NaHCO3 administration for 5 d may prevent acid-base balance disturbances and improve performance during anaerobic exercise in a dose-dependent manner.

Background/Aims: Elevated wave reflections and arterial stiffness, as well as ambulatory blood pressure (BP) are independent predictors of cardiovascular risk in end-stage-renal-disease. This study is the first to evaluate in hemodialysis patients the validity of a new ambulatory oscillometric device (Mobil-O-Graph, IEM, Germany), which estimates aortic BP, augmentation index (AIx) and pulse wave velocity (PWV). Methods: Aortic SBP (aSBP), heart rate-adjusted AIx (AIx(75)) and PWV measured with Mobil-O-Graph were compared with the values from the most widely used tonometric device (Sphygmocor, ArtCor, Australia) in 73 hemodialysispatients. Measurements were made in a randomized order after 10 min of rest in the supine position at least 30 min before a dialysis session. Brachial BP (mercury sphygmomanometer) was used for the calibration of Sphygmocor's waveform. Results: Sphygmocor-derivedaSBP and AIx(75) did not differ from the relevant Mobil-O-Graph measurements (aSBP: 136.3 ± 19.6 vs. 133.5 ± 19.3 mm Hg, p = 0.068; AIx(75): 28.4 ± 9.3 vs. 30.0 ± 11.8%, p = 0.229). The small difference in aSBP is perhaps explained by a relevant difference in brachial SBP used for calibration (146.9 ± 20.4 vs. 145.2 ± 19.9 mm Hg, p = 0.341). Sphygmocor PWV was higher than Mobil-O-Graph PWV (10.3 ± 3.4 vs. 9.5 ± 2.1 m/s, p < 0.01). All 3 parameters estimated by Mobil-O-Graph showed highly significant (p < 0.001) correlations with the relevant measurements of Sphygmocor (aSBP, r = 0.770; AIx(75), r = 0.400; PWV, r = 0.739). The Bland-Altman Plots for aSBP and AIx(75) showed acceptable agreement between the two devices and no evidence of systemic bias for PWV. Conclusion: As in other populations, acceptable agreement between Mobil-O-Graph and Sphygmocor was evident for aSBP and AIx(75) in hemodialysis patients; PWV was slightly underestimated by Mobil-O-Graph.

The influence of L-carnitine supplementation on hematocrit (Hct) and hemoglobin (Hb) levels, in patients suffering from end stage renal disease (ESRD) on maintenance hemodialysis, are well known from several studies. The data concerning the serum levels of carnitine, in patients with ESRD on continuous ambulatory peritoneal dialysis (CAPD) are contradictory, but most of them support that they are rather normal. In this study the effect of L-carnitine supplementation on Hct, and Hb levels were investigated in patients suffering from ESRD on CAPD. In the study 12 patients were included (5F, 7M), aged from 39 to 92 years old (median 65.5 years), who were on CAPD for more than 6 months (from 6 to 15 months, mean +/- SD = 8.6 +/- 3.6), with normal serum ferrum and ferritin levels at the beginning of the study. Two grams of L-carnitine/ day per os (Superamin, Vianex Hellas), were administered in all the patients and the serum ferrum levels were tried to be kept stable, by exogenous ferrum administration, during the study period. If the Hct levels were more than 36% per month the erythropoietin (rHuEpo) dose of the patient was decreased monthly at the half dose/week. The changes of Hct, Hb, ferrum and ferritin levels, as well as the Indice de Rigidite (IR) of the erythrocytes were recorded, before and after the first, second and third month of the study period. Finally, the rHuEpo dose/ patient was registered monthly before and during the study. During the observations, Hct (35.4 +/- 3.3 vs. 38.1 +/- 3.4, ANOVA, p < 0.03) and Hb levels (11.0 +/- 1.1 vs. 11.9 +/- 1, ANOVA, p < 0.01), were significantly increased. On the other hand, rHuEpo dose necessity/patient/week was decreased significantly (3,833 +/- 3326 vs. 1,292 +/- 1,712, ANOVA, p < 0.01), in order to succeed the target Hct level. Furthermore, red blood cells IR also appeared to have a significant decrease (16.6 +/- 7.4 vs. 13.0 +/- 3.9, paired t-test, p < 0.03). Finally, the ferrum and ferritin levels were stable during the study period. It was concluded, that in patients on, CAPD the per os L-carnitine supplementation decreased, the red blood cells IR which contributes to the: (a) Increase of Hct and Hb levels and (b) decrease of the patients rHuEpo dose/week.

BPV is increased in interdialytic Day 2 compared with Day 1 in hemodialysis patients; this could be another mechanism involved in the complex cardiovascular pathophysiology and increased cardiovascular mortality of these individuals.

Anemia is a serious problem in hemodialysis patients, the main cause of which is erythropoietin deficiency. After the discovery of recombinant human erythropoietin (rHuEpo) at the end of the last decade, the hematological profile of hemodialysis patients improved significantly but at considerable expense. The deformability of red blood cells (RBC) influences their microcirculation and tissue oxygen delivery along with their life span. We investigated the deformabilty of RBCs in 15 hemodialysis patients before and after three months on L-carnitine supplementation (30 mg/Kg body wt/dialysis session). We excluded from the study all patients who received blood transfusions three months before or during the study, patients who had hemorrhagic episodes, those with hyperparathyroidism or infections, and any who required surgical intervention during the study. The serum iron, folic acid and vitamin B-12 levels were kept normal during the duration of the study. The erythropoietin dose taken before the beginning of L-cartnitine supplementation was not changed. The deformability of RBCs before and after dialysis, prior to and following three months on L-carnitine was determined and compared to the deformability of RBCs from a control group. Hematocrit levels were measured before entry into the study and every month for three months. We found that the deformability of RBCs before the dialysis session was significantly greater than that found in the control group (t-test, p < 0.00001), and that there was a further increase after the end of the dialysis session. Three months following L-carnitine supplementation, we found a significant reduction of RBCs deformability (paired t-test, p < 0.004), and a significant increase in the hematocrit (ANOVA, p < 0.0001). We concluded that abnormalities in the deformability of RBCs improved after L-carnitine and that this was responsible for the increase in the hematocrit. This may allow a substantial reduction in rHuEpo dose.