Coronary artery calcification, systemic inflammation markers and mineral metabolism in a peritoneal dialysis population.

AIMS: To assess the prevalence of coronary artery calcification (CAC) in peritoneal dialysis (PD) patients and to determine whether comorbidities such as inflammation, dyslipidemia and mineral metabolism disorders correlate with its development. METHODS: Forty-nine PD patients (45% male; median age, 52 years) were submitted to multislice computed tomography. Inflammatory markers, anti-oxidized LDL antibody, calcium-phosphate balance and lipid profiles were assessed. RESULTS: Twenty-nine patients (59.2%) presented CAC (median calcium score, 234.7 Agatston units). Patients with CAC were older than those without, more frequently presented a history of coronary artery disease or hypertension and had lower HDL cholesterol levels, as well as presenting higher levels of osteoprotegerin and LDL oxidation. The logistic regression revealed that the independent determinants of CAC were age (odds ratio = 1.12; p = 0.006) and number of prescribed anti-hypertensive drugs (odds ratio = 2.38; p = 0.048). When the population was stratified by calcium score quartile, soluble Fas levels were significantly higher in patients with severe calcification. In patients younger than 45, CAC correlated positively with phosphorus levels (r = 0.52; p = 0.04). CONCLUSION: In PD patients, CAC is highly prevalent. Our results indicate that conditions such as inflammation and mineral disturbances are associated with its development.

Coronary calcification in hemodialysis patients: the contribution of traditional and uremia-related risk factors.

BACKGROUND: Coronary artery calcification is a common feature of atherosclerosis, occurring in 90% of angiographically significant lesions. There is recent evidence that coronary artery calcification is frequent in hemodialysis patients and it has been suggested that this increased incidence may be associated to uremia-related factors. The development and progression of coronary artery calcification is similar to osteogenesis. The aim of this study was to evaluate the relationship between coronary artery calcification, uremia-related factors, and bone histomorphometry in hemodialysis patients. METHODS: A total of 101 hemodialysis patients were assessed for biochemical markers of inflammation, oxidative stress, and bone metabolism. Subsequently, they were submitted to multislice coronary tomography (MSCT) and transiliac bone biopsy. RESULTS: The median calcium score was 116.2 (range 0 to 5547). Fifty-two percent of the patients showed moderate and severe coronary artery calcification, 20% had calcium scores greater than 1000. In univariate analysis, age (r= 0.57, P < 0.000001), osteoprotegerin (OPG) (r= 0.44, P= 0.00002), and body mass index (BMI) (r= 0.24, P= 0.01) correlated positively with calcium score. Bone trabecular volume and trabecular thickness correlated negatively with calcium score (r=-0.24, P= 0.02; r=-0.22, P= 0.03). There was a correlation of borderline significance between calcium score and C-reactive protein (CRP) (r= 0.18, P= 0.062). The multiple linear regression analysis identified OPG as the only variable independently associated with coronary artery calcification. CONCLUSION: Coronary artery calcification is highly prevalent in the hemodialysis population and is associated with older age, higher BMI, inflammation and reduced trabecular bone volume. Higher OPG is independently associated with coronary artery calcification and may represent an incomplete self-defensive response to the progression of atherosclerosis in hemodialysis patients.

Comparison of three methods for the determination of body fat in patients on long-term hemodialysis therapy.

OBJECTIVE: To compare three simple methods of body composition analysis for the assessment of body fat in patients on long-term hemodialysis therapy. DESIGN: Cross-sectional study using the skinfold thickness, bioelectrical impedance analysis, and near-infrared interactance techniques after a hemodialysis session. SUBJECTS/SETTING: Ninety clinically stable patients (57 male/33 female) undergoing hemodialysis at the Dialysis Unit of the Federal University of São Paulo. STATISTICAL ANALYSIS: Analysis of variance, intraclass correlation coefficient, and Bland-Altman plot analysis were used for the comparative analysis between the methods. RESULTS: Body fat measurements obtained by skinfold thickness (13.5+/-6.2 kg) and bioelectrical impedance analysis (13.7+/-6.7 kg) were similar, whereas those measured by near-infrared interactance (11.3+/-5.1 kg) were significantly lower in comparison with skinfold thickness and bioelectrical impedance analysis (P<.001). The strongest intraclass correlation coefficient was found between bioelectrical impedance analysis and skinfold thickness (r=0.87), and near-infrared interactance vs skinfold thickness and bioelectrical impedance analysis methods yielded r=0.78 and r=0.76, respectively. Near-infrared interactance showed a progressive underestimation of body fat values in comparison with the bioelectrical impedance analysis technique in patients with higher amount of adiposity. CONCLUSION: In our study, we cannot consider that one method of body composition analysis is more accurate than the other because we did not apply a gold standard method. However, the most simple, long-established, and inexpensive method of skinfold thickness seems to be still very useful to the dietitians' routine for assessing body fat in patients on long-term hemodialysis therapy.