Venous thromboembolism has the same risk factors as atherosclerosis: A PRISMA-compliant systemic review and meta-analysis

Abstract

Background: Previous studies have shown that idiopathic pulmonary embolism is positively associated with other cardiovascular events, such as myocardial infarction and stroke, suggesting a potentially important association between atherosclerosis risk factors and venous thromboembolism (VTE). We performed a meta-analysis to evaluate the correlation between risk factors for atherosclerosis and VTE.

Methods: In December 2014, we searched MEDLINE and EMBASE for studies evaluating the associations between VTE and risk factors for atherosclerosis and pooled outcome data using random-effects meta-analysis. In addition, we analyzed publication bias.

Results: Thirty-three case-control and cohort studies with a total of 185,124 patients met the inclusion criteria. We found that participants with body mass index (BMI) ≥30 kg/m had a significantly higher prevalence of VTE than those with BMI <30 kg/m in both case-control studies (odds ratio [OR] = 2.45, 95% confidence interval [CI]: 1.78-3.35) and cohort studies (relative risk [RR] = 2.39, 95% CI: 1.79-3.17). VTE was more prevalent in patients with hypertension than without hypertension (OR = 1.40, 95% CI: 1.06-1.84; RR = 1.36, 95% CI: 1.11-1.67). The findings were similar for VTE prevalence between patients with and without diabetes (OR = 1.78, 95% CI: 1.17-2.69; RR = 1.41, 95% CI: 1.20-1.66). Current smoking was significantly associated with VTE prevalence in case-control studies (OR = 1.34, 95% CI: 1.01-1.77), but not in cohort studies (RR = 1.29, 95% CI: 0.96-1.72). In addition, we found that total cholesterol and triglyceride concentrations were significantly higher in patients with VTE than without VTE (weighted mean differences [WMD] = 8.94 mg/dL, 95% CI: 3.52-14.35 mg/dL, and WMD = 14.00 mg/dL, 95% CI: 8.85-19.16 mg/dL, respectively). High-density lipoprotein cholesterol concentrations were significantly lower in patients with VTE than without VTE (WMD = -2.03 mg/dL, 95% CI: -3.42 to -0.63 mg/dL). Higher quality studies were more homogeneous, but confirmed the same significant associations.

Conclusions: Based on our systematic review and meta-analysis, we observed a significant association between VTE and the risk factors for atherosclerosis. These results may make an important contribution to clinical practice regarding VTE treatment.

Figure 1

Study selection flow diagram adapted from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

Figure 2

Meta-analysis of the effect of obesity (body mass index ≥30 kg/m²) on venous thromboembolism (based on 10 case-control and 4 cohort studies). Squares represent point estimates for effect size expressed as an OR/RR with the size proportional to the inverse variance of the estimate. Diamond represents pooled estimate. Lines represent 95% CIs. CI = confidence interval, OR = odds ratio, RR = relative risk.

Figure 3

Meta-analysis of the effect of diabetes mellitus on venous thromboembolism (based on 9 case-control and 6 cohort studies). Squares represent point estimates for effect size expressed as an OR/RR with the size proportional to the inverse variance of the estimate. Diamond represents pooled estimate. Lines represent 95% CIs. CI = confidence interval, OR = odds ratio, RR = relative risk.

Figure 4

Meta-analysis of the effect of hypertension on venous thromboembolism (based on 7 case-control and 6 cohort studies). Squares represent point estimates for effect size expressed as an OR/RR with the size proportional to the inverse variance of the estimate. Diamond represents pooled estimate. Lines represent 95% CIs. CI = confidence interval, OR = odds ratio, RR = relative risk.

Figure 5

Meta-analysis of the effect of smoking on venous thromboembolism (based on 8 case-control and 6 cohort studies). Squares represent point estimates for effect size expressed as an OR/RR with the size proportional to the inverse variance of the estimate. Diamond represents pooled estimate. Lines represent 95% CIs. CI = confidence interval, OR = odds ratio, RR = relative risk.

Figure 6

Meta-analysis of the effect of total cholesterol concentrations (mg/dL) on venous thromboembolism (based on 10 case-control and 6 cohort studies). Squares represent point estimates for effect size expressed as a WMD with the size proportional to the inverse variance of the estimate. Diamond represents pooled estimate. Lines represent 95% CIs. CI = confidence interval, WMD = weighted mean difference.

Figure 7

Meta-analysis of the effect of high-density lipoprotein cholesterol concentrations (mg/dL) on venous thromboembolism (based on 5 case-control and 4 cohort studies). Squares represent point estimates for effect size expressed as a WMD with the size proportional to the inverse variance of the estimate. Diamond represents pooled estimate. Lines represent 95% CIs. CI = confidence interval, WMD = weighted mean difference.

Figure 8

Meta-analysis of the effect of triglyceride concentrations (mg/dL) on venous thromboembolism (based on 10 case-control and 5 cohort studies). Squares represent point estimates for effect size expressed as a WMD with the size proportional to the inverse variance of the estimate. Diamond represents pooled estimate. Lines represent 95% CIs. CI = confidence interval, WMD = weighted mean difference.