Predictive performance of the new race-free Chronic Kidney Disease Epidemiology Collaboration equations for kidney outcome in Korean patients with chronic kidney disease

The new Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations without a race coefficient have gained recognition across the United States. We aimed to test whether these new equations performed well in Korean patients with chronic kidney disease (CKD). Methods: This study included 2,149 patients with CKD G1–G5 without kidney replacement therapy from the Korean Cohort Study for Outcome in Patients with CKD (KNOW-CKD). The estimated glomerular filtration rate (eGFR) was calculated using the new CKD-EPI equations with serum creatinine and cystatin C. The primary outcome was 5-year risk of kidney failure with replacement therapy (KFRT). Results: When we adopted the new creatinine equation [eGFRcr (NEW)], 81 patients (23.1%) with CKD G3a based on the current creatinine equation (eGFRcr) were reclassified as CKD G2. Accordingly, the number of patients with eGFR of <60 mL/min/1.73 m2 decreased from 1,393 (64.8%) to 1,312 (61.1%). The time-dependent area under the receiver operating characteristic curve for 5-year KFRT risk was comparable between the eGFRcr (NEW) (0.941; 95% confidence interval [CI], 0.922–0.960) and eGFRcr (0.941; 95% CI, 0.922–0.961). The eGFRcr (NEW) showed slightly better discrimination and reclassification than the eGFRcr. However, the new creatinine and cystatin C equation [eGFRcr-cys (NEW)] performed similarly to the current creatinine and cystatin C equation. Furthermore, eGFRcr-cys (NEW) did not show better performance for KFRT risk than eGFRcr (NEW). Conclusion: Both the current and the new CKD-EPI equations showed excellent predictive performance for 5-year KFRT risk in Korean patients with CKD. These new equations need to be further tested for other clinical outcomes in Koreans.

Associations among Alzheimer disease, depressive disorder, and risk of end-stage kidney disease in elderly people

Alzheimer disease (AD) and depressive disorder (DD) are prevalent among elderly end-stage kidney disease (ESKD) patients. However, whether preexisting mental health disorders increase the risk of ESKD is not well understood. The risk of incident ESKD in patients with or without underlying AD or DD was evaluated in a nationwide cohort of elderly people in Republic of Korea. Methods: This study used data from the National Health Insurance Service-Senior cohort in Republic of Korea. Among the 558,147 total subjects, 49,634 and 54,231 were diagnosed with AD (AD group) or DD (DD group), respectively, during the follow-up period. Propensity score matching was conducted to create non-AD and non-DD groups of subjects. AD and DD diagnoses were analyzed as time-varying exposures, and the study outcome was development of ESKD. Results: The incidence rates of ESKD were 0.36 and 1.17 per 1,000 person-years in the non-AD and AD groups, respectively. After adjustment for clinical variables and competing risks of death, the risk of incident ESKD was higher in the AD group than in the nonAD group (hazard ratio [HR], 1.67; 95% confidence interval [CI], 1.34–2.08). The incidence rates of ESKD in the non-DD and DD groups were 0.36 and 0.91 per 1,000 person-years, respectively. The risk of ESKD development was also higher in the DD group than the non-DD group (HR, 1.44; 95% CI, 1.19–1.76). Conclusion: The risk of ESKD development was higher in subjects diagnosed with AD or DD, suggesting that central nervous system diseases can adversely affect kidney function in elderly people.

Intensity of statin therapy and renal outcome in chronic kidney disease: Results from the Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease

Background@#Higher statin intensity is associated with a lower risk of mortality in patients with cardiovascular disease. However, little is known about the relationship between statin intensity and chronic kidney disease (CKD) progression. @*Methods@#We studied whether statin intensity affects kidney function decline in 1,073 patients from the Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease. The participants were classified based on statin intensity as low, moderate, and high. The study endpoint was CKD progression (composite of doubling of serum creatinine, ≥ 50% decrease in estimated glomerular filtration rate [eGFR] from baseline, or end-stage renal disease). @*Results@#The mean age was 56.0 ± 11.4 years, and 665 (62.0%) participants were male. The mean eGFR was 51.7 ± 26.7 mL/min/1.73 m2; there were no differences in baseline eGFR among statin intensity groups. During the median follow-up of 39.9 (25.4-61.6) months, 255 (23.8%) patients reached the study endpoint. In multivariable Cox model after adjustment of confounders, the hazard ratios (95% confidence interval) for adverse kidney outcome were 0.97 (0.72-1.30) and 1.15 (0.60-2.20) in moderate and high statin intensity groups, respectively, compared with the low intensity group. In addition, no significant association was observed in subgroups stratified by age, sex, eGFR, and atherosclerotic cardiovascular disease risk scores. @*Conclusion@#We did not observe any significant association between intensity of statin therapy and progression of CKD. Long-term kidney outcomes may not be affected by statin intensity.

Framingham risk score and risk of incident chronic kidney disease: A community-based prospective cohort study

BACKGROUND: Cardiovascular disease and chronic kidney disease share several common risk factors. The Framingham risk score is hypothesized to predict chronic kidney disease development. We determined if the Framingham risk scoring system can correctly predict incident chronic kidney disease in the general population. METHODS: This study included 9,080 subjects who participated in the Korean Genome and Epidemiology Study between 2001 and 2014 and had normal renal function. The subjects were classified into low- ( 20%) risk groups based on baseline Framingham risk scores. The primary endpoint was de novo chronic kidney disease development (estimated glomerular filtration rate [eGFR], < 60 mL/min/1.73 m²). RESULTS: During a mean follow-up duration of 8.9 ± 4.3 years, 312 (5.3%), 217 (10.8%), and 205 (16.9%) subjects developed chronic kidney disease in the low, intermediate, and high risk groups, respectively (P < 0.001). Multivariable analysis after adjustment for confounding factors showed the hazard ratios for the high- and intermediate risk groups were 2.674 (95% confidence interval [CI], 2.197–3.255) and 1.734 (95% CI, 1.447–2.078), respectively. This association was consistently observed irrespective of proteinuria, age, sex, obesity, or hypertension. The predictive power of this scoring system was lower than that of renal parameters, such as eGFR and proteinuria, but increased when both were included in the prediction model. CONCLUSION: The Framingham risk score predicted incident chronic kidney disease and enhanced risk stratification in conjunction with traditional renal parameters in the general population with normal renal function.

Incidence of Acute Kidney Injury after Adrenalectomy in Patients with Primary Aldosteronism

BACKGROUND@#Aldosterone-induced glomerular hyperfiltration can lead to masked preoperative renal dysfunction in primary aldosteronism(PA) patients. We evaluated whether PA patients had a higher prevalence of acute kidney injury (AKI) after unilateral adrenalectomy. In addition, we identified risk factors for AKI in these subjects.@*METHODS@#This retrospective study included 107 PA patients, and 186 pheochromocytoma patients as a control group, all of whom underwent adrenalectomy between January 2006 and November 2017 at Yonsei University Severance Hospital. The primary outcome was AKI within 48 hours after adrenalectomy. Univariate and multivariate logistic regression analyses were performed to identify predictors of AKI after adrenalectomy.@*RESULTS@#Overall incidence of AKI was 49/293 (16.7%). In PA patients, the incidence of AKI was 29/107 (27.1%). In contrast, incidence of AKI was 20/186 (10.7%) in pheochromocytoma patients. Univariate and multivariate logistic regression analysis both showed a higher risk of postoperative AKI in PA patients compared to pheochromocytoma patients. In addition, old age, diabetes, longer duration of hypertension, lower preoperative estimated glomerular filtration rate, high aldosterone-cortisol ratio (ACR) and lateralization index (LI) were identified as independent risk factors for postoperative AKI in PA patients after unilateral adrenalectomy.@*CONCLUSION@#Incidence and risk of postoperative AKI were significantly higher in PA patients after surgical treatment. High ACR on the tumor side and high LI were associated with higher risk of AKI in PA patients compared to pheochromocytoma patients.

The Effect of Specialized Continuous Renal Replacement Therapy Team in Acute Kidney Injury Patients Treatment

PURPOSE: Continuous renal replacement therapy (CRRT) has been established for critically ill acute kidney injury (AKI) patients. In addition, some centers consist of a specialized CRRT team (SCT) with physicians and nurses. To our best knowledge, however, ona a few studies have yet been carried out on the superiority of SCT management. MATERIALS AND METHODS: A total of 551 patients, who received CRRT between January 2008 and March 2009, were divided into two groups based on the controller of CRRT. The impact of the CRRT management on 28-day mortality was compared between two groups by Kaplan-Meier curve and Cox analysis. RESULTS: During the study period, the number of filters used, down-time per day, and intensive care unit length of day were significantly higher in non-SCT group than in SCT group (6.2 hrs vs. 5.0 hrs, p=0.042; 5.0 hrs vs. 3.8 hrs, p<0.001; 27.5 days vs. 21.1 days, p=0.027, respectively), while net ultrafiltration rate was significantly lower in non-SCT group than SCT group (28.0 mL/kg/hr vs. 29.5 mL/kg/hr, p=0.043, respectively). In addition, 28-day mortality rate was significantly lower in SCT group than with non-SCT group (p=0.031). Moreover, Cox regression analysis showed that 28-day mortality rate was significantly lower in SCT control group, even after adjusting for age, gender, severity scores, biomarkers, risk, injury, failure, loss, and end-stage renal disease, and contributing factors (hazard ratio 0.91, p=0.046). CONCLUSION: A well-trained CRRT team could be beneficial for mortality improvement of AKI patients requiring CRRT.

Etiologies and Underlying Diseases of Leg Edema in Elderly Patients

BACKGROUND: Leg edema is a common symptom among elderly patients with multiple underlying diseases. This study was aimed to investigate the etiologies and underlying diseases of leg edema in elderly patients. METHODS: We retrospectively reviewed medical records of 247 patients aged over 65, who visited an Emergency Department of a tertiary hospital due to leg edema from January 2010 to December 2012. RESULTS: A total of 226 patients with complete medical records were included. The most common cause of leg edema in elderly patients was renal failure (42 cases, 18.6%), followed by heart failure (37 cases, 16.4%), and deep vein thrombosis (32 cases, 14.2%). However, the etiologies were not established in 66 cases (29.2%). Patients with leg edema caused by renal and heart failure had renal (40 cases, 95.2%) and cardiovascular diseases (29 cases, 78.4%), respectively, while others had diabetes mellitus and trauma. Patients with leg edema caused by deep vein thrombosis had underlying conditions such as cancer (13 cases, 40.6%), trauma, surgery within 1 year, and diabetes mellitus. Overall, chronic bilateral edema (120 cases, 53.1%) was most commonly observed form of leg edema in elderly patients. Deep vein thrombosis, cellulitis, and lymphedema usually caused unilateral edema, whereas systemic diseases such as renal failure, heart failure, and liver cirrhosis caused bilateral edema. CONCLUSION: Leg edema in elderly patients is usually caused by systemic diseases such as renal and heart failure closely related to underlying diseases. Therefore, it is important to consider the variety of underlying diseases, when approaching the cause and treatment of leg edema in elderly patients.

Insulin resistance is associated with new-onset cardiovascular events in nondiabetic patients undergoing peritoneal dialysis

BACKGROUND: Chronic exposure to high glucose-containing peritoneal dialysis solution and consequent abdominal obesity are potential sources of insulin resistance in patients requiring prevalent peritoneal dialysis. The aim of this study was to elucidate the prognostic values of insulin resistance on new-onset cardiovascular events in nondiabetic patients undergoing prevalent peritoneal dialysis. METHODS: A total of 201 nondiabetic patients undergoing prevalent peritoneal dialysis were recruited. Insulin resistance was assessed by homeostatic model assessment of insulin resistance (HOMA-IR). The primary outcome was new-onset cardiovascular events during the follow-up period. Cox proportional hazard analysis was performed to ascertain the independent prognostic value of HOMA-IR for the primary outcome. RESULTS: The mean age was 53.1 years and male was 49.3% (n=99). The mean HOMA-IR was 2.6+/-2.1. In multivariate linear regression, body mass index (beta=0.169, P=0.011), triglyceride level (beta=0.331, P<0.001), and previous cardiovascular diseases (beta=0.137, P=0.029) were still significantly associated with HOMA-IR. During a mean follow-up duration of 36.8+/-16.2 months, the primary outcome was observed in 36 patients (17.9%). When patients were divided into tertiles according to HOMA-IR, the highest tertile group showed a significantly higher incidence rate for new-onset cardiovascular events compared to the lower two tertile groups (P=0.029). Furthermore, multivariate Cox analysis revealed that HOMA-IR was an independent predictor of the primary outcome (hazard ratio=1.18, 95% confidence interval=1.03-1.35, P=0.014). CONCLUSION: Insulin resistance measured by HOMA-IR was an independent risk factor for new-onset cardiovascular events in nondiabetic patients undergoing prevalent peritoneal dialysis.

Syndrome of Inappropriate Secretion of Antidiuretic Hormone after Lung Transplantation / 이화의대지

A 54-year-old man was diagnosed as syndrome of inappropriate secretion of antidiuretic hormone (SIADH) 7 days after lung transplantation, whereas the preoperative serum sodium level was normal. Hypertonic saline infusion with furosemide did not improve hyponatremia, however, tolvaptan corrected his serum sodium levels from 123 mEq/L to 131 mEq/L. Seven days after maintenance of tolvaptan, this drug was discontinued and hyponatremia did not occur. Herein, we report a case of SIADH after lung transplantation treated with tolvaptan.