Risk of venous thrombosis in persons with increased body mass index and interactions with other genetic and acquired risk factors

Genome-wide association analyses identified novel susceptibility loci for pulmonary embolism among Han Chinese population

BACKGROUND

A large proportion of pulmonary embolism (PE) heritability remains unexplained, particularly among the East Asian (EAS) population. Our study aims to expand the genetic architecture of PE and reveal more genetic determinants in Han Chinese.

METHODS

We conducted the first genome-wide association study (GWAS) of PE in Han Chinese, then performed the GWAS meta-analysis based on the discovery and replication stages. To validate the effect of the risk allele, qPCR and Western blotting experiments were used to investigate possible changes in gene expression. Mendelian randomization (MR) analysis was employed to implicate pathogenic mechanisms, and a polygenic risk score (PRS) for PE risk prediction was generated.

RESULTS

After meta-analysis of the discovery dataset (622 cases, 8853 controls) and replication dataset (646 cases, 8810 controls), GWAS identified 3 independent loci associated with PE, including the reported loci FGG rs2066865 (p-value = 3.81 × 10^-14), ABO rs582094 (p-value = 1.16 × 10^-10) and newly reported locus FABP2 rs1799883 (p-value = 7.59 × 10^-17). Previously reported 10 variants were successfully replicated in our cohort. Functional experiments confirmed that FABP2-A163G(rs1799883) promoted the transcription and protein expression of FABP2. Meanwhile, MR analysis revealed that high LDL-C and TC levels were associated with an increased risk of PE. Individuals with the top 10% of PRS had over a fivefold increased risk for PE compared to the general population.

CONCLUSIONS

We identified FABP2, related to the transport of long-chain fatty acids, contributing to the risk of PE and provided more evidence for the essential role of metabolic pathways in PE development.

Association between cardiovascular risk factors and venous thromboembolism in the elderly

Background

The preponderance of the evidence supports no association between traditional cardiovascular risk factors and venous thromboembolism (VTE), other than obesity. There are limited data in older people.

Objectives

To investigate whether cardiovascular risk factors (body mass index, smoking, alcohol intake, hypertension, and diabetes) are associated with the risk of VTE in elderly and to assess the combined effect between cardiovascular risk factors and genetic risk factors for VTE (factor V Leiden/prothrombin 20210A, positive family history of VTE, and non‐O blood group).

Methods

The Age and Thrombosis, Acquired and Genetic risk factors in the Elderly study is a multicenter case‐control study performed in Vermont, USA and Leiden, the Netherlands, comprising 401 cases with first VTE and 431 control subjects, all aged ≥70 years. To assess the risk of VTE, odds ratios (OR) with 95% confidence intervals (CIs) were calculated, adjusting for potential confounders.

Results

Both height and weight were positively associated with VTE risk: the ORs were 2.2 (95% CI, 1.2–3.9) and 1.5 (95% CI, 1.0–2.4) in the top quartile for height and weight separately. This risk was more pronounced for unprovoked VTE. Smoking, alcohol intake, and diabetes were not associated with VTE. Higher systolic and diastolic blood pressure and hypertension were associated with a decreased risk of VTE. In the presence of a genetic predisposition, height and weight further increased the risk of VTE.

Conclusions

In the elderly, height and weight are positively associated with the risk of VTE. With genetic predisposition, higher levels of height and weight further increase the risk of VTE.

Joint Effect of Multiple Prothrombotic Genotypes and Obesity on the Risk of Incident Venous Thromboembolism

BACKGROUND

 The impact of the combination of obesity and multiple prothrombotic genotypes on venous thromboembolism (VTE) risk remains unclear.

OBJECTIVE

 To investigate the joint effect of obesity and a genetic risk score (GRS) composed of established prothrombotic single nucleotide polymorphisms (SNPs) on VTE risk using a population-based case-cohort.

METHODS

 Cases with incident VTE (n = 1,470) and a subcohort (n = 12,826) were derived from the Tromsø Study (1994-2012) and the Trøndelag Health Study (HUNT) (1995-2008). Participants were genotyped for ABO (rs8176719), F5 (rs6025), F2 (rs1799963), FGG (rs2066865), and F11 (rs2036914) SNPs. Age- and sex-adjusted hazard ratios (HRs) were estimated according to body mass index (BMI) categories and number of risk alleles for individual SNPs and the GRS (0-1, 2, 3, ≥4 alleles).

RESULTS

 The combination of obesity (BMI ≥ 30kg/m²) and risk alleles, either as individual SNPs or as a GRS, had an additive effect on VTE risk (i.e., no biological interaction). Obese subjects who were carriers of ≥4 risk alleles had a 2.85-fold (95% confidence interval [CI]: 2.05-3.96) increased risk of overall VTE compared with those with BMI <25 kg/m² and 0 to 1 risk allele. However, in subgroups, the combination of obesity and ≥4 risk alleles was more pronounced for deep vein thrombosis (DVT) (HR: 3.20; 95% CI: 2.09-4.90) and unprovoked VTE (HR: 3.82; 95% CI: 2.25-6.47), suggesting a supra-additive effect.

CONCLUSION

 Our findings indicate that the combination of obesity and GRS has an additive effect on the risk of overall VTE. However, it may have a supra-additive effect on the risk of DVT and unprovoked VTE.

Clinical factors associated with massive pulmonary embolism and PE-related adverse clinical events

Background

Clinicians evaluating acute PE patients often have to identify risks for massive PE, a measure of hemodynamic instability and its consequence, massive PE related adverse clinical events (PEACE). We investigated the association of these risk factors with massive PE and PEACE in a consecutive PE cohort (n = 364).

Methods

Massive PE was defined as an acute central clot (proximal to the lobar artery) in a patient with right heart strain and systolic blood pressure ≤ 90 mg. PEACE was defined as any massive PE who died or required one or more of the following: ACLS, assisted ventilation, vasopressor use, thrombolytic therapy, or invasive thrombectomy, within seven days of PE diagnosis. Univariate and multivariate analysis assessing associations between the risk factors (age, gender, comorbidities, PE provoking risks, and whether the PE was felt to be idiopathic) and massive PE or PEACE were performed. Significance was determined at p < 0.05.

Results

Thirteen percent (n = 48) of patients presented with massive PE, and 9% (n = 32) had PEACE. In the final multivariate model, recent invasive procedure (RR = 7.4, p = 0.007), recent hospitalization (RR = 7.3, p = 0.002), and idiopathic PE (RR = 6.5, p = 0.003) were associated with massive PE. Only idiopathic PE (RR = 5.7, p = 0.005) was significantly associated with PEACE. No comorbidities or other PE provoking risks were associated with massive PE or PEACE.

Conclusions

As a take-home message, recent invasive procedure, recent hospitalization, and idiopathic PE were associated with massive PE, and only idiopathic PE was associated with PEACE. Simultaneously, comorbidities like age or chronic cardiopulmonary disease seem not to be associated with massive PE or PEACE.

Lifestyle Moderates Genetic Risk of Venous Thromboembolism: The ARIC Study

OBJECTIVE

Venous thromboembolism (VTE) is a common disease that has a genetic basis. Lifestyle factors contribute to risk, but it is unknown whether healthy lifestyle can mitigate the genetic risk. We studied whether greater adherence to the American Heart Association's cardiovascular health metric, Life's Simple 7 (LS7), is associated with lower incidence of VTE in individuals across categories of a genetic risk score (GRS) for VTE. Approach AND RESULTS: We followed 9026 White participants from the ARIC (Atherosclerosis Risk in Communities) Study, a prospective cohort enrolled in 1987 to 1989 until 2015. We tested the joint associations with VTE of a validated VTE GRS comprising 5 well-known gene variants and baseline LS7 categories. There were 466 incident VTE events over 22.8 years. Participants with an optimal LS7 score had a lower incidence of VTE (3.9%) than those with inadequate LS7 (5.7%). Compared with the high GRS and inadequate LS7 group (hazard ratio=1), those with high GRS and optimal LS7 indeed had a reduced hazard ratio of VTE: 0.65 (95% CI, 0.48-0.89). The group with low GRS and optimal LS7 had the lowest hazard ratio of VTE (0.39 [95% CI, 0.25-0.61]). Of the LS7 components, in all GRS groups, the factor most strongly protective for VTE was normal weight.

CONCLUSIONS

Among people at low or high genetic risk for VTE, healthier lifestyle factors, particularly normal weight, were associated with a lower incidence of VTE. Further studies should determine the impact of lifestyle changes among patients at high genetic risk of VTE, such as in thrombophilic families.

Association of apolipoproteins C-I, C-II, C-III and E with coagulation markers and venous thromboembolism risk

Purpose

Apolipoproteins C-I, C-II, C-III and E have been associated with risk of arterial thrombotic diseases. We investigated whether these apolipoproteins have prothrombotic properties and are associated with risk of venous thromboembolism (VTE).

Patients and methods

A total of 127 VTE patients and 299 controls were randomly selected from the Multiple Environmental and Genetic Assessment of Risk Factors for Venous Thrombosis study (1999–2004), in the Netherlands. The apolipoproteins were quantified using mass spectrometry (LC/MS/MS), and their levels were analyzed as continuous variable (per SD increase).

Results

In controls, increases in levels of apolipoproteins were associated with increases in levels of vitamin K-dependent factors, factor XI, antithrombin and clot lysis time. Additionally, increasing apolipoproteins C-III and E levels were associated with higher factor VIII and von Willebrand factor levels. Levels of C-reactive protein were not associated with any apolipoprotein. The age- and sex-adjusted odds ratios of apolipoproteins E, C-III, CII and CI to the risk of venous thrombosis were 1.21 (95% CI, 0.98–1.49), 1.19 (95% CI, 0.99–1.44), 1.24 (95% CI, 0.95–1.61) and 1.06 (95% CI, 0.87–1.30) per SD increase, respectively. These odds ratios did not attenuate after adjustments for statin use, estrogen use, BMI, alcohol use, and self-reported diabetes.

Conclusions

Levels of apolipoproteins C-I, C-II, C-III and E are associated with those of several coagulation factors. However, whether these apolipoproteins are also associated with an increased risk of VTE remains to be established.

Thrombosis and Thromboprophylaxis in Gynecology Surgery

Gynecologic surgery offers unique challenges, as pelvic surgery places patients at an increased risk of venous thromboembolism (VTE). Prevention of VTE is a goal of patients, policy makers, and surgeons. In this review, we address the current research and recommendations for VTE prophylaxis.

Joint effects of prothrombotic genotypes and body height on the risk of venous thromboembolism: the Tromsø study

Essentials Body height and prothrombotic genotypes are associated with risk of venous thromboembolism (VTE). The joint effect of prothrombotic genotypes and tall stature on VTE risk is scarcely investigated. We investigated the joint effect of prothrombotic genotypes and tall stature on VTE risk. Prothrombotic genotypes did not yield excess risk of VTE in subjects with a tall stature.

SUMMARY

Background Studies have reported synergistic effects of prothrombotic single-nucleotide polymorphisms (SNPs) and obesity on the risk of venous thromboembolism (VTE). Tall stature is associated with an increased VTE risk, but the joint effect of prothrombotic genotypes and tall stature on the VTE risk is unknown. Aims To investigate the joint effects of prothrombotic genotypes and tall stature on the VTE risk. Methods Cases with incident VTE (n = 676) and a randomly selected age-weighted subcohort (n = 1842) were sampled from the Tromsø study (cohort follow-up: 1994-2012). DNA was genotyped for rs6025 (factor V Leiden), rs1799963 (FII), rs8176719 (ABO blood group), rs2066865 (fibrinogen-γ), and rs2036914 (FIX). Age-adjusted and sex-adjusted hazard ratios (HRs) of VTE were calculated by categories of risk alleles (de Haan 5-SNP score: 0-1, 2-3, and ≥ 4) and body height (< 40th, 40th-80th and > 80th percentiles). Results The VTE risk increased by increasing category of body height, and subjects with height ≥ 178 cm had a two-fold higher VTE risk (HR 2.03; 95% confidence interval [CI] 1.51-2.73) than those with height ≤ 165 cm. The VTE risk also increased across categories of risk alleles. However, the combination of a tall stature and risk alleles, either individual SNPs or risk score, did not result in an excess VTE risk. Subjects with four or more risk alleles and height ≥ 178 cm had a two-fold (HR 2.08; 95% CI 1.24-3.52) higher VTE risk than subjects ≤ 165 cm with no risk allele or one risk allele. Conclusions In contrast to obesity, the presence of prothrombotic genotypes did not result in an excess VTE risk in subjects with a tall stature.

Oestrogen and anti-androgen therapy for transgender women

Transgender women experience lifelong gender dysphoria due to a gender assignment at birth that is incongruent with their gender identity. They often seek hormone therapy, with or without surgery, to improve their gender dysphoria and to better align their physical and psychological features with a more feminine gender role. Some of the desired physical changes from oestrogen and anti-androgen therapy include decreased body and facial hair, decreased muscle mass, breast growth, and redistribution of fat. Overall the risks of treatment are low, but include thromboembolism, the risk of which depends on the dose and route of oestrogen administration. Other associated conditions commonly seen in transgender women include increased risks of depression and osteoporosis. The risk of hormone-sensitive cancer seems to be low in transgender women, with no increased risk of breast cancer compared with women and no increase in prostate cancer when compared with men. The evidence base for the care of transgender women is limited by the paucity of high-quality research, and long-term longitudinal studies are needed to inform future guidelines.