Obesity‐Related Coagulation Activation in Adolescents and Children: A Systematic Review and Meta‐Analysis

Obesity is recognized as a pro-thrombotic condition, yet the extent of coagulation activation across biomarkers remains unclear. This meta-analysis evaluates the impact of obesity on parameters-D-dimer, fibrinogen, plasminogen activator inhibitor-1 (PAI-1), von Willebrand factor (vWF), factor VIII (FVIII), and endogenous thrombin potential (ETP)-in children and adults. METHODS: Sixty-four studies comprising 59,503 individuals were analyzed. Plasma biomarker levels were compared between non-obese and obese groups using standardized mean differences (SMDs), with subgroup analyses. RESULTS: D-dimer was significantly elevated in adults with obesity (SMD 1.36, 95% CI 0.47-2.25, p = 0.003) and children with obesity (SMD 0.77, 95% CI 0.19-1.36, p = 0.009), indicating increased fibrin turnover. Fibrinogen levels were markedly higher in both adults (SMD 1.17, 95% CI 0.14-2.20, p = 0.03) and children (SMD 1.43, 95% CI 0.93-1.92, p < 0.0001). PAI-1 showed the most pronounced increase in adults (SMD 2.30, 95% CI 0.1.51-3.09, p < 0.0001) and children (SMD 3.54, 95% CI 1.65-5.43, p = 0.0002). FVIII levels were modestly elevated (SMD 0.52, 95% CI 0.10-0.94, p = 0.02), whereas vWF levels showed inconsistent changes. ETP was significantly higher in obesity, in children (SMD 1.06, 95% CI 0.24-1.88, p = 0.01) and adults (SMD 0.71, 95% CI 0.46-0.97, p < 0.0001). Gender-stratified data indicated higher PAI-1, fibrinogen, and ETP levels in females. CONCLUSION: Obesity is associated with increased coagulation activation, suggesting a pro-thrombotic shift. These findings support the need for age- and gender-specific research into obesity-related hemostatic alterations.