Causal Associations Between Cardiovascular Risk Factors and Venous Thromboembolism

Circulating Cytokines and Venous Thromboembolism: A Bidirectional Two-Sample Mendelian Randomization Study

BACKGROUND

 Epidemiological evidence has linked circulating cytokines to venous thromboembolism (VTE). However, it remains uncertain whether these associations are causal due to confounding factors or reverse causality. We aim to explore the causality between circulating cytokines and VTE, encompassing deep vein thrombosis (DVT) and pulmonary embolism (PE).

METHODS

 In the current bidirectional Mendelian randomization (MR) study, instrumental variables of 41 circulating cytokines were obtained from the genome-wide association study meta-analyses (8,293 individuals). Summary statistics for the association of VTE (17,048 cases and 325,451 controls), DVT (8,077 cases and 295,014 controls), and PE (8,170 cases and 333,487 controls) were extracted from the FinnGen Study. A multivariable MR study was conducted to adjust for potential confounders. The inverse-variance weighted method was employed as the main analysis, and comprehensive sensitivity analyses were conducted in the supplementary analyses.

RESULTS

 The MR analysis indicated stromal cell-derived factor-1α was suggestively associated with a reduced risk of VTE (odds ratio [OR]: 0.90; 95% confidence interval [CI]: 0.81-0.99; p = 0.033) and DVT (OR: 0.85; 95% CI: 0.75-0.97; p = 0.015). In addition, suggestive association of granulocyte colony-stimulating factor with PE (OR: 1.20; 95% CI: 1.06-1.37; p = 0.005) was observed. Multivariable MR analysis showed that the effect of cytokines on VTE was partly mediated through hemoglobin A1c and systolic blood pressure. Reverse MR analysis revealed that VTE was linked to decreased levels of several cytokines.

CONCLUSION

 We provide suggestive genetic evidence supporting the bidirectional causal effect between circulating cytokines and VTE, highlighting the importance of targeting circulating cytokines to reduce the incidence of VTE.

The causality between Type 2 diabetes and breast cancer: a bidirectional two-sample Mendelian randomization study

Objective: Observational studies showed that Type 2 diabetes increased the risk of breast cancer, and vice versa. However, it is uncertain whether the link is causal or just due to confounding factors. Using bidirectional Mendelian randomization analysis, we assessed the bidirectional causal relationship from a genetic level. Methods: Large genome-wide association studies yielded summary-level data for Type 2 diabetes and breast cancer. Results: Genetically predicted Type 2 diabetes presented no statistically significant association with overall breast cancer or its subtypes. Similarly, genetically predicted overall breast cancer or its subtypes had no causal effect on Type 2 diabetes. Sensitivity analyses yielded similar results. Conclusion: Our bidirectional Mendelian randomization studies revealed no causal links between Type 2 diabetes and breast cancer.

Exploring Risk Factors for Lower Extremity Deep Vein Thrombosis Patients with Co-existing Pulmonary Embolism Based on Multiple Logistic Regression Model

Valuable data on deep vein thrombosis (DVT) patients with coexisting pulmonary embolism (PE) is scarce. This study aimed to identify risk factors associated with these patients and develop logistic regression models to select high-risk DVT patients with coexisting PE. We retrospectively collected data on 150 DVT patients between July 15, 2022, and June 15, 2023, dividing them into groups based on the presence of coexisting PE. Univariate and multivariate logistic regression analyses were performed to identify significant risk factors and construct predictive models. Discrimination and calibration statistics evaluated the validation and accuracy of the developed models. Of the 130 patients analyzed, 40 (30.77%) had coexisting PE. Univariate analysis revealed four significant predictors of DVT patients with coexisting PE: sex (OR 3.83, 95% CI: [1.76; 8.59], P = 0.001), body mass index (BMI) (OR 1.50, 95% CI: [1.28; 1.75], P < 0.001), chronic disease (OR 5.15, 95% CI: [2.32; 11.8], P < 0.001), and high-density lipoprotein (HDL) (OR 0.03, 95% CI: [0.01; 0.20], P < 0.001). Additionally, BMI > 24 kg/m2 (OR 9.70, 95% CI: [2.70; 67.5], P < 0.001) and BMI > 28 kg/m2 (OR 4.80, 95% CI: [2.15; 11.0], P < 0.001) were associated with concurrent PE. Three multiple regression models were constructed, with areas under the receiver-operating characteristic curves of 0.925 (95% CI: [0.882; 0.968]), 0.908 (95% CI: [0.859; 0.957]), and 0.890 (95% CI: [0.836; 0.944]), respectively. Sex, BMI, chronic disease, and HDL levels are significant predictors of DVT patients with coexisting PE.

Anatomic distribution of lower extremity deep venous thrombosis is associated with an increased risk of pulmonary embolism: A 10-year retrospective analysis

Aims

To investigate the potential relationship between anatomic distribution of lower extremity deep venous thrombosis (LEDVT) and pulmonary embolism (PE).

Methods

A retrospective case-control study was performed in patients diagnosed with LEDVT, which were confirmed by bilateral lower extremity compression ultrasonography (CUS) examination. According to the ultrasound reports, thrombus sidedness was categorized as unilateral and bilateral lower extremity, thrombus location was classified into distal and proximal LEDVT. Anatomic distributions of LEDVT were further subdivided depending on the combination of thrombus sidedness and location. Patients with PE were identified using the International Classification of Diseases-10 (ICD-10) codes (I26.0 and I26.9), and divided into PE group and Non-PE group. Univariate and multivariate logistic regression analyses were used to assess the association between anatomic distribution of LEDVT and PE. Sensitivity analyses were also conducted.

Results

A total of 2,363 consecutive patients with LEDVT were included, of whom 66.10% and 33.90% were unilateral and bilateral LEDVT, as well as 71.39% and 28.61% were isolated distal and proximal LEDVT, respectively. After the diagnosis of LEDVT, 185 patients (7.83%) developed PE. The proportions of PE ranged between the lowest (4.07%) in unilateral-distal LEDVT and highest (14.55%) in bilateral-proximal LEDVT. Multivariate logistic regression analysis showed that bilateral LEDVT (odds ratios [OR] = 2.455, 95% confidence interval [CI]: 1.803-3.344, P < 0.001) and proximal LEDVT (OR = 1.530, 95% CI: 1.105-2.118, P = 0.010) were risk factors for developing PE. Moreover, unilateral-proximal (OR = 2.129, 95% CI: 1.365-3.320, P = 0.00), bilateral-distal (OR = 3.193, 95% CI: 2.146-4.752, P < 0.001) and bilateral-proximal LEDVT(OR = 3.425, 95% CI: 2.093-5.603, P < 0.001) were significantly associated with an increased risk of PE. Sensitivity analyses also confirmed the robustness of these associations.

Conclusion

Patients with unilateral-proximal, bilateral-distal or bilateral-proximal are more likely to suffer from PE than those with unilateral-distal LEDVT.