Adults with varicose veins are five times more likely to develop deep venous thrombosis (DVT), a large retrospective cohort study has found.
“Varicose veins are rarely associated with serious health risks. In contrast, [DVT], pulmonary embolism (PE), and peripheral artery disease (PAD) are vascular diseases that are associated with serious systemic effects. Patients with varicose veins have increased levels of inflammatory and prothrombotic markers,” the authors explain.
Shyue-Luen Chang, MD, from the Vein Clinic, Department of Dermatology, Chang Gung Memorial Hospital, Taoyuan; Chang Gung University College of Medicine, Taoyuan; and the Department of Cosmetic Science, Chang Gung University of Science and Technology, Linkou, all in Taiwan, and colleagues report their findings in an article published in the February 27 issue of JAMA.
The researchers analyzed claims data from Taiwan’s National Health Insurance program from 212,984 adult patients with varicose veins (mean age, 54.5 years; 69.3% women) and 212,984 randomly selected propensity score-matched patients without varicose veins, DVT, PAD, or PE (mean age, 54.3 years; 70.3% women).
With a mean follow-up of 7.3 to 7.8 years, patients with varicose veins had a higher incidence of DVT, at 6.55 per 1000 person-years vs 1.23 for those in the control group.
PE incidence was also higher among those with varicose veins (0.48 per 1000 person-years) compared with participants in the control group (0.28 per 1000 person-years). Similarly, the risk for PAD was elevated in the varicose vein group, at 10.73 per 1000 person-year vs 6.22 for the control group.
The hazard ratios for those in the varicose veins group were 5.30 (95% confidence interval, 5.05 – 5.56) for DVT, 1.73 (95% confidence interval, 1.54 – 1.94) for PE, and 1.72 (95% confidence interval, 1.68 – 1.77) for PAD compared with those in the control group. These results did not differ significantly by sex or age.
Potential limitations of the study include the lack of claims information on patients who did not seek medical care; some patients may have failed to obtain medical care as a result of embarrassment about the appearance of varicosities, which could mean that they may have waited until their varicose veins were severe before seeking care. The study was observational in nature; thus, causal inferences cannot be made.
In addition, because the magnitude of association was smaller for PE and PAD, “the findings for PE and PAD are less clear due to the potential for confounding. Whether the association between varicose veins and DVT is causal or represents a common set of risk factors requires further research,” the researchers conclude.