Kyung Woo Yoon

Geriatric Nutritional Risk Index as a prognostic factor in peritoneal dialysis patients.

♦ Background: The Geriatric Nutritional Risk Index (GNRI) might be a useful screening tool for malnutrition in dialysis patients. However, data concerning the GNRI as a prognostic factor in peritoneal dialysis (PD) patients are scarce. ♦ Methods: We reviewed the medical records at Yeungnam University Hospital in Korea to identify all adults (>18 years) who received PD; 486 patients were enrolled in the study. ♦ Results: The initial low, middle, and high GNRI tertiles included 162, 166, and 158 patients respectively. Significant correlations were noted between the initial GNRI and body mass index, creatinine, albumin, arm circumference, fat mass index, and comorbidities. The cut-off value for the time-averaged GNRI over 1 year was 96.4, and the sensitivity and specificity for a diagnosis of a decline in lean mass were 77.1% and 40.0% respectively. A multivariate analysis adjusted for age, risk according to the Davies comorbidity index, and C-reactive protein showed that an low initial GNRI tertile was associated with mortality in PD patients. ♦ Conclusions: The GNRI is a simple method for predicting nutrition status and clinical outcome in PD patients.

Onodera's Prognostic Nutritional Index as a Risk Factor for Mortality in Peritoneal Dialysis Patients

The aim of this study was to evaluate the clinical relevance and usefulness of the Onoderas prognostic nutritional index (OPNI) as a prognostic and nutritional indicator in peritoneal dialysis (PD) patients. Patients were divided into 3 groups based on the initial OPNI score: group A (n = 186, < 40), group B (n = 150, 40-45), and group C (n = 186, > 45). Group A was associated with a higher grade according to the Davies risk index than the other groups. Serum creatinine and albumin levels, total lymphocyte count, and fat mass increased with an increase in OPNI. According to the edema index, the correlation coefficient for OPNI was -0.284 and for serum albumin was -0.322. Similarly, according to the C-reactive protein (CRP), the correlation coefficient for OPNI was -0.117 and for serum albumin was -0.169. Multivariate analysis adjusted for age, Davies risk index, CRP, and edema index revealed that the hazard ratios for low OPNI, serum albumin, and CRP were 1.672 (P = 0.003), 1.308 (P = 0.130), and 1.349 (P = 0.083), respectively. Our results demonstrate that the OPNI is a simple method that can be used for predicting the nutritional status and clinical outcome in PD patients.

Association of Visceral Fat Area with Chronic Kidney Disease and Metabolic Syndrome Risk in the General Population: Analysis Using Multi-Frequency Bioimpedance

Background/Aims: Advances in bioimpedance analysis (BIA) technologies now enable visceral fat area (VFA) to be assessed using this method. The aim of this study was to evaluate the clinical relevance and usefulness of VFA as a predictor of chronic kidney disease (CKD) and metabolic syndrome (MS), using BIA. Methods: We identified 24,791 adults who underwent voluntary routine health checkups at Yeungnam University Hospital. In total 22,480 patients were recruited into our study. Participants were divided into 3 tertiles based on their VFA: low, middle, and high tertiles. CKD was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73m2. Results: The higher tertile of VFA was associated with a higher prevalence of diabetes mellitus, hypertension, and male sex. Waist-to-hip ratio, body mass index, blood pressure, lean mass, body fat %, and fasting glucose, total cholesterol, triglyceride, GGT, AST, ALT, and uric acid levels all increased as the VFA tertile increased (P < 0.001 for all variables). The prevalence of CKD was 6.9% in the low tertile, 13.9% in the middle tertile, and 25.2% in the high tertile (P < 0.001). The prevalence of MS was 2.2% in the low tertile, 12.8% in the middle tertile, and 36.7% in the high tertile (P < 0.001). The AUROC values for VFA were higher than those for BMI and WHR. For VFA, the sensitivity and specificity for predicting CKD were 62.66% (95% CI, 61.0-64.3) and 64.22% (95% CI, 63.5-64.9), respectively, and 77.65% (95% CI, 76.3-79.0), and 68.81% (95% CI, 68.1-69.5), respectively for predicting MS. Conclusion: Our results demonstrated that the VFA, measured by BIA, is a simple method for predicting the risk of CKD and MS.

Risk Factors for Mortality in Stable Peritoneal Dialysis Patients

Background: The mortality rates of end-stage renal disease patients have significantly declined over the past decade. However, there are few reports on the risk factors for mortality in stable peritoneal dialysis (PD) patients who survive for a considerable time. Patients and methods: We reviewed the medical records and identified all adult patients who received PD between April 2001 and March 2009 in our institution. The total cohort was 550 patients. Among these patients, 383 patients were enrolled as stable PD patients. Results: The cumulative survival of the stable PD patients was 91.6% at 3 years and 78.7% at 5 years. On univariate analysis, old age (≥65 years of age), hypoalbuminemia (<35 g/L), log C-reactive protein (CRP) (≥0.84), phosphorus (<1.13 mmol/L), statin, icodextrin, and the Davies index were associated with mortality for all PD patients. Old age, hypoalbuminemia, log CRP, phosphorus, the residual renal function (RRF) (≤4 mL/min/1.73 m2) at 24 months, renin–angiotensin system blockade, icodextrin, and the Davies index were associated with mortality for the stable PD patients. Multivariate analysis showed that, among the variables, age, log CRP, phosphorus, initial RRF, and the Davies index were associated with mortality for all PD patients. In stable PD patients, age, log CRP, phosphorus, RRF at 24 months, and the Davies index were associated with mortality. Conclusion: Initial high RRF combined with the RRF preservation, maintenance of proper phosphorus, control of inflammation, and proper management of comorbidities may help to improve the survival of PD patients including stable PD patients.

The association between metabolic syndrome or chronic kidney disease and hearing thresholds in Koreans: the Korean National Health and Nutrition Examination Survey 2009-2012.

Background The aim of this study was to determine whether metabolic syndrome (MetS) or chronic kidney disease (CKD) is associated with hearing thresholds in the general Korean population. Patients and Methods A total of 16,554 participants were included in this study. MetS was defined using the National Cholesterol Education Program Adult Treatment Panel III guidelines, and CKD was defined as an estimated glomerular filtration rate <60 mL/min/1.73 m2 or a dipstick proteinuria result of ≥1+. The hearing thresholds were measured at 0.5, 1, 2, 3, 4, and 6 kHz. Low-frequency (Freq) was defined as pure-tone averages at 0.5 and 1 kHz, while Mid-Freq and High-Freq were defined as the average thresholds at mid-frequency (2 and 3 kHz) and high frequency (4 and 6 kHz), respectively. Results In men, the hearing thresholds were 15.1 ± 14.5 dB, 22.2 ± 21.3 dB, and 37.3 ± 26.5 dB for Low-, Mid-, and High-Freq, respectively. In women, the hearing thresholds were 14.9 ± 15.3 dB, 16.6 ± 18.0 dB, and 26.1 ± 21.5 dB for Low-, Mid-, and High-Freq, respectively. The hearing thresholds for men were significantly higher than the hearing thresholds for women in all 3 threshold categories. Male and female subjects with MetS or CKD had higher hearing thresholds than the subjects that did not have these disorders. In the multivariate analysis, MetS was associated with increased hearing thresholds in women, and CKD was associated with increased hearing thresholds in men and women. Conclusion MetS is associated with hearing thresholds in women, and CKD is associated with hearing thresholds in men and women. Therefore, patients with MetS or CKD should be closely monitored for hearing impairment.

Characteristics and clinical outcomes of hyponatraemia in peritoneal dialysis patients.

There are few reports on the incidence, aetiology, and mortality of peritoneal dialysis (PD) patients with hyponatraemia.

Comparison of bioimpedance analysis and dual-energy X-ray absorptiometry body composition measurements in peritoneal dialysis patients according to edema.

BACKGROUND Changes in the difference between bioimpedance analysis (BIA) and dual-energy X-ray absorptiometry (DXA) body composition measurements according to edema is an important issue for peritoneal dialysis (PD) patients. METHODS We reviewed the medical records of patients to identify all adults who had undergone PD and composition measurements by both BIA and DXA techniques. The aim of this study was to evaluate any change in the difference between BIA and DXA body composition measurements according to edema. RESULTS We identified 409 patients whose body compositions were measured by both techniques one or more times, for a total of 1,109 pairs of measurements. The measurements were divided into 4 quartiles on the basis of the edema index. Significant correlations and intraclass correlations were noted between the two methods for lean mass (LM), fat mass (FM), and bone mineral content. Simple linear regression analyses using DXA measurements for the prediction of body compositions by BIA showed that non-standardized-βs of total LM decreased as the grade of edema index increased (from 1.008 to 0.949), whereas non-standardized-βs of total FM increased as the grade of edema index increased (from 1.034 to 1.162). Bias for total LM changed from positive to negative, and this negative bias amplified as the grade of edema index escalated (from 0.406 kg to -2.276 kg). A positive bias was observed for total FM in the 1st quartile, and this positive bias increased with an increase in the grade of edema index (from 0.594 kg to 2.863 kg). CONCLUSION LM measured by DXA is overestimated in PD patients with edema compared to the measurements by BIA. However, FM and bone mineral content measured by BIA are is overestimated in PD patients, compared to the measurements by DXA, especially in patients with worsening edema. The difference between the two techniques grows more prominent as the grade of edema increases. A combination of two methods will allow clinicians to conduct more accurate body composition assessments for PD patients with edema.

Limb/Trunk Lean Mass Ratio as a Risk Factor for Mortality in Peritoneal Dialysis Patients

BACKGROUND This study was performed to determine the clinical relevance of limb/trunk lean mass ratio (LTLM) in continuous ambulatory peritoneal dialysis (CAPD) patients. METHODS This retrospective cohort study included 534 CAPD patients. Body compositions were measured using a dual-energy X-ray absorptiometry apparatus. RESULTS In males, the sensitivity and specificity for the diagnosis of sarcopenia were 70.3% and 85.9%, respectively. Respective values in females were 62.3% and 83.8%. The initial low LTLM tertile was associated with mortality in male CAPD patients and in female CAPD patients. Among patients who maintained CAPD for a year, the maintenance of low LTLM tertile was associated with mortality. CONCLUSIONS LTLM is associated with other lean mass indices, nutritional status, and mortality in CAPD patients. Therefore, LTLM is a novel marker that is useful for the prediction of the nutritional status and mortality in patients with CAPD.

Paricalcitol Ameliorates Epithelial-to-Mesenchymal Transition in the Peritoneal Mesothelium

Background: The purpose of the present study was to examine the effectiveness of paricalcitol for the prevention of epithelial-to-mesenchymal transition (EMT). Materials and Methods: Human peritoneal mesothelial cells (HPMCs) were cultured in media containing transforming growth factor β1 (TGF-β1) with or without paricalcitol. Forty-two male Sprague-Dawley rats were divided into three groups. In the control group, the catheter was inserted but no dialysate was infused. The peritoneal dialysis (PD) group was infused with a conventional 4.25% dialysis solution. The paricalcitol group was infused with 4.25% dialysis solution and cotreated with paricalcitol. Results: Exposure of HPMCs to TGF-β1 decreased the protein level of the epithelial cell marker and increased the expression levels of the mesenchymal markers. Cotreatment with paricalcitol increased the protein levels of the epithelial cell marker and decreased those of mesenchymal markers compared with their levels in cells treated with TGF-β1 alone. Exposure of HPMCs to TGF-β1 significantly increased the phosphorylation of Smad2 and Smad3. Cotreatment with paricalcitol significantly decreased the phosphorylation of Smad2 and Smad3 compared with that of cells treated with TGF-β1 alone. After 8 weeks of experimental PD in rats, the thickness of the peritoneal membrane in the PD group was significantly increased compared with that of the control group. Cotreatment with paricalcitol decreased peritoneal thickness. Conclusion: The present study showed that paricalcitol attenuates the TGF-β1-induced EMT in peritoneal mesothelial cells. We suggest that paricalcitol may preserve peritoneal mesothelial cells during PD and could thus be of value for the success of long-term PD.

Proteinuria as a Risk Factor for Decline in Residual Renal Function in Non-Diabetic Peritoneal Dialysis Patients

Background: Preservation of residual renal function (RRF) is a major issue for patients on peritoneal dialysis (PD). Whether proteinuria is associated with a decline in RRF in patients on PD remains unclear. Patients and Methods: We reviewed the medical records at the Yeungnam University Hospital in Korea and identified patients who started PD between June 1995 and August 2011. A total of 147 non-diabetic patients were enrolled in the study. The patients were divided into 3 groups with respect to the tertile of initial proteinuria level: Low (n = 49; <320 mg/day), Middle (n = 49; 320-822 mg/day), and High groups (n = 49; >822 mg/day). Results: The mean patient age was 50.2 ± 15.0 years in the Low tertile, 50.2 ± 15.4 years in the Middle tertile, and 49.0 ± 15.1 years in the High tertile. Decline in RRF during follow-up period was greater in the High tertile than that in the other tertiles (P = 0.001). The proportion of patients with RRF >50% of baseline at 24 months after the initiation of PD was 83% in the Low tertile, 66% in the Middle tertile, and 40% in the High tertile (P < 0.001). The multivariate analysis after adjusting for initial RRF, age, gender, underlying disease of end-stage renal disease except diabetes mellitus, PD modality, use of icodextrin, PD-associated peritonitis, and tertile of the initial proteinuria level revealed that High tertile of the initial proteinuria level was associated with a decline in RRF (hazard ratios: 2.442 for the Middle tertile, P = 0.007 ; 3.713 for the Low tertile, P < 0.001). Conclusion: The present study demonstrates that proteinuria may be is associated with a rapid decline in RRF in non-diabetic patients on PD, although the potential role of additional factors should be further investigated in prospective studies.