Search

Background/aims: Obesity has known to be a modifiable risk factor associated with worse outcomes in chronic kidney disease (CKD), but few studies have examined the impact of obesity on CKD incidence in the general population. The purpose of this study was to investigate the role of body mass index (BMI) and waist-to-hip ratio (WHR) as predictors of incident CKD and to evaluate the impact of weight reduction on CKD prevention., Methods: A total of 2,711 participants from a community-based cohort with normal renal function were prospectively analyzed. Among participants with obesity, we analyzed the change in WHR to evaluate the association of obesity reduction with CKD development., Results: During a mean follow-up of 11.03 ± 4.22 years, incident CKD occurred in 190 (7.0%) participants. In the fully adjusted multivariable Cox proportional hazard models, the risk of incident CKD increased with higher BMI (hazard ratio, 1.06; 95% confidence interval, 1.00-1.11; p = 0.033) and higher WHR (hazard ratio, 1.33; 95% confidence interval, 1.07-1.66; p = 0.009). In the Kaplan-Meier analysis, cumulative adverse renal events were significantly more common in the maintained obesity group than in the reduced obesity group (p = 0.001)., Conclusion: Both higher BMI and WHR were associated with development of CKD, but the magnitude of the effect of WHR was higher than that of BMI. Moreover, reducing obesity would be beneficial for renal prognosis.

Background/aims: The neutrophil-to-lymphocyte ratio (NLR) has a prognostic value in cardiovascular disease, infection, inflammatory disease, and several malignancies. Therefore, the NLR has a possible predictive value in patients with chronic kidney disease (CKD), but this predictive value has not been validated. Here, we aimed to investigate the possibility of NLR as a predictor of CKD progression., Methods: This retrospective observational study included 141 patients with non-dialysis CKD. The participants were divided into terciles (T1, T2, and T3) according to NLR. The primary outcome was defined as a composite kidney event, which included a decline in the estimated glomerular filtration rate (eGFR) of at least 50% or initiation of renal replacement therapy during the follow-up period., Results: The mean follow-up duration was 5.45 ± 2.11 years. The mean NLRs were 1.35 ± 0.05 in T1 (n = 47), 2.16 ± 0.04 in T2 (n = 47), and 4.29 ± 0.73 in T3 (n = 47). The group with the highest NLR (T3) had higher baseline CKD and serum creatinine and lower eGFR levels than the group with the lowest NLR (T1). The cumulative incidence rate of composite kidney events was significantly higher in T3 compared with T1 (p < 0.001, log-rank test). Cox regression analysis revealed that high NLR was associated with the risk of composite kidney events (adjusted hazard ratio, 3.33; 95% confidence interval, 1.43-7.76)., Conclusion: A higher NLR reflects the more advanced stage of CKD and suggests a role for NLR as a biomarker for predicting CKD progression.

Background/aims: The obesity paradox has been known in end-stage renal disease (ESRD). However, the effect of body mass index (BMI) or waist circumference (WC) prior to percutaneous coronary intervention (PCI) on the development of ESRD is not clear., Methods: Using nationally representative data from the Korean National Health Insurance System, we enrolled 140,164 subjects without ESRD at enrolment who underwent PCI between 2010 and 2015, and were followed-up until 2017. Patients were stratified into five levels based on their baseline BMI and six levels based on their WC with 5-cm increments. BMI and WC were measured at least 2 years prior to PCI. The primary outcome was the development of ESRD., Results: During a median follow-up of 5.4 years, 2,082 (1.49%) participants developed ESRD. The underweight group (hazard ratio [HR], 1.331; 95% confidence interval [CI], 0.955 to 1.856) and low WC (< 80/< 75) (HR, 1.589; 95% CI, 1.379 to 1.831) showed the highest ESRD risk and the BMI 25 to 30 group showed the lowest ESRD risk (HR, 0.604; 95% CI, 0542 to 0.673) in all participants after adjusting for all covariates. In the subgroup analysis for diabetes mellitus (DM) duration, WC < 85/80 cm (men/women) increased ESRD risk in only the DM group (DM < 5 years and DM ≥ 5 years) compared to the reference group (85-90/80-85 of WC), but not the normal or impaired fasting glucose group., Conclusion: Low WC prior to PCI showed an increased ESRD risk in patients with DM undergoing PCI as compared to those without DM.

Background/aims: Hypertension is considered a risk factor in immunoglobulin A nephropathy (IgAN). However, after IgAN diagnosis, the relationship between early blood pressure control and renal prognosis remains unclear. This study aimed to analyze the association between the prognosis of IgAN patients and a controlled status of hypertension within the first year of IgAN diagnosis., Methods: We retrospectively analyzed 2,945 patients diagnosed with IgAN by renal biopsy. The patients were divided into 'normal,' 'new-onset,' 'well-controlled,' and 'poorly-controlled' groups using blood pressure data from two consecutive measurements performed within a year. The Kaplan-Meier survival analysis and Cox proportional-hazards regression model were used to survey the independent association between recovery from hypertension and the risk of IgAN progression. The primary endpoint was IgAN progression defined as the initiation of dialysis or kidney transplantation., Results: Before IgAN diagnosis, 1,239 patients (42.1%) had been diagnosed with hypertension. In the fully adjusted Cox proportional-hazards models, the risk of IgAN progression increased by approximately 1.7-fold for the prevalence of hypertension. In the subgroup analyses, the 'well-controlled' group showed a statistically significant risk of IgAN progression (hazard ratio [HR], 3.19; 95% confidence interval [CI], 1.103 to 9.245; p = 0.032). Moreover, the 'new-onset' and 'poorly-controlled' groups had an increased risk of IgAN progression compared to the 'normal' group (HR, 2.58; 95% CI, 1.016 to 6.545; p = 0.046 and HR, 3.85;95% CI, 1.541 to 9.603; p = 0.004, respectively)., Conclusion: Although hypertension was well-controlled in the first year after IgAN diagnosis, it remained a risk factor for IgAN progression.

Background/aims: This study aimed to investigate whether urinary angiotensinogen (UAGT) excretion was associated with elevated blood pressure in patients with chronic kidney disease (CKD) and to evaluate the relationship among blood pressure, intra-renal renin-angiotensin system (RAS) activity, and dietary sodium in patients with CKD., Methods: Participants from the Korean Cohort Study for Outcome in Patients with Chronic Kidney Disease (KNOW-CKD) were included. Of the total cohort of 2,238 individuals with CKD, we included 1,955 participants who underwent complete 24-hour urinary sodium (24-hour UNa) analysis. They were categorized into three groups according to three tertiles of their 24-hour UNa, reflecting daily salt intake. To measure intra-renal RAS activity, the UAGT excretion was assayed with an enzyme-linked immunosorbent assay., Results: Elevated 24-hour UNa levels, logarithm of UAGT-to-creatinine ratio (UAGT/Cr), increased waist-to-hip ratio, and decreased estimated glomerular filtration rate were the risk factors for increased systolic blood pressure. Systolic blood pressure showed a positive correlation with 24-hour UNa levels and logarithm of UAGT/Cr., Conclusion: UAGT and urinary sodium excretion are independent determinants of systolic blood pressure in patients with CKD. These findings suggest that increased systolic blood pressure in CKD patients is associated with both increased dietary sodium levels and intra-renal RAS activity. The risk of elevated systolic blood pressure in the 3rd tertile of both the UAGT/Cr and 24-hour UNa groups was about 2.3 times higher than that in the reference group.

In the decades since the discovery of angiotensin-converting enzyme 2 (ACE2), its protective role in terms of antagonizing activation of the classical renin-angiotensin system (RAS) axis has been recognized in clinical and experimental studies on kidney and cardiovascular diseases. The effects of ACE inhibitor/angiotensin type 1 receptor blockers (ACEi/ARBs) on ACE2-angiotensin-(1-7) (Ang- (1-7))-Mas receptor (MasR) axis activation has encouraged the use of such blockers in patients with kidney and cardiovascular diseases, until the emergence of coronavirus disease 2019 (COVID-19). The previously unchallenged functions of the ACE2-Ang-(1-7)-MasR axis and ACEi/ARBs are being re-evaluated in the era of COVID-19; the hypothesis is that ACEi/ARBs may increase the risk of severe acute respiratory syndrome coronavirus 2 infection by upregulating the human ACE2 receptor expression level. In this review, we examine ACE2 molecular structure, function (as an enzyme of the RAS), and distribution. We explore the roles played by ACE2 in kidney, cardiovascular, and pulmonary diseases, highlighting studies that defined the benefits imparted when ACEi/ARBs activated the local ACE2- Ang-(1-7)-MasR axis. Finally, the question of whether ACEi/ARBs therapies should be stopped in COVID-19-infected patients will be reviewed by reference to the available evidence.

Background/aims: Despite recent improvements in the quality of life of patients with systemic lupus erythematosus (SLE), osteoporosis, and osteoporotic fractures are one of the major complications of SLE. Furthermore, limited data are available on the incidence and predictor of osteoporotic fractures in Korean patients with SLE. Herein, we aimed to assess the incidence and risk factors for osteoporotic fractures in Korean SLE patients compared to those without SLE., Methods: SLE patients aged ≥ 40 years (n = 10,434; mean age, 51.3 ± 9.1 years; women, 89.7%) were selected from the Korean National Health Insurance Service database, spanning a period from 2008 to 2014. Age- and sex-matched controls (n = 52,170) were randomly sampled in a 5:1 ratio from non-SLE individuals. The primary outcome was the first occurrence of osteoporotic fracture., Results: The incidence of osteoporotic fractures was significantly higher in the SLE patients (19.085 per 1,000 person-years) than in matched controls (6.530 per 1,000 person-years). According to the multivariable Cox proportional analysis, patients with SLE exhibited a higher osteoporotic fracture rate than the control group (hazards ratio, 2.964; 95% confidence interval, 2.754 to 3.188), even after adjustment for confounding variables. In the subgroup analysis, male SLE patients or SLE patients aged 40 to 65 years were associated with a higher osteoporotic fracture rate than women SLE patients or SLE patients aged ≥ 65 years, respectively., Conclusion: We found a 2.964-fold increased risk of osteoporotic fracture in SLE patients compared to age- and sex-matched non-SLE controls. Male or middle-aged SLE patients had a relatively higher fracture risk among patients with SLE.

Background/aims: The aim of this study was to evaluate the trend of incidence and prevalence of systemic lupus erythematosus (SLE) in South Korea from 2005 to 2015., Methods: From 2005 to 2015, individuals with SLE were identified from the National Health Insurance database, which records information on almost all Koreans. SLE was defined according to the International Classification of Diseases, 10th revision (ICD-10), code M32. The incidence was calculated per 100,000 person-years. The prevalence was calculated per 100,000 people and stratified by year, age group, sex, region, and income., Results: The annual prevalence of SLE increased slightly from 21.25/100,000 people in 2005 to 35.45/100,000 people in 2015. In contrast, the annual incidence of SLE decreased slightly from 5.42/100,000 person-years in 2005 to 3.6/100,000 person-years in 2015. The prevalence and incidence of SLE were 10- and 6-fold higher in women than in men, respectively. The peak age of prevalence and incidence was 30 to 39 years in 2005; in 2015, the peak age of prevalence was 30 to 49 years and of incidence was 20 to 49 years. Regional variation was observed in both incidence and prevalence of SLE. Jeju province showed the highest prevalence of SLE (44.54/100,000 person-years), and Gwangju province showed the highest incidence of SLE (6.98/100,000 person-years) in 2015. The income status did not affect the prevalence or incidence of SLE except in patients without income who received medical aid., Conclusion: The incidence of SLE has declined, but the prevalence has increased in Korea in recent years. Peak age of SLE trend to right shift in Korea.

The prevalence rates of hypertension and chronic kidney disease (CKD) are increasing with the aging of the population. Hypertension and CKD are closely related, and hypertension with accompanying CKD is difficult to control. This difficulty controlling blood pressure (BP) can be explained by changes in diurnal variation in BP, such as non-dipping and reverse dipping patterns, increased pulse pressure, and BP variability in CKD patients resulting in a high frequency of nocturnal hypertension or masked hypertension. CKD patients with uncontrolled or nocturnal hypertension are at increased risk for cardiovascular disease, progression of CKD, and all-cause death. Recent studies have shown that intensive reduction of systolic BP below 120 mmHg is seems to favor in CKD patients regardless of the presence or absence of diabetes. As BP control is difficult in patients with CKD, appropriate measurement of BP is important. Automated BP monitoring could reduce the so-called "white coat effect" (spike in BP) that may be triggered by measurement in a clinical setting. Moreover, out-of-office BP monitoring at home or ambulatory BP monitoring for 24 hours may provide critical information regarding diurnal BP variability and nocturnal BP in patients with CKD.

Background/aims: This study aims to demonstrate whether the association between initial vascular access and mortality among hemodialysis patients varies by age., Methods: We conducted a retrospective study that included 2,552 patients who started hemodialysis. Vascular access was divided into three categories: percutaneous catheter, tunneled cuffed catheter, and arteriovenous (AV) access., Results: Survival rates for patients who received a central venous catheter, such as percutaneous or tunneled cuffed catheter, aged 65 to 74 years and those ≥ 75 years were reduced, but not for those aged < 65 years (log-rank test; p < 0.001, p = 0.007, and p = 0.278). After fully adjusting for potential confounding factors in the patients aged < 65 years, percutaneous and tunneled cuffed catheter were not associated with 5-year mortality. On the other hand, for patients aged 65 to 74 or ≥ 75 years, percutaneous catheter and tunneled cuffed catheter were associated with higher 5-year mortality rates. As age increased, the conversion rate from central venous catheter, including percutaneous catheter and tunneled cuffed catheter, to AV access decreased (94.1%, 90.5%, and 80.3% for patients aged < 65, 65 to 74, and ≥ 75 years, respectively; p < 0.001)., Conclusion: In patients aged ≥ 65 years, initial vascular access was associated with long-term mortality. We suggest that a "fistula first" strategy is superior for elderly patients and demonstrates that it is desirable to change to AV access, and not maintain an initial central vascular catheter.

Background/aims: Indoxyl sulfate (IS) is a uremic toxin and an important causative factor in the progression of chronic kidney disease. Recently, paricalcitol (19-nor-1,25-dihydroxyvitamin D2) was shown to exhibit protective effects in kidney injury. Here, we investigated the effects of paricalcitol treatment on IS-induced renal tubular injury., Methods: The fluorescent dye 2',7'-dichlorofluorescein diacetate was used to measure intracellular reactive oxygen species (ROS) following IS administration in human renal proximal tubular epithelial (HK-2) cells. The effects of IS on cell viability were determined using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays and levels of apoptosis-related proteins (Bcl-2-associated protein X [Bax] and B-cell lymphoma 2 [Bcl-2]), nuclear factor-κB (NF- κB) p65, and phosphorylation of mitogen-activated protein kinase (MAPK) and protein kinase B (Akt) were determined by semiquantitative immunoblotting. The promoter activity of NF-κB was measured by luciferase assays and apoptosis was determined by f low cytometry of cells stained with f luorescein isothiocyanate-conjugated Annexin V protein., Results: IS treatment increased ROS production, decreased cell viability and induced apoptosis in HK-2 cells. IS treatment increased the expression of apoptosis-related protein Bax, decreased Bcl-2 expression, and activated phosphorylation of MAPK, NF-κB p65, and Akt. In contrast, paricalcitol treatment decreased Bax expression, increased Bcl-2 expression, and inhibited phosphorylation of MAPK, NF-κB p65, and Akt in HK-2 cells. NF-κB promoter activity was increased following IS, administration and was counteracted by pretreatment with paricalcitol. Additionally, flow cytometry analysis revealed that IS-induced apoptosis was attenuated by paricalcitol treatment, which resulted in decreased numbers of fluorescein isothiocyanate-conjugated Annexin V positive cells., Conclusion: Treatment with paricalcitol inhibited IS-induced apoptosis by regulating MAPK, NF-κB, and Akt signaling pathway in HK-2 cells.

Background/aims: Proteinuria is associated with hypertension and preeclampsia in pregnancy. However, the impact of random urine proteinuria on fetal and maternal outcomes has not been established. We investigated the influence of random urine proteinuria on the clinical outcomes of pregnancy., Methods: From January 2008 to December 2010, 2,822 patients were retrospectively studied. A total of 536 pregnant women with proteinuria in random urine and matched controls without proteinuria via propensity score matching were analyzed. Proteinuria was checked by the dipstick method., Results: The patients' mean age was 33.0 ± 4.7 years, and the mean gestational age was 235.6 ± 50.6 days on admission. The prevalence of hypertension and chronic kidney disease was 2.4% (n = 67) and 1.0% (n = 29), respectively. Women with random urine proteinuria showed higher blood urea nitrogen levels and a higher incidence of hematuria. These women also had a higher incidence of preeclampsia, preterm labor, premature rupture of membranes, and intrauterine growth restriction. Proteinuria was strongly correlated with preeclampsia in both propensity score matching (p < 0.001, r = 0.783) and unmatched whole samples (p < 0.001, r = 0.851)., Conclusions: These findings suggest that random urine proteinuria is associated with preeclampsia, preterm labor, premature rupture of membrane, and intrauterine growth restriction.

Background/aims: This study aimed to investigate the prevalence of chronic kidney disease (CKD) and associated risk factors in a high-risk population in Korea., Methods: A total of 6,045 participants aged ≥ 65 years (mean age, 73.0 ± 5.5) with diabetes or hypertension were enrolled. Participants were screened for CKD, which was defined as the presence of albuminuria (urine albumin-to-creatinine ratio ≥ 30 mg/g) or an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m(2)., Results: The prevalence of CKD was 39.6% (women, 40.3%; men, 38.4%). Albuminuria was detected in 22.6% of participants, whereas eGFR < 60 mL/min/1.73 m(2) was found in 24.6% of participants. The prevalence of CKD by stage was 4.4% for stage 1, 10.4% for stage 2, 23.4% for stage 3, 0.9% for stage 4, and 0.3% for stage 5. Older age, concomitant diabetes and hypertension, higher body mass index, higher systolic and diastolic blood pressure, and higher hemoglobin A1c levels were independently associated with the presence of CKD in multivariate-adjusted analyses that included with age, sex, body mass index, hypertension, diabetes, and smoking., Conclusions: The prevalence of CKD was very high in the present high-risk Korean population. Our results suggest that a screening method for early detection of CKD in high-risk populations is needed in Korea., Competing Interests: No potential conflict of interest relevant to this article was reported.

Background/aims: Continuous renal replacement therapy (CRRT) has been widely used for treating critically ill patients with acute kidney injury (AKI). Whether CRRT is better than intermittent hemodialysis for the treatment of AKI remains controversial. We sought to identify the clinical features that can predict survival for the patients who are treated with CRRT., Methods: We analyzed the data of 125 patients who received CRRT between 2005 and 2007. We identified the demographic variables, the underlying diagnoses, the duration of CRRT, the mean arterial blood pressure (ABP) and the Simplified Acute Physiology Score (SAPS) II. The classification/staging system for acute kidney injury (AKI) was applied to all the patients, who were then divided into stage 1-3 subgroups., Results: The average age of the patients was 61.414.3 years and the mortality rate was 60% (75 of 125 patients). The survivors had a significantly higher mean ABP and a higher mean serum bicarbonate level, which were measured the day after CRRT, than the nonsurvivors (86.723.7 vs. 69.224.6 mm Hg, respectively, 21.43.5 vs. 16.45.4 mmol/L, respectively,; p<0.05 for each). The stage 3 AKI patients showed the worst parameters for the SAPS II score and the serum levels of creatinine and blood urea nitrogen. The mortality rate was higher for the stage 3 subgroup than the other groups (70.5%, p<0.05)., Conclusions: The patients with AKI and who require CRRT continue to have a high mortality rate. A higher mean ABP and a higher serum bicarbonate level measured the day after CRRT may predict a more favorable prognosis. The staging system for AKI can improve the ability to predict the outcomes of CRRT patients.

Ureteropelvic junction obstruction is usually intrinsic and is most common in children. Aberrant renal arteries are present in about 30% of individuals. Aberrant renal arteries to the inferior pole cross anteriorly to the ureter and may cause hydronephrosis. To the best of our knowledge, although there are some papers about aberrant renal arteries producing ureteropelvic junction obstruction, there is no report of a case which is diagnosed by the new modalities, such as computed tomography angiogram (CTA) or magnetic resonance angiogram (MRA). We describe a 36-year-old woman with right hydronephrosis. Kidney ultrasonogram and excretory urogram revealed right hydronephrosis. CTA and MRA clearly displayed an aberrant renal artery and hydronephrosis. The patient underwent surgical exploration. For the evaluation of hydronephrosis by an aberrant renal artery, use of CTA and MRA is advocated.

Background: Patients on continuous ambulatory peritoneal dialysis (CAPD) have increased risk of low-turnover bone disease and relative hypoparathyroidism. Recently, it has been believed that magnesium plays an important role in regulating secretion of parathyroid hormone (PTH). The aim of this study was to evaluate the relationship between serum PTH and serum magnesium as a factor increasing the frequency of relative hypoparathyroidism., Methods: We analyzed the data of 56 patients who had been on CAPD for more than 6 months without any significant problems. No patient had been previously treated with vitamin D or aluminum hydroxide. The patients had used peritoneal dialysate with the magnesium concentration of 0.5 mEq/L. Biochemical parameters, such as BUN, creatinine, alkaline phosphatase bony isoenzyme, total protein, albumin, total calcium, ionized calcium and intact parathyroid hormone level were measured., Results: The mean serum magnesium level was 1.99 +/- 0.36 mEq/L. Among total 56 patients, 15 patients (26.8%) showed hypermagnesemia (serum magnesium > 2.2 mEq/L) and 5 patients (8.9%) showed hypomagnesemia (serum magnesium < 1.6 mEq/L). Among all 56 patients, serum iPTH (intact PTH) level was not correlated with serum magnesium level. However, it was inversely correlated with serum total calcium and ionized calcium levels, respectively (r = -0.365, p = 0.006; r = -0.515 p < 0.001). Among 49 patients whose serum iPTH level was less than 300 pg/mL, serum iPTH level was inversely correlated with serum magnesium level (r = -0.295, p = 0.039) and inversely correlated with serum total calcium and ionized calcium levels, respectively (r = -0.546, p < 0.001; r = -0.572 p < 0.001). Among 49 patients whose serum iPTH level was less than 300 pg/mL, lower iPTH group (serum iPTH < 120 pg/mL) showed higher serum magnesium level (p = 0.037), higher serum total calcium level (p < 0.001) and lower bone isoenzyme of alkaline phosphatase level (p < 0.001) than those of higher iPTH group (120 pg/mL < or = serum iPTH < 300 pg/mL)., Conclusion: Among the CAPD patients whose serum iPTH level was less than 300 pg/mL, there was a significant inverse correlation between serum iPTH level and serum magnesium level. This study indicates that not only serum calcium level but also serum magnesium level are important in the regulation of serum iPTH levels of CAPD patients who have been dialyzed by low-magnesium peritoneal dialysate.

Objectives: The present study was aimed at evaluating the clinical experiences in the internal jugular venous catheterization for hemodialysis., Methods: We retrospectively analyzed the data on internal jugular venous catheterization at Chonnam National University Hospital from May 2000 to February 2001., Results: There were 132 uremic patients with a total of 150 attempts of internal jugular cannulation. Overall success rate was 90.9% with average puncture trials of 2.3 +/- 2.1. 124 (82.7%) of the catheterization attempts were made on the right side and 26 (17.3%) were made on the left. The catheters were left in place from 2 to 87 days with an average of 19.5 +/- 15.3 days per catheter. The dialysis sessions per catheter were from 2 to 58 with an average of 11.3 +/- 6.8. The mean blood flow during hemodialysis immediately after catheterization was 213.4 +/- 42.2 ml/min. Thirty two (21.3%) patients had early complications. These included carotid artery puncture (11.3%), local bleeding (4.7%), local pain (3.3%), neck hematoma (0.7%) and malposition of the catheter (1.3%). Seventeen (11.3%) patients had late complications. These included fever or infection (11.3%), inadequate blood flow rate (3.3%) and inadvertent withdrawal (2.0%). There was no catheter-related mortality., Conclusions: Our experiences revealed that the internal jugular vein catheterization is relatively safe and efficient for temporary vascular access for hemodialysis.

Background: The present study was aimed at investigating the predictive parameters of erythropoietin (epoetin) hyporesponsiveness in patients on continuous ambulatory peritoneal dialysis (CAPD)., Methods: We studied 40 patients with end-stage renal disease who had been receiving CAPD for at least 6 months and epoetin therapy for at least more than 2 months. Pearson's simple correlation and multiple stepwise linear regression analysis was used to discover what parameter can predict epoetin resistance. We expressed epoetin resistance index (ERI) as weekly epoetin dose/hematocrit/body weight'. The dose of epoetin is titrated by about 25% every 2 to 4 weeks to maintain a target hematocrit level between 33% and 36%., Results: We analyzed the relationship between ERI and other predictive parameters by Pearson's correlation. These results showed ERI has a statistically significant correlation with transferrin saturation (TS) (r = -0.327, p = 0.042), total weekly Kt/Vurea (r = -0.423, p = 0.018), serum albumin level (r = -0.458, p = 0.003), normalized protein catabolic rate (nPCR) (r = -0.479, p = 0.006), normalized protein equivalent of total nitrogen appearance (nPNA) (r = -0.488, p = 0.005) and serum C-reactive protein (CRP) (r = 0.332, p = 0.036). Regression analysis was performed using stepwise linear regression for multiple variables to discover the most independent variable which is correlated with ERI. ERI was entered as a dependent variable, whereas the other parameters (age, duration of peritoneal dialysis, serum albumin level, CRP, serum ferritin, total weekly Kt/Vurea, nPCR, nPNA, serum iPTH, serum aluminium, TS) were entered as independent variables. This analysis showed CRP is the most significant variable and, if CRP is excluded, nPNA is the significant variable. CRP has a statistically significant correlation with serum albumin level (r = -0.418, p = 0.007) and total weekly Kt/Vurea (r = -0.366, p = 0.043). High CRP group has more increased level of ERI (p < 0.05), age (p < 0.05) and serum creatinine level (p < 0.05) than normal control, but more decreased level of serum albumin (p < 0.01) and serum iron levels (p < 0.05)., Conclusion: These results indicate that CRP is the most important predictor of epoetin hyporesponsiveness.