Disturbed blood flow worsens endothelial dysfunction in moderate-very severe chronic obstructive pulmonary disease

Endotelna disfunkcija se smatra jednom od patofizioloških poveznica KOPB-a i kardiovaskularnih bolesti, koje su među najčešćim komorbiditetima i uzrocima smrti oboljelih od KOPB-a. Mehanizmi koji su odgovorni za poremećaj funkcije endotela s pro-aterogenim fenotipom endotelnih stanica u bolesnika s KOPB-om su u značajnoj mjeri još neistraženi. Cilj ovog istraživanja bio je ispitati u bolesnika sa stabilnim, napredovalim KOPB-om i kroničnom respiracijskom insuficijencijom hemodinamiku brahijalne arterije i pokazatelje endotelne funkcije: dilataciju brahijalne arterije posredovanu protokom (FMD) i plazmatsku koncentraciju endotelnih mikročestica (EMP). Također planirano je utvrditi pogoršava li akutni poremećaj protoka krvi, u obliku oscilirajućeg smičnog opterećenja, endotelnu funkciju te kakva je uloga kronične hipoksemije i njezine korekcije na hemodinamiku brahijalne arterije, poboljšava li korekcija hipoksemije akutnim udisanjem kisika endotelnu funkciju, odnosno štiti li je od eventualnog dodatnog pogoršanja induciranog oscilirajućim smičnim opterećenjem. U 17 hipoksemičnih bolesnika s KOPB-om i 10 kontrolnih zdravih ispitanika odgovarajuće dobi ispitani su pri udisanju sobnog zraka: obrazac smicanja (antegradna stopa smicanja (aSR), retrogradna stopa smicanja (rSR) i oscilirajući smični indeks (OSI)), FMD brahijalne arterije te razina cirkulirajućih EMP-ova prije i nakon 20 minuta eksperimentalno induciranog oscilirajućeg smičnog opterećenja inflacijom podlaktične manžete na 75 mm Hg. Bolesnici s KOPB-om su ponovno podvrgnuti testiranju nakon korekcije hipoksemije 20-minutnim udisanjem kisika preko nosnih vila. U bolesnika s KOPB-om je, u odnosu na zdrave ispitanike, utvrđen oko šest puta veći bazalni rSR (p

Endothelial dysfunction is considered to be one of the pathophysiological links of COPD and cardiovascular diseases, which are among the most common comorbidities and causes of death in COPD. Mechanisms that are responsible for the endothelial dysfunction with pro-atherogenic phenotype of endothelial cells in COPD patients are significantly unexplored. The aim of this study was to examine brachial artery hemodynamics and endothelial function indicators in patients with stable, advanced COPD and chronic respiratory insufficiency: flow-mediated dilation (FMD) of brachial artery and plasma concentration of endothelial microparticles (EMP). It was also planned to test whether acutely induced oscillatory shear stress worsens endothelial function in hypoxemic, stable COPD patients, how chronic hypoxemia and its correction influence brachial artery hemodynamics, whether acute low-flow oxygen administration improves endothelial function and if it is protective against potential oscillatory shear stress-induced endothelial dysfunction. In 17 hypoxemic, stable COPD patients and 10 age-matched, non-smoking, healthy control subjects shear pattern (antegrade and retrograde shear rate (aSR and rSR), oscillatory shear index (OSI)), brachial artery FMD and circulating EMPs were examined during room air breathing before and after 20 minutes of experimentally-induced oscillatory shear stress (forearm cuff inflated to 75 mm Hg). COPD patients underwent the same protocol a second time following a 20-minute wash-in period of low-flow supplemental oxygen to normalize arterial oxygen saturation. Compared to healthy controls, COPD patients had around six-fold greater baseline rSR (p