Abstract
Background
Dosing guidance for anticoagulation, the mainstay of venous thromboembolism (VTE) treatment, is lacking for obese children. We aimed to compare unfractionated heparin (UFH) and low-molecular-weight heparins (LMWH) dosing requirements and clinical outcomes between obese/overweight and nonobese children.
Methods
This monocentric retrospective cohort study included patients aged < 18 years old receiving anticoagulation for VTE. The outcomes were: (1) number of dose adjustments to reach therapeutic levels, (2) variation from initial dose, (3) thrombotic progression/recurrence, and (4) clinically relevant bleeding. Characteristics and dosing requirements of obese/overweight and nonobese children were compared using Pearson chi-square, Fisher exact, and Wilcoxon Mann–Whitney tests. Kaplan–Meier estimator compared the cumulative incidence of thrombotic recurrence/progression and clinically relevant bleeding between groups.
Results
We included 212 patients (median age: 6.2 years, 23.6% obese/overweight) having 258 anticoagulation encounters (LMWH: 82.6%, UFH: 17.4%). Most children had therapeutic levels following one dosage (66.7% in obese/overweight vs. 51.8% in nonobese, p = 0.201). Dosing requirements significantly differed between obese/overweight and nonobese children (average increase from initial dose: 3.2 vs. 11.3%, p < 0.001). In obese/overweight children, 11.1% of patients required ≥ 10% dose reduction versus 2.1% in nonobese children (p < 0.001). The cumulative incidence of thrombotic progression/recurrence was comparable between groups (obese/overweight: 12.0%, nonobese: 10.5%, p = 0.786). Similarly, clinically significant bleeding was rare for both groups (obese/overweight: 2.0%, nonobese: 3.1%, p = 0.609).
Conclusion
In children treated for VTE, obesity/overweight was associated with lower anticoagulation requirements. Further prospective work is urgently needed to explore alternate regimens, such as dose capping, reduced initial dosing, or the use of fat-free mass.
Keywords
thrombosis - obesity - children - heparin
