Long-term blood pressure control in a cohort of peritoneal dialysis patients and its association with residual renal function.

BACKGROUND: Hypertension is the prime contributor for cardiovascular mortality in the dialysis population. Peritoneal dialysis (PD) has been thought to improve blood pressure (BP) control in the short term, but the long-term benefits are not conclusively proven. We aimed to evaluate the degree of BP control in PD patients in the long term and analyse the factors associated with poor control. METHODS: Data of all patients who were initiated on PD at one centre between July 1994 and July 1998 and completed at least 1 year of PD were analysed retrospectively at initiation of PD, at 6 months, and annually thereafter until 5 years or until discontinuation of therapy. Hypertension was defined as per WHO/ISH criteria. A 'Blood Pressure Control Index' was empirically defined to account for the effect of antihypertensives on measured BP. Factors associated with poor BP control were analysed. RESULTS: Out of 207 patients (age 57.0+/-16.0 years, 103 male, 104 female) 91.3% were hypertensive at the start of PD. About 33.8% had diabetic nephropathy. Systolic and mean arterial pressure index improved in early phase reaching a nadir between 6 months and 1 year followed by steady progressive worsening through out the rest of follow up. On multiple linear regression analysis age (P<0.001), duration of hypertension prior to dialysis (P<0.001), and declining residual renal function, expressed as both average of urea and creatinine clearance (P=0.002) and residual urine output (P<0.001) were independently associated with poor BP control. Diabetes (P=0.836), peritoneal transport (D/P 4 of creatinine at start) (P=0.218), peripheral oedema (P=0.479) and dose of erythropoetin (P=0.488) were not associated. CONCLUSIONS: Initiation of PD results in early improvement of hypertension in end-stage renal disease (ESRD). BP control thereafter deteriorates steadily with time and this is associated with age, duration of hypertension, and declining residual renal function. This suggests that hypertension in ESRD patients is a progressive disease primarily related to falling glomerular filtration rate, the preservation of which might improve BP control and possibly modify cardiovascular risk.     

Efficacy of Roxadustat on anemia and residual renal function in patients new to peritoneal dialysis

BackgroundBoth early correction of anemia and preserving residual renal function (RRF) are reported to improve patient survival. The aim of this study was to explore the efficacy and safety of Roxadustat for treatment of renal anemia in patients new to peritoneal dialysis (PD) and to assess its impact on RRF.MethodsA retrospective analysis was performed on 60 initial peritoneal dialysis (PD) patients with renal anemia. Twenty-eight cases were treated with Roxadustat (Roxadustat group) and 32 with recombinant human erythropoietin (control group). Clinical characteristics, hemoglobin (Hb), C-reactive protein, blood lipids, iron metabolism, dialysis adequacy and RRF of the two groups were evaluated and adverse events were recorded. All patients were followed up for at least 40 weeks.ResultsAfter 40 weeks of treatment, mean Hb levels were significantly higher from baseline values in both groups, the mean Hb change in Roxadustat group was higher than control group (3.46 ± 1.59 g/dL vs. 2.28 ± 2.27 g/dL, p < 0.05). At 40 weeks, 92.9% patients met the target level of Hb in Roxadustat group and 84.4% in control group. Total iron binding was higher and ferritin was lower in Roxadustat group from baseline values and Roxadustat-induced Hb increases were independent of baseline C-reactive protein levels and history of rhuEPO administration. RRF decreased over time in both groups, the mean RRF change was lower in Roxadustat group than control group (1.15 ± 1.66 mL/min/1.73 m² vs. 2.31 ± 1.46 mL/min/1.73 m², p < 0.01). Compared with control group, patients in Roxadustat group had higher levels of total iron binding, 24 h urine volume, total weekly Ccr, and lower systolic pressure, ferritin, C-reactive protein, total cholesterol, LDL. No serious adverse reactions occurred in either group.ConclusionIn patients new to PD, Roxadustat effectively and safely improved renal anemia and delay the decline of RRF.     

C-reactive protein and chronic Chlamydia pneumoniae infection--long-term predictors for cardiovascular disease and survival in patients on peritoneal dialysis.

BACKGROUND: Accelerated arteriosclerosis with cardiovascular disease is the main cause of death in end-stage renal disease patients. Increased, levels of C-reactive protein (CRP) and evidence of chronic Chlamydia pneumoniae infection have been identified as risk factors for cardiovascular disease in the general population. We tested the hypothesis that elevation of CRP, indicating chronic inflammation, and positive serum antibody titres for C. pneumoniae are associated with an increased cardiovascular mortality in patients on chronic peritoneal dialysis. METHODS: We measured CRP and antibodies to C. pneumoniae in 34 patients on peritoneal dialysis. CRP was measured by a sensitive ELISA and C. pneumoniae antibodies by microimmunofluorescence. In addition, risk factors such as lipids, smoking status and hypertension were assessed. Coronary artery disease (CAD) was defined by cardiac stress testing and/or angiography. Patients showing clinical evidence of systemic or peritoneal dialysis-associated infection during the investigation period of 6 months (between 1990 and 1991) were excluded. RESULTS: The incidence of CAD was significantly increased in patients with CRP values >1.5 mg/l (odds ratio 7.0, P<0.022) during 72 months of follow-up. In addition, in patients seropositive for IgA C. pneumoniae antibodies, the incidence of CAD was significantly increased (odds ratio 7.2, P<0.014). These findings resulted in an increased risk of death in patients with mean CRP values >1.5 mg/l at the start of the study (odds ratio 20.0, P<0.001). Furthermore, in patients seropositive for IgA C. pneumoniae antibodies, the risk of death (odds ratio 10.2, P<0.005) was significantly increased. There was a highly significant correlation between CRP and seropositivity for IgA C. pneumoniae antibodies (r=0.445, P<0.01). CONCLUSIONS: Increased circulating CRP and seropositivity for C. pneumoniae in patients on chronic peritoneal dialysis are associated with reduced survival due to cardiovascular complications. CRP and C. pneumoniae antibodies may indicate a chronic inflammatory process as an underlying cause and/or result of arteriosclerosis.     

The association between BP and mortality in patients on chronic peritoneal dialysis.

BACKGROUND: The relationship between blood pressure (BP) and mortality in haemodialysis patients is unconventional. It is not clear if this is the consequence of uraemia or related to the dialysis type. The goal of this project was to identify the relationship between BP and mortality in patients on chronic peritoneal dialysis (PD). METHODS: Patients on PD (n = 1053) from the USRDS prospective DMMS Wave 2 study were analysed. Primary outcomes were all-cause and cardiovascular mortality and duration of hospitalization. RESULTS: Low systolic BP categories, <100 mmHg [hazard ratio (HR), 2.71, P<0.001; and HR 3.83, P<0.001, respectively] and 101-110 mmHg (HR 1.85, P<0.05; and HR 2.92, P<0.005, respectively), but not high systolic BP, increased the risk of all-cause and cardiovascular mortality, with systolic BP 111-120 mmHg as the reference. Pulse BP, but not diastolic BP, followed a similar trend. In subgroup analysis, this association was demonstrated only in patients with a history of heart failure, in patients with diabetes and in those treated with antihypertensive medications. CONCLUSION: Systolic BP <111 mmHg in PD patients is associated with higher mortality risk, while systolic BP >120 mmHg is associated with fewer hospital days. Aggressive treatment of hypertension in the PD population should be cautioned.     

Relation of ankle-brachial index to the rate of decline of residual renal function in peritoneal dialysis patients

Aim: The aim of this study was to determine whether ankle‐brachial index (ABI) predicts the rate of decline of residual renal function (RRF) in peritoneal dialysis (PD) patients. Previous studies demonstrated the importance of loss of RRF in predicting all‐cause risk and cardiovascular mortality in PD patients. It is also known that patients with a low ABI value have a greater risk for deteriorating renal function in the general population. The relationship between ABI and the declining rate of RRF in PD patients with an additional dialysis‐specific risk factor is uncertain. Methods: Seventy‐four PD patients with RRF of more than 1 mL/min per 1.73 m² were analyzed. ABI was used as the surrogate measure of pre‐existing cardiovascular disease and atherosclerosis burden to further determine the outcome of RRF in this study. The slope of decline of RRF was used to determine the outcome. Results: Based on the multivariate analysis, only ABI (P < 0.001), diabetes (P = 0.02) and baseline RRF (P = 0.009) independently predicted a faster decline in RRF. A stepwise multiple linear regression analysis demonstrated that ABI was an independent predictor for the slope of decline of RRF (P < 0.001). Conclusion: A low ABI is an independent predictor of not only the known atherosclerotic events, but also of the rate of decline of RRF over time in PD patients.     

Effect of peritoneal dialysis on renal morphology and function.

BACKGROUND: Results of clinical studies suggest that peritoneal dialysis (PD) is less harmful to the residual renal function than haemodialysis. However, we have no objective data describing the potential injuring effect of PD to kidney. We studied in rats after unilateral nephrectomy changes in renal structure and function after 12 weeks exposure to standard, glucose-based PD fluid. METHODS: One month after removing one kidney PD catheters were implanted in rats and during the following 12 weeks, twice a day, animals were infused with 20 ml of 3.9% glucose dialysis fluid containing high concentration of glucose degradation products. Rats not infused with the dialysis fluid served as control (CON). At the beginning and after 12 weeks of the study renal creatinine clearance, urinary excretion of albumin, N-acetyl-beta-glucosaminidase (NAG) and cytokines were measured. Concentration of malondialdehyde (MDA), advanced glycation end products (AGEs) and monocyte chemoattractant protein-1 (MCP-1) were measured in serum samples. Morphology of the kidneys was evaluated in the light microscope. RESULTS: After 12 weeks exposure to the dialysis fluid serum MDA, AGEs and MCP levels were increased as compared with CON by 80%, P < 0.002, 29%, P < 0.05 and 71%, P < 0.005, respectively. Renal clearance of creatinine was comparable in both groups, but urinary excretion of albumin was increased by 55% in control group and by 160% in the studied group, P < 0.001; whereas urinary excretion of NAG was not changed in control group but increased by 125% in the studied group, P < 0.01. Increase of the remnant kidney's weight was higher (+77%, P < 0.01) in the CON group, but accumulation of the extramesangial matrix in glomeruli and collagen in the peritubular space was stronger in the studied group by 69%, P < 0.0001 and 274%, P < 0.0001, respectively. CONCLUSION: Chronic exposure of rats to the glucose-based dialysis fluid causes morphological changes in the renal glomeruli similar to diabetic nephropathy. Albuminuria increases what may accelerate progression of the kidney damage.     

Association between residual renal function, inflammation and patient survival in new peritoneal dialysis patients.

BACKGROUND: The recent ADEMEX study (Paniagua R, Amato D, Vonesh E et al. J Am Soc Nephrol 2002; 13: 1307-1320) indicates that peritoneal small solute clearance is not as critical for the survival of peritoneal dialysis (PD) patients as thought previously. On the other hand, low residual renal function (RRF), inflammation and an increased peritoneal transport rate (PTR) as evaluated by the peritoneal equilibration test (PET) are reported to be associated with increased mortality in PD patients, but the relationships between these factors and their separate and combined impact on the survival of PD patients are not clear. In this retrospective analysis, we evaluated possible relationships between RRF, inflammation and initial PTR in patients starting PD and the impact of these factors on patient survival. METHODS: A total of 117 patients with initial assessments for RRF, serum C-reactive protein (CRP) and PET at a mean period of 0.4+/-0.2 months (range 0.1-1.0 months) after start of PD were included in this study. Based on RRF (cut-off point, 4 ml/min/1.73 m(2)), serum CRP (cut-off point, 10 mg/l), and the dialysate to plasma creatinine ratio at 4-h of dwell (mean+1 SD), the patients were divided into different groups: low RRF and high RRF group, high CRP and normal CRP group and high PTR and other PTR group, respectively. RESULTS: Of 117 patients, 54 patients (46%) were in low RRF (<4 ml/min/1.73 m(2)) group, 36 patients (31%) were in high serum CRP (> or = 10 mg/l) group and 17 patients (15%) were in high PTR group. Forty-nine patients (42%) had one of these characteristics, 26 patients (22%) had two of these characteristics, two patients (2%) had three, and 40 patients (34%) had none of these characteristics. Patients with low RRF were older and had a higher prevalence of high CRP, lower normalized protein equivalent of total nitrogen appearance (nPNA), lower total Kt/V(urea) and lower total creatinine clearance (CCr) whereas patients with high CRP were older and had a higher proportion of men, lower serum albumin, lower nPNA, lower RRF and lower total CCr. Patients with high PTR had lower serum albumin, higher RRF and higher total CCr compared with patients with other PTR. Upon logistic multiple regression analysis, age and RRF were identified as factors affecting inflammation. Overall patient survival was significantly lower in the patients with low RRF, with high CRP, and in patients with more than two of the following: low RRF, high CRP and high PTR. In contrast, in patients with none of the discriminators low RRF, high CRP and high PTR, the 5-year survival was 100%. A high PTR was associated with decreased survival during the initial year on PD, but not thereafter. Patients who died during the follow-up period had a higher prevalence of high CRP and lower serum albumin, lower RRF, lower Kt/V(urea) and lower total CCr. Upon Cox proportional hazards multivariate analysis, age and RRF were predictors of mortality. CONCLUSIONS: These results indicate that in patients starting PD, low initial RRF is associated with inflammation, and low RRF and inflammation are both associated with high overall mortality. A high PTR was associated with higher mortality, but only during the initial year on PD, whereas Kt/V(urea) did not predict mortality. These results indicate the importance of RRF and inflammation as predictors of mortality in PD patients whereas the predictive power of PTR as such may lose its significance if these two parameters are taken into consideration.     

Plasma ghrelin levels in patients undergoing haemodialysis and peritoneal dialysis.

BACKGROUND: Ghrelin has been characterized as a relevant physiologic regulator of appetite and body weight in humans. However, the potential relationships between ghrelin levels, inflammation and malnutrition in dialysis patients have not been adequately studied. METHODS: We used a cross-sectional design to study 20 haemodialysis (HD) and 21 peritoneal dialysis (PD) patients, and compared their plasma ghrelin (PGhr) levels with that of an age-matched control group. We also explored correlations between ghrelin and selected hormonal, renal adequacy, nutritional and inflammation markers in both groups. RESULTS: PGhr levels were higher in HD (median 119.8 pg/ml, range 71.1-333.7, P = 0.001) and PD (99.3, range 45.8-578.5, P = 0.045) patients than in healthy controls (78, range 29-158) (HD vs PD, not significant). Ghrelin levels were strongly and inversely correlated with age (r = -0.46, P = 0.02 for patients; r = -0.61, P = 0.001 for controls). Except for a positive correlation between ghrelin and growth hormone (r = 0.48, P = 0.002), univariate analysis failed to detect associations between PGhr and the measured hormonal values, renal adequacy, nutritional indicators and markers of inflammation. However, multivariate analysis revealed significant inverse correlations between PGhr levels and nutritional markers, including subjective global assessment (P = 0.013), albumin (P = 0.001), transferrin (P = 0.01) and protein nitrogen appearance (as an estimate of protein intake) (P = 0.035), after controlling for the confounding effect of age. CONCLUSIONS: PGhr levels were moderately and similarly increased in patients undergoing HD and PD. Age was a strong determinant of PGhr levels, both in uraemic patients and in healthy controls. Dialysis adequacy, residual renal function and inflammation did not appear to influence ghrelin levels in these patients. The negative correlation between PGhr and nutritional markers suggests that low dietary intake causes increases in ghrelin secretion in dialysis patients.     

Conventional nutritional counselling maintains nutritional status of patients on continuous ambulatory peritoneal dialysis in spite of systemic inflammation and decrease of residual renal function

Aim: To evaluate the effect of nutritional counselling on nutritional status in peritoneal dialysis patients. Methods: Twenty‐nine peritoneal dialysis patients were randomly selected to receive conventional nutritional counselling during 6 months of follow up. All patients had monthly clinical and biochemical evaluations, and assessments of dialysis adequacy, inflammation and nutritional status at 0, 3 and 6 months. Results: Moderate‐severe malnutrition decreased 28% whereas normal nutrition increased 23% at final evaluation (non‐significant). Calorie and protein intake remained stable throughout the study (baseline vs final, calorie: 24 ± 8 vs 23 ± 5 Kcal/kg; protein: 1.1 ± 0.5 vs 1.0 ± 0.3 g/Kg, respectively). On the other hand, triceps (16 ± 6 vs 18 ± 8 mm) and subscapular (17 ± 8 vs 20 ± 5 mm) skinfold thicknesses, and mid‐arm circumference (27 ± 3 vs 28 ± 3 mm) significantly increased; mid‐arm muscle area displayed a non‐significant trend to increase (30 ± 9 vs 31 ± 9 cm²) whereas serum albumin significantly increased at the end of study (2.67 ± 0.46 vs 2.94 ± 0.48 g/dL). At final evaluation, median renal creatinine clearance decreased (6.3 (0.8–15.3) vs 2.0 (0.1–6.3) L/week per 1.73 m²) whereas interleukin‐6 increased (2.33 (1.9–7.0) vs 4.02 (2.1–8.4) pg/mL). Conclusion: Even though conventional nutritional counselling, as an isolated measure, did not significantly improve all nutritional parameters, it prevented a greater deterioration during 6 months. Nutritional counselling maintained the nutritional status in spite of a decrease in residual renal function and higher systemic inflammation.     

Associations of serum fetuin-A with malnutrition, inflammation, atherosclerosis and valvular calcification syndrome and outcome in peritoneal dialysis patients.

BACKGROUND: Fetuin-A (alpha2-Heremans Schmid glycoprotein) has recently been identified as a circulating inhibitor of calcification and is regulated as a negative acute phase protein. However, its relationships with cardiac valvular calcification and atherosclerosis and outcome have not been evaluated in peritoneal dialysis (PD) patients. METHOD: We performed a prospective follow-up study in 238 PD patients with echocardiography done at baseline to detect cardiac valvular calcification and biochemical analysis performed for serum fetuin-A, albumin and C-reactive protein (CRP). RESULTS: Baseline serum fetuin-A concentration was (mean+/-SD) 0.309+/-0.068 g/l (normal range 0.4-0.95). Across the three tertiles of increasing serum fetuin-A, a significant trend effect was observed for age (P = 0.023), diabetes (P = 0.008), background atherosclerotic vascular disease (P = 0.010), cardiac valvular calcification (P = 0.002), serum albumin (P<0.001), subjective global assessment (P = 0.005) and CRP (P<0.001). Adjusting for CRP and calcium x phosphorus product, every 0.01 g/l increase in serum fetuin-A remained independently associated with a 6% decrease in the risk of valvular calcification (95% confidence intervals, 0.90-0.99; P = 0.028). Furthermore, serum fetuin-A showed a significant decrease across the four groups of patients with increasing components of the malnutrition, inflammation, atherosclerosis/calcification (MIAC) syndrome (P<0.001) and was the lowest among patients with all components of the MIAC syndrome (0.263+/-0.055 g/l) and highest among those who do not have the MIAC syndrome at all (0.338+/-0.063 g/l). Lower serum fetuin-A was associated with greater all-cause mortality (P = 0.0011) and fatal and non-fatal cardiovascular events (P = 0.0017), but its significance was lost when atherosclerotic vascular disease, valvular calcification, inflammation and malnutrition were included in the model. CONCLUSIONS: Serum fetuin-A showed important associations with valvular calcification, atherosclerosis, malnutrition and inflammation, and was linked to mortality and cardiovascular events in PD patients via its close relationships with the MIAC syndrome.     

Is malnutrition an independent predictor of mortality in peritoneal dialysis patients?

BACKGROUND: It has been established that malnutrition (MN) is a strong predictor of mortality in peritoneal dialysis (PD) patients. However, MN is often the consequence of co-morbid diseases (CMD), and the confounding effect of CMD on mortality in malnourished PD patients has not been clearly defined. In this study, we tested the hypothesis that MN without CMD may not be associated with significant mortality. This study was, therefore, designed to dissociate the influence of CMD on mortality in PD patients from that of MN. METHODS: A total of 153 consecutive PD patients (88 males, mean age 53.3 +/- 12.3 years) were included in this study. All underwent initial assessment of nutrition, CMD survey and peritoneal equilibration test at a mean of 7 days (range 3-24 days) after beginning PD. Nutritional status was assessed by subjective global assessment (SGA) and other methods. CMD surveyed included diabetes, cardiovascular disease, liver disease and respiratory disease, and co-morbidity was graded by Davies index. Based on the nutritional status as assessed by SGA and presence of CMD, patients were divided into four groups; MN with (n = 50) or without (n = 14) CMD, and normal nutrition (NN) with (n = 53) or without (n = 36) CMD. RESULTS: Of 153 patients, 64 (41.8%) were malnourished and 103 (67.3%) had one or more CMD. Of the 103 patients with CMD, 48.5% had MN, and 78% of the 64 patients with MN had CMD. Patients with MN and CMD were older and had lower initial serum albumin (sAlb), serum creatinine, fat-free oedema-free body mass, percentage lean body mass and SGA score and higher initial dialysate/plasma creatinine concentration ratio at 4 h dwell (D4/P4 Cr) and co-morbidity score. On Kaplan-Meier analysis, 2-year patient survival was significantly lower in patients with MN and CMD than in the other groups (63.1, 90.9, 87.5 and 96.4% for subgroups with both MN and CMD, MN without CMD, NN with CMD and NN without CMD, respectively, P = 0.001). On Cox proportional hazards analysis, age, co-morbidity score and D4/P4 Cr, but not SGA score or sAlb concentration, were found to be independent risk factors for mortality. After adjustment for age, gender, sAlb, residual renal function and D4/P4 Cr, patients with both MN and CMD had a risk of mortality that was 3.3 times that of patients with MN but without CMD (risk ratio 9.01 vs 2.72). Patients with MN without CMD had a risk ratio of 2.72 compared with NN without CMD, but this difference was not statistically significant. In patients with NN and CMD, the risk ratio for mortality was five times that of patients with NN without CMD. CONCLUSIONS: This study demonstrates that there is a high prevalence of MN and CMD at the start of PD and that the combined presence of CMD and MN is associated with high mortality. MN alone is associated with a statistically insignificant increase in mortality. This underlines the importance of CMD as a cause of poor clinical outcome in malnourished PD patients. However, in the present study, a relatively limited number of patients with MN but without CMD were analysed and a type two error therefore cannot be excluded.     

Preservation of residual renal function and factors affecting its decline in patients on peritoneal dialysis

SUMMARY:     The decline of residual renal function (RRF) in peritoneal dialysis (PD) patients was analysed and assessed, and risk factors affecting its decline were identified. Residual glomerular filtration rate (GFR) was calculated from averaging the urea and creatinine clearance by 24-h urine collection, and peritoneal solute removal was evaluated by creatinine clearance calculated from 24-h effluent collection. Both GFR and peritoneal solute removal were chronologically examined in 34 PD patients from the time of initiation, and risk factors associated with rapid GFR decline were investigated. The RRF contributed to 43.1 ± 17.6% of total (peritoneal and renal) weekly creatinine clearance at 1 month after initiation of PD. Residual GFR, however, declined continuously with time (−0.19 ± 0.14 mL/min per month), and the reduction rate was high with a higher GFR, higher normalized dietary protein intake, higher urine volume and higher urine protein excretion at the initiation of PD. Other factors related to the rapid decline of GFR were: being older than 60 years of age, automated peritoneal dialysis (APD) rather than continuous ambulatory peritoneal dialysis, mean blood pressure higher than 110 mmHg, and serum human atrial natriuretic peptide level higher being than 60 pg/dL. These data suggest that while RRF plays an important role in the removal of uraemic solute in PD patients, they show a significant decrease over 2 years. The factors related to the rapid decline of GFR corresponded to older age, modality of PD (APD), higher GFR and higher amount of urine protein at initiation, higher dietary protein intake, and inadequate control of hypertension and body fluid volume.     

Consequences of chronic inflammation in peritoneal dialysis

The mortality of end-stage renal disease (ESRD) patients, including those receiving long-term peritoneal dialysis (PD), has remained unacceptably high owing to the prevalence of cardiovascular disease. It is well recognized that both traditional Framingham risk factors and kidney disease-related risk factors may contribute to the high prevalence of cardiovascular disease in these patients. Of the different risk factors, chronic inflammation frequently is observed in long-term PD patients. The causes of inflammation are usually complex and multifactorial, involving both dialysis-related and dialysis-unrelated factors. Inflammation is strongly associated with cardiovascular disease and malnutrition, and has been shown consistently to be a powerful predictor of mortality and adverse cardiovascular outcomes in PD patients. In this article we review the prevalence and potential causes of chronic inflammation in PD patients. More importantly, we provide emerging evidence that shows the serious consequences of chronic systemic inflammation in PD patients and the important contribution of inflammation to adverse clinical outcomes.     

Baseline hyponatremia does not predict two-year mortality in patients with chronic peritoneal dialysis

Purpose: Hyponatremia is a common electrolyte abnormality in a variety of medical conditions. Lower predialysis serum sodium concentration is associated with an increased risk of death in oligoanuric patients on hemodialysis. However, whether hyponatremia affects the short-term mortality in chronic peritoneal dialysis (CPD) patients remains unclear. Methods: We conducted a cross-sectional and two-year follow-up review retrospectively, and 318 patients with CPD were enrolled in a medical center. Serum sodium levels were measured at baseline and categorized as quartile of Na: quartile 1 (124–135?mEq/L), quartile 2 (136–139), quartile 3 (140–141) and quartile 4 (142–148). Mortality and cause of death were recorded for longitudinal analyses. Results: The patients with higher quartile (higher serum sodium) had a trend of lower age, peritoneal dialysis (PD) duration, co-morbidity index, D/P Cr and white blood cell counts and higher renal Kt/Vurea (Kt/V) and serum albumin level. Stepwise multiple linear regression analysis showed that serum sodium level was positively associated with albumin, residual renal Kt/V and negatively associated with age and PD duration in CPD patients. After two-year follow-up, stepwise multivariate Cox proportional hazards model demonstrated that age, co-morbidity index and serum albumin were the significant risk factors for all-cause two-year mortality, but not serum sodium levels. Conclusions: Serum sodium level in CPD patients is associated with nutritional status, residual renal function and duration of PD. However, baseline serum sodium level is not an independent predictor of two-year mortality in CPD patients.