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

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