Summary

Obesity (body mass index: BMI ≥ 30 kg/m²) is named as a risk factor for chronic venous insufficiency (CVI) in phlebologic studies, even though the mechanisms of effects are still unclear. Therefore we examined literature for current data and hypotheses and described them.On the one hand, the correlation between obesity and CVI is explained by chronically inflammatory processes, affected by the lipometabolism of obese and the metabolic syndrome. On the other hand, this particular correlation is explained by a mechanical approach based on an elevated intraabdominal pressure (IAP), which is transmitted to the venous system of the lower extremities. Recent studies show that the chronically inflammatory processes promote the frequency and manifestation of thrombosis. In regard to the IAP, only the pressure of the elevated abdominal mass (paunch) seems to have a minimal effect in the supine position.Several studies relativised the correlation between obesity and CVI because of the rising prevalence of venous disease with age, which correlates with a higher BMI as well. Furthermore, studies have shown the phenomena of so-called venous hydrostatic ulcerations in obese patients. That means those patients show the typical skin changes of the CVI without any venous reflux. Depending on the study, their proportion is estimated between 21% and 64% of venous leg ulcers. Additionally, it was shown that after weight loss the skin seems to regenerate from the typical signs of CVI. At the moment, the pathomechanism causing hydrostatic ulcers in obese is unclear.