Single-pool model urea clearance index is associated with sarcopenia and nutritional status in patients undergoing maintenance hemodialysis: a cross-sectional study.

BACKGROUND: The single-pool model urea clearance index (single-pool Kt/Vurea; spKt/V) is the most commonly used method for dialysis adequacy assessment. However, only a few studies have examined the relationship between spKt/V values and parameters related to sarcopenia and nutritional status. This study aimed to evaluate whether the spKt/V is an indicator of sarcopenia and nutritional status in patients undergoing maintenance hemodialysis (MHD). METHODS: A total of 142 patients were included in this single-center, cross-sectional study. Venous blood samples were collected shortly before the hemodialysis session. The adequacy of dialysis in patients receiving MHD was assessed using spKt/V. Sarcopenia was identified according to the Asian Working Group for Sarcopenia (2019) definition. Receiver operating characteristic curve and area under the curve were used to evaluate the predictive value of spKt/V in sarcopenia. Univariate and multivariate binary logistic regression analyses were used to determine the association between spKt/V and sarcopenia and nutritional status. RESULTS: The mean spKt/V level was 1.3 ± 0.2, the prevalence of sarcopenia was 15.5% in patients on MHD. The best cutoff value of spKt/V in sarcopenia was 1.45 for both sexes, 1.33 and 1.45 for men and women, respectively (P < 0.05). The multivariate binary logistic regression shown that the spKt/V was independently positively associated with sarcopenia (OR = 122.88, 95% CI = 0.64-0.87, P = 0.002). Grouping spKt/V by the best cutoff value, when spKt/V ≥ 1.45, the OR of sarcopenia was 11.75 (95% CI = 3.16-43.67, P < 0.001). Subgroup analyses showed that when spKt/V ≥ 1.33 in men and spKt/V ≥ 1.45 in woman, the OR of sarcopenia was 9.73 (95% CI = 2.25-42.11, P = 0.002) and 14.52 (95% CI = 1.06-199.67, P = 0.045), respectively. CONCLUSIONS: The present study showed that spKt/V was an important influencing factor of sarcopenia and malnutrition in Asian patients on MHD.

Effects of overhydration, Kt/Vurea, ß2-microglobulin on coronary artery calcification and mortality in haemodialysis patients.

AIM: We studied the effects of overhydration (OH), Kt/Vurea and ß2-microglobulin (ß2-MG) on coronary artery calcification and mortality in patients undergoing haemodialysis (HD). METHODS: The Agatston coronary artery calcium score (CACS), postdialysis body composition using bioimpedance analysis, single-pool Kt/Vurea and predialysis ß2-MG at baseline were assessed and followed up for 3 years in patients undergoing HD. We performed logistic regression analyses for a CACS ≥400 and Cox proportional hazard analyses for all-cause and cardiovascular mortality. RESULTS: The study involved 338 patients with a median age of 67 (56-74) years, dialysis duration of 70 (33-141) months and diabetes prevalence of 39.1% (132/338). Patients with a CACS ≥400 (n = 222) had significantly higher age, dialysis duration, male prevalence, diabetes prevalence, C-reactive protein, predialysis ß2-MG, OH, extracellular water/total body water and overhydration/extracellular water (OH/ECW) but significantly lower Kt/Vurea than patients with a CACS <400 (n = 116) (p < .05). OH/ECW, Kt/Vurea and predialysis ß2-MG were significant predictors of a CACS ≥400 (p < .05) after adjusting for age, dialysis duration, serum phosphate and magnesium. In all patients, cut-off values of OH/ECW, Kt/Vurea and predialysis ß2-MG for a CACS ≥400 were 16%, 1.74 and 28 mg/L, respectively. After adjusting for dialysis duration, OH/ECW ≥16%, Kt/Vurea ≥1.74 and ß2-MG ≥28 mg/L were significant predictors of 3-year all-cause mortality but not 3-year cardiovascular mortality. CONCLUSION: Higher OH/ECW, higher predialysis ß2-MG and lower Kt/Vurea values are significant risk factors for a CACS ≥400 and 3-year all-cause mortality in patients undergoing maintenance HD.

Dialysis for older adults: why should the targets be different?

The number of patients aged > 75-years treated by dialysis continues to increase, particularly in developed countries. Haemodialysis is a well-established treatment with national and international clinical guidelines designed to provide patients with optimal treatment. However, these were developed when the dialysis population was younger, and less co-morbid. This change in patient demographics questions whether these guideline targets still apply to older patients. More patients now start dialysis with residual kidney function and could benefit from a less frequent dialysis schedule. Older patients have a lower thirst drive, so lower interdialytic gains, reduced appetite, muscle mass and physical activity would potentially allow starting dialysis with less frequent sessions a practical option. Similarly, patients with residual kidney function and lower metabolic activity may not need to meet current dialyser Kt/Vurea clearance targets to remain healthy. Instead, some elderly patients may be at risk of malnutrition and might need liberalisation of the low salt, potassium and phosphate dietary restrictions, or even additional supplements to ensure adequate protein intake. Although a fistula is the preferred vascular access, a forearm fistula may not be an option due to vascular disease, while a brachial fistula can potentially compromise cardiovascular reserve, so a dialysis catheter becomes the de facto access, especially in patients with limited life expectancy. Thus, clinical guideline targets designed for a younger less co-morbid dialysis population may not be equally applicable to the older patient initiating dialysis, and so a more individualised approach to dialysis prescription and vascular access is required.

Glucose absorption from peritoneal dialysate is associated with a gain in fat mass and a reduction in lean body mass in prevalent peritoneal dialysis patients.

The majority of peritoneal dialysates use glucose to generate an osmotic gradient for the convective removal of water and Na. Although glucose can potentially be absorbed, previous studies have failed to establish whether this leads to increased fat weight gain. We measured body composition using bioimpedance in peritoneal dialysis (PD) patients, electively starting PD, attending for their first assessment of peritoneal membrane function after 2-3 months, and then after 12 months. We studied 143 patients: eighty-nine (62·2 %) males, fifty-three (37·1 %) diabetics, mean age 61·3 (SD 14·9) years, with ninety (62·1 %) patients treated by automated PD cyclers with a daytime icodextrin exchange and thirty-seven (25·9 %) by continuous ambulatory PD. Median fat mass increased by 1·8 (-0·5 to 4·1) kg, whereas fat-free mass fell -1·3 (-2·9 to 1·0) kg, and the increase in fat mass was negatively associated with the fall in soft lean mass (r -0·41, P < 0·001). Increased fat mass was associated with measured peritoneal glucose absorption (r 0·69, P < 0·001), and glucose absorption was associated with the amount of 22·7 g/l glucose dialysate (OR 2·0, 95 % CI 1·5, 2·5, P < 0·001), peritoneal urea clearance (OR 9·5, 95 % CI 2·4, 37·1, P = 0·001) and male sex (OR 4·8, 95 % CI 1·5, 14·9, P = 0·008). We report an observational study in prevalent PD patients following body composition from their first assessment of PD membrane function for approximately 12 months, and despite the majority of patients prescribed icodextrin, we have demonstrated not only an association between intra-peritoneal glucose absorption and fat weight gain but also loss of fat-free mass.

Association of B-Type Natriuretic Peptide Level With Residual Kidney Function in Incident Peritoneal Dialysis Patients.

BACKGROUND: Residual kidney function (RKF) is an important factor influencing both technique and patient survival in peritoneal dialysis (PD) patients. B-type natriuretic peptide (BNP) is considered a marker of cardio-renal syndrome. The relationship between BNP and RKF in PD patients remains unclear. METHODS: We conducted a prospective study of 89 patients who had started and continued PD for 6 months or more in Kyushu University Hospital between June 2006 and September 2015. Participants were divided into low BNP (≤ 102.1 ng/L) and high BNP (> 102.1 ng/L) groups according to median plasma BNP level at PD initiation. The primary outcome was RKF loss, defined as 24-hour urine volume less than 100 mL. We estimated the association between BNP and RKF loss using a Kaplan-Meier method and Cox proportional hazards model and compared the rate of RKF decline between the 2 groups. To evaluate the consistency of the association, we performed subgroup analysis stratified by baseline characteristics. RESULTS: During the median follow-up of 30 months, 30 patients lost RKF. Participants in the high BNP group had a 5.87-fold increased risk for RKF loss compared with the low BNP group after adjustment for clinical and cardiac parameters. A high plasma BNP level was more clearly associated with RKF loss in younger participants compared with older participants in subgroup analysis. CONCLUSIONS: B-type natriuretic peptide may be a useful risk marker for RKF loss in PD patients. The clinical importance of plasma BNP level as a marker of RKF loss might be affected by age.

Solute Clearance and Fluid Removal: Large-Dose Cyclic Tidal Peritoneal Dialysis.

Large-dose cyclic tidal peritoneal dialysis (TPD) is an original prescription of TPD involving frequent infusion and drainage of the dialysate to increase weekly urea clearance normalized to total body water (Kt/Vurea ) and fluid removal. This study aimed to evaluate the efficiency of solute clearance and fluid removal achieved with large-dose cyclic TPD compared to that achieved with nightly peritoneal dialysis (NPD). Seventeen patients with end-stage renal disease, for whom maintenance PD was changed from NPD to large-dose cyclic TPD, were enrolled. Their median age at administration of PD was 4.9 years. Kt/Vurea and fluid removal were compared between large-dose cyclic TPD and NPD. The median peritoneal Kt/Vurea achieved with NPD and large-dose cyclic TPD was 1.5 and 2.7, respectively. The median peritoneal Kt/Vurea per hour with large-dose cyclic TPD was significantly higher than that with NPD (P = 0.0003). Among nine patients who used dialysates with the same glucose concentration for both NPD and large-dose cyclic TPD, nightly fluid removal amount per hour with large-dose cyclic TPD was significantly higher than that with NPD (P = 0.0039). Large-dose cyclic TPD is a useful prescription of PD for increasing Kt/Vurea and fluid removal.

Moving beyond small solute clearance: What evidence is there for more permeable dialyzers and haemodiafiltration?

Dialyzers were initially developed for diffusive clearance of uraemic toxins. Diffusion most effectively clears small uncharged solutes from plasma water, such as urea. Sessional urea clearance targets have been shown to be important for short-term patient survival, but over the longer term, although low-flux dialysis can prolong patient survival, accumulation of middle-sized uraemic toxins, such as ß2 microglobulin can lead to disabling arthropathy. Although the introduction of high-flux dialyzers, designed to increase ß2 microglobulin clearance, has reduced the prevalence of arthropathy; this has not been translated into a demonstrable significant improvement in patient survival. However, analysis of individual patients recruited into trials of haemo-diafiltration reported that greater convective clearance was associated with better survival, although the individual trials reported mixed outcomes. Most haemodiafiltration trials were not designed to study the effect of convective dose, so although reported patient survival was greater for those receiving greater convective volume exchange, these results could potentially be confounded by patient or center effects. An alternative approach to increasing middle-sized solute clearances would be to use more permeable dialyzers, but as yet there are no trials reporting survival with larger cutoff dialyzers. As such, although there is increasing evidence that increasing middle-sized molecular uraemic solute clearance is associated with improved patient survival, further prospective trials are required to determine whether as with Kt/Vurea there is a threshold effect of how much convective or middle-sized solute clearance is required to improve patient survival.

Comparison of resting energy equations and total energy expenditure in haemodialysis patients and body composition measured by multi-frequency bioimpedance.

AIM: Waste products of metabolism are retained in haemodialysis (HD) patients. Cellular metabolism generates energy, and patients with greater energy expenditure may therefore require more dialysis. The aim of the present study was to determine the amount of dialysis required, to determine equations estimating the required resting and total energy expenditure (REE, TEE). METHODS: Estimates of REE in HD patients were compared using established equations with a novel equation recently validated in HD patients (HD equation). TEE was derived from REE (HD equation) and estimates of physical activity obtained by questionnaire. REE and TEE relationships with bioimpedance measured body composition were then determined. RESULTS: A total of 317 HD patients were studied: 195 males (61.5%), 123 diabetic (38.9%), mean age 65.0 ± 15.3 and weight 73.1 ± 16.8 kg. REE from HD Equation was 1509 ± 241 kcal/day, which was greater than for Mifflin St Joer 1384 ± 259, Harris-Benedict 1437 ± 244, Katch-McArdle 1345 ± 232 (all P < 0.05 vs. HD Equation), but less than Cunningham 1557 ± 236 kcal/day. Bland-Altman mean bias ranged from -263 to 55 kcal/day. TEE was 1727 (1558-1976) kcal/day, and on multi-variable analysis was positively associated with skeletal muscle mass (ß 23.3, P < 0.001), employment (ß 406.5, P < 0.001), low co-morbidity (ß 105.1, P = 0.006), and protein nitrogen appearance (ß 2.7, P = 0.015), and negatively with age (ß -7.9, P < 0.001), and dialysis vintage (ß -121.2, P = 0.002). CONCLUSIONS: Most standard equations underestimate REE in HD patients compared to the HD Equation. TEE was greater in those with higher skeletal muscle mass and protein nitrogen appearance, lower co-morbidity, age, and dialysis vintage, and the employed. More metabolically active patients may require greater dialytic clearances.

Comparison of equations of resting and total energy expenditure in peritoneal dialysis patients using body composition measurements determined by multi-frequency bioimpedance.

BACKGROUND & AIMS: Waste products of metabolism accumulate in patients with kidney failure and it has been proposed that the amount of dialysis treatment patients require be adjusted for energy expenditure. This requires validation of methods to estimate energy expenditure in dialysis patients. METHODS: We compared values of resting energy expenditure (REE) estimated in peritoneal dialysis (PD) patients using a selection of available equations with estimates derived using a novel equation recently validated in chronic kidney disease patients (CKD equation). We also determined the relationship of these estimates of REE and of total energy expenditure (TEE - which is REE plus physical activity associated energy expenditure (PAEE) estimated using the Recent Physical Activity Questionnaire) - to bioimpedance-derived parameters of body composition. RESULTS: We studied 118 adult PD patients; 75 male (63.6%), 33 diabetic (28.5%), Caucasoid (42.4%), mean age 59.3 ± 18.2 years and weight 73.1 ± 16.6 kg. REE with the CKD equation was 1532 ± 237 kcal/day, which was more than that for Mifflin-St. Joer 1425 ± 254, Harris-Benedict 1489 ± 267, Katch-McArdle 1492 ± 243, but less than Cunningham 1648 ± 248 kcal/day. Bland Altman mean bias ranged from -107 to 111 kcal/day. TEE was 1924 (1700-2262) kcal/day, and on multi-variate analysis was associated with appendicular muscle mass and nitrogen appearance rate (ß 34.3, p < 0.001 and ß 5.6, p = 0.002, respectively). CONCLUSION: With reference to the CKD equation, the majority of standard equations underestimate REE in PD patients. Whereas the Cunningham equation overestimates REE. TEE was associated with appendicular muscle mass and estimated dietary protein intake.

A single weekly Kt/Vurea target for peritoneal dialysis patients does not provide an equal dialysis dose for all.

Dialysis adequacy is traditionally based on urea clearance, adjusted for total body volume (Kt/Vurea), and clinical guidelines recommend a Kt/Vurea target for peritoneal dialysis. We wished to determine whether adjusting dialysis dose by resting and total energy expenditure would alter the delivered dialysis dose. The resting and total energy expenditures were determined by equations based on doubly labeled isotopic water studies and adjusted Kturea for resting energy expenditure and total energy expenditure in 148 peritoneal dialysis patients (mean age, 60.6 years; 97 male [65.5%]; 54 diabetic [36.5%]). The mean resting energy expenditure was 1534 kcal/d, and the total energy expenditure was 1974 kcal/day. Using a weekly target Kt/V of 1.7, Kt was calculated using V measured by bioimpedance and the significantly associated (r = 0.67) Watson equation for total body water. Adjusting Kt for resting energy expenditure showed a reduced delivered dialysis dose (ml/kcal per day) for women versus men (5.5 vs. 6.2), age under versus over 65 years (5.6 vs. 6.4), weight <65 versus >80 kg (5.8 vs. 6.1), low versus high comorbidity (5.9 vs. 6.2), all of which were significant. Adjusting for the total energy expenditure showed significantly reduced dosing for those employed versus not employed (4.3 vs. 4.8), a low versus high frailty score (4.5 vs. 5.0) and nondiabetic versus diabetic (4.6 vs. 4.9). Thus, the current paradigm for a single target Kt/Vurea for all peritoneal dialysis patients does not take into account energy expenditure and metabolic rate and may lead to lowered dialysis delivery for the younger, more active female patient.

KP Index at the Initiation of Dialysis for Patients with End-stage Renal Disease

BACKGROUND: The time at which renal replacement therapy (RRT) is initiated in patients with end-stage renal disease (ESRD) has a great influence on the prognosis of the patient; however, there are currently no accurate guidelines for the initiation of RRT. Traditionally, nephrologists usually initiate RRT on the basis of the observation of the uremic symptoms and changes in the laboratory parameters, such as the serum creatinine concentration and/or glomerular filtration rate (GFR). DOQI guidelines suggest a weekly Kt/Vurea 2.0 and KP index 2.0 group, while there were no significant differences between the groups in the serum albumin concentration, serum creatinine concentration, FFEFBM and RRF. Also, there was a statistically significant higher rate of incidence of patients starting RRT in the KP index 2.0 group. There was a significant correlation between the KP and other indices in all patients. When comparing the number of patients starting RRT, the weekly Kt/Vurea index demonstrated no significant differences between the 1.5 < weekly Kt/Vurea < 2.0 and 2.0 < weekly Kt/Vurea < 2.5 groups, but the number of patients starting RRT in the 1.5 < KP index < 2.0 group was significantly higher than that in the 2.0 < KP index < 2.5 group. CONCLUSION: The KP index is considered a clinically useful index in ESRD patients for determining an appropriate time for the initiation of RRT. Also, the timing of the initiation of RRT should be fixed with regard to the various other indices and clinical features for a desirable prognosis of the patients. In addition, further studies will be required to determine accurate guidelines for an appropriate time for RRT initiation.

KP index at the timing of initiation of dialysis for patients with end-stage renal disease / 대한내과학회지

BACKGROUND: An initiating time of renal replacement therapy (RRT) for patients with end-stage renal disease (ESRD) has great influence on prognosis of the patients, however, there are currently no accurate guidelines for initiation of renal replacement therapy. Traditionally, nephrologists usually initiate RRT on the basis of observation of uremic symptoms and changes of laboratory parameters, such as serum creatinine concentration and/or glomerular filtration rate (GFR). DOQI guidelines suggest weekly Kt/Vurea 2.0 and KP index 2.0, while no significant differences between the groups were in serum albumin concentration, serum creatinine concentration, FFEFBM and RRF. And the frequency of patients starting RRT was significantly higher in the group of KP index 2.0 in statistics. There was a significant correlation between KP index and other indices in all patients. In comparing and analyzing the number of patients starting RRT, weekly Kt/Vurea index did not demonstrate significant differences between two groups of 1.5 < weekly Kt/Vurea < 2.0 and 2.0 < weekly Kt/Vurea < 2.5, but the frequency of patients in the group of 1.5 < KP index < 2.0 was significantly higher than that in the group of 2.0 < KP index < 2.5. CONCLUSION: It is considered that KP index is an index clinically useful for ESRD patients to determine an appropriate timing for the initiation of RRT, and that the timing should be fixed with regard for other various indices and clinical features for advisable prognosis of the patients. In addition, accurate guideline to determine such an appropriate time needs to be suggested by further new studies.

Daily Dialysis and Flexible Schedules: How to Assess Kt/V and EKRc ?

Despite the growing interest in daily hemodialysis (DHD), logistic and economic factors limit its dissemination. Not the least of these factors is the lack of uniform criteria for measuring efficiency. From November 1998 to November 2000, 19 patients were on DHD in our unit. The dialysis prescription was bicarbonate buffer; 6 sessions per week; 2 - 3 hours; blood flow 250 - 350 mL/min; individual K, HCO3 , and Na levels; membrane 1.6 - 2 m2 (polysulfone, polycarbonate). The prescription represented the minimum dialysis requirement; patients were free to add up to 30 minutes per session, further increase or any decreases needed confirmation by the caregivers. The aim of the study was to assess Kt/Vurea variability in this clinical setting, and to identify the minimum number of dialysis sessions required to obtain a reliable estimate of weekly Kt/Vurea [relative error (RE) < 10%]. We studied 169 dialysis sessions in 13 clinically stable patients on DHD for ≥ 3 months, with ≥ 3 Kt/Vurea measurements within 2 weeks (median: 10; range: 3 - 32 sessions), tested in the same laboratory. To assess variability, we employed the simplest formula (the Lowrie Kt/Vurea ), the widely used Daugirdas II formula, and the derived single-pool equivalent renal clearance (EKRc ), according to Casino. The variability of Kt/Vurea per session was high (Lowrie: RE = 2.5% - 22.1%; Daugirdas II and EKRc : RE = 3.6% - 24%). Averaging several dialysis sessions leads to a more reliable estimate of weekly efficiency (6 sessions: RE = 0; 3 sessions, Lowrie formula: Kt/Vurea RE = 1.1% - 9.7%; Daugirdas II and EKRc : RE = 1.6% - 10.6%). In patients with wide time variations, variability may be lower if weekly efficiency is determined on the basis of "average hourly Kt/Vurea ," which is calculated by dividing Kt/Vurea by the number of hours in the studied sessions, and then multiplying by the hours of dialysis performed in the whole week (Lowrie formula, Kt/Vurea : RE = 4.8% - 16.6% for 1 session, 2.1% - 7.3% for 3 sessions). Once again, the RE decreases sharply when data from 3 sessions are considered. Therefore, for flexible DHD, we suggest averaging the data from ≥ 3 sessions for weekly Kt/Vurea assessment.

The Clinical Impact of Increasing the Hemodialysis Dose.

Good evidence suggests that improvements in dialysis efficiency reduce morbidity and mortality of hemodialysis (HD) patients. Dialysis efficiency has also been related to better control of arterial blood pressure (BP), anemia, and serum phosphorus levels, and to improvement in patients' nutritional status. Over a 2-year period, the present self-controlled study of 34 HD patients (23 men, 11 women; age, 52.6 ± 14.5 years; HD duration, 55.9 ± 61.2 months) looked at the effect on clinical and laboratory parameters of increasing the delivered dialysis dose under a strict dry-weight policy. Dialysis dose was increased without increasing dialysis time and frequency. A statistically significant increase was seen in delivered HD dose: the urea reduction ratio (URR) increased to 60% ± 10% from 52% ± 8%, and then to 71% ± 7% (p < 0.001); Kt/Vurea increased to 1.22 ± 0.28 from 0.93 ± 0.19, and then to 1.55 ± 0.29 (p < 0.001). A statistically significant increase in hemoglobin concentration also occurred-to 10.8 ± 1.9 g/dL from 10.4 ± 1.7 g/dL, and then to 11.0 ± 1.3 g/dL (p < 0.05 as compared to baseline)-with no significant difference in weekly erythropoietin dose. Statistically significant decreases occurred in the systolic and diastolic blood pressures during the first year; they then remained unchanged. Systolic blood pressure decreased to 131 ± 23 mmHg from 147 ± 24 mmHg (p < 0.001); diastolic blood pressure decreased to 65 ± 11 mmHg from 73 ± 12 mmHg (p < 0.001). Serum albumin increased insignificantly to 4.4 ± 0.4 g/dL from 4.3 ± 0.4 g/dL, and then significantly to 4.6 ± 0.3 g/dL (p = 0.002 as compared to both previous values). Normalized protein catabolic rate increased significantly to 1.16 ± 0.15 g/kg/day from 0.93 ± 0.16 g/kg/ day (p < 0.001), and then to 1.20 ± 0.17 g/kg/day (p < 0.001 as compared to baseline). We conclude that the increases achieved in average Kt/Vurea per hemodialysis session by increasing dialyzer membrane area, and blood and dialysate flows, without increasing dialysis time above 4 hours, in patients hemodialyzed thrice weekly, coupled with strict dry-weight policy, resulted in improvements in hypertension, nutritional status, and anemia.

Dialysis Adequacy and Nutritional Status in Patients with Continuous Ambulatory Peritoneal Dialysis(CAPD) / 대한신장학회잡지

PURPOSE: Malnutrition is common in CAPD patients and depends on many factors such as dialysis-related and nondialysis-related factors. The present study aimed to assess nutritional status, dialysis adequacy and their relationships with overall mortality and morbidity. METHODS: We studied 102 patients who had been receiving CAPD for at least 6 months. Dialysis adequacy was assessed by parameters derived from urea kinetic modeling(UKM) and nutritional status was assessed by serum biochemical measurement, normalized protein catabolic rate(nPCR), normalized protein equvalent of total nitrogen appearance(nPNA) and urea kinetic studies. Spearman's simple correlation and multiple linear stepwise regression analysis were used to assess correlation between dialysis adequacy and nutritional status in CAPD patients. We compared the differences between patients who suf fered morbid events, defined as either an infectious complication or hospitalization, and patients who remained well. RESULTS: The results showed that the total dialysis dose(total weekly Kt/Vurea) has statistically significant correlation with nPCR(r=0.234, p=0.028), nPNA (r=0.246, p=0.021), total weekly creatinine clearance (WCC)(r=0.479, p=0.0001), serum albumin levels(r= 0.233, p=0.029), serum cholesterol(r=0.266, p=0.013), serum BUN(r=-0.290, p=0.006) and serum creatinine levels(r=-0.408, p=0.0001). nPNA was positively correlated with serum cholesterol(r=0.217, p=0.045), serum transferrin(r=0.218, p=0.042) and serum ferritin levels(r=0.220, p=0.043). Patients who suffered morbid events had an old age(p=0.001), long duration of CAPD(p=0.0001), higher CRP(p=0.021), lower serum albumin level(p=0.020), lower hematocrit(p=0.049) and lower WCC(p=0.017). Conclusions : These results indicate that adequate dialysis is very important for the maintenance of adequant nutrition because nutritional status positively correlated with dialysis dose, which is best assessed by UKM. In addition, assessment of nutritional status and dialysis adequacy are important in predicting clinical outcomes in CAPD patients.

The Effect of Declining Small Solute Clearance on Protein Intake and Nutritional Status in Progressive Renal Failure / 대한신장학회잡지

BACKGROUNDS: Malnutrition is common in patients with chronic renal failure(CRF) and various signs of malnutrition are strong predictors of increased morbidity and mortality. Monitoring of protein intake and nutritional status is therefore important in the clinical management of CRF patients. Few studies have demonstrated direct correlations among renal function, protein intake, and nutritional status in a prospective study although clinical experiences suggest such relationship. The aim of this study was to prospectively evaluate correlations between renal function, protein intake, and nutritional status during progressive renal failure. METHODS: A total of 431 studies on renal function, protein intake, and nutritional status was carried out in 282 patients with normal renal function and varying degrees of renal failure before beginning dialysis. Renal functional indices included weekly Kt/Vurea, total weekly creatinine clearance(Ccr, L/week/1.73m2), creatinine clearance(Ccr, mL/min/1.73m2), urea clearance(Curea, mL/min) and residual renal function(RRF, mL/min). Protein intake was assessed from the protein equivalent of total nitrogen appearance normalized by standard weight(nPNA, g/kg/day) by DOQI formula[nPNA(D)], Bergstr m formula 1[nPNA(B1)] and Bergstr m formula 2[nPNA(B2)]. Nutritional indices were fat free edema free body mass(FFEFBM, kg) by creatinine kinetics, %lean body mass(LBM, %) and serum albumin(g/dL). We evaluated correlations between renal function, protein intake and nutritional status by linear regression analysis. In a separate analysis, 237 studies from 94 patients with follow-up studies were analyzed for correlations among renal function, protein intake, and nutritional status. RESULTS: There was a highly significant correlation among weekly Kt/Vurea, weekly creatinine clearance, and residual renal function, among nPNA(D), nPNA (B1), nPNA(B2), and between FFEFBM and %LBM. Significant correlation was also observed between weekly Kt/Vurea and nPNA, between weekly Kt/ Vurea and FFEFBM, between weekly Kt/Vurea and %LBM, between nPNA and FFEFBM, and between nPNA and %LBM. The results were the same in patients with follow-up studies. CONCLUSION: These results clearly demonstrate that renal urea and creatinine clearance is closely correlated with protein intake and nutritional status in predialysis patients. With declining small solute clearances, protein intake decreased and nutritional status became worse. Starting dialysis before malnutrition becomes apparent may improve patient morbidity and mortality after dialysis.

Effects of Postdialysis Urea Rebound on Dialysis Adequacy in Hemodialysis Patients / 대한신장학회잡지

Urea reduction ratio (URR) and Kt/Vurea are objective parameters of dialysis delivery in hemodialysis patients and correlate with nutritional status and patient outcome. URR and Kt/Vurea depend on postdialysis blood urea nitrogen (BUN). In patients with severe postdialysis urea rebound (PDUR), these parameters do not accurately reflect dialysis adequacy. We measured PDUR 30 minutes after dialysis in 26 chronic stable hemodialysis patients. The impact of PDUR on dialysis delivery assessed by URR and Kt/Vurea and the independent factors affecting on PDUR were evaluated. All patients had been dialyzed for 4 hours thrice a week using hemophan membrane. 1) The mean age of patients was 48.6+/-14.8 years and sex ratio was 1:2.3. The mean duration of hemodialysis was 42.7+/-45.0 months. Primary renal diseases were chronic glomerulonephritis 11 (42.3%), diabetic nephropathy 7 (26.9%), and hypertension 4 (15.4%). 2) The mean blood flow was 209.2+/-17.4ml/min. URR, Kt/Vurea, and nPCR using immediate postdialysis BUN were 60+/-7%, 1.13+/-0.21, 1.09+/-0.28g/kg/ day, respectively. The mean recirculation rate was 4.4+/-2.3%. 3)The mean PDUR was 12.2+/-4.6% (range:6-22 %). URR, Kt/Vurea, and nPCR using BUN 30 minutes after dialysis were 55+/-7%, 0.99+/-0.18, and 1.02+/-0.25 g/kg/day, respectively and were significantly lower than those using immediate postdialysis BUN (P or = 12%), high PDUR group was significantly higher than low PDUR group in hematocrit (27.0+/-2.6 vs. 23.5+/-3.6%, P=0.008), URR (64.3+/-5.4 vs. 55.8+/-6.8%, P=0.002), Kt/Vurea (1.26+/-0.17 vs. 1.03+/-0.18, P=0.002), and total recirculation rate (5.6+/-2.7 vs. 3.6+/-1.7%, P=0.05). There were no differences in age, sex, postdialysis body weight, ultrafiltration rate, blood flow, serum albumin, predialysis BUN, creatinine, and nPCR. 5) In multiple regression analysis, the independent factors affecting on PDUR were Kt/Vurea (beta=0.546, P<0.001), recirculation rate (beta=0.422, P<0.001), and hematocrit (beta=0.366, P=0.0017). In conclusion, we think that PDUR should be considered in hemodialysis patients when estimating dialysis delivery, especially if they had high Kt/ Vurea, recirculation rate, and hematocrit.