Different risk factors for the maximum and the mean carotid intima-media thickness in hemodialysis patients.

OBJECTIVE High-resolution B-mode ultrasonography has been widely used for the noninvasive assessment of atherosclerosis in hemodialysis patients. But, there are two major methods of carotid ultrasonography: one including plaque and the other excluding plaque. METHODS The subjects were 112 hemodialysis patients (58 men and 54 women) with a mean age of 55.8 +/- 13.0 years. The maximum intima-media thickness (IMT) of the carotid artery (including plaque) was measured as an index of arterial wall thickening and atheroma formation, while the mean IMT (without plaque) was measured as an index of arterial wall thickening. In addition the value of (maximum-mean) IMT was calculated as an index of atheroma formation. Therefore, the independent risk factors associated with the maximum IMT, mean IMT, and (maximum-mean) IMT were investigated by stepwise multiple regression analysis. RESULTS The independent risk factors associated with the maximum IMT were age, diabetes mellitus, smoking, and intact parathyroid hormone (PTH) (R = 0.569, p < 0.0001), while factors associated with the mean IMT were age, hypertension, dyslipidemia, intact PTH, and lipoprotein (a) (R = 0.602, p < 0.0001). The independent risk factors associated with the (maximum-mean) IMT were age, diabetes mellitus, smoking, and intact PTH (R = 0.515, p < 0.0001). CONCLUSION These findings suggest that risk factors for the maximum IMT and mean IMT are somewhat different in hemodialysis patients.