Status In Peritoneal Dialysis Patients Research Articles

Bicarbonate/lactate- and bicarbonate-buffered peritoneal dialysis fluids improve ex vivo peritoneal macrophage TNFalpha secretion.

Peritoneal macrophage (PMO) function was examined ex vivo after their in vivo exposure to either acidic, lactate-buffered solutions (PD4; 40 mM lactate, pH 5.2), bicarbonate/lactate-buffered solution (TBL; 25 mM/15 mM bicarbonate/lactate, pH 7.3), or bicarbonate-buffered solution (TB; 38 mM bicarbonate, pH 7.3), containing either 1.36 or 3.86% glucose. Initial experiments demonstrated that tumor necrosis factor-alpha (TNFalpha) release (assessed by TNF-direct immunoassay [DIA]) from PMO isolated from the peritoneal cavities of patients exposed to conventional fluid (PD4 1.36% glucose) was lowest after 30 min of intraperitoneal dwell (3591+/-1200 versus 28,946+/-9359 for 240-min dwell [pg/ml], n=5, P < 0.05). Five patients were exposed on 3 successive days to PD4, TBL, and TB for 30-min acute dwells containing 1.36% glucose in the first week and 3.86% glucose during the second. PMO TNFalpha release was assessed after ex vitro exposure to lipopolysaccharide (LPS). Exposure of PMO to TBL or TB (1.36% glucose) resulted in a significant increase in the generation of TNFalpha (pg/2 X 10(6) PMO) compared with PD4. TBL: 68,659+/-35,633, TB: 53,682+/-26,536 versus PD4 17,107+/-8996 (LPS 1.0 ng/ml, n=5 patients, P=0.043 versus PD4 for both). PMO that were recovered from PD4 and TB dwells (3.86% glucose) showed no significant difference in TNFalpha secretion (21,661+/-6934 and 23,923+/-9147, respectively). In contrast, exposure to TBL resulted in a significant increase (41,846+/-11,471) compared with PD4 (LPS 1.0 ng/ml, n=5 patients, P=0.043). These data demonstrate enhanced PMO function after in vivo exposure to bicarbonate- and bicarbonate/lactate-buffered solutions. This response was sustained in TBL alone at the highest glucose concentrations. These results suggest that the newer solutions, and particularly bicarbonate/lactate, might improve host defense status in peritoneal dialysis patients.

Comparison of five body-composition methods in peritoneal dialysis patients

Body-composition assessment is an important method of evaluating nutritional status in peritoneal dialysis patients. Because body-composition measurement estimates have not been fully validated in this population, we assessed five body-composition methods in 30 well-dialyzed peritoneal dialysis patients. The techniques studied included bioelectrical impedance analysis, dual-energy X-ray absorptiometry, total-body potassium counting, and anthropometry by two techniques. The dialysis patients were matched for age, race, sex, height, weight, and body mass index with 29 healthy control subjects in our laboratory database. By 5 x 2 x 2 analysis of variance, significant differences were found between results by modality (P < 0.0001) as well as by sex, with women having an increased percentage of fat (P < 0.0001). However, there was no significant intermethod difference by condition (peritoneal dialysis or control). That is, although significantly different percentage fat values were found between the body-composition techniques, this variability was independent of whether the measurement was made on control or peritoneal dialysis patients. Despite the differences between modalities, all techniques were found to correlate significantly with each other (P < 0.01 or better for men and P < 0.001 or better for women). Our experience shows that these routine techniques for measuring body composition can be readily applied to stable peritoneal dialysis patients.