Search Results (128)

Background/Objectives: Sudden sensorineural hearing loss (SSNHL) is an acute condition with unclear etiology, commonly hypothesized to be associated with viral infections. Acute respiratory tract infections (RTIs), particularly those of viral origin, have been implicated in SSNHL through proposed mechanisms such as cochlear invasion and immune-mediated damage. However, robust large-scale epidemiological evidence examining this association remains limited. This study aimed to investigate the potential association between acute RTIs and subsequent risk of developing SSNHL across diverse populations. Methods: We conducted a multinational retrospective cohort study using data from the TriNetX Global Collaborative Network. Adults diagnosed with acute RTIs between 1 January 2012 and 30 June 2023 were compared to matched controls without RTI exposure. Patients with predisposing conditions for SSNHL were excluded. Propensity score matching (1:1) was performed by age and sex. SSNHL diagnoses within 60 days post index were analyzed using Cox proportional hazards models. Subgroup and sensitivity analyses were conducted by race, sex, and age strata. Results: Among 37 million patients analyzed, individuals with acute RTIs had a lower incidence of SSNHL compared to matched controls. Hazard ratios (HRs) for SSNHL were significantly reduced across all racial groups: Whites (HR: 0.572), Blacks (HR: 0.563), and Asians (HR: 0.409). Subgroup analyses revealed stronger inverse associations in males and younger age groups, particularly those aged 18–25 years. Conclusions: Contrary to prior assumptions, acute RTIs were associated with a lower incidence of SSNHL in a large, diverse cohort. While the findings raise the possibility of immunological or physiological factors influencing this association, the results should be interpreted with caution due to unmeasured confounding and the observational nature of the study. Full article

Municipal Solid Waste Incinerators (MSWIs) are facilities designed to burn municipal solid waste to reduce its volume and mass and generate energy. A significant concern related to MSWIs is the emission of toxic and carcinogenic pollutants, including polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), heavy metals, and particulate matter. This review synthesizes global epidemiological and exposure assessment studies investigating cancer risks associated with residential proximity to MSWIs. Findings reveal a complex relationship: older incinerators with high emissions correlate with elevated risks of non-Hodgkin lymphoma (NHL), soft-tissue sarcoma (STS), and liver cancer in some studies, particularly in Europe. However, results remain inconsistent due to methodological limitations such as exposure misclassification, latency periods, and confounding factors like socioeconomic status. Modern facilities equipped with advanced pollution control technologies demonstrate reduced risks, often within regulatory thresholds. Key challenges include accurately quantifying historical exposures and disentangling MSWI-specific risks from other environmental or lifestyle factors. While advancements in dispersion modeling and biomonitoring have improved risk assessments, geographical and temporal variations in findings underscore the need for continued research. The review concludes that while historical evidence suggests potential cancer risks near older MSWIs, stricter emissions regulations and technological improvements have mitigated health impacts, although vigilance through long-term monitoring remains essential to safeguard public health. Full article

Background/Objectives: Type 2 diabetes mellitus (T2DM) and Alzheimer’s disease (AD) are significant global health issues. Epidemiological studies suggest T2DM increases AD risk, though confounding factors and reverse causality complicate this association. This study aims to clarify the causal relationship between T2DM and AD through a systematic review and meta-analysis of Mendelian randomization (MR) studies and a new two-sample MR analysis. Methods: A literature search across major databases was conducted through May 2024 to identify MR studies linking T2DM and AD. Fixed/random-effect models provided pooled odds ratios (ORs) with 95% confidence intervals (CIs), and heterogeneity was assessed with the I² statistic. For our MR analysis, we pooled genetic variants from selected studies and analyzed AD outcomes using IGAP, EADB, and UKB databases. Multiple MR methods, including inverse variance weighted (IVW) and pleiotropy–robust approaches, were applied for validation. Results: Of 271 articles, 8 MR studies were included (sample sizes: 68,905 to 788,989), all from European ancestry. Our meta-analysis found no significant causal link between T2DM and AD (OR = 1.02, 95% CI: 1.00–1.04) with moderate heterogeneity (I² = 31.3%). Similarly, our MR analysis using 512 SNPs as instrumental variables showed no significant associations in IGAP, EADB, or UKB data, which is consistent across sensitivity analyses. Conclusions: This meta-MR and MR analysis revealed no significant causal association between T2DM and AD, indicating that genetic predisposition to T2DM does not appear to causally influence AD risk, though modifiable clinical or environmental aspects of T2DM may still contribute to neurodegenerative processes. Further research should explore other mechanisms linking these conditions. Full article

To stimulate further research, this review summarizes studies linking liver fibrosis with the risk of abdominal aortic aneurysms (AAA). AAA is defined as a permanently weakened and dilated abdominal aorta, which develops due to inflammation of the tunica media, activation of the renin–angiotensin–aldosterone system, immune system activation, and coagulation disorders. Typically asymptomatic, AAA is often incidentally detected through imaging done for abdominal symptoms or as part of screening programs. AAA follows a variable course and has a mortality rate strongly dependent on age and sex. Risk factors for AAA include age, male sex, ethnicity, family history of AAA, lifestyle habits, arterial hypertension, dyslipidemia, and comorbid atherosclerotic cardiovascular disease. Conversely, individuals with type 2 diabetes, female sex, and certain ethnicities are at a reduced risk of AAA. Liver fibrosis, resulting from chronic liver diseases owing to varying etiologies, is increasingly recognized as a potential contributor to AAA development. Evidence increasingly indicates that metabolic dysfunction-associated steatotic liver disease (MASLD) and other chronic liver conditions may intensify inflammatory pathways shared with AAA, thereby potentially exacerbating AAA progression. This review specifically examines the epidemiology and risk factors associated with the link between AAA and liver fibrosis. It also highlights potential pathomechanisms, including systemic inflammation, oxidative stress, and extracellular matrix remodeling, which may contribute to both conditions. Although these findings underscore significant overlaps in risk profiles, additional research is needed to clarify whether type 2 diabetes, female sex, and certain ethnicities truly confer protection against AAA or if this association is influenced by other confounding variables. Ultimately, addressing these open questions will help guide targeted therapeutic interventions and the identification of novel biomarkers to predict disease progression. Full article

Background: An increasing amount of evidence, derived from both human epidemiological studies and animal research, suggests that exposure to maternal obesity in utero is linked to adverse neurodevelopmental outcomes in the offspring. These can include attention deficit hyperactivity disorder, autism spectrum disorders, intellectual disability, and cerebral palsy. Methods: A thorough search in Medline/PubMed and Google Scholar databases was performed by two independent reviewers in order to investigate the link between the exposure to maternal obesity and neurodevelopmental outcomes in the offspring. A list of keywords, including maternal obesity, maternal overweight, maternal diet, neurodevelopment, and neuropsychiatric disorders, was used in the search algorithm. Results: The existing evidence regarding the potential mechanisms through which maternal obesity may impact offspring neurodevelopment and programming, such as inflammation, hormone dysregulation, alterations to the microbiome, and epigenetics, as well as evidence from animal studies, was summarized in this narrative review. Conclusions: Maternal obesity seems to be overall associated with various neuropsychiatric and neurodevelopmental disorders. However, more robust data from future studies are needed to establish this association, which will take into account the role of potential confounders such as genetic factors and gene–environment interactions. Full article

Despite significant advancements in early diagnosis and treatment, breast cancer (BC) remains a major global health challenge. Ongoing research is essential to identify novel risk factors, implement innovative screening programs, and develop personalized treatment approaches. Among the various risk factors, infection with certain oncogenic viruses has emerged as a potential contributor to BC development. Increasing evidence suggests that bovine leukemia virus (BLV) may contribute to zoonotic infections in humans, with a potential role in BC initiation and progression. This review evaluates clinical and experimental data on BLV presence in both malignant and non-malignant breast tissues, exploring potential mechanisms through which BLV may access human breast tissue and contribute to carcinogenesis. Current data reveal a higher prevalence of BLV infection in BC tissues compared to non-tumor tissues, correlating with an increased risk of BC development. In this context, dairy and meat products from BLV-infected animals have been proposed as potential transmission sources. BLV-encoded proteins disrupt key oncogenic pathways, which support their possible role in breast carcinogenesis. However, the interpretation of these findings is limited by potential confounding factors such as genetic predisposition, environmental exposures, and dietary influences. Further research, including well-controlled epidemiological studies, longitudinal cohorts, and mechanistic investigations into BLV proteins in human breast cells, is necessary to determine its role in BC development. Full article

Oxidative stress is implicated in insulin resistance, obesity, and metabolic syndromes (MetSs). However, the interplay between oxidative stress and genetic predisposition during the development of MetS remains unclear. In this study, we aimed to investigate the effects of the interaction between oxidative balance score (OBS) and polygenic risk score (PRS) on the incidence of MetS in middle-aged Korean adults. We analyzed data from 25,879 participants aged ≥40 years from the Health Examinees Cohort of the Korean Genome and Epidemiology Study. The OBS was calculated using 11 antioxidant and five pro-oxidant factors. A genome-wide association study and clumping analysis identified 16 independent single-nucleotide polymorphisms associated with MetS that were used to calculate individual PRSs. Multivariable Cox proportional hazard models adjusted for confounding variables were used to assess the impact of OBS and PRS on the incidence of MetS. During a mean follow-up period of 4.3 years, we recorded 3153 cases of MetS. In both men and women, the group with the lowest OBS and a high PRS had a 1.50-fold (hazard ratio [HR] 1.50, 95% confidence interval [CI] 1.07–2.11) and 1.89-fold (HR 1.89, 95% CI 1.40–2.56) higher incidence, respectively, of MetS compared to those with the highest OBS and a low PRS. Among women with a high PRS, the HRs decreased significantly across OBS quintiles 1 through 5 (p for trend = 0.009). These findings suggest that managing the oxidative balance may be particularly crucial for individuals with a high genetic risk for MetS. Full article

Background/Objectives: This study examined the association between adherence to the Mediterranean dietary approaches to stop hypertension Intervention for Neurodegenerative Delay (MIND) diet, its components, and recurrent depressive symptoms (DepSs). Methods: The analyses included 4824 participants (73% men, mean age = 61; SD = 5.9) from the British Whitehall II cohort study. The MIND diet scores were derived from a validated 127-item food frequency questionnaire in 2002–2004. DepSs were assessed by the Center for Epidemiologic Studies Depression Scale (score ≥ 16) or by use of antidepressant drugs, and recurrence was defined as having DepSs in at least two of the four repeated measurements in the 2002–2004, 2007–2009, 2012–2013, and 2015–2016 follow-up phases. Results: Recurrent DepSs were observed in 13.3% of the participants over 13 years of follow-up. After adjusting for potential confounders, participants in the highest tertile of the MIND diet score (where a higher score represents a higher diet quality) had 26% lower odds of experiencing recurrent DepSs (OR = 0.74; 95% CI 0.58–0.93) compared to those in the lowest tertile. In mutually adjusted analyses of 14 MIND diet components in relation to recurrent DepSs, independent associations were observed for green leafy vegetables (OR = 0.59, 95% CI: 0.45–0.78), other vegetables (OR = 0.43, 95% CI:0.24–0.77), and berries (OR = 0.74, 95% CI: 0.61–0.89). Conclusions: In this British prospective cohort, good adherence to the MIND diet, particularly to the recommendations for vegetables and berries, was associated with a lower risk of recurrent depressive symptoms, independent of socio-economic, health behavior, and health status factors, including baseline cognitive impairment and antecedents of DepSs. Full article

(1) Background: Worldwide, refugees may have some difficulties in accessing healthcare services. However, little is known about the factors that may predict the level of accessibility to the public healthcare system in the host countries. (2) Aim: To examine the level of accessibility of Syrian refugees to the public healthcare system in Jordan and further to identify the prediction of socioeconomic factors and barriers to healthcare access. (3) Methods: A cross-sectional study was conducted with a convenient sample of 356 Syrian refugees residing outside camps (Irbid, Ajloun, and Jarash). Data were collected using the Access to Healthcare Services Scale instrument (adopted from the Canadian Community Health Survey), which is composed of 2 sections: the general access scale (8 items) and the difficulties scale (20 items). One-way ANOVA test and independent t-test were used to examine epidemiological correlations among variables, whereas a hierarchical linear regression model was used to examine the predictability of socioeconomic factors and barriers to overall access to the public healthcare system by exploring the incremental impact of additional predictors. (4) Results: the mean age of the 356 participants was 35.22 years old, 56.5% were female, 67.4% were married, most of them 46.1% have secondary education, and non-employed 69.9%. Significant associations were observed among participants with different marital status (p < 0.001), educational level (mean 11.85 vs. 19.85, p < 0.001), working status (15.47 vs. 17.93, p < 0.001), family household number (16.42 vs. 17.0, p < 0.001), and health insurance (none: 15.50 vs. governmental 24.50, p < 0.001). Multivariate analysis revealed that the most important factors that may predict the overall access to healthcare services were: family monthly income (beta −0.19, p < 0.001), household family number (beta 0.17, <0.001), health insurance (beta −0.09, p = 0.047), and barriers (beta −0.43, <0.001), even after adjusting for potential confounding effects: sex, age, educational level, and place of residence. (5) Conclusions: Our findings indicate that socioeconomic factors and barriers may considerably predict overall access to public healthcare in Jordan. It is crucially important, therefore, for the Jordanian government and international organizations to create and develop strategic plans and programs that enhance refugees’ access to health services, positively impacting their health and wellness. Full article

Background/Objectives: Directed acyclic graphs (DAGs) inform the epidemiologic statistical modeling confounders to determine close to true causal relationships in a study context. They inform the inclusion of the predictive model variables that affect the causal relationship. Non-small cell lung cancer (NSCLC) is frequently diagnosed, aggressive, and the second leading cause of cancer deaths in the United States. Determining factors affecting both the guideline-concordant treatment receipt and survival outcomes for early-stage lung cancer will help inform future statistical models aiming to achieve a close to true causal relationship. Methods: Peer-reviewed original research published during 2002–2023 was identified through PubMed, Embase, Web of Sciences, Clinical trials registry, and the gray literature. DAGitty version 3.1, an online software program, developed implied DAGs and integrated DAG graphics. The evidence synthesis for constructing directed acyclic graphs (ESC-DAGs) protocol was utilized to guide DAG development. The conceptual models utilized were Andersen and Aday for factors affecting treatment receipt and Shi and Steven for survival outcome factors. Results: A total of 36 studies were included in the DAG synthesis out of 9421 retrieved across databases. Eight studies served in the synthesis of treatment receipt DAG, while 28 studies were used for the survival outcomes DAG. There were 10 causal paths and 13 covariates for treatment receipt and 2 causal pathways and 32 covariates for survival outcomes. Conclusions: There are very few studies reporting on factors affecting early-stage NSCLC guideline-concordant care receipt compared to factors affecting its survival outcomes in the past two decades of original research. Future investigations can utilize data extracted in the current study to develop a meta-analysis informing effect size. Full article

While the macronutrient content of a ketogenic diet specifically utilized for childhood epilepsy is clearly defined in the literature, variations among other ketogenic diets exhibit substantial heterogeneity. Furthermore, studies utilizing ketogenic diets contain several confounders with notable impacts on outcomes, thereby rendering both their findings and those of the meta-analyses less reliable. The objective of this meta-epidemiological assessment was to scrutinize existing clinical trials that investigated the effects of ketogenic diets on patients with obesity and diabetes, thereby determining the feasibility of conducting a meta-analysis. The Ovid Medline, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and Embase databases were searched from 1946 to 24 September 2024. Of the studies reviewed, none met the predefined inclusion criteria. However, seven articles met these criteria very closely. In the future, studies investigating the effects of ketogenic diets containing significant confounding factors should adopt a single definition of a ketogenic diet. Additionally, accurate measurement of actual macronutrient and caloric intake, along with regularly monitored nutritional ketosis, will be essential to highlight the true effects of a ketogenic diet. Full article

Depression is common in patients with chronic kidney disease (CKD). Experimental studies suggest the role of urea toxicity in depression. We assessed both the incidence of antidepressant prescriptions and depressive symptoms (measured by CESD (Center for Epidemiologic Depression) scale) in 2505 patients with CKD (Stage 3–4) followed up over 5 years in the Chronic Kidney Disease Renal Epidemiology and Information Network (CKD-REIN) cohort. We used a joint model to assess the association between the serum urea level and incident antidepressant prescriptions, and mixed models for the association between the baseline serum urea level and CESD score over the 5-year follow-up. Among the 2505 patients, 2331 were not taking antidepressants at baseline. Of the latter, 87 started taking one during a median follow-up of 4.6 years. After adjustment for confounding factors, the hazard ratio for incident antidepressant prescription associated with the serum urea level (1.28 [95%CI, 0.94,1.73] per 5 mmol/L increment) was not significant. After adjustment, the serum urea level was associated with the mean change in the CESD score (β = 0.26, [95%CI, 0.11,0.41] per 5 mmol/L increment). Depressive symptoms burden was associated with serum urea level unlike depression events. Further studies are needed to draw firm conclusions and better understand the mechanisms of depression in CKD. Full article

Background and aims: Thromboangiitis obliterans (TAO), also known as Buerger’s disease, is a rare vasculitis. Observational epidemiology studies have suggested a relationship between the gut microbiota and TAO. However, due to confounding factors and reverse causality, the causal relationship remains unclear. Based on the assumption of their association, this study sought specific gut microbiota causally linked to TAO. Methods: The case–control study was conducted at the Xiangya Hospital of Central South University from November 2022 to January 2023 including twelve TAO patients and nine healthy controls. We conducted a Mendelian randomization (MR) study using summary statistics from a genome-wide association study (GWAS) of gut microbiota and TAO. Considering the scale and accessibility of the data, the MiBioGen consortium served as the exposure, whereas the FinnGen consortium GWAS study served as the outcome. Finally, we compared the results of the MR with those of the case–control studies. Results: The inverse variance weighted (IVW) (OR = 0.119, 95% CI: 0.021–0.688, p = 0.017) and maximum likelihood (ML) (OR = 0.121, 95% CI: 0.020–0.742, p = 0.022) estimates suggest that Ruminiclostridium 5 has a suggestive protective effect on TAO while the IVW (OR = 5.383, 95% CI: 1.128–25.693, p = 0.035) and ML (OR = 5.658, 95% CI: 1.142–28.021, p = 0.034) estimates suggest that Eubacterium (xylanophilum group) has a suggestive risk effect on TAO, and the ML (OR = 0.055, 95% CI: 0.004–0.755, p = 0.030) estimates suggest that Lachnospira has a suggestive protective effect on TAO. No significant heterogeneity of instrumental variables or horizontal pleiotropy was found. The results of the case–control study showed that the TAO had a lower relative abundance of Ruminiclostridium 5 (p = 0.015) and Lachnospira (p = 0.048), and a higher relative abundance of Eubacterium (xylanophilum group) (p = 0.029) than the healthy controls. These results were consistent with the MR analysis. Conclusions: Our study demonstrates that Ruminiclostridium 5, Lachnospira, and Eubacterium (xylanophilum group) are causally related to TAO, suggesting their potential significance for the prevention and treatment of TAO. Full article

Population-based databases in Nordic countries offer unique opportunities for large-scale population-based epidemiological studies. The personal identity number enables researchers to link different registers at the individual level, which can be used for large-scale epidemiological population-based studies. This review outlines how these opportunities have been used so far in the field of gout research, as well as the potential challenges and limitations. Their major advantage is that they cover the entire population, minimizing problems such as selection bias and loss to follow-up. This has enabled us to provide information on gout regarding risk factors; occurrence; association with comorbidities in relation to gout onset; treatment patterns; as well as its effect on other outcomes, such as sick leave and mortality. Validity issues, missing data, and legal issues are some of the challenges that researchers need to deal with. Choosing the most appropriate combination of databases to use for a specific question is crucial in order to maximize validity and adjust for confounders. Despite challenges and potential limitations, the Swedish registers have provided valuable epidemiological results and will continue to play an important role in the years to come. Full article

The influence of iodine-rich foods on thyroid cancer (TC) risk remains inadequately understood. Therefore, we aimed to comprehensively investigate the relationship between three iodine-rich food groups and TC prevalence using extensive data from a large Korean population. We assessed the dietary intake of 169,057 participants in the Korean Genome and Epidemiology Study (2004–2013) using a food frequency questionnaire. The top-three iodine-rich food groups (including egg, seaweed, and dairy) were selected based on Korean dietary reference intakes and categorized by weekly consumption frequency. We conducted multiple logistic regression models to examine the relationship between food consumption and TC prevalence. After adjusting for confounding factors, higher seaweed consumption (>5 times/week) was significantly associated with lower TC prevalence (odds ratio [OR], 95% confidence interval [CI] = 0.42, 0.32–0.56, p-value < 0.001). In contrast, compared with moderate dairy consumption (3–4 times/week), lower dairy product intake (<1 time/week) was associated with higher TC prevalence (OR, 95% CI = 1.32, 1.05–1.67, p-value = 0.017). Our findings suggest that sufficient seaweed consumption may offer protection against TC, and incorporating dairy products into the diet may lower TC incidence in the Korean population. The most significant limitations of our study are the absence of 24 h urine samples for iodine status assessment and the lack of clinical data on the diagnosis of thyroid cancer. Full article