Could differential under-reporting of loneliness between men and women bias the gender-specific association between loneliness duration and rate of memory decline? A probabilistic bias analysis of effect modification.

Gender is an observed effect modifier of the association between loneliness and memory aging. However, this effect modification may be a result of information bias due to differential loneliness under-reporting by gender. We applied probabilistic bias analyses to examine whether effect modification of the loneliness-memory decline relationship by gender is retained under three simulation scenarios with various magnitudes of differential loneliness under-reporting between men and women. Data were from biennial interviews with adults aged 50+ in the US Health and Retirement Study from 1996-2016 (5,646 women and 3,386 men). Loneliness status (yes vs. no) was measured from 1996-2004 using the CES-D loneliness item and memory was measured from 2004-2016. Simulated sensitivity and specificity of the loneliness measure were informed by a validation study using the UCLA Loneliness Scale as a gold standard. The likelihood of observing effect modification by gender was higher than 90% in all simulations, although the likelihood reduced with an increasing difference in magnitude of the loneliness under-reporting between men and women. The gender difference in loneliness under-reporting did not meaningfully affect the observed effect modification by gender in our simulations. Our simulation approach may be promising to quantify potential information bias in effect modification analyses.

Effect modification by statin use status on the association between fine particulate matter (PM2.5) and cardiovascular mortality.

BACKGROUND: Numerous studies have linked fine particulate matter (PM2.5) to increased cardiovascular mortality. Less is known how the PM2.5-cardiovascular mortality association varies by use of cardiovascular medications. This study sought to quantify effect modification by statin use status on the associations between long-term exposure to PM2.5 and mortality from any cardiovascular cause, coronary heart disease (CHD), and stroke. METHODS: In this nested case-control study, we followed 1.2 million community-dwelling adults aged ≥66 years who lived in Ontario, Canada from 2000 through 2018. Cases were patients who died from the three causes. Each case was individually matched to up to 30 randomly selected controls using incidence density sampling. Conditional logistic regression models were used to estimate odds ratios (ORs) for the associations between PM2.5 and mortality. We evaluated the presence of effect modification considering both multiplicative (ratio of ORs) and additive scales (the relative excess risk due to interaction, RERI). RESULTS: Exposure to PM2.5 increased the risks for cardiovascular, CHD, and stroke mortality. For all three causes of death, compared with statin users, stronger PM2.5-mortality associations were observed among non-users [e.g. for cardiovascular mortality corresponding to each interquartile range increase in PM2.5, OR = 1.042 (95% CI, 1.032-1.053) vs OR = 1.009 (95% CI, 0.996-1.022) in users, ratio of ORs = 1.033 (95% CI, 1.019-1.047), RERI = 0.039 (95% CI, 0.025-0.050)]. Among users, partially adherent users exhibited a higher risk of PM2.5-associated mortality than fully adherent users. CONCLUSIONS: The associations of chronic exposure to PM2.5 with cardiovascular and CHD mortality were stronger among statin non-users compared to users.

Sex Modifies the Effect of COVID-19 on Arterial Elasticity.

There is limited long-term evidence on the effects of COVID-19 on vascular injury between male and female sex. An adult cohort of COVID-19 survivors (COVID+) and confirmed SARS-CoV-2 antibody-negative participants (COVID-) were prospectively enrolled. COVID+ participants who have documented the presence of persistent symptoms four weeks following infection were considered to have post-acute sequelae of COVID-19 (PASC). Non-invasive, FDA-approved EndoPAT (Endo-PAT2000) was used for endothelial assessment. COVID-(n = 94) were 1:1 propensity score matched to COVID+ (n = 151) on baseline covariates including sex. Among COVID+, 66.2% (n = 100) had PASC. Higher levels of coagulation marker, D-dimer (p = 0.001), and gut permeability marker, zonulin (p = 0.001), were associated with female sex. Estimated differences in augmentation index (AI) between COVID- (0.9 ± 17.2) and COVID+ (8.4 ± 15.7; p = 0.001) and between female and male sex (12.9 ± 1.9; p < .0001) were observed. Among COVID+ with PASC, the average AI (10.5 ± 1.6) was 9.7 units higher than COVID- (p < .0001) and 6.2 units higher compared to COVID+ with no PASC (p = 0.03). COVID+ PASC+ female sex had the highest AI (14.3 ± 1.9). The effects of SARS-CoV-2 infection on vascular function varies across strata of sex and female sex in the post-acute phase of COVID-19 have the worse arterial elasticity (highest AI).

Assessing Additive Interactions between Protective Factors Using Relative Risk Reduction Due to Interaction.

Background and Objectives: In the context of disease prevention, interaction on an additive scale is commonly assessed to determine synergistic effects between exposures. While the "Relative Excess Risk due to Interaction" represents the main measure of additive interaction between risk factors, in this study we aimed to extend this approach to assess additive interaction between factors known to prevent the event's occurrence, such as medical interventions and drugs. Materials and Methods: We introduced and described the "Relative Risk Reduction due to Interaction" (RRRI) as a key measure to assess additive interactions between preventive factors, such as therapeutic interventions and drug combinations. For RRRI values closer to 1, the combination of exposures has a greater impact on reducing the event risk due to their interaction. As a purely illustrative example, we re-evaluated a previous investigation of the synergistic effect between statins and blood pressure-lowering drugs in preventing major adverse cardiovascular events (MACE). Moreover, simulation studies were used to empirically evaluate the performance of a robust Poisson regression model to estimate RRRI across different scenarios. Results: In our example, the drug combination revealed a positive additive interaction in further reducing MACE risk (RRRI > 0), even if not statistically significant. This result is more straightforward to interpret as compared to the original one based on the RERI. Additionally, our simulations highlighted the importance of large sample sizes for detecting significant interaction effects. Conclusion: We recommend RRRI as the main measure to be considered when exploring additive interaction effects between protective exposures, such as the investigation of synergistic effects between drug combinations or preventive treatments.

Sex differences in the association between plasma branched-chain amino acids and risk of ischemic stroke: A nested case-control study from China.

OBJECTIVES: The aim of this study was to investigate the prospective associations between plasma branched-chain amino acids (BCAAs) and the risk of ischemic stroke in men and women. METHODS: We conducted a nested case-control study within a community-based cohort in China. The cohort consisted of 15,926 participants in 2013-2018. A total of 321 ischemic stroke cases were identified during the follow up and individually matched with 321 controls by date of birth (±1 year) and sex. Females accounted for 55.8% (n = 358, 179 cases vs 179 controls) of the study population. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the association between plasma BCAAs and ischemic stroke risk by conditional logistic regression. RESULTS: Elevated plasma isoleucine was associated with a higher risk of ischemic stroke in women. The OR for the highest compared to the lowest quartile was 2.22 (95% CI: 1.11-4.44, P trend = 0.005) after adjustment for body mass index, education attainment, smoking, hypertension, renal function, menopause and physical activity. A similar association was found for total BCAAs (adjusted OR = 2.03, 95% CI: 1.05-3.95, P trend = 0.04). In contrast, no significant association of plasma BCAAs with ischemic stroke risk was observed in men. CONCLUSIONS: Plasma isoleucine and total BCAAs were significantly associated with ischemic stroke risk in women, but not in men, highlighting sex differences in BCAAs metabolism and stroke pathogenesis.

Modification Role of Dietary Antioxidants in the Association of High Red Meat Intake and Lung Cancer Risk: Evidence from a Cancer Screening Trial.

Evidence on the association between red meat consumption and lung cancer risk is weak. This study examined the associations between red meat and lung cancer across levels of antioxidant intake from foods or supplements. Cox proportional hazard models were applied to assess hazard ratios (HRs) for lung cancer incidence in the Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial. Baseline food frequency questionnaires measured red meat and antioxidant intake. The food-based Composite Dietary Antioxidant Index (fCDAI) evaluated the overall natural intake of vitamin A, vitamin C, vitamin E, zinc, magnesium, and selenium. During 13 years of follow-up, 95,647 participants developed 1599 lung cancer cases. Higher red meat consumption was associated with a higher risk of lung cancer (HRQ4vsQ1 1.43, 95%CI 1.20-1.71, p-trend < 0.001). We observed similar trends across groups with low or medium levels of antioxidant intake. However, no association was noticed in the group with the highest fCDAI (HRQ4vsQ1 1.24, 95%CI 0.90-1.72, p-trend = 0.08) and highest independent natural antioxidant intake. The attenuated risk was not consistently observed among groups with high supplement use. Lastly, we did not notice evidence of interactions between red meat and antioxidant intake. Our findings emphasize the importance of limiting red meat in lung cancer prevention.

Computational simulation of the potential improvement in clinical outcomes of cardiovascular diseases with the use of a personalized predictive medicine approach.

IMPORTANCE AND OBJECTIVES: The current medical paradigm of evidence-based medicine relies on clinical guidelines derived from randomized clinical trials (RCTs), but these guidelines often overlook individual variations in treatment effects. Approaches have been proposed to develop models predicting the effects of individualized management, such as predictive allocation, individualizing treatment allocation. It is currently unknown whether widespread implementation of predictive allocation could result in better population-level outcomes over guideline-based therapy. We sought to simulate the potential effect of predictive allocation using data from previously conducted RCTs. METHODS AND RESULTS: Data from 3 RCTs (positive trial, negative trial, trial stopped for futility) in pediatric cardiology were used in a computational simulation study to quantify the potential benefits of a personalized approach based on predictive allocation. Outcomes were compared when using a universal approach vs predictive allocation where each patient was allocated to the treatment associated with the lowest predicted probability of negative outcome. Compared to results from RCTs, predictive allocation yielded absolute risk reductions of 13.8% (95% confidence interval [CI] -1.9 to 29.5), 13.9% (95% CI 4.5-23.2), and 15.6% (95% CI 1.5-29.6), respectively, corresponding to a number needed to treat of 7.3, 7.2, and 6.4. The net benefit of predictive allocation was directly proportional to the performance of the prediction models and disappeared as model performance degraded below an area under the curve of 0.55. DISCUSSION: These findings highlight that predictive allocation could result in improved group-level outcomes, particularly when highly predictive models are available. These findings will need to be confirmed in simulations of other trials with varying conditions and eventually in RCTs of predictive vs guideline-based treatment allocation.

The Association between Autism Spectrum Disorder and Precocious Puberty: Considering Effect Modification by Sex and Neuropsychiatric Comorbidities.

Limited knowledge is available about the association between autistic spectrum disorder (ASD) and precocious puberty. Our study examined the association between the two medical conditions and effect modification by sex and neuropsychiatric comorbidities in a nationwide population. To compare the risk of precocious puberty between ASD and non-ASD cases, we conducted a Cox regression analysis using ASD as the exposure and time to precocious puberty as the outcome. We adjusted for sex, attention-deficit/hyperactivity disorder (ADHD), tic disorder, obsessive-compulsive disorder (OCD), anxiety disorder, intellectual disability, and epilepsy. We performed a moderation analysis to examine the potential moderating effects of sex and comorbidities. Patients with ASD were prone to have precocious puberty, with an adjusted hazard ratio (aHR) of 1.80 (95% CI: 1.61-2.01). For effect modification, sex, specifically females, moderated the association between ASD and precocious puberty, with a relative excess risk due to interaction (RERI) of 7.35 (95% CI 4.90-9.80). No significant effect modification was found for any of the comorbidities within the scope of additive effect modification. We found that patients with ASD were prone to precocious puberty, regardless of sex or comorbid neuropsychiatric disorders. Girls with ASD are at a particularly higher risk of developing precocious puberty.

Combined impact of dynamic air pollution and transportation noise on cardiometabolic disorders in San Diego County.

Air pollution and noise exposure may synergistically contribute to increased cardiometabolic disorders; however, few studies have examined this potential interaction nor considered exposures beyond residential location. This study investigates the combined impact of dynamic air pollution and transportation noise on cardiometabolic disorders in San Diego County. Using the Community of Mine Study (2014-2017), 602 ethnically diverse participants were assessed for obesity, dyslipidemia, hypertension, and metabolic syndrome (MetS) using anthropometric measurements and biomarkers from blood samples. Time-weighted measures of exposure to PM2.5, NO2, road and aircraft noise were calculated using global positioning system (GPS) mobility data and Kernel Density Estimation. Generalized estimating equation models were used to analyze associations. Interactions were assessed on the multiplicative and additive scales using relative excess risk due to interaction (RERI). We found that air pollution and noise interact to affect metabolic disorders on both multiplicative and additive scales. The effect of noise on obesity and MetS was higher when air pollution was higher. The RERI of aircraft noise and NO2 on obesity and MetS were 0.13 (95%CI 0.03, 0.22) and 0.13 (95%CI 0.02, 0.25), respectively. This finding suggests that aircraft noise and air pollution may have synergistic effects on obesity and MetS.

Psychological Status as an Effect Modifier of the Association Between Allergy Symptoms and Allergy Testing.

OBJECTIVE: Patient-reported outcome measures, while valuable, may not correlate with diagnostic test results. To better understand this potential discrepancy, our objective was to determine whether psychological health is an effect modifier of the association between patient-reported allergy outcome scores and allergy test results. STUDY DESIGN: Prospective outcomes study. SETTING: Tertiary care hospital and community-based clinic. METHODS: This study included 600 patients at least 18 years of age who presented for symptoms related to allergic rhinitis and completed the related sinonasal outcome test (SNOT), which includes validated nasal, allergy, and psychological domains. Stratified analyses of odds ratios and Spearman correlation coefficients were utilized to assess for effect modification by psychological status. RESULTS: Worse patient-reported allergic rhinitis symptoms were significantly associated with positive allergy test results (odds ratio [OR] 1.69, 95% confidence interval [CI] 1.22-2.34, P = .002) in patients with better psychological health. In contrast, there was no association in patients with worse psychological health (OR 1.06, 95% CI 0.36-3.10, P = .92). These findings were corroborated by assessments of correlation: allergy domain scores were positively correlated with allergy testing scores (Spearman rho 0.18, 95% CI 0.10-0.25, P < .001) in patients with better psychological health, while there was no correlation in patients with worse psychological health (-0.02, 95% CI -0.16-0.12, P = .77). CONCLUSIONS: Psychological status was an effect modifier of the association between allergy domain and allergy testing data. When assessing the relationship between subjective measures, such as sinonasal validated instruments, and objective measures, such as allergy test results, accounting for effect modifiers such as psychological state can provide clinical and research-related insights.

The Effect of Retained Hardware on Failure Among Prosthetic Joint Infections of the Knee in the Presence and Absence of Staphylococcus aureus.

Background: The risk of failure associated with different surgical strategies for prosthetic joint infections (PJIs) among patients with and without Staphylococcus aureus is uncertain. The purpose of this study was to assess whether S. aureus modifies the association between retained hardware and failure following revision surgery for PJI of the knee. Methods: This was a single-center retrospective cohort study of 106 first PJIs of the knee between 2016 and 2020 at a rural academic medical center. The exposure was retained hardware following revision surgery for PJI, and the outcomes were recurrent infection, any infection, and a composite outcome including any infection, unplanned revision, failure to undergo reimplantation, amputation, or death within 2 years of revision. We used negative binomial regression to quantify the association between the exposure and outcome and to assess the presence of S. aureus as an effect modifier. Results: Retained hardware was significantly associated with failure when defined as recurrent infection among S. aureus PJI (adjusted risk difference [aRD], 0.38; 95% CI, 0.12-0.64) but not in the absence of S. aureus (aRD, -0.02; 95% CI, -0.17 to 0.13), and S. aureus was an effect modifier (P interaction = .01). Conclusions: We report a significant association between the presence of retained hardware and recurrent infection among S. aureus PJI of the knee, but not for non-S. aureus PJI. This could help inform the surgical management of PJI of the knee in cases where the microbiology is known before surgery.

Prevalence of functional difficulty among school-aged children and effect on school enrolment in rural southern India: A cross-sectional analysis.

Despite the large number of children in India, there is little information on the impact of children's disability on school enrolment, and how this differs by population. We estimated the prevalence of childhood disability in two sites in Tamil Nadu, southern India, and the effect of functional difficulty on school enrolment. We used a parent-reported survey containing the UNICEF-Washington Group questions to identify children aged 5 to 17 years with functional difficulty during a census conducted for an ongoing trial. We estimated pooled- and gender-specific prevalence of functional difficulty among 29,044 children. We fitted regression models to identify subgroups with higher rates of functional difficulty and the effect of functional difficulty on reported school enrolment. We estimated the modification of the effect of functional difficulty by age, gender, socioeconomic status, household education, and sub-site, on additive and multiplicative scales. We found of 29,044 children, 299 (1.0%) had any functional difficulty, equal among boys and girls. Being understood (0.5%) and walking (0.4%) were the most common difficulties. Functional difficulty was strongly associated with non-enrolment in school (Prevalence ratio [PR] 4.59, 95% CI: 3.87, 5.43) after adjusting for age, gender, and site. We show scale-dependent differences between age and socioeconomic groups in the effect of functional difficulty on enrolment. This study shows that at least one in a hundred children in this region have severe functional difficulties and nearly half of these children are not enrolled in school, highlighting the need for further efforts and evidence-based interventions to increase school enrolment among these groups.

Clinical Predictors and Outcomes of Invasive Anal Cancer for People With Human Immunodeficiency Virus in an Inception Cohort.

BACKGROUND: Due to the heterogeneity of risk for invasive anal cancer (IAC) among people with human immunodeficiency virus (PWH), we investigated predictors of IAC and described outcomes among those with a cancer diagnosis. METHODS: Using a longitudinal inception cohort of anal cancer screening, we evaluated risk factors and outcome probabilities for incident IAC in Cox models. Screening included anal cytology and digital anorectal examination, and, if results of either were abnormal, high-resolution anoscopy. RESULTS: Between 30 November 2006 and 3 March 2021, a total of 8139 PWH received care at the University of California, San Diego, with 4105 individuals undergoing screening and subsequently followed up over a median of 5.5 years. Anal cancer developed in 33 of them. IAC was more likely to develop in patients with anal high-grade squamous intraepithelial lesions (aHSILs) on initial or subsequent follow-up cytology (hazard ratio, 4.54) and a nadir CD4 cell count ≤200/µL (2.99). The joint effect of aHSILs and nadir CD4 cell count ≤200/µL amplified the hazard of IAC by 9-fold compared with the absence of both. PWH with time-updated cytology aHSIL and CD4 cell counts ≤200/µL had 5- and 10-year probabilities of IAC of 3.40% and 4.27%, respectively. Twelve individuals with cancer died, 7 (21% of the total 33) due to cancer progression, and they had clinical stage IIIA or higher cancer at initial diagnosis. CONCLUSIONS: PWH with both aHSIL and a nadir CD4 cell count ≤200/µL have the highest risk of IAC. PWH who died due to IAC progression had clinical stage IIIA cancer or higher at diagnosis, highlighting the importance of early diagnosis through high-resolution anoscopic screening.

School racial composition, effect modification by caring teacher/staff presence, and mid/late-life depressive symptoms: findings from the Study of Healthy Aging among African Americans.

For Black students in the United States, attending schools with a higher proportion of White students is associated with worse mental and physical health outcomes in adolescence/early adulthood. No prior studies evaluate K-12 school racial composition and later-life mental health. In a cohort of Black adults ages 50+ in Northern California who retrospectively self-reported school racial composition for grades 1, 6, 9, and 12, we assessed the association between attending a school with mostly Black students vs. not and mid/late-life depressive symptoms (8-item PROMIS depression score, standardized to US adult population) using age-, sex/gender-, southern US birth-, and parental education-adjusted generalized estimating equations, and assessed effect modification by caring teacher/staff presence. Later-life depressive symptoms were lower among those who attended schools with mostly Black students in grades 1 and 6 (b=-0.12, 95% CI: -0.23, 0.00 and b=-0.11, 95% CI: -0.22, 0.00, respectively). In grade 6, this difference was larger for students without an adult at school who cared about them (b=-0.29, 95% CI: -0.51, -0.07 vs. b=-0.04, 95% CI: -0.17, 0.09). Among Black Americans, attending early school with mostly Black students may have later life mental health benefits; this protective association appears more important for students without caring teachers/staff.

Influence of Low-Density Lipoprotein Cholesterol Levels on NSAID-Associated Cardiovascular Risks After Myocardial Infarction: A Population-Based Cohort Study.

Aim: To examine whether low-density lipoprotein cholesterol (LDL-C) levels influence the cardiovascular risk associated with non-aspirin non-steroidal anti-inflammatory drug (NSAID) use after myocardial infarction (MI). Methods: Using Danish health registries, we conducted a population-based cohort study of all adult patients with first-time MI during 2010-2020 with an LDL-C value before discharge. Based on the latest LDL-C value, we categorized patients into a low and a high LDL-C group (<3.0 vs ≥3.0 mmol/L). We used time varying Cox regression to compute hazard ratios (HRs) with 95% confidence intervals of the association between NSAID use and a major adverse cardiovascular event (MACE: recurrent MI, ischemic stroke, and all-cause death). Results: We followed 50,573 patients for a median of 3.1 years. While exposed, 521 patients experienced a MACE: 312 in the low LDL-C group and 209 in the high LDL-C group. The HRs for MACE comparing NSAID use with non-use were 1.21 (1.11-1.32) overall, 1.19 (1.06-1.33) in the low LDL-C group, and 1.23 (1.07-1.41) in the high LDL-group. The HRs for recurrent MI and ischemic stroke were comparable between the LDL-C subgroups. The HRs for all-cause death were 1.22 (1.07-1.39) in the low LDL-C group and 1.54 (1.30-1.83) in the high LDL-C group. Changing the cut-off value for LDL-C to 1.8 and 1.4 mmol/L showed consistent results. Conclusion: In patients with MI, LDL-C levels did not influence the increased risk of MACE associated with NSAID use, but might influence the association between NSAID use and all-cause death.

Synergistic interaction of co-exposure to humidifier disinfectant chemicals CMIT/MIT and PHMG in lung injury.

A number of biocidal disinfectant chemicals are used as household products to prevent spread of pathogens. People are commonly exposed to multiple chemicals through those disinfectants. However, effects of interactions (e.g., synergism) between disinfectants on human health outcomes have been rarely studied. In this study, we aimed to investigate associations of a mixture of chloromethylisothiazolinone/methylisothiazolinone (CMIT/MIT) and polyhexamethylene guanidine (PHMG), which had been used as humidifier disinfectants (HDs) in South Korea, with HD-associated lung injury (HDLI) in a Korean population (n = 4058) with HD exposure through use of HD products. Exposure to HD was retrospectively assessed by an interview-based standardized survey, and HDLI was determined by clinical assessment. After adjusting for covariates, PHMG-specific exposure indices (e.g., amount of use, indoor air concentration, and weekly exposure level) were dose-dependently associated with HDLI (their odds ratios for the comparison of third tertile versus first tertile were 1.95, 1.77, and 2.16, respectively). CMIT/MIT exposure was not observed to have a significant association with HDLI in a single chemical exposure model; however, associations between PHMG exposure and HDLI were strengthened by co-exposure to CMIT/MIT in combined chemical exposure models, where synergistic interactions between CMIT/MIT use and PHMG indices (amount of use and weekly exposure level) were observed (p-interaction in additive scale: 0.02 and 0.03, respectively). Our findings imply that adverse effects of PHMG exposure on lung injury among HD users might be worsened by co-exposure to CMIT/MIT. Given that plenty of household products contain disinfectants on global markets, epidemiological and toxicological investigations are warranted on interaction effects of co-exposure to disinfectants.

Dietary intake changes the associations between long-term exposure to fine particulate matter and the surrogate indicators of insulin resistance.

The relationship of fine particulate matter (PM2.5) exposure and insulin resistance remains inclusive. Our study aimed to investigate this association in the project of Prediction for Atherosclerotic Cardiovascular Disease Risk in China (China-PAR). Specifically, we examined the associations between long-term PM2.5 exposure and three surrogate indicators of insulin resistance: the triglyceride-glucose index (TyG), TyG with waist circumference (TyG-WC) and metabolic score for insulin resistance (METS-IR). Additionally, we explored potential effect modification of dietary intake and components. Generalized estimating equations were used to evaluate the associations between PM2.5 and the indicators with an unbalanced repeated measurement design. Our analysis incorporated a total of 162,060 observations from 99,329 participants. Each 10 µg/m3 increment of PM2.5 was associated with an increase of 0.22 % [95 % confidence interval (CI): 0.20 %, 0.25 %], 1.60 % (95 % CI: 1.53 %, 1.67 %), and 2.05 % (95 % CI: 1.96 %, 2.14 %) in TyG, TyG-WC, and METS-IR, respectively. These associations were attenuated among participants with a healthy diet, particularly those with sufficient intake of fruit and vegetable, fish or tea (pinteraction < 0.0028). For instance, among participants with a healthy diet, TyG increased by 0.11 % (95 % CI: 0.08 %, 0.15 %) per 10 µg/m3 PM2.5 increment, significantly lower than the association observed in those with an unhealthy diet. The findings of this study emphasize the potential of a healthy diet to mitigate these associations, highlighting the urgency for improving air quality and implementing dietary interventions among susceptible populations in China.

Lifestyle and incident dementia: A COSMIC individual participant data meta­analysis.

INTRODUCTION: The LIfestyle for BRAin Health (LIBRA) index yields a dementia risk score based on modifiable lifestyle factors and is validated in Western samples. We investigated whether the association between LIBRA scores and incident dementia is moderated by geographical location or sociodemographic characteristics. METHODS: We combined data from 21 prospective cohorts across six continents (N = 31,680) and conducted cohort-specific Cox proportional hazard regression analyses in a two-step individual participant data meta-analysis. RESULTS: A one-standard-deviation increase in LIBRA score was associated with a 21% higher risk for dementia. The association was stronger for Asian cohorts compared to European cohorts, and for individuals aged ≤75 years (vs older), though only within the first 5 years of follow-up. No interactions with sex, education, or socioeconomic position were observed. DISCUSSION: Modifiable risk and protective factors appear relevant for dementia risk reduction across diverse geographical and sociodemographic groups. HIGHLIGHTS: A two-step individual participant data meta-analysis was conducted. This was done at a global scale using data from 21 ethno-regionally diverse cohorts. The association between a modifiable dementia risk score and dementia was examined. The association was modified by geographical region and age at baseline. Yet, modifiable dementia risk and protective factors appear relevant in all investigated groups and regions.