Increased Aortic Calcification Index in Hemodialysis Patients

Accessible online at: http://BioMedNet.com/karger Dear Sir, Atherosclerosis is a frequent cause of morbidity in patients with end-stage renal disease. Myocardial infarction and cerebrovascular events occupy an important place in the mortality of these patients. This was shown in previous studies [1, 2] and led to the hypothesis of the existence of accelerated atherosclerosis in hemodialysis patients [1]. This hypothesis by Lindner et al. [1] has been continuously cited since first stated two decades ago. Its validity appears to be supported by several subsequent reports. Previous epidemiological studies [3, 4] have reported that sclerosis of the abdominal aorta reflects early arteriosclerosis and correlates significantly with coronary arteriosclerosis. However, it remains uncertain whether the atherosclerosis of hemodialysis patients is effectively accelerated [5]. Their high cardiovascular mortality rate is not proof of acceleration of the disease process. Many hemodialysis patients already have more or less marked vascular lesions at the start of dialysis treatment. Risk factors present in the predialysis phase may be of primary importance. These patients often exhibit a number of concomitant risk factors, such as hypertension, dyslipidemia, glucose intolerance, and cigarette smoking. Therefore, there has been continuous controversy as to whether long-term hemodialysis accelerates arteriosclerosis. Noninvasive ultrasonography studies have recently documented the extent of atherosclerotic lesions in the carotid arteries of hemodialysis patients [6, 7]. Burdick et al. [6] reported a significant positive correlation between carotid intimal medial thickness and length of time on dialysis, and there was a significant correlation between intimal medial thickness and low-density lipoprotein as well. Kawagishi et al. [7] also reported that the intimal medial thickness of the carotid arteries of hemodialysis patients was significantly greater than that of age-matched control subjects. They indicated that age, cigarette smoking, and uremic state were independent risk factors associated with the extent of the intimal medial thickness of the carotid arteries. Since the accuracy of ultrasonographic analysis depends on the experience of the investigator, we quantified aortosclerosis morphometrically by CT scans of the abdominal aorta of hemodialysis patients. The study consisted of 28 maintenance hemodialysis patients in the Dialysis Unit of the Minami Senju Hospital. Their mean age was 57.5 B 22.3 (range 37–77) years. The mean duration of hemodialysis therapy was 8.2 B 2.5 (range 1–21) years. The underlying renal diseases was glomerulonephritis in 22 patients, diabetes mellitus in 5 patients, and polycystic kidney disease in 1 patients. The control group consisted of 21 patients, 34–72 years of age, randomly selected without renal diseases. The abdominal aorta was studied by non-contrast CT in consecutive sequential 8-mm slices (Hitachi W-200). After identification of the slice with the most extensive Table 1. Aortic calcification index (ACI) in the different age groups of control patients (n = 20) and hemodialysis patients (n = 28)