Dong Eun Yoo

Red blood cell distribution width is an independent predictor of mortality in acute kidney injury patients treated with continuous renal replacement therapy

BACKGROUND A potential independent association was recently demonstrated between high red blood cell distribution width (RDW) and the risk of all-cause mortality in patients with cardiovascular disease, although the mechanism remains unclear. However, there have been no reports on the relationship between RDW and mortality in acute kidney injury (AKI) patients treated with continuous renal replacement therapy (CRRT). In this study, we assessed whether RDW was associated with mortality in AKI patients on CRRT treatment in the intensive care unit (ICU). METHODS We enrolled 470 patients with AKI who were treated with CRRT at the Yonsei University Medical Center ICU from August 2007 to September 2009 in this study. We performed a retrospective analysis of demographic, biochemical parameters and patient outcomes. Following CRRT treatment, 28-day all-cause mortality was evaluated. RESULTS At the initiation of CRRT treatment, RDW level was significantly correlated with white blood cell count, hemoglobin (Hb) and total cholesterol. Patients with high RDW levels exhibited significantly higher 28-day mortality rates than patients with low RDW levels (P < 0.01). Baseline RDW level, Sequential Organ Failure Assessment (SOFA) score, low mean arterial pressure (MAP) and low cholesterol levels were independent risk factors for mortality. In multivariate Cox proportional hazard analyses, RDW at CRRT initiation was an independent predictor for 28-day all-cause mortality after adjusting for age, gender, MAP, Hb, albumin, total cholesterol, C-reactive protein and SOFA score. CONCLUSION Our study demonstrates that RDW could be an additive predictor for all-cause mortality in AKI patients on CRRT treatment in the ICU.

Renal outcomes in patients with type 2 diabetes with or without coexisting non-diabetic renal disease

AIMS We sought not only to determine the independent predictors of non-diabetic renal disease (NDRD) but also to investigate the impact of NDRD on renal outcomes in patients with type 2 diabetes who underwent renal biopsy and were followed-up longitudinally. METHODS The present study was conducted by reviewing the medical records of 119 type 2 diabetic patients who underwent renal biopsy at Yonsei University Health System from January 1988 to December 2008. RESULTS Renal biopsy findings declared that 43 patients (36.1%) had diabetic nephropathy alone, 12 (10.1%) had NDRD superimposed on diabetic nephropathy, and 64 (53.8%) had only NDRD. On multivariate analysis, the absence of diabetic retinopathy, higher hemoglobin levels, and shorter duration of diabetes were independent predictors of NDRD in these patients. During the follow-up period, end-stage renal disease (ESRD) developed in 33 patients (27.7%). On multivariate Cox regression, higher serum creatinine levels, higher systolic blood pressure, longer duration of diabetes, and the presence of diabetic nephropathy were identified as significant independent predictors of ESRD. When the presence of diabetic retinopathy was included in the multivariate model, higher serum creatinine levels, higher systolic blood pressure, and the presence of retinopathy were shown to be independent predictors of ESRD. CONCLUSIONS Since diabetic patients with NDRD have significantly better renal outcomes compared to patients with biopsy-proven diabetic nephropathy, it is important to suspect, identify, and manage NDRD as early as possible, especially in type 2 diabetic patients with short duration of diabetes and those without diabetic retinopathy or anemia.

Decreased circulating C3 levels and mesangial C3 deposition predict renal outcome in patients with IgA nephropathy.

Background and Aims Mesangial C3 deposition is frequently observed in patients with IgA nephropathy (IgAN). However, the role of complement in the pathogenesis or progression of IgAN is uncertain. In this observational cohort study, we aimed to identify the clinical implications of circulating C3 levels and mesangial C3 deposition and to investigate their utility as predictors of renal outcomes in patients with IgAN. Methods A total of 343 patients with biopsy-proven IgAN were enrolled between January 2000 and December 2008. Decreased serum C3 level (hypoC3) was defined as C3 <90 mg/dl. The study endpoint was end-stage renal disease (ESRD) and a doubling of the baseline serum creatinine (D-SCr). Results Of the patients, there were 66 patients (19.2%) with hypoC3. During a mean follow-up of 53.7 months, ESRD occurred in 5 patients (7.6%) with hypoC3 compared with 9 patients (3.2%) with normal C3 levels (P = 0.11). However, 12 patients (18.2%) with hypoC3 reached D-SCr compared with 17 patients (6.1%) with normal C3 levels [Hazard ratio (HR), 3.59; 95% confidence interval (CI), 1.33–10.36; P = 0.018]. In a multivariable model in which serum C3 levels were treated as a continuous variable, hypoC3 significantly predicted renal outcome of D-SCr (per 1 mg/dl increase of C3; HR, 0.95; 95% CI, 0.92–0.99; P = 0.011). The risk of reaching renal outcome was significantly higher in patients with mesangial C3 deposition 2+ to 3+ than in patients without deposition (HR 9.37; 95% CI, 1.10–80.26; P = 0.04). Conclusions This study showed that hypoC3 and mesangial C3 deposition were independent risk factors for progression, suggesting that complement activation may play a pathogenic role in patients with IgAN.

Left atrial volume is an independent predictor of mortality in CAPD patients

BACKGROUND Echocardiography is an established technique to estimate the risk for cardiovascular complications in patients with end-stage renal disease (ESRD). An enlarged left atrium (LA) has recently emerged as a marker of adverse cardiovascular outcomes in various pathologic conditions. However, there have been few studies to evaluate its prognostic value in patients with ESRD, particularly those receiving continuous ambulatory peritoneal dialysis (CAPD). METHODS We conducted an observational cohort study to investigate whether enlarged LA can predict patient outcome in 216 patients with CAPD. Study outcomes were all-cause and cardiovascular mortality. RESULTS Increased left atrium volume index (LAVI > 32 mL/m(2)) was observed in 99 (45.8%) of the CAPD patients. During the follow-up (26.3 ± 18.6 months), 20 patients (9.3%) died. Kaplan-Meier analysis revealed that the 5-year survival rate was significantly lower in patients with LAVI > 32 mL/m(2) than those with LAVI ≤ 32 mL/m(2) (69 versus 82%, P = 0.024). In multivariate analyses adjusted for echocardiographic parameters and clinical and laboratory data, increased LAVI was an independent predictor of all-cause mortality [hazard ratio (HR) 1.05, 95% confidence interval (CI) 1.01-1.10, P = 0.03] and cardiovascular mortality (HR 1.08, 95% CI 1.02-1.14, P = 0.006). Furthermore, increased LAVI provided the highest predictive value for all-cause mortality [area under the receiver operating characteristic curve (AUC) = 0.766, P < 0.001] and cardiovascular mortality (AUC = 0.836, P < 0.001) among the measured echocardiographic parameters. CONCLUSIONS We showed that increased LAVI predicted adverse outcomes better than other echocardiographic parameters in patients with CAPD.

Clinical outcomes, when matched at presentation, do not vary between adult-onset Henöch-Schönlein purpura nephritis and IgA nephropathy

Henöch-Schönlein purpura nephritis (HSPN) is considered a systemic form of immunoglobulin A nephropathy (IgAN). Although these are different pictures of a single disease, there are no studies directly comparing long-term outcomes of these two clinical entities. To clarify this, we studied 120 patients with biopsy-proven HSPN and 1070 patients with IgAN. The primary outcome was the composite of a doubling of baseline serum creatinine, end-stage renal disease, or death. Secondary outcomes included the individual renal outcomes or the rate of decline in estimated glomerular filtration rate. In the unmatched cohort, patients with HSPN had more vasculitic symptoms, more favorable histologic features, and were more commonly treated with steroids than patients with IgAN. The risk of reaching the primary outcome was significantly lower in HSPN patients than patients with IgAN (hazard ratio, 0.67). The 1:2 propensity score matching gave matched pairs of 89 patients with HSPN and 178 patients with IgAN, resulting in no differences in baseline conditions. In this matched cohort, there were no significant differences in reaching the primary and secondary outcomes between the two groups. Thus, after adjustment by propensity score matching, clinical outcomes did not differ between HSPN and IgAN, suggesting the two forms of the same disease have a similar prognosis.

Progression of Aortic Arch Calcification Over 1 Year Is an Independent Predictor of Mortality in Incident Peritoneal Dialysis Patients

Backgrounds and Aims The presence and progression of vascular calcification have been demonstrated as important risk factors for mortality in dialysis patients. However, since the majority of subjects included in most previous studies were hemodialysis patients, limited information was available in peritoneal dialysis (PD) patients. Therefore, the aim of this study was to investigate the prevalence of aortic arch calcification (AoAC) and prognostic value of AoAC progression in PD patients. Methods We prospectively determined AoAC by chest X-ray at PD start and after 12 months, and evaluated the impact of AoAC progression on mortality in 415 incident PD patients. Results Of 415 patients, 169 patients (40.7%) had AoAC at baseline with a mean of 18.1±11.2%. The presence of baseline AoAC was an independent predictor of all-cause [Hazard ratio (HR): 2.181, 95% confidence interval (CI): 1.336–3.561, P = 0.002] and cardiovascular mortality (HR: 3.582, 95% CI: 1.577–8.132, P = 0.002). Among 363 patients with follow-up chest X-rays at 12 months after PD start, the proportion of patients with AoAC progression was significantly higher in patients with baseline AoAC (64.2 vs. 5.3%, P<0.001). Moreover, all-cause and cardiovascular death rates were significantly higher in the progression groups than in the non-progression group (P<0.001). Multivariate Cox analysis revealed that AoAC progression was an independent predictor for all-cause (HR: 2.625, 95% CI: 1.150–5.991, P = 0.022) and cardiovascular mortality (HR: 4.008, 95% CI: 1.079–14.890, P = 0.038) in patients with AoAC at baseline. Conclusions The presence and progression of AoAC assessed by chest X-ray were independently associated with unfavorable outcomes in incident PD patients. Regular follow-up by chest X-ray could be a simple and useful method to stratify mortality risk in these patients.

Good glycemic control is associated with better survival in diabetic patients on peritoneal dialysis: a prospective observational study.

Background The effect of glycemic control after starting peritoneal dialysis (PD) on the survival of diabetic PD patients has largely been unexplored, especially in Asian population. Methods We conducted a prospective observational study, in which 140 incident PD patients with diabetes were recruited. Patients were divided into tertiles according to the means of quarterly HbA1C levels measured during the first year after starting PD. We examined the association between HbA1C and all-cause mortality using Cox proportional hazards models. Results The mean age was 58.7 years, 59.3% were male, and the mean follow-up duration was 3.5 years (range 0.4–9.5 years). The mean HbA1C levels were 6.3%, 7.1%, and 8.5% in the 1st, 2nd, and 3rd tertiles, respectively. Compared to the 1st tertile, the all-cause mortality rates were higher in the 2nd [hazard ratio (HR), 4.16; 95% confidence interval (CI), 0.91–18.94; p = 0.065] and significantly higher in the 3rd (HR, 13.16; 95% CI, 2.67–64.92; p = 0.002) tertiles (p for trend = 0.005), after adjusting for confounding factors. Cardiovascular mortality, however, did not differ significantly among the tertiles (p for trend = 0.682). In contrast, non-cardiovascular deaths, most of which were caused by infection, were more frequent in the 2nd (HR, 7.67; 95% CI, 0.68–86.37; p = 0.099) and the 3rd (HR, 51.24; 95% CI, 3.85–681.35; p = 0.003) tertiles than the 1st tertile (p for trend = 0.007). Conclusions Poor glycemic control is associated with high mortality rates in diabetic PD patients, suggesting that better glycemic control may improve the outcomes of these patients.

Visceral Fat Thickness Is Associated With Carotid Atherosclerosis in Peritoneal Dialysis Patients

Visceral fat has been known to associate with atherosclerosis, inflammation, and insulin resistance. However, the influence of visceral fat on cardiovascular disease (CVD) in peritoneal dialysis (PD) patients has never been elucidated. We investigated whether visceral fat thickness (VFT) has a predictive role in carotid atherosclerosis determined by carotid intima‐media thickness (cIMT) in PD patients. A cross‐sectional study was undertaken in 88 prevalent PD patients. BMI and waist circumference (WC) were measured as anthropometric indexes of obesity. VFT and subcutaneous fat thickness (SFT) were determined by sonographic measurement of abdominal fat. Carotid atherosclerosis was defined as increased cIMT (>1.0 mm) or presence of plaque. Thirty‐two (36.3%) patients had carotid atherosclerosis. Patients with carotid atherosclerosis showed significantly higher VFT, BMI, and WC. In univariate logistic analysis, BMI, WC, and VFT except SFT were significant risk factors of carotid atherosclerosis. However, multivariate analysis revealed VFT was an independent factor associated with carotid atherosclerosis after adjusting for demographic, biochemical parameters, and anthropometric indexes (per 1 mm increase, odds ratio (OR) = 2.294, 95% confidence interval: 1.048–5.021, P = 0.038). When the patients were divided into three groups according to VFT, log high sensitivity C‐reactive protein (hs‐CRP), and homeostasis model assessment‐insulin resistance (HOMAIR) were both higher in the third tertile compared to other tertiles. In conclusion, VFT, not SFT, is independently associated with carotid atherosclerosis in PD patients. Therefore sonographic measurement of VFT could be useful to stratify the risk of cardiovascular disease in PD patients.

LEPTIN/ADIPONECTIN RATIO IS AN INDEPENDENT PREDICTOR OF MORTALITY IN NONDIABETIC PERITONEAL DIALYSIS PATIENTS

♦ Background: The leptin/adiponectin (L/A) ratio has been suggested to be an atherosclerotic index for diabetic patients and a useful marker of insulin resistance in patients with and without diabetes. Even though end-stage renal disease (ESRD) patients on peritoneal dialysis (PD) are well characterized by abnormal adipocytokine metabolism, the significance of alterations in the L/A ratio is largely unexplored in these patients. In this prospective study, we investigated the associations of leptin, adiponectin, and the L/A ratio with clinical outcomes in nondiabetic PD patients. ♦ Methods: The study included 131 stable nondiabetic ESRD patients who had been on PD for more than 3 months. Serum leptin and adiponectin levels were determined at baseline. Mortality was evaluated over a 5-year follow-up period. ♦ Results: During the follow-up period, 22 patients died (16.8%), including 10 (45.5%) as a result of cardiovascular disease. The L/A ratio showed a significant positive correlation with body mass index [BMI (r = 0.47, p < 0.001)], high-sensitivity C-reactive protein (r = 0.32, p < 0.001), and triglycerides (r = 0.43, p < 0.001). In addition, we observed significant inverse correlations between the L/A ratio and percentage lean body mass (r = -0.30, p = 0.001) and high-density lipoprotein cholesterol (r = -0.31, p = 0.001). In contrast to individual leptin and adiponectin levels, the L/A ratio was found to be independently associated with an increased mortality risk (relative risk: 1.15; 95% confidence interval: 1.05 to 1.27; p = 0.003) even after adjustments for age and BMI. ♦ Conclusions: The L/A ratio might be better related to patient outcomes than adipocytokines are individually in nondiabetic patients undergoing PD.

Elevated osteoprotegerin is associated with inflammation, malnutrition and new onset cardiovascular events in peritoneal dialysis patients.

BACKGROUNDS Osteoprotegerin (OPG) is known to regulate bone mineral metabolism and to be also associated with inflammation, cardiovascular disease (CVD) and mortality. Malnutrition-inflammation-atherosclerosis (MIA) syndrome is commonly found and closely linked to mortality in dialysis patients. The aim of this study was to investigate the associations between OPG and MIA syndrome in prevalent peritoneal dialysis (PD) patients. METHODS Prevalent PD patients for more than 6 months were prospectively followed up from March 2005 to May 2010. At baseline, OPG, hs-CRP, albumin, and %lean body mass (LBM) by creatinine kinetics were checked, and subjective global assessment (SGA) was performed. New-onset cardiovascular events were evaluated during the study period. Based on the median level of OPG, patients were classified as lower OPG (LO) group (n = 88) and higher OPG (HO) group (n = 88). RESULTS A total of 176 patients (age 52.0 ± 11.8 years, male 50.6%, duration of PD 105.3 ± 67.2 months) were recruited and followed. In HO group, age, hs-CRP level and Charlsons comorbidity indices were higher, whereas serum albumin level, %LBM and SGA score were significantly lower than LO group. OPG levels were positively correlated with inflammatory markers, whereas negatively correlated with nutritional status. Cardiovascular events occurred in 51 patients during the study period. Newly developed cardiovascular events were significantly common in HO group (n = 36, 40.9%) than LO group (n = 15, 17%, p = 0.002). Cox regression analysis revealed that higher OPG level (per 1-SD increase in OPG, HR: 1.44; 95% CI: 1.03-2.00; p = 0.034) was a significant risk factor for cardiovascular events even after adjustments for demographic and biochemical parameters. CONCLUSION OPG was significantly correlated with markers of systemic inflammation and malnutrition and was a significant predictor of CVD in PD patients. These findings suggest OPG might be a prognostic indicator of MIA syndrome in prevalent PD patients.