Association of inflammation and protein-energy wasting with endothelial dysfunction in peritoneal dialysis patients

Background. Cardiovascular disease is the main cause of mortality in end-stage renal disease (ESRD) patients. Recent studies have indicated that non-traditional risk factors such as endothelial dysfunction (ED), chronic inflammation and protein-energy wasting (PEW) may contribute significantly to the increased cardiovascular mortality among dialysis patients. To further ascertain this association, we carried out a cross-sectional assessment of nutritional status, inflammatory markers and endothelial dysfunction in peritoneal dialysis (PD) patients.Methods. We measured ED functionally by flow-mediated vasodilatation (FMD) using doppler ultrasonography and biochemically by soluble intercellular adhesion molecule-1 (sICAM-1) in 105 stable PD patients and 32 age-and sex-matched healthy controls. We also simultaneously measured inflammatory markers and performed a subjective global assessment (SGA) of their nutritional status using a seven-point scoring scale. Subjects were subgrouped according to their nutritional and inflammatory status.Results. In PD patients, FMD was markedly lower (9.9±4.8% vs. 16.4±4.8%, P<0.05), and sICAM-1 was significantly higher than those in controls. The malnourished patients had significantly lower FMD (8.4±4.6% vs. 10.8±4.7%, P<0.05) and higher sICAM-1 than the nourished patients. The inflamed group had significantly lower FMD (7.1±3.8 vs.11.1±4.6%, P<0.05) and higher sICAM-1 than the non-inflamed group. In all PD patients, lean body mass/body weight %, albumin and SGA correlated positively with FMD (r = +0.207, r = +0.224, r = +0.285, P<0.05). However, age, log high sensitivity C-reactive protein (hsCRP), log IL-6 and sICAM-1 were negatively correlated with FMD (r=-0.275, r =-0.361, r =-0.360, r =-0.271, P<0.05). A multiple regression analysis showed that log hsCRP was an independent factor affecting FMD. Endothelial function, demonstrated as FMD and sICAM-1 in the nourished PD patients without inflammation, was well preserved compared to other subgroups.Conclusion. Our data suggest that chronic inflammation and PEW are closely linked to ED in PD patients.