Changes in common carotid artery intima-media thickness over 1 year in patients on peritoneal dialysis

Accelerated atherosclerosis and vascular calcifications increase cardiovascular morbidity and mortality in patients on dialysis. Common carotid artery (CCA) intima-media thickness (IMT) is considered useful for imaging atherosclerosis non-invasively. Since chronic inflammation may accelerate atherosclerosis in end-stage renal disease patients, the aim of this 1 year study was to assess changes in CCA-IMT in stable peritoneal dialysis (PD) patients, and to search for possible associations between these changes and selected cytokines, acute phase proteins and other risk factors of atherosclerosis.

Of the original cohort of 61 stable patients on PD-28 female, 33 male; mean age 50.4+/-13.6 years; dialyse for a median of 17.5 months at inclusion (range 1-96 months)-47 patients survived the 1 year period on PD. CCA-IMT was assessed at baseline and after 12 months. Pro-inflammatory cytokines (IL-6, TNFalpha), acute phase proteins (CRP, fibrinogen), calcium-phosphate balance and lipid profile were assessed at baseline and after 6 and 12 months. Anthropometric parameters (age, weight, BMI, waist-to-hip ratio) were measured at baseline.

The mean CCA-IMT at baseline, 0.66+/- 0.19 mm, increased by a mean of 0.098+/-0.17 to 0.76+/-0.21 mm (P<0.001) in 1 year. In 14 patients (29.8%) at least one plaque was found in the CCAs examined. At the end of follow-up: 28 patients (59.6%) had increases in CCA-IMT (from 0.63+/-0.2 to 0.83+/- 0.21 mm; P = 0.03), and 19 (40.4%) remained stable or even showed slight, but non-significant, decreases of CCA-IMT (from 0.72+/-0.17 to 0.66+/-0.17 mm, P = NS). The 'progressors' had significantly higher initial BMI (P<0.05), and mean concentrations of calcium (P = 0.005), IL-6 (P = 0.05), TNFalpha (P = 0.05), CRP (P = 0.005) and lower HDL-cholesterol than 'non-progressors'. In univariate analysis, DeltaCCA-IMT correlated positively with age (R = 0.32, P = 0.03), BMI (R = 0.29, P = 0.05) and mean concentrations of CRP (R = 0.37, P = 0.01), TNFalpha (0.52, P = 0.0002), but inversely with HDL-cholesterol (R = -0.37, P = 0.01). In multiple regression analysis, however, only age appeared to be independently associated with increase in CCA-IMT (beta = 0.37, P<0.01; R(2) for the model 0.14).

Our results suggest a possible role of non-specific inflammation in the progression of atherosclerosis in patients treated with PD, in addition to age.