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.