Varicose veins in the lower extremities in relation to occupational mechanical exposures: a longitudinal study
Objectives To evaluate if occupational mechanical exposures are associated with an increased risk of surgery for varicose veins (VV) in the lower extremities.
Methods We conducted a longitudinal study of persons from the Musculoskeletal Research Database at the Danish Ramazzini Centre who were 18–65 years old when they provided baseline questionnaire data during 1993–2004. Exposure estimates were obtained from a job exposure matrix based on expert ratings. The register information on first-time surgery for VV was retrieved. We used Cox regression analyses.
Results During 416 317 person-years of follow-up among 38 036 persons, 851 first-time operations for VV occurred. Using standing/walking <4 h/day and uncommon lifting as references, exposure–response relationships with risk of surgery were found for men. For women, the risk increased too, but without clear exposure–response patterns. The adjusted HRs for ≥6 h/day spent standing/walking were 3.17 (95% CI 2.06 to 4.89) and 2.34 (95% CI 1.72 to 3.19) for men and women, respectively. For high lifting exposures (≥1000 kg/day), the adjusted HRs were 3.95 (95% CI 2.32 to 6.73) for men and 2.54 (95% CI 1.95 to 3.31) for women. Other risk factors were increasing age for men and parity for women. Minimal leisure-time physical activity, a high body mass index and smoking were not associated with increased risk.
Conclusions The results suggested an increased risk of surgery for VV in relation to prolonged standing/walking and heavy lifting and a preventive potential of more than 60% of all cases in exposed occupations.