The relationship between vitamin D status and idiopathic lower-extremity deep vein thrombosis

Kamal Khademvatani,1 Mir Hossein Seyyed-Mohammadzad,1 Mohammad Akbari,1 Yousef Rezaei,2 Ramin Eskandari,3 Alireza Rostamzadeh1 1Department of Cardiology, Seyyed-al-Shohada Heart Center, Urmia University of Medical Sciences, Urmia, Iran; 2Seyyed-al-Shohada Heart Center, Urmia University of Medical Sciences, Urmia, Iran; 3Department of Cardiology, Firoozgar Hospital, Iran University of Medial Sciences, Tehran, Iran Background: Vitamin D has been shown to have an anticoagulant effect. A decrease in 25-hydroxyvitamin D [25(OH)D] concentration has also been associated with an increased risk of venous thromboembolism. Hence, we sought to determine the relationship between 25(OH)D levels and idiopathic lower-extremity deep vein thrombosis (DVT). Methods: In a case control study, a total of 82 participants with idiopathic lower-extremity DVT were enrolled along with 85 sex- and age-matched healthy participants as controls. The plasma 25(OH)D levels were measured in all the studied samples. Results: The participants' mean age was 47.1±12.3 years. Baseline characteristics were not significantly different between the groups. The concentration of 25(OH)D was significantly lower in the DVT group compared to that of the control group (17.9±10.3 versus 23.1±12.5 ng/mL, P=0.004). The prevalence of participants with deficient 25(OH)D levels was significantly higher in the both DVT and control groups than those with sufficient 25(OH)D levels (68.3% versus 13.4%, and 49.4% versus 28.2%, respectively, P=0.027). In a multivariate analysis, 25(OH)D levels and sex were found to be the only independent predictors of DVT (odds ratio [OR] 1.05, 95% confidence interval [CI] 1.02–1.08, P=0.001 and OR 0.51, 95% CI 0.26–1.00, P=0.049, respectively). Conclusion: Low levels of 25(OH)D are associated with idiopathic lower-extremity DVT. Further investigation is needed to establish determinants and probable causative role of 25(OH)D. Keywords: vitamin D, venous thromboembolism, idiopathic deep vein thrombosi