Reduced fibrin clot lysis in Klinefelter syndrome associated with hypogonadism

Abstract

Objective: Klinefelter syndrome (KS) is associated with increased risk of thrombosis. Hypogonadism and accumulating body fat in KS have a potential impact on fibrinolysis. We assessed the fibrinolytic system and the association with testosterone levels in KS. Design: Cross-sectional comparison of men with KS and age-matched male controls. Methods: Fibrin clot lysis was evaluated by turbidity measurements and by measuring levels of individual fibrinolytic proteins in plasma samples. Total testosterone was measured by liquid chromatography tandem mass spectrometry. Body fat was evaluated by dual-energy X-ray absorptiometry. Results: Forty-five men with KS and 45 age and education matched controls were included. Men with KS had a 24 % reduction in fibrin clot lysis compared with controls (46.2 ± 17.1 versus 60.6 ± 18.8 %/h, p=0.0003), and higher levels of fibrinogen, factor XIII (p≤0.01) and plasminogen activator inhibitor type 1 (p=0.04). Men with KS had lower total testosterone (p=0.008) and higher body fat (p=0.001). In KS, reduced fibrin clot lysability was associated with higher higher fibrinogen and body fat related to decreasing total testosterone and hypogonadism among men with KS. Conclusions: Fibrin clot lysis in KS was markedly reduced, potentially contributing to a prothrombotic state and increased thrombotic risk. Hypogonadism in KS was associated with increased fibrinogen and total body fat, predicting reduced fibrin clot lysis.