By: D2- Gil Legarda and Joanalyn Balino
Title: CHANGES IN TOTAL SODIUM INTAKE DO NOT LEAD TO PROPORTIONATE CHANGES IN TOTAL SODIUM REMOVAL IN CAPD PATIENTS
Li-Tao Cheng and Tao Wang
Wang and Cheng conducted a follow- up observational study to elucidate the relationship between total sodium intake (TSI) and total sodium removal (TSR) in Continuous Ambulatory Peritoneal Dialysis patients. 40 Patients were included into this study; Treatment group: 15 patients for group with increase salt intake (ISI) and 9 patients for group with decrease salt intake(DSI).A total of 16 patients with stable TSI (control group). The exclusion criteria: (1) less than 3 months duration on Peritoneal Dialysis; (2) having an occurrence of peritonitis in the previous month; (3) unable to endow with detailed dietary records; (4) using sodium-containing medications like bicarbonate.All these patients included in the study received glucose- based dialysis solutions. 132 mmol/L. was the sodium concentration in dialysis solutions. Those 40 patients were closely followed for 3 months. The demographic data of 40 patients, including gender, age, height, weight, blood pressure, primary diagnoses, and duration on Peritoneal dialysis were recorded at baseline. Weight and blood pressure were also measured after the follow-up.
The group with increase sodium intake (ISI), the total sodium intake (TSI) increased 1.57 ± 0.97g/day or 68.3 ± 42.2 mmol/day from 1.42 ± 0.66 g/day or 61.7 ± 28.7 mmol/ day at baseline to 2.99 ± 0.56 g/day or 130 ± 31.7 mmol/ day at the end of the study. For the group with decrease salt intake (DSI), TSI decreased 1.54 ± 0.86 g/day or 67.0 ± 37.4 mmol/day, from 3.21 ± 0.57 g/day or 139.6 ± 24.9 mmol/day at baseline to 1.67 ± 0.23 g/day or 72.6 ± 10.0 mmol/day at the end of the study. In both groups, the changes in TSI reached statistical significance (p < 0.001). There were no significant differences in changes in sum of urinary sodium removal (USR), dialysate sodium removal (DSR), or total sodium removal (TSR) between the two groups.There was a significantly difference regarding the change in serum sodium concentration between the two groups. It was increased in group ISI and decreased in group DSI. On the other hand Urinary and dialysate sodium concentrations did not change.The changes in weight, blood pressure, number of antihypertensive medications, urine volume, ultrafiltration, and small solute removal (Kt/V and creatinine clearance) were not statistically significant between the two groups. The weights of patients in group ISI increased significantly during the follow-up (p < 0.05). The evaluation of fluid status between the 2 groups were ECW and E/T increased in group ISI and decreased in group DSI and these changes were all statistically significant (p < 0.05). There was no relationship was found between the TSI and TSR p = 0.193 and r is equal to -0.275. There were no significant changes in body weight, blood pressure, numbers of antihypertensive medications, or fluid status.
Alteration of dietary sodium intake might affect the difference in sodium concentration between blood and dialysates by slightly changing blood sodium concentration. The slight change has minimal impact on sodium removal as by dialysis in which to a large extent depends on convective transport induced by ultrafiltration. The product of ECW times serum sodium concentration increased for those who ate more salt and decreased remarkably in those who ate less salt. The study found that there is no relationship between sodium intake and residual renal sodium excretion in peritoneal dialysis patients. Patients in continuous ambulatory peritoneal dialysis changes in total sodium intake were not reflected in changes in total sodium removal through dialysate. With this result, it’s very important to cautiously measure and monitor dietary salt intake in CAPD patients.
Cheng, L. and Wang, T.. (2006). Changes in Total Sodium Intake Do Not Lead to Proportionate Changes in Total Sodium Removal in CAPD Patients.Peritoneal Dialysis International, Vol. 26, pp. 218–223. Retrieved June 26, 2009 from http://www.pdiconnect.com/cgi/reprint/26/2/218?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=salt+intake&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT
Last edited by gillegarda/joanalynbalino on Tue 07 Jul 2009, 2:14 am; edited 3 times in total