Pathogenesis of chronic venous insufficiency by obesity

Abstract

SummaryObesity (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.

Effect of obesity on venous blood flow in the lower limbs

“…These findings are consistent with those of Van Rij et al., 33 who also demonstrated a position‐dependent increase in lower extremity venous pressure in obese patients. Taken together, Goestl et al., 9 proposed that these findings suggest that centripetal obesity may lead to lower limb venous hypertension and changes in the microcirculation, ultimately resulting in the characteristic clinical signs of chronic venous insufficiency. Our observation that volume flow increases when the abdominal panniculus is elevated, i.e., when intra‐abdominal pressure decreases, further supports this theory.…”

“…To what extent this is due to a purely mechanical effect, via reduced lower limb venous return due to increased intra‐abdominal pressure, or is mediated by chronic inflammation, characterized by adipokine release, neutrophil infiltration, endothelial dysfunction and/or increased coagulase activity, is currently unclear 4,6,7 . Moreover, given the sex‐ and age‐ dependent distribution of adipose tissue, it is conceivable that abdominal adipose tissue may be more associated with the development of chronic venous disease than viscerally deposited fat, given that it may directly restrict venous return from the legs 6,8,9 …”

“…4,6,7 Moreover, given the sex-and age-dependent distribution of adipose tissue, it is conceivable that abdominal adipose tissue may be more associated with the development of chronic venous disease than viscerally deposited fat, given that it may directly restrict venous return from the legs. 6,8,9 Therefore, we sought to objectively investigate structural and hemodynamic changes in the lower limb veins in patients with abdominally distributed fat (the so-called abdominal panniculus) using standard duplex sonography. In order to easily and reproducibly investigate any compressive effects of the abdominal panniculus on lower limb blood flow, patients meeting WHO criteria for obesity were recruited and their deep and superficial venous systems were investigated at rest and during elevation of their abdominal panniculus.…”

Einfluss von Adipositas auf die Hämodynamik der Beinvenen

“…Es ist bekannt, dass ein erhöhtes Körpergewicht den intraabdominalen Druck erhöht. 9,29,30 Daher kann ein aktives Anheben des abdominalen Pannikulus durch den Patienten zu einer vorübergehenden Senkung des intraabdominalen Drucks führen, was wiederum einen verbesserten venösen Abstrom begünstigt. Zur Unterstützung dieser Hypothese berichteten sowohl Noblett et al, 31 , als auch Arfvidsson et al, 32 , dass adipöse Patienten im Vergleich zu nicht adipösen Personen einen erhöhten intraabdominalen Druck aufwiesen, insbesondere Personen mit einem BMI von mehr als 30 kg/m 2 , und dass eine Korrelation zwischen dem intraabdominalen Druck und dem erhöhten Druck in den Beckenvenen besteht.…”

“…4,6,7 Angesichts der geschlechts-und altersabhängigen Verteilung des Fettgewebes ist es zudem denkbar, dass Bauchfettgewebe stärker mit der Entwicklung chronischer Venenerkrankungen assoziiert ist als viszeral abgelagertes Fett, da es den venösen Rückfluss aus den Beinen direkt einschränken kann. 6,8,9 Daher haben wir versucht, strukturelle und hämodynamische Veränderungen in den Beinvenen bei Patienten mit vorwiegend abdomineller Adipositas (abdominaler Pannikulus) mittels Duplexsonographie objektiv zu untersuchen. Um einfach und reproduzierbar etwaige Kompressions-effekte des adipösen Bauchs auf den Blutfluss der unteren Extremitäten zu untersuchen, wurden Patienten rekrutiert, welche die WHO-Kriterien für Adipositas erfüllten, und deren tiefe und oberflächliche Venensysteme in Ruhe und während der Anhebung des abdominalen Pannikulus untersucht.…”