Brain natriuretic peptide variations are linked to volume status in hemodialysis patients.

AIMS: To evaluate the usefulness of monthly brain natriuretic peptide (BNP) dosage in assessing dry weight in hemodialysis patients. PATIENTS AND METHODS: Over a 2-year period, we performed in 46 hemodialysis patients monthly BNP level measurements, and adapted dry weight following the determination of variations in BNP concentrations for each month during the study period. Then we tested our approach by looking for a statistical relation between monthly alterations in BNP levels and monthly variations in the patients' weight, blood pressure, hemoglobinemia and albuminemia which are in themselves related to fluid status variations. RESULTS: Monthly BNP level variations were found to be positively correlated with monthly end-dialysis weight alterations (r = +0.24, p < 0.001), with monthly systolic and diastolic blood pressure variations before dialysis (r = +0.09, p < 0.001; r = +0.24, p < 0.001), and with systolic and diastolic blood pressure changes after dialysis (r = +0.09, p = 0.001; r = +0.25, p < 0.001). Moreover, monthly BNP level variations were negatively correlated with monthly hemoglobinemia changes (r = -0.17, p = 0.004) and with monthly albuminemia alterations (r = -0.14, p = 0.001). CONCLUSION: In a non-selected population of hemodialysis patients it was found that monthly BNP level variations were positively correlated with monthly volume status alterations as evaluated by clinical and biological criteria. BNP appears to be a useful tool for dry weight assessment despite the absence of a standardized cut-off point for BNP levels in hemodialysis patients.

Correction of selenium deficiency in hemodialyzed patients.

Selenium is an essential trace element important for glutathione peroxidase activity. Selenium deficiency has been found in association with skeletal and cardiac myopathy and may increase the risk for cardiovascular diseases and for cancer. We studied 39 hemodialysis patients and 15 control subjects. Plasma selenium, plasma glutathione peroxidase activity and erythrocyte glutathione peroxidase activity were lower than in controls (38 +/- 14 vs. 88 +/- 17 micrograms/liter (P less than 0.01); 153 +/- 32 vs. 334 +/- 41 IU/liter (P less than 0.01), 19 +/- 4 vs. 26 +/- 4 IU/g Hb (P less than 0.01), respectively). Plasma selenium and plasma glutathione peroxidase activity were strongly correlated with duration of dialysis. There was no correlation between plasma selenium and protein or calorie intakes. Plasma selenium was lower in patients dialyzed with highly permeable membranes (P less than 0.01). The total muscle mass, assessed by anthropometry, was lower in the patients who had the lowest plasma selenium (P less than 0.01) and plasma glutathione peroxidase activity (P less than 0.05). Interventricular septum hypertrophy, documented by echocardiography, was greater in patients with the lowest plasma selenium and plasma glutathione peroxidase activity (P less than 0.01). Twenty hemodialysis patients had oral supplementation of 500 micrograms/day of sodium selenite for three months, and then, 200 micrograms/day for the next three months. Plasma selenium increased as early as the first week and reached a plateau similar to the control levels after three weeks. Plasma glutathione peroxidase activity increased after two months but remained below controls. Erythrocyte glutathione peroxidase activity reached a higher value than controls after one month.(ABSTRACT TRUNCATED AT 250 WORDS)

[Correction of selenium deficiency in patients with renal failure undergoing hemodialysis]. / Correction du déficit en sélénium chez des insuffisants rénaux hémodialysés.

Plasma selenium levels (p Se) as well as glutathione peroxidase activity in plasma (p GPx) and in erythrocytes (e GPx) were measured in 39 haemodialysis patients. Glutathione peroxidase is a selenium-dependent enzyme which protects cells against oxidation. The mean level values obtained were significantly lower in patients than in controls: p Se: 38 +/- 14 versus 88 +/- 17 micrograms/l; p GPx: 15 +/- 32 versus 334 +/- 41 IU/l; e GPx: 19 +/- 4 versus 26 +/- 4 IU/g Hb. These values were found to correlate significantly with the duration of dialysis and with the type of membrane utilized. The total muscular mass was significantly smaller in patients with the lowest p Se or p GPx values. At echocardiography, septal hypertrophy correlated with both p Se and p GPx. Twenty patients were supplemented with sodium selenite administered orally at the end of each haemodialysis session during 6 months. After this period, muscular mass and septal hypertrophy were decreased and the echocardiographic contractility parameters were improved, albeit not significantly.