mediation effect and causal effects for which causal mediation test and two-sample Mendelian randomisation (2SMR) methods were used, respectively.

RESULTS

In the targeted metabolomics, we observed four (15), 34 (99) and 50 (108) metabolites (number of metabolites observed in untargeted metabolomics appear in parentheses) that were significantly different when comparing normal glucose regulation vs impaired glucose regulation/prediabetes, normal glucose regulation vs type 2 diabetes, and impaired glucose regulation vs type 2 diabetes, respectively. Significant metabolites were mainly branched-chain amino acids (BCAAs), with some derivatised BCAAs, lipids, xenobiotics and a few unknowns. Metabolites such as lysophosphatidylcholine a C17:0, sum of hexoses, amino acids from BCAA metabolism (including leucine, isoleucine, valine, N-lactoylvaline, N-lactoylleucine and formiminoglutamate) and lactate, as well as an unknown metabolite (X-24295), were associated with HbA1c progression rate and were significant mediators of type 2 diabetes from baseline to 18 and 48 months of follow-up. 2SMR was used to estimate the causal effect of an exposure on an outcome using summary statistics from UK Biobank genome-wide association studies. We found that type 2 diabetes had a causal effect on the levels of three metabolites (hexose, glutamate and caproate [fatty acid (FA) 6:0]), whereas lipids such as specific phosphatidylcholines (PCs) (namely PC aa C36:2, PC aa C36:5, PC ae C36:3 and PC ae C34:3) as well as the two n-3 fatty acids stearidonate (18:4n3) and docosapentaenoate (22:5n3) potentially had a causal role in the development of type 2 diabetes.

CONCLUSIONS/INTERPRETATION

Our findings identify known BCAAs and lipids, along with novel N-lactoyl-amino acid metabolites, significantly associated with prediabetes and diabetes, that mediate the effect of diabetes from baseline to follow-up (18 and 48 months). Causal inference using genetic variants shows the role of lipid metabolism and n-3 fatty acids as being causal for metabolite-to-type 2 diabetes whereas the sum of hexoses is causal for type 2 diabetes-to-metabolite. Identified metabolite markers are useful for stratifying individuals based on their risk progression and should enable targeted interventions.

Genetic and vascular risk factors for ischemic stroke and cortical morphometry in individuals without a history of stroke: A UK Biobank observational cohort study

BACKGROUND

Stroke risk factors may contribute to cognitive decline and dementia by altering brain tissue integrity. If their effects on brain are nonnegligible, the target regions for stroke rehabilitation with brain stimulation identified by cross-sectional case-control studies may be biased due to the pre-existing brain differences caused by these risk factors. Here, we investigated the effects of stroke risk factors on cortical thickness (CT) and surface area (SA) in individuals without a history of stroke.

METHODS

In this observational study, we used data from the UK Biobank cohort to explore the effects of polygenic risk score for ischemic stroke (PRSIS), systolic blood pressure (SBP), diastolic blood pressure (DBP), glycated hemoglobin (HbA1c), triglycerides (TG), and low-density lipoprotein (LDL) on CT and SA of 62 cerebral regions. We excluded non-Caucasian participants and participants with missing data, unqualified brain images, or a history of stroke or any other brain diseases. We constructed a multivariate linear regression model for each phenotype to simultaneously test the effect of each factor and interaction between factors. The results were verified by sensitivity analyses of SDP or DBP input and adjusting for body-mass index, high-density lipoprotein cholesterol, or smoking and alcohol intake. By excluding participants with abnormal blood pressure, glucose, or lipid, we tested whether vascular risk factor within normal range also affected cortical phenotypes. To determine clinical relevance of our findings, we also investigated the effects of stroke risk factors and cortical phenotypes on cognitive decline assessed by fluid intelligence score (FIQ) and the mediation of cortical phenotype for the association between stroke risk factor and FIQ.

RESULTS

The study consisted of 27 120 eligible participants. Stroke risk factors were associated with 16 CT and two SA phenotypes in both main and sensitivity analyses (all p < 0.0004, Bonferroni corrected), which could explain portions of variances (partial R2, median 0.62 % [IQR 0.44-0.75 %] in main analyses) in these phenotypes. Among the 18 cortical phenotypes associated with stroke risk factors, we identified 26 specific predictor-phenotype associations (all p < 0.0026), including the positive associations between PRSIS and SA and between HbA1c and CT, negative associations of SBP and TG with CT, and mixed associations of PRSIS and DBP with CT. Neither LDL nor interactions between risk factors affected cortical phenotypes. Of the 16 associations between vascular risk factors and cortical phenotypes, ten were still significant after excluding participants with abnormal vascular risk assessments and diagnoses. Stroke risk factors were associated with FIQ in all analyses (p < 0.0004; partial R2, range 0.22-0.3 %), of which the associations of PRSIS and SBP with cognitive decline were mediated by CT phenotypes.

CONCLUSIONS

Stroke risk factors have substantial effects on cortical morphometry and cognitive decline in middle-aged and older people, which should be considered in the prevention of dementia and in the identification of target regions for stroke rehabilitation with brain stimulation.

The mediating effect of TyG-related indicators between long-term exposure to particulate matter and cardiovascular disease: evidence from a national longitudinal cohort study

BACKGROUND

Ambient particulate matter (PM) exposure is recognized as a risk factor for cardiovascular disease (CVD). However, the extent to which PM exposure is associated with CVD via triglyceride glucose (TyG)-related indicators remains unknown. This study examines the relationship between long-term PM exposure and CVD events, further assessing whether TyG-related indicators mediate this association.

METHODS

This cohort study involved 7,532 individuals aged at least 45 years who were not diagnosed with CVD in 2011 from the China Longitudinal Study of Health and Retirement (CHARLS) and were followed up for the occurrence of CVD until 2020. The annual PM concentration data at the city level, with aerodynamic diameters ≤ 1 μm (PM1), ≤ 2.5 μm (PM2.5), and ≤ 10 μm (PM10), were obtained from the ChinaHighAirPollutants (CHAP). The average concentration of PM in the 3 years before the baseline survey in 2011 was defined as the long-term exposure level of the individual. The relationship between PM exposure and CVD incidence was examined via Cox proportional hazards models, with a focus on probing the role of TyG-related indicators through mediation analysis.

RESULTS

A total of 1,865 individuals with CVD were diagnosed over the span of a 7.4-year follow-up period. The 3-year average concentrations before baseline were 31.29 µg/m³ for PM1, 56.03 µg/m³ for PM2.5, and 95.73 µg/m³ for PM10. In fully adjusted model, the Cox proportional hazards models revealed that an increase of 10 µg/m³ in the PM1, PM2.5, and PM10 exposure concentrations corresponded to elevated CVD risk, with HRs (95% CI) of 1.135 (1.078-1.195), 1.092 (1.062-1.123), and 1.075 (1.059-1.090), respectively. Mediation analyses further suggested that the correlation between PM exposure and CVD could be partly mediated via TyG-BMI, TyG-WC, and TyG-WHtR, with mediation proportions varying from 5.54 to 15.30%.

CONCLUSION

A significant correlation was observed between long-term PM exposure and increased CVD risk, with TyG-related indicators, such as TyG-BMI, TyG-WC, and TyG-WHtR, partially mediating this relationship.

Sarcopenia is associated with increased major adverse cardiovascular event incidence in maintenance hemodialysis patients: a prospective cohort study and mediation analysis

Background

Few studies have investigated the relationship between sarcopenia and the incidence of major adverse cardiovascular events (MACE), which are common complications in maintenance hemodialysis (MHD) patients. This study thus explored the association between sarcopenia and MACE in a prospective cohort with mediation analysis.

Methods

Adult MHD patients in Jiangdu People's Hospital in December 2019 were screened. The exposure was sarcopenia, as defined by the 2019 Asian Working Group. The primary endpoint was the occurrence of MACE, defined as the composite of all-cause mortality or hospital admission with a primary diagnosis of acute myocardial infarction, stroke, or heart failure during a 3-year follow-up period. Multivariate Cox regression analyses were used to test the association between sarcopenia and subsequent MACE incidence. Mediation analyses were used to investigate whether potential mediators influenced the association between sarcopenia and MACE.

Results

Of the 230 patients enrolled, 57% were male, with a median age of 57 years (interquartile range [IQR]: 50 to 66), and a median dialysis vintage of 67 months (IQR: 32 to 119). The prevalence of sarcopenia was 45.2%. The presence of sarcopenia was significantly correlated with age (Spearman's r = 0.47, p < 0.001), C-reactive protein (Spearman's r = 0.13, p = 0.044), serum albumin (Spearman's r = -0.22, p < 0.001), 25(OH) vitamin D (Spearman's r = -0.26, p < 0.001), and coronary artery calcification score (Spearman's r = 0.20, p = 0.002). Over the 3-year follow-up period, MACE were observed in 59/104 (56.7%) patients with sarcopenia and 38/126 (30.2%) patients without sarcopenia (log-rank p < 0.001). After accounting for potential confounders, patients with sarcopenia presented a 66% (4-168%, p = 0.035) increase in their risk of MACE incidence as compared to non-sarcopenic individuals. However, adjusted mediation analyses did not detect any indication of a causal mediation pathway linking the effects of sarcopenic status on coronary artery calcification score, C-reactive protein, serum albumin, or 25(OH) vitamin D levels to MACE outcomes. Conversely, sarcopenia exhibited a potential direct effect (average direct effect range: -1.52 to -1.37, all p < 0.05) on MACE incidence.

Conclusion

These results revealed that the presence of sarcopenia was associated with a higher incidence of MACE in MHD patients. The putative effects of sarcopenia on this cardiovascular endpoint are possibly not mediated by any causal pathways that include vascular calcification, inflammation, hypoalbuminemia, or vitamin D.

Social Behaviors Associated with SARS-CoV-2 Test Positivity Among Children Evaluated in Canadian Emergency Departments, 2020 to 2022: A Cross-Sectional Survey Study

OBJECTIVE

To evaluate how social behaviors relate to SARS-CoV-2 test positivity across pediatric age groups.

METHODS

Multicenter, cross-sectional study recruiting children <18 years old tested for SARS-CoV-2 infection in emergency departments between 2020 and 2022. We used multivariate logistic regression to assess how self-reported social behaviors affect SARS-CoV-2 test positivity across four age groups. Causal mediation analysis quantified how mask-wearing and presence of an infected close contact mediated the SARS-CoV-2 risk of given behaviors.

RESULTS

Seven thousand two hundred and seventy two children were enrolled and 1457 (20.0%) tested positive for SARS-CoV-2. Attending a social gathering was associated with increased odds (aOR 1.64, 95% CI: 1.05, 2.57) of SARS-CoV-2 positivity among children aged 5-<12 years. Those attending in-person school/daycare were less likely to test positive for SARS-CoV-2 across all age categories. Attending childcare was associated with 16.3% (95% CI: -21.0%, -11.2%) and 9.0% (95% CI: -11.6%, -6.5%) reductions in the probability of testing positive for SARS-CoV-2 infection, with 53.5% (95% CI: 39.2%, 73.9%) and 22.8% (95% CI: 9.7%, 36.2%) of the effects being mediated by the presence of a close contact among <1 year and 1-<5 year age groups, respectively. Masking in public mediated the association between childcare attendance and SARS-CoV-2 positivity in children aged <1 year.

CONCLUSIONS

Attending social gatherings increased the risk of SARS-CoV-2 test positivity in 5-<12-year-old children, but in-person daycare/school was associated with a reduced odds of testing positive across all ages. Settings with high public health adherence (ie, schools) reduced the risk of testing positive for SARS-CoV-2, possibly from reduced close contact with SARS-CoV-2 positive individuals.

Psycho-social dimensions of cardiovascular risk: exploring the impact of social isolation and loneliness in middle-aged and older adults

BACKGROUND

Cardiovascular disease (CVD) is a major health concern for middle-aged and older adults, with lifestyle and metabolic risk factors well-studied. However, the role of psychosocial factors in CVD remains underexplored.

OBJECTIVE

This study aims to delve into the connection between psychosocial factors and the occurrence of CVD.

METHODS

We utilized data from the UK Biobank, a large-scale study covering adults aged 38 to 73 recruited from various centers across the UK between 2006 and 2010. We employed Cox proportional hazards models to analyze the relationship between social isolation, loneliness, and incident CVD. CVD diagnoses were confirmed through hospital records and death-register data. Additionally, we conducted mediation analyses to assess the impact of low-grade inflammation.

RESULTS

The study encompassed 427,942 participants free from CVD, 55.8% of whom are women. High levels of social isolation and loneliness were linked to a higher risk of CVD (HRs 1.11, 95% CI 1.06-1.16; HRs 1.17, 95% CI 1.11-1.23). Depression also emerged as a predictor of CVD onset (HRs 1.25, 95% CI 1.19-1.31), with each psychosocial factor independently contributing to increased CVD risk. Mediation analyses pinpointed inflammation as a crucial mediator, especially for loneliness (indirect effect proportion: 4.7%).

CONCLUSIONS

This study underscores the significance of psychosocial factors in relation to CVD. Integrating assessments for social isolation, loneliness, and depression into routine healthcare could potentially aid in CVD prevention among middle-aged and elderly individuals. This study underscores the significance of psychosocial factors in relation to CVD, emphasizing the association between social isolation or loneliness and the heightened risk of CVD.

Investigating the causal relationship between wealth index and ICT skills: a mediation analysis approach

This study examines the relationship between the wealth index (WI) and Information and Communication Technology (ICT) skills among women aged 15-49 in Bangladesh. The research aims to establish a cause-and-effect relationship between WI and ICT skills, while also examining how education mediates this relationship. Using the data from the Bangladesh Multiple Indicator Cluster Survey (MICS) Program 2019, a two-stage stratified clustered sampling method yielded a sample of 64,378 women. The analysis employed inverse probability weighting (IPW) to assess the causal effect of WI on ICT skills while investigating the mediating role of education in this cause-and-effect relationship through causal mediation analysis. The findings demonstrate a significant relationship between higher economic status and increased ICT proficiency among women aged 15-49 in Bangladesh. Mediation analysis reveals education status as a significant mediator, indicating that educational attainment plays a vital role in linking wealth and ICT skills among women. Sensitivity analysis indicates the observed effect estimates are robust to unmeasured confounding. This research underscores the importance of economic empowerment and educational interventions in narrowing the digital divide and fostering ICT skills development among women, particularly in rural and economically disadvantaged communities.

The association between rs6859 in NECTIN2 gene and Alzheimer's disease is partly mediated by pTau

Introduction

Emerging evidence suggests a connection between vulnerability to infections and Alzheimer's disease (AD). The nectin cell adhesion molecule 2 (NECTIN2) gene coding for a membrane component of adherens junctions is involved in response to infections, and its single nucleotide polymorphism (SNP) rs6859 was significantly associated with AD risk in several human cohorts. It is unclear, however, how exactly rs6859 influences the development of AD pathology. The aggregation of hyperphosphorylated tau protein (pTau) is a key pathological feature of neurodegeneration in AD, which may be induced by infections, among other factors, and potentially influenced by genes involved in both AD and vulnerability to infections, such as NECTIN2.

Materials and methods

We conducted a causal mediation analysis (CMA) on a sample of 708 participants in the Alzheimer's disease Neuroimaging Initiative (ADNI). The relationship between rs6859 and Alzheimer's disease (AD), with AD (yes/no) as the outcome and pTau-181 levels in the cerebrospinal fluid (CSF) acting as a mediator in this association, was assessed. Adjusted estimates from the probit and linear regression models were used in the CMA model, where an additive model considered an increase in dosage of the rs6859 A allele (AD risk factor).

Results

The increase in dose of allele A of the SNP rs6859 resulted in about 0.144 increase per standard deviation (SD) of pTau-181 (95% CI: 0.041, 0.248, p < 0.01). When included together in the probit model, the change in A allele dose and each standard deviation change in pTau-181 predicted 6.84% and 9.79% higher probabilities for AD, respectively. In the CMA, the proportion of the average mediated effect was 17.05% and was higher for the risk allele homozygotes (AA), at 19.40% (95% CI: 6.20%, 43.00%, p < 0.01). The sensitivity analysis confirmed the evidence of a robust mediation effect.

Conclusion

This study reported a new potential causal relationship between pTau-181 and AD. We found that the association between rs6859 in the NECTIN2 gene and AD is partly mediated by pTau-181 levels in CSF. The rest of this association may be mediated by other factors. Our finding sheds light on the complex interplay between genetic susceptibility, protein aggregation, and neurodegeneration in AD. Further research, using other biomarkers, is needed to uncover the remaining mechanisms of the association between the NECTIN2 gene and AD.

Parenting Behaviors as Mediators of the Association Between Parental Internalizing Symptoms and Child Externalizing Symptoms

This study analyzes whether the association between parental internalizing symptoms (depression, anxiety, stress) and child symptoms of attention-deficit/hyperactivity disorder (ADHD) or oppositional defiant disorder (ODD) is mediated by positive and negative parenting behaviors. Cross-sectional data of 420 parents of children (age 6-12 years) with elevated levels of externalizing symptoms were collected in a randomized controlled trial. Measures included parent ratings of their internalizing symptoms and parenting behaviors and of their child's externalizing symptoms. Two mediation models were examined, one including ADHD symptoms and one including ODD symptoms as the dependent variable. Parental internalizing symptoms were modeled as the independent variable and positive and negative parenting behaviors were modeled as parallel mediators. Regression analyses support negative parenting behavior as a mediator of the association between parental internalizing symptoms and child ODD symptoms. For the ADHD model, no significant mediator could be found. Future studies should use prospective designs and consider reciprocal associations.

Effect of hyperuricemia on paroxysmal atrial fibrillation after catheter ablation and influence of alcohol consumption

Background

Evidence regarding the association between hyperuricemia and arrhythmia recurrence after catheter ablation for paroxysmal atrial fibrillation (AF) is scarce. We investigated whether hyperuricemia predicts arrhythmia recurrence after catheter ablation for paroxysmal AF and the relationship between hyperuricemia and alcohol consumption in AF recurrence.

Methods

Patients who underwent catheter ablation for paroxysmal AF were divided into the hyperuricemia (index serum uric acid [UA] >7.0 mg/dL; n = 114) and control (UA ≤7.0 mg/dL; n = 609) groups and were followed for a median of 24 (12-48) months after ablation.

Results

The hyperuricemia group had more patients with an alcohol intake of ≥20 g/day (33.3% vs. 22.7%, p = .017) and a lower incidence of AF-free survival (p = .019). Similarly, those with an alcohol intake of ≥20 g/day had a lower incidence of AF-free survival than other patients. Multivariate Cox regression analysis revealed the following independent predictors of AF recurrence (adjusted hazard ratio, 95% confidence interval): hyperuricemia (1.64, 1.12-2.40), female gender (1.91, 1.36-2.67), brain natriuretic peptide level >100 pg/mL (1.59, 1.14-2.22), and alcohol consumption ≥20 g/day (1.49, 1.03-2.15) (all p < .05). In addition, causal mediation analysis revealed that alcohol consumption of ≥20 g/day directly affected AF recurrence, independent of hyperuricemia.

Conclusions

Patients with hyperuricemia may be at a high risk of arrhythmia recurrence after catheter ablation for paroxysmal AF. Although high alcohol consumption may contribute to increased UA levels, the presence of hyperuricemia may independently predict AF recurrence.

Deciphering the tumour microenvironment of clear cell renal cell carcinoma: Prognostic insights from programmed death genes using machine learning

Clear cell renal cell carcinoma (ccRCC), a prevalent kidney cancer form characterised by its invasiveness and heterogeneity, presents challenges in late-stage prognosis and treatment outcomes. Programmed cell death mechanisms, crucial in eliminating cancer cells, offer substantial insights into malignant tumour diagnosis, treatment and prognosis. This study aims to provide a model based on 15 types of Programmed Cell Death-Related Genes (PCDRGs) for evaluating immune microenvironment and prognosis in ccRCC patients. ccRCC patients from the TCGA and arrayexpress cohorts were grouped based on PCDRGs. A combination model using Lasso and SuperPC was constructed to identify prognostic gene features. The arrayexpress cohort validated the model, confirming its robustness. Immune microenvironment analysis, facilitated by PCDRGs, employed various methods, including CIBERSORT. Drug sensitivity analysis guided clinical treatment decisions. Single-cell data enabled Programmed Cell Death-Related scoring, subsequent pseudo-temporal and cell-cell communication analyses. A PCDRGs signature was established using TCGA-KIRC data. External validation in the arrayexpress cohort underscored the model's superiority over traditional clinical features. Furthermore, our single-cell analysis unveiled the roles of PCDRG-based single-cell subgroups in ccRCC, both in pseudo-temporal progression and intercellular communication. Finally, we performed CCK-8 assay and other experiments to investigate csf2. In conclusion, these findings reveal that csf2 inhibit the growth, infiltration and movement of cells associated with renal clear cell carcinoma. This study introduces a PCDRGs prognostic model benefiting ccRCC patients while shedding light on the pivotal role of programmed cell death genes in shaping the immune microenvironment of ccRCC patients.

The association between rs6859 in NECTIN2 gene and Alzheimer's disease is partly mediated by pTau

Introduction

Emerging evidence suggests a connection between vulnerability to infections and Alzheimer's disease (AD). The nectin cell adhesion molecule 2 (NECTIN2) gene coding for a membrane component of adherens junctions is involved in response to infection, and its single nucleotide polymorphism (SNP) rs6859 was significantly associated with AD risk in several human cohorts. It is unclear, however, how exactly rs6859 influences the development of AD pathology. The aggregation of hyperphosphorylated tau protein (pTau) is a key pathological feature of neurodegeneration in AD, which may be induced by infections, among other factors, and potentially influenced by genes involved in both AD and vulnerability to infections, such as NECTIN2.

Materials and methods

We conducted a causal mediation analysis (CMA) on a sample of 708 participants in the Alzheimer's Disease Neuroimaging Initiative (ADNI). The relationship between rs6859 and Alzheimer's disease (AD), with AD (yes/no) as the outcome and pTau-181 levels in the cerebrospinal fluid (CSF) acting as a mediator in this association, was assessed. Adjusted estimates from the probit and linear regression models were used in the CMA model, where an additive model considered an increase in dosage of the rs6859 A allele (AD risk factor).

Results

The increase in dose of allele A of the SNP rs6859 resulted in about 0.144 increase per standard deviation (SD) of pTau-181 (95% CI: 0.041, 0.248, p<0.01). When included together in the probit model, the change in A allele dose and each standard deviation change in pTau-181 predicted 6.84% and 9.79% higher probabilities for AD, respectively. In the CMA, the proportion of the average mediated effect was 17.05% and was higher for the risk allele homozygotes (AA), at 19.40% (95% CI: 6.20%, 43.00%, p<0.01). The sensitivity analysis confirmed the evidence of a robust mediation effect.

Conclusion

This study reported a new causal relationship between pTau-181 and AD. We found that the association between rs6859 in the NECTIN2 gene and AD is partly mediated by pTau-181 levels in CSF. The rest of this association may be mediated by other factors. Further research, using other biomarkers, is needed to uncover the remaining mechanisms of the association between the NECTIN2 gene and AD.

The role of coagulation factors VIII, IX and XI in the prediction and mediation of recurrent thrombotic events in children with non-central venous catheter deep vein thrombosis

BACKGROUND

The role of elevated coagulation factors VIII (FVIII), FIX, FXI for the prediction of recurrent thrombotic events in children after an index non-central venous catheter (non-CVC) related deep vein thrombosis (DVT) remains unclear.

OBJECTIVE

This study investigates the predictive role of FVIII, FIX, and FXI for recurrent thrombosis in children with index non-CVC DVTs, and the mediation effect of FVIII on chronic inflammation and recurrent thrombosis.

METHODS

Children aged 0-18 years diagnosed with an index non-CVC related DVT (1993-2020) were included in this single-center retrospective cohort study. Plasma levels of FVIII, FIX, FXI were measured cross-sectionally ≥30 days after the acute DVT. The association between the continuous variables FVIII, FIX, FXI and thrombosis recurrence was investigated using uni- and multivariable logistic regression, adjusting for age, sex, and chronic inflammation. Mediation analysis assessed the role of FVIII as a mediator between chronic inflammation and recurrent thrombosis. Ethics approval was obtained.

RESULTS

A total of 139 children with an index non-CVC related DVT were included. Thirty-eight (27 %) had a recurrent thrombosis at a median of 237 days (P25-P75 65-657 days) after the index DVT. In uni- and multivariable-analysis, FVIII, FIX or FXI did not predict thrombosis recurrence; However, chronic inflammation was an independent predictor. There was no evidence that FVIII mediated the effect of chronic inflammation on thrombosis recurrence.

CONCLUSION

We found no evidence that elevated FVIII, FIX or FXI predicted thrombosis recurrence, or evidence of a mediating role of FVIII. Underlying chronic inflammation predicted venous recurrent thrombotic events in this cohort.

Sleep deprivation alters pubertal timing in humans and rats: the role of the gut microbiome

STUDY OBJECTIVES

Evidence implied that sleeping duration is associated with the timing of puberty and that sleep deprivation triggers early pubertal onset in adolescents. Sleep deprivation can affect metabolic changes and gut microbiota composition. This study investigated the effects of sleep deprivation on pubertal onset and gut microbiota composition in animal models and a human cohort.

METHODS

This study comprised 459 boys and 959 girls from the Taiwan Pubertal Longitudinal Study. Sleep duration was evaluated using the self-report Pittsburgh Sleep Quality Index questionnaire. Early sexual maturation was defined by pediatric endocrinologist assessments. Mediation analyses were done to examine the association between sleep parameters, obesity, and early sexual maturation. Besides, Sprague Dawley juvenile rats were exposed to 4 weeks of chronic sleep deprivation. Vaginal opening (VO) and preputial separation (PS) were observed every morning to determine pubertal onset in female and male rats.

RESULTS

The sleep-deprived juvenile rats in the sleep-deprived-female (SDF) and sleep-deprived-male (SDM) groups experienced delayed VO (mean VO days: 33 days in control; 35 days in SDF; p-value < 0.05) and PS (mean PS days: 42 days in control; 45 days in SDM; p-value < 0.05), respectively. Relative to their non-sleep-deprived counterparts, the sleep-deprived juvenile rats exhibited lower body weight and body fat percentage. Significant differences in relative bacterial abundance at genus levels and decreased fecal short-chain-fatty-acid levels were identified in both the SDF and SDM groups. In the human cohort, insufficient sleep increased the risk of early sexual maturation, particularly in girls (OR, 1.44; 95% CI: 1.09 to 1.89; p-value < 0.01). Insufficient sleep also indirectly affected early sexual maturation in girls, with obesity serving as the mediator.

CONCLUSIONS

Overall, sleep deprivation altered the timing of puberty in both animal and human models but in different directions. In the rat model, sleep deprivation delayed the pubertal onset in juvenile rats through gut dysbiosis and metabolic changes, leading to a low body weight and body fat percentage. In the human model, sleep deprivation led to fat accumulation, causing obesity in girls, which increased the risk of early puberty.

Effects of mixed metal exposures on MRI diffusion features in the medial temporal lobe

Background

Environmental exposure to metal mixtures is common and may be associated with increased risk for neurodegenerative disorders including Alzheimer's disease.

Objective

This study examined associations of mixed metal exposures with medial temporal lobe (MTL) MRI structural metrics and neuropsychological performance.

Methods

Metal exposure history, whole blood metal, and neuropsychological tests were obtained from subjects with/without a history of mixed metal exposure from welding fumes (42 exposed subjects; 31 controls). MTL structures (hippocampus, entorhinal and parahippocampal cortices) were assessed by morphologic (volume, cortical thickness) and diffusion tensor imaging [mean (MD), axial (AD), radial diffusivity (RD), and fractional anisotropy (FA)] metrics. In exposed subjects, correlation, multiple linear, Bayesian kernel machine regression, and mediation analyses were employed to examine effects of single- or mixed-metal predictor(s) and their interactions on MTL structural and neuropsychological metrics; and on the path from metal exposure to neuropsychological consequences.

Results

Compared to controls, exposed subjects had higher blood Cu, Fe, K, Mn, Pb, Se, and Zn levels (p's<0.026) and poorer performance in processing/psychomotor speed, executive, and visuospatial domains (p's<0.046). Exposed subjects displayed higher MD, AD, and RD in all MTL ROIs (p's<0.040) and lower FA in entorhinal and parahippocampal cortices (p's<0.033), but not morphological differences. Long-term mixed-metal exposure history indirectly predicted lower processing speed performance via lower parahippocampal FA (p=0.023). Higher whole blood Mn and Cu predicted higher entorhinal diffusivity (p's<0.043) and lower Delayed Story Recall performance (p=0.007) without overall metal mixture or interaction effects.

Discussion

Mixed metal exposure predicted MTL structural and neuropsychological features that are similar to Alzheimer's disease at-risk populations. These data warrant follow-up as they may illuminate the path for environmental exposure to Alzheimer's disease-related health outcomes.

A Randomized Controlled Trial of a Parenting Intervention During Infancy Alters Amygdala-Prefrontal Circuitry in Middle Childhood

OBJECTIVE

Early adverse parenting predicts various negative outcomes, including psychopathology and altered development. Animal work suggests that adverse parenting might change amygdala-prefrontal cortex (PFC) circuitry, but work in humans remains correlational. The present study leveraged data from a randomized controlled trial examining the efficacy of an early parenting intervention targeting parental nurturance and sensitivity (Attachment and Biobehavioral Catch-up [ABC]) to test whether early parenting quality causally affects amygdala-PFC connectivity later in life.

METHOD

Participants (N = 60, mean age = 10.0 years) included 41 high-risk children whose parents were referred by Child Protective Services and randomly assigned to receive either ABC (n = 21) or a control intervention (n = 20) during the children's infancy and a comparison sample of low-risk children (n = 19). Amygdala-PFC connectivity was assessed via functional magnetic resonance imaging while children viewed fearful and neutral faces.

RESULTS

Across facial expressions, ABC produced different changes than the control intervention in amygdala-PFC connectivity in response to faces. The ABC group also exhibited greater responses than the control intervention group to faces in areas classically associated with emotion regulation, including the orbitofrontal cortex and right insula. Mediation analysis suggested that the effect of ABC on PFC activation was mediated by the intervention's effect on amygdala-PFC connectivity.

CONCLUSION

Results provide preliminary causal evidence for the effect of early parenting intervention on amygdala-PFC connectivity and on PFC responses to face viewing. Findings also highlight amygdala-PFC connectivity as a potential mediator of the effects of early parenting intervention on children's emotion regulation development.

CLINICAL TRIAL REGISTRATION INFORMATION

Intervening Early With Neglected Children; https://clinicaltrials.gov/; NCT02093052.

DIVERSITY & INCLUSION STATEMENT

We worked to ensure sex and gender balance in the recruitment of human participants. We worked to ensure race, ethnic, and/or other types of diversity in the recruitment of human participants. We worked to ensure that the study questionnaires were prepared in an inclusive way. One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented racial and/or ethnic groups in science. One or more of the authors of this paper self-identifies as a member of one or more historically underrepresented sexual and/or gender groups in science. One or more of the authors of this paper received support from a program designed to increase minority representation in science. While citing references scientifically relevant for this work, we also actively worked to promote sex and gender balance in our reference list.

Exploring the Mediating Role of Multiple Organ Dysfunction in Sepsis-Induced Disseminated Intravascular Coagulation and Its Impact on Worsening Prognosis

Disseminated intravascular coagulation (DIC) poses a high mortality risk, yet its exact impact remains contentious. This study investigates DIC's association with mortality in individuals with sepsis, emphasizing multiple organ function. Using data from the Peking University People's Hospital Investigation on Sepsis-Induced Coagulopathy database, we categorized patients into DIC and non-DIC groups based on DIC scores within 24 h of ICU admission (< 5 cutoff). ICU mortality was the main outcome. Initial data comparison preceded logistic regression analysis of mortality factors post-propensity score matching (PSM). Employing mediation analysis estimated direct and indirect associations. Of 549 participants, 131 were in the DIC group, with the remaining 418 in the non-DIC group. Following baseline characteristic presentation, PSM was conducted, revealing significantly higher nonplatelet sequential organ failure assessment (nonplt-SOFA) scores (6.3 ± 2.7 vs 5.0 ± 2.5, P < 0.001) and in-hospital mortality rates (47.3% vs 29.5%, P = 0.003) in the DIC group. A significant correlation between DIC and in-hospital mortality persisted (OR 2.15, 95% CI 1.29-3.59, P = 0.003), with nonplt-SOFA scores (OR 1.16, 95% CI 1.05-1.28, P = 0.004) and hemorrhage (OR 2.33, 95% CI 1.08-5.03, P = 0.032) as predictors. The overall effect size was 0.1786 (95% CI 0.0542-0.2886), comprising a direct effect size of 0.1423 (95% CI 0.0153-0.2551) and an indirect effect size of 0.0363 (95% CI 0.0034-0.0739), with approximately 20.3% of effects mediated. These findings underscore DIC's association with increased mortality risk in patients with sepsis, urging anticoagulation focus over bleeding management, with organ dysfunction assessment recommended for anticoagulant treatment efficacy.

History of induced abortion and the risk of preterm birth: a retrospective cohort study

OBJECTIVES

To explore the relationship between a history of induced abortion and follow-up preterm birth.

METHODS

We performed a retrospective cohort study of 27,176 women aged 19 to 48 years old in the city of Dongguan. Participants were divided into two groups according to the history of induced abortion. We used log-binomial regression to estimate adjusted risk ratios of preterm birth (gestation at less than 37 weeks) and early preterm birth (gestation at less than 34 weeks) for women with a history of induced abortion. Four models adjusted for different baseline data were used to verify the stability of the results. We also performed a subgroup analysis and mediation effect analysis to control for the influence of confounding factors and analyzed the relationship between the number of abortions and subsequent preterm birth.

RESULTS

Our study included 2,985 women who had undergone a prior induced abortion. Women who reported having a prior induced abortion were more likely to have preterm births before 37 weeks and 34 weeks, with risk ratios of 1.18 (95% CI 1.02-1.36) and 1.65 (95% CI 1.23-2.21), respectively. The above associations were stable in all models. We also found that a history of induced abortion was independently associated with a higher risk of preterm birth and early preterm birth in the subgroups. After controlling for the indirect effect of demographic data, the direct effect of abortion history on follow-up preterm delivery was still significantly different. The higher the number of abortions, the greater the risk of subsequent preterm birth.

CONCLUSIONS

This study suggests that induced abortion increases the risk of subsequent preterm birth.

Prognostic value of oxygen saturation index trajectory phenotypes on ICU mortality in mechanically ventilated patients: a multi-database retrospective cohort study

BACKGROUND

Heterogeneity among critically ill patients undergoing invasive mechanical ventilation (IMV) treatment could result in high mortality rates. Currently, there are no well-established indicators to help identify patients with a poor prognosis in advance, which limits physicians' ability to provide personalized treatment. This study aimed to investigate the association of oxygen saturation index (OSI) trajectory phenotypes with intensive care unit (ICU) mortality and ventilation-free days (VFDs) from a dynamic and longitudinal perspective.

METHODS

A group-based trajectory model was used to identify the OSI-trajectory phenotypes. Associations between the OSI-trajectory phenotypes and ICU mortality were analyzed using doubly robust analyses. Then, a predictive model was constructed to distinguish patients with poor prognosis phenotypes.

RESULTS

Four OSI-trajectory phenotypes were identified in 3378 patients: low-level stable, ascending, descending, and high-level stable. Patients with the high-level stable phenotype had the highest mortality and fewest VFDs. The doubly robust estimation, after adjusting for unbalanced covariates in a model using the XGBoost method for generating propensity scores, revealed that both high-level stable and ascending phenotypes were associated with higher mortality rates (odds ratio [OR]: 1.422, 95% confidence interval [CI] 1.246-1.623; OR: 1.097, 95% CI 1.027-1.172, respectively), while the descending phenotype showed similar ICU mortality rates to the low-level stable phenotype (odds ratio [OR] 0.986, 95% confidence interval [CI] 0.940-1.035). The predictive model could help identify patients with ascending or high-level stable phenotypes at an early stage (area under the curve [AUC] in the training dataset: 0.851 [0.827-0.875]; AUC in the validation dataset: 0.743 [0.709-0.777]).

CONCLUSIONS

Dynamic OSI-trajectory phenotypes were closely related to the mortality of ICU patients requiring IMV treatment and might be a useful prognostic indicator in critically ill patients.

How Does Exercise, With and Without Diet, Improve Pain and Function in Knee Osteoarthritis? A Secondary Analysis of a Randomized Controlled Trial Exploring Potential Mediators of Effects

OBJECTIVE

To explore the mediators of effects of two 6-month telehealth-delivered exercise programs, including exercise with and without weight-loss diet, on pain and function improvements in knee osteoarthritis (OA).

METHODS

Secondary analysis of 345 participants from a 3-arm randomized controlled trial of exercise (Exercise program) and exercise plus diet (Diet + Exercise program) versus information (Control program) was conducted. Outcomes were changes in pain (11-point numeric rating scale) and function (Western Ontario and McMaster Universities Osteoarthritis Index [score range 0-68]) at 12 months. Potential mediators were change at 6 months in attitudes toward self-management, fear of movement, arthritis self-efficacy, weight, physical activity, and willingness for knee surgery. For the Diet + Exercise program versus the Exercise program, only change in weight was evaluated.

RESULTS

Possible mediators of the Exercise program versus the Control program included reduced fear of movement (accounting for -1.11 units [95% confidence interval (95% CI) -2.15, -0.07] improvement in function) and increased arthritis self-efficacy (-0.40 units [95% CI -0.75, -0.06] reduction in pain, -1.66 units [95% CI -3.04, -0.28] improvement in function). The Diet + Exercise program versus the Control program mediators included reduced fear of movement (-1.13 units [95% CI -2.17, -0.08] improvement in function), increased arthritis self-efficacy (-0.77 units [95% CI -1.26, -0.28] reduction in pain, -5.15 units [95% CI -7.34, -2.96] improvement in function), and weight loss (-1.20 units [95% CI -1.73, -0.68] reduction in pain, -5.79 units [95% CI -7.96, -3.63] improvement in function). Weight loss mediated the Diet + Exercise program versus the Exercise program (-0.89 units [95% CI -1.31, -0.47] reduction in pain, -4.02 units [95% CI -5.77, -2.26] improvement in function).

CONCLUSION

Increased arthritis self-efficacy, reduced fear of movement, and weight loss may partially mediate telehealth-delivered exercise program effects, with and without diet, on pain and/or function in knee OA. Weight loss may partially mediate the effect of diet and exercise compared to exercise alone.

Effect of Waiting Time for Radioactive Iodine Therapy on Outcome in N1 Stage Papillary Thyroid Cancer

CONTEXT

The waiting time for radioactive iodine therapy (WRAIT) after total thyroidectomy (TT) in patients with papillary thyroid cancer (PTC) and lymph node metastases (N1) has not been sufficiently investigated for risk of adverse outcomes.

OBJECTIVE

This work aimed to estimate the effect of WRAIT on the outcomes of disease persistence and recurrence among patients with N1 PTC and investigate factors predictive of delayed radioactive iodine therapy (RAIT).

METHODS

This retrospective cohort study was conducted in a university hospital. A total of 909 patients with N1 PTC were referred for RAIT between 2014 and 2018. WRAIT is the duration between TT and initial RAIT. The optimal WRAIT threshold determined using recursive partitioning analysis was used to define early and delayed RAIT. The primary end point was tumor persistence/recurrence. We compared the outcomes of patients with early and delayed RAIT using inverse probability weighting based on the propensity score.

RESULTS

The WRAIT threshold that optimally differentiated worse long-term remission/excellent response outcomes was greater than 88 days (51% of our cohort; n = 464). WRAIT exceeding 88 days was associated with an augmented risk of disease persistence/recurrence (odds ratio, 2.47; 95% CI, 1.60-3.82) after adjustment. Predictors of delayed RAIT included residence in lower-income areas, reoperation before the initial RAIT, TT at a nonuniversity-affiliated hospital, multifocality, extrathyroidal extension, N1b disease, and pre-RAIT-stimulated thyroglobulin level less than 1 ng/mL.

CONCLUSION

Delayed RAIT beyond 88 days after TT in patients with N1 PTC independently increased the risk of disease persistence/recurrence. Evaluation of the predictive determinants of prolonged WRAIT may help target at-risk patients and facilitate interventions.

Mediating effect of body fat percentage in the association between ambient particulate matter exposure and hypertension: a subset analysis of China hypertension survey

BACKGROUND

Hypertension caused by air pollution exposure is a growing concern in China. The association between air pollutant exposure and hypertension has been found to be potentiated by obesity, however, little is known about the processes mediating this association. This study investigated the association between fine particulate matter (aerodynamic equivalent diameter ≤ 2.5 microns, PM2.5) exposure and the prevalence of hypertension in a representative population in southern China and tested whether obesity mediated this association.

METHODS

A total of 14,308 adults from 48 communities/villages in southern China were selected from January 2015 to December 2015 using a stratified multistage random sampling method. Hourly PM2.5 measurements were collected from the China National Environmental Monitoring Centre. Restricted cubic splines were used to analyze the nonlinear dose-response relationship between PM2.5 exposure and hypertension risk. The mediating effect mechanism of obesity on PM2.5-associated hypertension was tested in a causal inference framework following the approach proposed by Imai and Keele.

RESULTS

A total of 20.7% (2966/14,308) of participants in the present study were diagnosed with hypertension. Nonlinear exposure-response analysis revealed that exposure to an annual mean PM2.5 concentration above 41.8 µg/m3 was associated with increased hypertension risk at an incremental gradient. 9.1% of the hypertension burden could be attributed to exposure to elevated annual average concentrations of PM2.5. It is noteworthy that an increased body fat percentage positively mediated 59.3% of the association between PM2.5 exposure and hypertension risk, whereas body mass index mediated 34.3% of this association.

CONCLUSIONS

This study suggests that a significant portion of the estimated effect of exposure to PM2.5 on the risk of hypertension appears to be attributed to its effect on alterations in body composition and the development of obesity. These findings could inform intersectoral actions in future studies to protect populations with excessive fine particle exposure from developing hypertension.

Smoking, blood DNA methylation sites and lung cancer risk

Altered DNA methylation (DNAm) might be a biological intermediary in the pathway from smoking to lung cancer. In this study, we investigated the contribution of differential blood DNAm to explain the association between smoking and lung cancer incidence. Blood DNAm was measured in 2321 Strong Heart Study (SHS) participants. Incident lung cancer was assessed as time to event diagnoses. We conducted mediation analysis, including validation with DNAm and paired gene expression data from the Framingham Heart Study (FHS). In the SHS, current versus never smoking and pack-years single-mediator models showed, respectively, 29 and 21 differentially methylated positions (DMPs) for lung cancer with statistically significant mediated effects (14 of 20 available, and five of 14 available, positions, replicated, respectively, in FHS). In FHS, replicated DMPs showed gene expression downregulation largely in trans, and were related to biological pathways in cancer. The multimediator model identified that DMPs annotated to the genes AHRR and IER3 jointly explained a substantial proportion of lung cancer. Thus, the association of smoking with lung cancer was partly explained by differences in baseline blood DNAm at few relevant sites. Experimental studies are needed to confirm the biological role of identified eQTMs and to evaluate potential implications for early detection and control of lung cancer.

Automated detection of causal relationships among diseases and imaging findings in textual radiology reports

OBJECTIVE

Textual radiology reports contain a wealth of information that may help understand associations among diseases and imaging observations. This study evaluated the ability to detect causal associations among diseases and imaging findings from their co-occurrence in radiology reports.

MATERIALS AND METHODS

This IRB-approved and HIPAA-compliant study analyzed 1 702 462 consecutive reports of 1 396 293 patients; patient consent was waived. Reports were analyzed for positive mention of 16 839 entities (disorders and imaging findings) of the Radiology Gamuts Ontology (RGO). Entities that occurred in fewer than 25 patients were excluded. A Bayesian network structure-learning algorithm was applied at P < 0.05 threshold: edges were evaluated as possible causal relationships. RGO and/or physician consensus served as ground truth.

RESULTS

2742 of 16 839 RGO entities were included, 53 849 patients (3.9%) had at least one included entity. The algorithm identified 725 pairs of entities as causally related; 634 were confirmed by reference to RGO or physician review (87% precision). As shown by its positive likelihood ratio, the algorithm increased detection of causally associated entities 6876-fold.

DISCUSSION

Causal relationships among diseases and imaging findings can be detected with high precision from textual radiology reports.

CONCLUSION

This approach finds causal relationships among diseases and imaging findings with high precision from textual radiology reports, despite the fact that causally related entities represent only 0.039% of all pairs of entities. Applying this approach to larger report text corpora may help detect unspecified or heretofore unrecognized associations.

Negative Parenting Mediates the Longitudinal Association between Parental Internalizing Symptoms and Child Oppositional Symptoms

Research has pointed to both cross-sectional and longitudinal associations between parental internalizing symptoms and child externalizing symptoms. This study analyzed whether the association is mediated by negative parenting behavior in view of previous reports that both parental internalizing symptoms and child externalizing symptoms are related to parenting behaviors. Longitudinal data for the current analyses were derived from a randomized controlled trial on the efficacy of a web-assisted self-help intervention for parents of children with elevated levels of externalizing symptoms. Two different mediation models were analyzed, one using attention-deficit/hyperactivity disorder (ADHD) symptoms as the dependent variable and the other using oppositional defiant disorder (ODD) symptoms. Both models included parental internalizing symptoms as the independent variable, negative parenting behavior as a mediator, and study condition as a confounder. The longitudinal analyses support the mediating role of negative parenting behavior in the association between early parental internalizing symptoms and later child ODD symptoms.

Role of BMI in the relationship between dietary inflammatory index and non-alcoholic fatty liver disease: an intermediary analysis

OBJECTIVE

Previous studies have indicated that a pro-inflammatory diet is associated with non-alcoholic fatty liver disease (NAFLD), but the role of BMI remains ambiguous. We aim to study the intermediary effect of BMI on the relationship between dietary inflammatory properties and NAFLD.

METHODS

A total of 19536 adult participants from the National Health and Nutrition Examination Surveys (NHANES) were included. Dietary inflammatory index (DII) was used to evaluate the dietary inflammatory properties and NAFLD was diagnosed by non-invasive biomarkers. Weighted multivariable logistic regression models estimated ORs and 95% CIs between DII and incidence of NAFLD. Interaction effect between DII and BMI on NAFLD was tested and the mediation analysis of BMI was performed.

RESULTS

Higher DII scores, representing higher inflammatory potential of diet, were positively associated with a higher risk of NAFLD. Compared with the first quartile of DII, people from the second quartile (OR: 1.23 [95% CI: 1.04, 1.46]) to the fourth quartile (OR: 1.59 [95% CI: 1.31, 1.94]) have a higher risk of NAFLD before adjustment for BMI. The overall association was completely mediated by BMI (89.19%).

CONCLUSIONS

Our findings suggested that a higher pro-inflammatory potential diet was associated with a higher prevalence of NAFLD, and this association might be mediated by BMI.

Title: Age, sex, and survival following ventricular fibrillation cardiac arrest: a mechanistic evaluation of the ECG waveform: Short title: Age, sex, and survival via VF waveform in OHCA

BACKGROUND

Studies of outcome differences by sex in out-of-hospital cardiac arrest (OHCA) have produced mixed results that may depend on age, a potential surrogate for menopausal status.

OBJECTIVE

We used quantitative measures of ventricular fibrillation (VF) waveforms - indicators of the myocardium's physiology - to assess whether survival differences according to sex and age group may be mediated via a biologic mechanism.

METHODS

We conducted a cohort study of VF-OHCA in a metropolitan EMS system. We used multivariable logistic regression to assess the association of survival to hospital discharge with sex and age group (<55, ≥55 years). We determined the proportion of outcome difference mediated by VF waveform measures: VitalityScore and amplitude spectrum area (AMSA).

RESULTS

Among 1526 VF-OHCA patients, the average age was 62 years, and 29% were female. Overall, younger women were more likely to survive than younger men (survival 67% vs 54%, p=0.02), while survival among older women and older men did not differ (40% vs 44%, p=0.3). Adjusting for Utstein characteristics, women <55 compared to men <55 had greater odds of survival to hospital discharge (OR=1.93, 95% CI 1.23-3.09), an association not observed between the ≥55 groups. Waveform measures were more favorable among women and mediated some of the beneficial association between female sex and survival among those <55 years: 47% for VitalityScore and 25% for AMSA.

CONCLUSIONS

Women <55 years were more likely to survive than men <55 years following VF-OHCA. The biologic mechanism represented by VF waveform mediated some, though not all, of the outcome difference.

Influence of maternal psychological distress during COVID-19 pandemic on placental morphometry and texture

The Coronavirus Disease 2019 (COVID-19) pandemic has been accompanied by increased prenatal maternal distress (PMD). PMD is associated with adverse pregnancy outcomes which may be mediated by the placenta. However, the potential impact of the pandemic on in vivo placental development remains unknown. To examine the impact of the pandemic and PMD on in vivo structural placental development using advanced magnetic resonance imaging (MRI), acquired anatomic images of the placenta from 63 pregnant women without known COVID-19 exposure during the pandemic and 165 pre-pandemic controls. Measures of placental morphometry and texture were extracted. PMD was determined from validated questionnaires. Generalized estimating equations were utilized to compare differences in PMD placental features between COVID-era and pre-pandemic cohorts. Maternal stress and depression scores were significantly higher in the pandemic cohort. Placental volume, thickness, gray level kurtosis, skewness and run length non-uniformity were increased in the pandemic cohort, while placental elongation, mean gray level and long run emphasis were decreased. PMD was a mediator of the association between pandemic status and placental features. Altered in vivo placental structure during the pandemic suggests an underappreciated link between disturbances in maternal environment and perturbed placental development. The long-term impact on offspring is currently under investigation.

Higher hippocampal diffusivity values in welders are associated with greater R2* in the red nucleus and lower psychomotor performance

INTRODUCTION

Chronic excessive welding exposure may be related to higher metal accumulation and structural differences in different subcortical structures. We examined how welding affected brain structures and their associations with metal exposure and neurobehavioral consequences.

METHODS

Study includes 42 welders and 31 controls without a welding history. Welding-related structural differences were assessed by volume and diffusion tensor imaging (DTI) metrics in basal ganglia, red nucleus (RN), and hippocampus. Metal exposure was estimated by both exposure questionnaires and whole blood metal levels. Brain metal accumulations were estimated by R1 (for Mn) and R2* (for Fe). Neurobehavioral status was assessed by standard neuropsychological tests.

RESULTS

Compared to controls, welders displayed higher hippocampal mean (MD), axial (AD), and radial diffusivity (RD) (p's < 0.036), but similar DTI or volume in other ROIs (p's > 0.117). Welders had higher blood metal levels (p's < 0.004), higher caudate and RN R2* (p's < 0.014), and lower performance on processing/psychomotor speed, executive function, and visuospatial processing tasks (p's < 0.046). Higher caudate and RN R2* were associated with higher blood Fe and Pb (p's < 0.043), respectively. RN R2* was a significant predictor of all hippocampal diffusivity metrics (p's < 0.006). Higher hippocampal MD and RD values were associated with lower Trail Making Test-A scores (p's < 0.025). A mediation analysis of both groups revealed blood Pb indirectly affected hippocampal diffusivity via RN R2* (p's < 0.041).

DISCUSSION

Welding-related higher hippocampal diffusivity metrics may be associated with higher RN R2* and lower psychomotor speed performance. Future studies are warranted to test the role of Pb exposure in these findings.

Metabolic signature of healthy lifestyle and risk of rheumatoid arthritis: observational and Mendelian randomization study

BACKGROUND

While substantial evidence reveals that healthy lifestyle behaviors are associated with a lower risk of rheumatoid arthritis (RA), the underlying metabolic mechanisms remain unclear.

OBJECTIVES

This study aimed to identify the metabolic signature reflecting a healthy lifestyle and investigate its observational and genetic linkage with RA risk.

METHODS

This study included 87,258 UK Biobank participants (557 cases of incident RA) aged 37 to 73 years with complete lifestyle, genotyping and nuclear magnetic resonance (NMR) metabolomics data. A healthy lifestyle was assessed based on five factors: healthy diet, regular exercise, not smoking, moderate alcohol consumption, and normal body mass index. The metabolic signature was developed by summing selected metabolites' concentrations weighted by the coefficients using elastic net regression. We used multivariate Cox model to assess the associations between metabolic signatures and RA risk, and examined the mediating role of the metabolic signature in the impact of a healthy lifestyle on RA. We performed genome-wide association analysis (GWAS) to obtain genetic variants associated with the metabolic signature, then conducted Mendelian randomization (MR) analyses to detect causality.

RESULTS

The metabolic signature comprised of 81 metabolites, robustly correlated with healthy lifestyle ( r = 0.45, P = 4.2 × 10^-15). The metabolic signature was inversely associated with RA risk (HR per SD increment: 0.76, 95% CI: 0.70-0.83), and largely explained protective effects of healthy lifestyle on RA with 64% (95%CI: 50.4-83.3) mediation proportion. One and two-sample MR analyses also consistently showed the associations of genetically inferred per SD increment in metabolic signature with a reduction in RA risk (HR: 0.84, 95% CI: 0.75-0.94, P = 0.002 and OR: 0.84, 95% CI: 0.73-0.97, P = 0.02 respectively).

CONCLUSION

Our findings implicate the metabolic signature reflecting healthy lifestyle as a potential causal mediator in the development of RA, highlighting the importance of early lifestyle intervention and metabolic tracking for precise prevention of RA.

Circulating neutrophil extracellular trap (NET)-forming 'rogue' neutrophil subset, immunotype [DEspR + CD11b +], mediate multi-organ failure in COVID-19-an observational study

Background

Cumulative research show association of neutrophils and neutrophil extracellular traps (NETs) with poor outcomes in severe COVID-19. However, to date, there is no curative intent therapy able to block neutrophil/NETs-mediated progression of multi-organ dysfunction. Because of emerging neutrophil heterogeneity, the study of subsets of circulating NET-forming neutrophils [NET + Ns] as mediators of multi-organ failure progression among patients with COVID-19 is critical to identification of therapeutic targets.

Methods

We conducted a prospective observational study of circulating levels of CD11b + [NET + N] immunotyped for dual endothelin-1/signal peptide receptor (DEspR ±) expression by quantitative immunofluorescence-cytology and causal mediation analysis. In 36 consented adults hospitalized with mod-severe COVID-19, May to September 2020, we measured acute multi-organ failure via SOFA-scores and respiratory failure via SaO2/FiO2 (SF)-ratio at time points t1 (average 5.5 days from ICU/hospital admission) and t2 (the day before ICU-discharge or death), and ICU-free days at day28 (ICUFD). Circulating absolute neutrophil counts (ANC) and [NET + N] subset-specific counts were measured at t1. Spearman correlation and causal mediation analyses were conducted.

Results

Spearman correlation analyses showed correlations of t1-SOFA with t2-SOFA (rho r S  = 0.80) and ICUFD (r S  = -0.76); circulating DEspR + [NET + Ns] with t1-SOFA (r S  = 0.71), t2-SOFA (r S  = 0.62), and ICUFD (r S  = -0.63), and ANC with t1-SOFA (r S  = 0.71), and t2-SOFA (r S  = 0.61).Causal mediation analysis identified DEspR + [NET + Ns] as mediator of 44.1% [95% CI:16.5,110.6] of the causal path between t1-SOFA (exposure) and t2-SOFA (outcome), with 46.9% [15.8,124.6] eliminated when DEspR + [NET + Ns] were theoretically reduced to zero. Concordantly, DEspR + [NET + Ns] mediated 47.1% [22.0,72.3%] of the t1-SOFA to ICUFD causal path, with 51.1% [22.8,80.4%] eliminated if DEspR + [NET + Ns] were reduced to zero. In patients with t1-SOFA > 1, the indirect effect of a hypothetical treatment eliminating DEspR + [NET + Ns] projected a reduction of t2-SOFA by 0.98 [0.29,2.06] points and ICUFD by 3.0 [0.85,7.09] days. In contrast, there was no significant mediation of SF-ratio through DEspR + [NET + Ns], and no significant mediation of SOFA-score through ANC.

Conclusions

Despite equivalent correlations, DEspR + [NET + Ns], but not ANC, mediated progression of multi-organ failure in acute COVID-19, and its hypothetical reduction is projected to improve ICUFD. These translational findings warrant further studies of DEspR + [NET + Ns] as potential patient-stratifier and actionable therapeutic target for multi-organ failure in COVID-19.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41231-023-00143-x.

Associations between residential greenness and the predicted 10-year risk for atherosclerosis cardiovascular disease among Chinese adults

BACKGROUND

Exposure to build environments, especially residential greenness, offers benefits to reduce the development of atherosclerotic cardiovascular diseases (ASCVD). The 10-year ASCVD risk is a useful indicator for long-term ASCVD risk, but the evidence on the association and potential pathway of residential greenness in mitigating its development remains unclear.

OBJECTIVES

This study aimed to investigate the associations between residential greenness and the 10-year predicted ASCVD risks, and potentially mediation effect on this association by air pollution, body mass index (BMI) and physical activity (PA).

METHODS

The baseline of the China Multi-Ethnic Cohort (CMEC) study, enrolling 99,556 adults during 2018-2019, was used in this cross-sectional study. The participants' 10-year ASCVD risks were predicted as low-, moderate-, and high-risk groups, based on the six risk factors: age, smoking, hypertension, low-density lipoprotein cholesterol (LDL-C), high high-density lipoprotein cholesterol (HDL-C), and high total cholesterol (TC). The 3-year mean value within the circular buffer of 500 m and 1000 m of Enhanced Vegetation Index (EVI_500m and EVI_1000m) were used to assess greenness exposure. Multiple logistic regression was used to evaluate the association between residential greenness and the 10-year ASCVD risks. Stratified analyses by sex, age and smoking status were performed to identify susceptible populations. Causal mediation analysis was used to explore the mediation effects of air pollution, BMI and PA.

RESULTS

A total of 75,975 participants were included, of which 17.9 % (n = 13,614) and 5.6 % (n = 4253) had the moderate and high 10-year ASCVD risks, respectively. Compared to the low-risk group, each interquartile increase in EVI_500m and EVI_1000m reduced the ASCVD risk of the moderate-risk group by 4 % (OR = 0.96 [0.94, 0.98]) and 4 % (OR = 0.96 [0.94, 0.98]), respectively; and reduced the risk of the high-risk group by 8 % (OR = 0.92 [0.90, 0.96]) and 7 % (OR = 0.93 [0.90, 0.97]), respectively. However, the increased greenness did not affect the ASCVD risk of the high-risk group when compared to the moderate-risk group. Effects of residential greenness on the ASCVD risk were stronger in women than in men (p < 0.05), and were not observed in those aged ≥55. PA and BMI partially mediated the association between greenness and the 10-year ASCVD risk.

CONCLUSIONS

ASCVD prevention strategies should be tailored to maximize the effectiveness within the groups with different ASCVD risks, better at early stages when the ASCVD risk is low.

A bad time for kids in lockdown: The relationship between negative pandemic events, parenting stress, and maltreatment related parenting behaviors

BACKGROUND

To date, several studies have shown that parenting stress, a kind of role strain, is related to child maltreatment. However, few studies have examined how the effects of crises, such as negative pandemic-related events on the household, may be related to parenting stress and maltreatment-related behavior.

OBJECTIVE

This study examines the impact of negative Covid-related events on parenting stress and parenting behaviors during a period that was likely to have been a peak point of stress for many parents during the Covid-19 pandemic.

PARTICIPANTS

Respondents were female caregivers (N = 720) of children under the age of six located in the Midwestern United States.

RESULTS

Three or more Covid-related impacts on the household were positively associated with parenting stress (B = 0.177, p < 0.05). Parenting stress fully mediated the weak relationship between these impacts and maltreatment-related behavior. Mothers of different employment statuses, including those who were recently laid off or who chose to stay at home, did not have significantly different probabilities of parenting stress or maltreatment-related behaviors. Contrary to theory, similar null results were found across other socio-demographic variables.

CONCLUSIONS

These null findings suggest that crises have effects that encompass family systems, potentially raising parenting stress levels in many groups that are typically considered low-risk for child maltreatment. Results have implications for scholarship on parenting stress, the targeting of social supports to mothers of young children, and rapid interventions to reduce stress, such as the stimulus check relief program.

Phenome-wide association study of genetically predicted B vitamins and homocysteine biomarkers with multiple health and disease outcomes: analysis of the UK Biobank

BACKGROUND

Although a number of health outcomes such as CVDs, metabolic-related outcomes, neurological disorders, pregnancy outcomes, and cancers have been identified in relation to B vitamins, evidence is of uneven quality and volume, and there is uncertainty about putative causal relationships.

OBJECTIVES

To explore the effects of B vitamins and homocysteine on a wide range of health outcomes based on a large biorepository linking biological samples and electronic medical records.

METHODS

First, we performed a phenome-wide association study (PheWAS) to investigate the associations of genetically predicted plasma concentrations (genetic component of the circulating concentrations) of folate, vitamin B6, vitamin B12, and their metabolite homocysteine with a wide range of disease outcomes (including both prevalent and incident events) among 385,917 individuals in the UK Biobank. Second, 2-sample Mendelian randomization (MR) analysis was used to replicate any observed associations and detect causality. We considered MR P <0.05 as significant for replication. Third, dose-response, mediation, and bioinformatics analyses were carried out to examine any nonlinear trends and to disentangle the underlying mediating biological mechanisms for the identified associations.

RESULTS

In total, 1117 phenotypes were tested in each PheWAS analysis. After multiple corrections, 32 phenotypic associations of B vitamins and homocysteine were identified. Two-sample MR analysis supported that 3 of them were causal, including associations of higher plasma vitamin B6 with lower risk of calculus of kidney (OR: 0.64; 95% CI: 0.42, 0.97; P = 0.033), higher homocysteine concentration with higher risk of hypercholesterolemia (OR: 1.28, 95% CI: 1.04, 1.56; P = 0.018), and chronic kidney disease (OR: 1.32, 95% CI: 1.06, 1.63; P = 0.012). Significant nonlinear dose-response relationships were observed for the associations of folate with anemia, vitamin B12 with vitamin B-complex deficiencies, anemia and cholelithiasis, and homocysteine with cerebrovascular disease.

CONCLUSIONS

This study provides strong evidence for the associations of B vitamins and homocysteine with endocrine/metabolic and genitourinary disorders.

Mendelian randomization and clinical trial evidence supports TYK2 inhibition as a therapeutic target for autoimmune diseases

BACKGROUND

To explore the associations of genetically proxied TYK2 inhibition with a wide range of disease outcomes and biomarkers to identify therapeutic repurposing opportunities, adverse effects, and biomarkers of efficacy.

METHODS

The loss-of-function missense variant rs34536443 in TYK2 gene was used as a genetic instrument to proxy the effect of TYK2 inhibition. A phenome-wide Mendelian randomization (MR) study was conducted to explore the associations of genetically-proxied TYK2 inhibition with 1473 disease outcomes in UK Biobank (N = 339,197). Identified associations were examined for replication in FinnGen (N = 260,405). We further performed tissue-specific gene expression MR, colocalization analyses, and MR with 247 blood biomarkers. A systematic review of randomized controlled trials (RCTs) on TYK2 inhibitor was performed to complement the genetic evidence.

FINDINGS

PheWAS-MR found that genetically-proxied TYK2 inhibition was associated with lower risk of a wide range of autoimmune diseases. The associations with hypothyroidism and psoriasis were confirmed in MR analysis of tissue-specific TYK2 gene expression and the associations with systemic lupus erythematosus, psoriasis, and rheumatoid arthritis were observed in colocalization analysis. There were nominal associations of genetically-proxied TYK2 inhibition with increased risk of prostate and breast cancer but not in tissue-specific expression MR or colocalization analyses. Thirty-seven blood biomarkers were associated with the TYK2 loss-of-function mutation. Evidence from RCTs confirmed the effectiveness of TYK2 inhibitors on plaque psoriasis and reported several adverse effects.

INTERPRETATION

This study supports TYK2 inhibitor as a potential treatment for psoriasis and several other autoimmune diseases. Increased pharmacovigilance is warranted in relation to the potential adverse effects.

FUNDING

None.

Relationships Between Systemic Inflammation, Intestinal Damage and Postoperative Organ Dysfunction in Adults Undergoing Low-Risk Cardiac Surgery

BACKGROUND

Approximately half of patients who undergo cardiac surgery develop systemic inflammatory response syndrome. Extracorporeal circulation and intestinal injury may play a role in this inflammatory response, although their relative contributions remain elusive. Moreover, it is largely unknown to what extent these factors contribute to cardiac surgery-induced postoperative organ dysfunction.

METHOD

In this secondary analysis, we measured circulating levels of the intestinal damage marker intestinal fatty acid binding protein (I-FABP) and of the inflammatory cytokines tumour necrosis factor (TNF)-α, interleukin (IL)-6, IL-8, IL-10, IL-1RA, monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1α, and MIP-1β in 180 patients undergoing on-pump cardiac surgery. The average Z-score of levels of the different cytokines was used as an integral measure of the cytokine response. Relationships between duration of extracorporeal circulation, extent of intestinal injury, inflammation, and postoperative organ dysfunction were explored.

RESULTS

Plasma I-FABP levels increased during surgery, with peak levels observed at the end of cardiopulmonary bypass (CPB). Except for TNF-α, the levels of all cytokines increased during surgery, with peak levels observed either 2 (MCP-1, MIP-1α, and MIP-1β), 4 (IL-6, IL-8, and IL-1RA) or 6 (IL-10) hours after the end of CPB. While the duration of CPB significantly correlated with cytokine Z-score (r=0.544, p<0.05), no relationship with I-FABP levels was found. Furthermore, no significant correlations between I-FABP and cytokine levels were observed. The duration of CPB correlated with a deterioration in postoperative kidney function (estimated glomerular filtration rate [eGFR]) and troponin levels. Cytokine Z-score was associated with postoperative troponin levels, fluid administration, inotropic score, pulmonary alveolar-arterial gradient on the first postoperative morning, and deterioration of kidney function (eGFR). I-FABP levels did not correlate with any of the cardiovascular, pulmonary, or renal parameters.

CONCLUSIONS

In patients undergoing low-risk cardiac surgery, the duration of CPB represents an important determinant of the systemic cytokine response, whereas both the CPB duration and the systemic inflammatory response contribute to subsequent organ dysfunction. Intestinal damage does not appear to play a relevant role in the postoperative inflammatory response and development of postoperative organ dysfunction in these patients.

Mediation Analysis in Manual Therapy Research

Objective

The purpose of this study was to illustrate the applicability of mediation analysis in the manual therapy field by assessing whether pain intensity, duration of pain, or the change in systolic blood pressure mediated the heart rate variability (HRV) of patients with musculoskeletal pain who received manual therapy.

Methods

A secondary data analysis from a 3-arm, parallel, randomized, placebo-controlled, assessor-blinded, superiority trial was performed. Participants were randomized into spinal manipulation, myofascial manipulation, or placebo groups. Cardiovascular autonomic control was inferred from resting HRV variables (low-high frequency power ratio; LF/HF) and blood pressure responsiveness to a sympathoexcitatory stimulus (cold pressor test). Pain intensity and duration were assessed. Mediation models analyzed whether pain intensity, duration, or blood pressure independently affected the improvement of the cardiovascular autonomic control of patients with musculoskeletal pain after intervention.

Results

The first assumption of mediation was met for LF/HF with statistical evidence of a total effect of spinal manipulation, as compared with placebo on HRV outcomes (β = 0.77 [0.17-1.30]); second and third assumptions showed no statistical evidence of a relationship between the intervention and pain intensity (β = -5.30 [-39.48 to 28.87]), pain intensity, and LF/HF (β = 0.00 [-0.01 to 0.01]).

Conclusion

In this study of causal mediation analysis, the baseline pain intensity, duration of pain, and responsiveness of the systolic blood pressure to a sympathoexcitatory stimulus did not mediate the effects of the spinal manipulation on the cardiovascular autonomic control of patients with musculoskeletal pain. Accordingly, the immediate effect of spinal manipulation on the cardiac vagal modulation of patients with musculoskeletal pain may more likely be related to the intervention rather than the mediators investigated.

Circulating neutrophil extracellular trap (NET)-forming 'rogue' neutrophil subset, immunotype [DEspR+CD11b+], mediate multi-organ failure in COVID-19 - an observational study

Background: Cumulative research show association of neutrophils and neutrophil extracellular traps (NETs) with poor outcomes in severe COVID-19. However, to date, no curative intent therapy has been identified to block neutrophil/NETs-mediated progression of multi-organ dysfunction. Because of emerging neutrophil heterogeneity, the study of subsets of circulating neutrophil-extracellular trap (NET)-forming neutrophils [NET+Ns] as mediators of multi-organ failure progression among patients with COVID-19 is critical to identification of therapeutic targets. Methods: We conducted a prospective observational study of circulating levels of CD11b+[NET+N] immunotyped for dual endothelin-1/signal peptide receptor, (DEspR±) expression by quantitative immunofluorescence-cytology and causal mediation analysis. In 36 consented adults hospitalized with mod-severe COVID-19, May to September 2020, we measured acute multi-organ failure via SOFA-scores and respiratory failure via SaO2/FiO2 (SF)ratio at time points t1 (average 5.5 days from ICU/hospital admission) and t2 (the day before ICU-discharge or death), and ICU-free days at day28 (ICUFD). Circulating absolute neutrophil counts (ANC) and [NET+N] subset-specific counts were measured at t1. Spearman correlation and causal mediation analyses were conducted. Results: Spearman correlation analyses showed correlations of t1-SOFA with t2-SOFA ( rho r _S =0.80) and ICUFD ( r _S =-0.76); circulating DEspR+[NET+Ns] with t1-SOFA ( r _S = 0.71), t2-SOFA ( r _S =0.62), and ICUFD ( r _S =-0.63), and ANC with t1-SOFA ( r _S =0.71), and t2-SOFA ( r _S =0.61). Causal mediation analysis identified DEspR+[NET+Ns] as mediator of 44.1% [95% CI:16.5,110.6] of the causal path between t1-SOFA (exposure) and t2-SOFA (outcome), with 46.9% [15.8,124.6] eliminated when DEspR+[NET+Ns] were theoretically reduced to zero. Concordantly, DEspR+[NET+Ns] mediated 47.1% [22.0,72.3%] of the t1-SOFA to ICUFD causal path, with 51.1% [22.8,80.4%] eliminated if DEspR+[NET+Ns] were reduced to zero. In patients with t1-SOFA >1, the indirect effect of a hypothetical treatment eliminating DEspR+[NET+Ns] projected a reduction of t2-SOFA by 0.98 [0.29,2.06] points and ICUFD by 3.0 [0.85,7.09] days. In contrast, there was no significant mediation of SF-ratio through DEspR+[NET+Ns], and no significant mediation of SOFA-score through ANC. Conclusions: Despite equivalent correlations, DEspR+[NET+Ns], but not ANC, mediated progression of multi-organ failure in acute COVID-19, and its hypothetical reduction is projected to improve ICUFD. These translational findings warrant further studies of DEspR+[NET+Ns] as potential patient-stratifier and actionable therapeutic target for multi-organ failure in COVID-19.

The mediating effects of depression, anxiety, and rapid eye movement sleep behavior disorder on the association between dopaminergic replacement therapy and impulse control disorders in Parkinson's disease

OBJECTIVES

This study aims to longitudinally explore whether and how rapid eye movement sleep behavior disorder (RBD), depression, and anxiety mediate the association between dopaminergic replacement therapy (DRT) and impulse control disorders (ICDs) in patients with Parkinson's disease (PD).

METHODS

Subjects were selected from the Parkinson's Progression Markers Initiative. After excluding missing data, 268, 223, 218, 238, and 219 patients with PD diagnosed at 12, 24, 36, 48, and 60 months prior, respectively, were included. We used the Questionnaire for Impulsive-Compulsive Disorders, RBD Screening Questionnaire, Geriatric Depression Scale, and State-Trait-Anxiety Inventory to assess ICBs, RBD, depression, and anxiety, respectively. We constructed three causal mediation analysis models to infer potential contingent pathways from DRT to ICD mediated by depression, anxiety, and RBD separately.

RESULTS

DRT was associated with an increased risk of PD incidence. Aggravation of ICDs was partly explained by improvements in depression (the average causal mediation effect accounted for 8.0% of the total effect) and RBD (the average causal mediation effect of RBD accounted for 16.4% of the total effect). This suggested that anxiety (the average causal mediation effect accounted for 12.7% of the total effect) plays a mediating role.

CONCLUSIONS

Focusing on changes in RBD, depression, and anxiety associated with hyperdopaminergic status should be an essential part of strategies to prevent ICDs in patients with Parkinson's disease.

Intravenous amino acids may mediate the adverse effect of early parenteral nutrition on mortality in critically ill patients requiring mechanical ventilation: A post hoc analysis of the NEED trial

BACKGROUND

There is controversy regarding the optimal timing of initiating parenteral nutrition (PN) in critically ill patients. We aimed to evaluate the association between early PN and clinical outcomes and explore the mediation effects of different macronutrients in a cohort of mechanically ventilated patients.

METHODS

This is a post hoc analysis of the NEED trial aiming to investigate the effect of implementing an evidence-based feeding guideline in newly-admitted critically ill patients. All eligible patients were divided into those who received early PN within the first 3 days of enrollment (early PN) or those who did not (non-early PN). Propensity score matching with a one-to-one nearest neighbor-matching algorithm was applied to control potential confounders. Mediation analysis was used to test the indirect effect of different macronutrients from PN on the relationship between early PN and 28-day mortality.

RESULTS

The propensity score matching created 370 matched pairs of 1154 patients that met the eligibility criteria. Compared with non-early PN, patients receiving early PN had significantly higher 28-day mortality (19.7% vs 12.4%; hazard ratio = 1.904; 95% CI, 1.063-3.410; P = 0.03). Mediation analysis showed that amino acids from early PN mediated 65% (mediation effect = 0.07; 95% CI, 0.02-0.13; P = 0.01) of the detrimental effect of early PN on the 28-day mortality.

CONCLUSION

Early PN is associated with increased 28-day mortality in critically ill patients requiring invasive mechanical ventilation. The detrimental effect may be mediated by intravenous amino acids from early PN.

Obesity is associated with postoperative outcomes in patients undergoing cardiac surgery: a cohort study

BACKGROUND

The purpose of present study was to determine whether obesity was associated with increased adverse outcomes after cardiac surgery.

METHODS

This is a retrospective cohort study from a large international database called the Medical Information Mart for Intensive Care III (MIMIC-III). Patients who underwent cardiac surgery and greater than 18 years old were divided into either nonobese (BMI < 30 kg/m²) or obese (BMI ≥ 30 kg/m²). The primary outcome of this study was 28-day mortality from the date of operation. Secondary outcomes included ICU mortality, 1-year mortality, incidence of postoperative atrial fibrillation (POAF), hospital length of stay (HOS_LOS) and ventilation-free days within 28 days (VFD_28).

RESULTS

Multivariate logistic regression analysis revealed a negative effect of obesity on 28-day mortality, with an adjusted odds ratio (OR) of 1.57 (95% CI 1.14-2.16; p = 0.005). The association remained significant when PSM analysis and double robust analysis with all covariates were performed. In terms of 28-day mortality, the mediating effect of longer ventilation duration on obese patients was noticeable, and the proportion of the effect mediated was 8.2% (95% CI 2.1-25.5%; p = 0.012).

CONCLUSIONS

Among patients with cardiac surgery, obesity is associated with higher 28-day mortality. The longer ventilation duration may have mediated this effect. In future, considering the elevated incidence of the obese patients undergoing cardiac surgery, obesity stat should be included as one of the predictive variables for stratification of perioperative death risk.

Trauma-related guilt as a mediator between post-traumatic stress disorder and suicidal ideation

Background

As a mental health issue, suicide is a growing global concern, with patients who have post-traumatic stress disorder (PTSD) being at particularly high risk. This study aimed to investigate whether the link between PTSD and suicidal ideation is mediated by trauma-related guilt.

Methods

Data were obtained from Wave 1, Time 1 (November 2016), and Time 2 (March 2017) of the National Survey for Stress and Health (NSSH) in Japan. The NSSH is an online longitudinal survey conducted on Japan's national population aged 18 years and older. The cumulative response rate of the survey was 66.7% at Time 2. A total of 1,005 patients with PTSD were included for analyses. The severity of PTSD symptoms was assessed with PTSD DSM-5 Checklist, and the trauma-related guilt were assessed using the two subscales (hindsight-bias/responsibility and global guilt scale) of the trauma-related guilt inventory (TRGI). Suicidal ideation was evaluated using the suicidal ideation attributes scale (SIDAS). Pearson's correlation was used to investigate the associations among PTSD symptoms, TRGI scores, and SIDAS scores. Causal mediation analysis was applied to evaluate the causal relationship between PTSD, trauma-related guilt, and suicidal ideation.

Results

Pearson's correlation did not show patients' age, gender, and household income significantly associated with SIDAS scores. On the other hand, severities of PTSD symptoms (r = 0.361, p < 0.001) and trauma-related guilt (r = 0.235, p < 0.001) were positively associated with SIDAS scores. After adjusting for age, gender, and household income, the mediation analysis revealed that trauma-related guilt significantly mediates the effects of PTSD symptoms on suicidal ideation.

Conclusion

Our results implied that trauma-related guilt may represent a critical link between PTSD and suicidal ideation, which may be a noteworthy target for therapeutic intervention.

Association between Wait Time for Transthoracic Echocardiography and 28-Day Mortality in Patients with Septic Shock: A Cohort Study

Background: the optimal timing of Transthoracic echocardiography (TTE) performance for patients with septic shock remains unexplored. Methods: a retrospective cohort study included patients with septic shock in the MIMIC-Ⅲ database. Risk-adjusted restricted cubic splines modeled the 28-day mortality according to time elapsed from ICU admission to receive TTE. The cut point when a smooth curve inflected was selected to define early and delayed group. We applied propensity score matching (PSM) to ensure our findings were reliable. Causal mediation analysis was used to assess the intermediate effect of fluid balance within 72 h after ICU admission. Results: 3264 participants were enrolled and the risk of 28-day mortality increased until the wait time was around 10 h (Early group) and then was relatively flat afterwards (Delayed group). A beneficial effect of early TTE in terms of the 28-day mortality was observed (HRs 0.73−0.78, all p < 0.05) in the PSM. The indirect effect brought by the fluid balance on day 2 and 3 was significant (both p = 0.006). Conclusion: early TTE performance might be associated with lower risk-adjusted 28-day mortality in patients with septic shock. Better fluid balance may have mediated this effect. A wait time within 10 h after ICU may represent a threshold defining progressively increasing risk.

General and abdominal obesity operate differently as influencing factors of fracture risk in old adults

To infer the causality between obesity and fracture and the difference between general and abdominal obesity, a prospective study was performed in 456,921 participants, and 10,142 participants developed an incident fracture with follow-up period of 7.96 years. A U-shape relationship was observed between BMI and fracture, with the lowest risk of fracture in overweight participants. The obesity individuals had higher fracture risk when BMD was adjusted, and the protective effect of moderate-high BMI on fracture was mostly mediated by bone mineral density (BMD). However, for abdominal obesity, the higher WCadjBMI (linear) and HCadjBMI (J-shape) were found to be related to higher fracture risk, and less than 30% of the effect was mediated by BMD. By leveraging genetic instrumental variables, it provided additional evidences to support the aforementioned findings. In conclusion, keeping moderate-high BMI might be of benefit to old people in terms of fracture risk, whereas abdominal adiposity might increase risk of fracture.