Inflammation is associated with carotid atherosclerosis in dialysis patients

Objective To investigate the relationship between inflammatory processes an d atherosclerosis in uraemic patients on chronic dialysis. Design A cross-sectional study in 138 dialysis patients (92 on haemodialysi s and 46 on continuous ambulatory peritoneal dialysis). Methods Serum C-reactive protein (CRP), IgG anti-Chlamydia pneumoniae antib odies, lipoprotein (a), fibrinogen and plasma homocysteine as well as the i ntima-media thickness and the number of atherosclerotic plaques of the caro tid arteries (by Echo-Colour-Doppler) were measured in each patient. Results One hundred and eight patients had at least one plaque and 26 had m ore than six plaques. Serum CRP was above the upper limit of the normal ran ge (5 mg/l) in 85 of 138 patients (62%). IgG anti-Chlamydia pneumoniae anti bodies were detectable in 64% of patients (high level in 24%, intermediate in 33% and low in 7%) and undetectable in the remaining 36% of patients. In a multiple regression model age (beta = 0.35), serum CRP (beta = 0.23), pl asma homocysteine (beta = 0.19), duration of dialysis (beta = 0.19) and pul se pressure (beta = 0.18) were independent predictors of intima-media thick ness (R = 0.54, P < 0.0001). Similarly, age (beta = 0.33), serum CRP (beta = 0.29), plasma homocysteine (beta = 0.20) and serum albumin (beta = -0.18) were independent correlates of the number of atherosclerotic plaques (R = 0.55, P < 0.0001). Furthermore, in smokers, the interaction serum CRP-IgG a nti-Chlamydia pneumoniae antibodies was the stronger independent predictor (beta = 0.43, P = 0.0001) of the number of atherosclerotic plaques while no such relationship (P = 0.73) was found in non-smokers. Conclusions In patients on chronic dialysis treatment CRP is independently associated to carotid atherosclerosis and appears at least in part to be ex plained by IgG anti-Chlamydia pneumoniae antibodies level. These data lend support to the hypothesis that inflammation plays a role in the pathogenesi s of atherosclerosis in these patients. J Hypertens 2000, 18:1207-1213 (C) Lippincott Williams & Wilkins.