Standing posture at work and overweight exacerbate varicose veins: Shimane CoHRE Study.

Varicose veins (VV) in legs are commonly observed in the general global population. However, the prevalence of and risk factors for VV in Japan are not clear. This study aimed at clarifying the risk factors for VV in traditional rural areas of Shimane prefecture. Subjects (113 men and 205 women aged ≥45 years) were recruited from health examinations in those areas in 2012. VV were defined as a reflux of blood in the great and/or small saphenous vein and incompetent perforating veins detected by ultrasonography. Risk factors for VV were analyzed using logistic regression models that included various parameters. We also investigated the possible interaction between standing at work and overweight and calculated the synergistic index. VV were found in 20.1% of the subjects (12.4% of men and 24.4% of women). The previously known risk factors of prolonged upright standing posture during work, higher body mass index (BMI), female sex, and age were also significant factors for VV. There was a significant combined effect of overweight (BMI ≥25) and prolonged upright standing posture at work [adjusted odds ratio = 3.42; 95% confidence interval (CI), 1.07-10.89], although the synergistic effect was not significant [synergistic index = 1.3; 95% CI, 0.2-8.7]. The prevalence of VV in the traditional rural area of Shimane prefecture was comparable to that reported previously in European countries. Our results confirm that exposure to both prolonged standing at work and overweight exacerbate VV development. This finding is useful to develop strategies for VV prevention.