Inflammation as a risk factor for carotid intimal-medial thickening, a measure of subclinical atherosclerosis in haemodialysis patients: the role of chlamydia and cytomegalovirus infection

Abstract

Objectives: Atherosclerotic vascular disease is the most frequent complication seen in haemodialysis (HD) patients. Evidence suggests that inflammation may play a role in the pathogenesis and progression of atherosclerosis. Our aim was to evaluate the causative role of inflammation in atherosclerosis among HD patients.

Methods: Intima-media thickness (IMT) in carotid arteries was determined in 54 HD patients and 52 controls. Plasma levels of lipids, glucose, albumin and several acute phase proteins, and immunoglobulin G titres against chlamydia and cytomegalovirus were measured in all subjects.

Results: Mean carotid IMT was significantly greater in HD patients than in controls (0.75 mm vs 0.56 mm, P < 0.005). While plasma levels of C-reactive protein (CRP), serum amyloid A (SAA), lipoprotein (a) Lp(a), fibrinogen and ferritin were higher in HD patients, albumin levels were lower. In HD patients, carotid IMT was correlated positively with CRP (R = 0.29, P = 0.019), SAA (R = 0.69, P < 0.001), Lp(a) (R = 0.42, P = 0.001), fibrinogen (R = 0.57, P < 0.001) and chlamydia pneumonia immunoglobulin G titres (R = 0.50, P < 0.001), and negatively with albumin levels (R = -0.33, P = 0.02); there was no relationship between carotid IMT and hypertension, plasma lipid levels and cytomegalovirus. In multivariate regression analysis, these variables still showed a significant relationship with IMT (R(2) = 0.694 and P < 0.001).

Conclusion: We conclude that atherosclerotic changes are more common in HD patients than in controls, and that inflammatory processes may play a role in the pathogenesis of atherosclerosis.