Donor fat-to-muscle ratio and kidney transplant outcomes: A proposition of metabolic memory.

AIMS: The impact of donor abdominal fat-to-muscle ratio (FMR) on kidney transplant (KT) outcomes was assessed. Given the transient nature of the donor's metabolic environment in transplant recipients, this study investigated the capacity of body composition to induce metabolic memory effects. MATERIALS AND METHODS: KT patients (n = 895) who received allografts from living donors (2003-2013) were included. Donor fat and muscle were quantified using pre-KT abdominal computed tomography scans. Patients were categorised into donor FMR tertiles and followed up for graft outcomes. Additionally, genome-wide DNA methylation analysis was performed on 28 kidney graft samples from KT patients in the low- and high-FMR groups. RESULTS: Mean recipient age was 42.9 ± 11.4 years and 60.9% were males. Donor FMR averaged 1.67 ± 0.79. Over a median of 120.9 ± 42.5 months, graft failure (n = 127) and death-censored graft failure (n = 109) were more frequent in the higher FMR tertiles. Adjusted hazard ratios for the highest versus lowest FMR tertile were 1.71 (95% CI, 1.06-2.75) for overall graft failure and 1.90 (95% CI, 1.13-3.20) for death-censored graft failure. Genome-wide DNA methylation analysis identified 58 differentially methylated regions (p < 0.05, |Δß| > 0.2) and 35 genes showed differential methylation between the high- (FMR >1.91) and low-FMR (FMR <1.27) groups. CONCLUSIONS: Donors with increased fat and reduced muscle composition may negatively impact kidney allograft survival in recipients, possibly through the transmission of epigenetic changes, implying a body-composition-related metabolic memory effect.

Effectiveness of regdanvimab on mortality in COVID-19 infected patients on hemodialysis.

BACKGROUND: Although several therapeutic agents have been evaluated for the treatment of coronavirus disease 2019 (COVID-19), there are lack of effective and proven treatments for end-stage renal disease (ESRD). The present study aims to evaluate the effectiveness of regdanvimab on mortality in COVID-19-infected patients on hemodialysis (HD). METHODS: We conducted an observational retrospective study in 230 COVID-19-infected patients on HD, of whom 77 (33.5%) were administered regdanvimab alone or in combination with dexamethasone or remdesivir during hospitalization (regdanvimab group) and 153 patients (66.5%) were not (no regdanvimab group). The primary outcome was in-hospital mortality. We compared mortality rates according to the use of regdanvimab and investigated the factors associated with mortality. RESULTS: Fifty-nine deaths occurred during hospitalization, 49 in the no regdanvimab group (32.0%) and 10 in the regdanvimab group (13.0%), and the mortality rate was significantly higher in the no regdanvimab group than that in the regdanvimab group (p = 0.001). Multivariate Cox regression analysis showed that malignancy (p = 0.001), SPO2 of <95% at admission (p = 0.003), and administration of antibiotics and regdanvimab (p = 0.007 and p = 0.002, respectively) were significantly associated factors with mortality. CONCLUSION: Regdanvimab administration is beneficial in improving prognosis in hospitalized COVID-19 patients on HD. Considering the vulnerability to infection and high mortality of ESRD patients, regdanvimab may be considered as a therapeutic option in COVID-19 patients on HD.

Vitamin D and narrowband ultraviolet B phototherapy for chronic kidney disease-associated pruritus.

BACKGROUND: In addition to improving the serum vitamin D balance, narrowband ultraviolet B (NB-UVB) phototherapy can effectively treat chronic kidney disease-associated pruritus (CKD-aP). We investigated the degree of CKD-aP amelioration according to changes in the serum vitamin D level after NB-UVB phototherapy. METHODS: This was a before-after clinical study in patients with refractory CKD-aP on hemodialysis. NB-UVB phototherapy was administered thrice weekly for 12 weeks. The response of CKD-aP to NB-UVB phototherapy was assessed as the change in pruritus intensity over time. A rapid response was defined as a reduction in the visual analog scale (VAS) score of ≥50% within the first 6 weeks of NB-UVB phototherapy. RESULTS: We included 34 patients in this study. Although serum 25-hydroxy vitamin D [25(OH)D] concentrations increased significantly, by a median of 17.4 ng/mL, after the phototherapy course, other serologic parameters did not change. NB-UVB phototherapy reduced the VAS score for pruritus intensity over time significantly more in patients with Δ25(OH)D of >17.4 ng/mL than in patients with Δ25(OH)D of ≤17.4 ng/mL (p = 0.001). Ten patients were rapid responders. Multivariate logistic regression analysis showed that Δ25(OH)D was independently associated with rapid response (odds ratio, 1.29; 95% confidence interval, 1.02-1.63; p = 0.04). CONCLUSION: The effect of NB-UVB phototherapy on patients with CKD-aP correlated with their increase in serum vitamin D levels. Further well-designed clinical and experimental studies are needed to clarify the relationship between NB-UVB phototherapy and serum vitamin D levels in patients with CKD-aP.

Direct oral anti-Xa anticoagulants versus warfarin in newly diagnosed atrial fibrillation and CKD: the Korean National Health Insurance Data.

Introduction: Despite the benefits of direct oral anti-Xa anticoagulants (DOACs), the risk-benefit profile of DOAC therapy compared to warfarin therapy in patients with non-valvular atrial fibrillation (AF) and chronic kidney disease (CKD), including end-stage renal disease (ESRD), is uncertain. Methods: We conducted a retrospective study using the Korea National Health Insurance Database from 2013 to 2018. We evaluated patients with incident non-valvular AF and CKD. The primary and secondary effectiveness outcomes were ischemic stroke and all-cause mortality. The primary safety outcomes included intracranial hemorrhage, gastrointestinal bleeding, and extracranial or unclassified major bleeding. Results: Among the 1,885 patients evaluated, 970 (51.5%) initiated warfarin therapy, and 915 (48.5%) initiated DOAC therapy. During a mean follow-up period of 23.8 months, there were 293 and 214 cases of ischemic stroke and all-cause death, respectively. Kaplan-Meier survival analysis showed significantly lower all-cause mortality in DOAC users than in warfarin users. In multivariate Cox regression analyses, DOAC therapy had a hazard ratio for all-cause mortality of 0.41 (95% CI, 0.30-0.56; p < 0.001) compared to warfarin therapy. Additionally, DOAC therapy significantly reduced intracranial hemorrhage and gastrointestinal bleeding. Discussion: Our study demonstrates that DOAC therapy has a better risk-benefit profile than warfarin therapy in patients with AF and CKD. Further well-designed clinical trials are needed to clarify the benefits of DOACs in this patient population.

Fibroblast growth factor-23 and cardiovascular disease among prevalent hemodialysis patients focusing on residual kidney function.

Background: In patients undergoing incident hemodialysis, increased fibroblast growth factor-23 (FGF-23) levels are associated with the development of cardiovascular disease (CVD), but the influence of residual kidney function (RFK) on this association is unclear. This study aimed to investigate the association between FGF-23 levels, RKF, and CVD in patients undergoing prevalent hemodialysis. Methods: This cross-sectional and longitudinal observational study included 296 patients undergoing maintenance hemodialysis for at least three months who were followed up for a median of 44 months. RKF was defined as 24-h urine output >200 mL, left ventricular (LV) diastolic dysfunction as E/E' >15 on echocardiographic parameters. CVD was defined as hospitalization or emergency room visits due to cardiovascular causes, such as angina, myocardial infarction, or congestive heart failure. Results: The median intact FGF-23 (iFGF-23) level was 423.8 pg/mL (interquartile range, 171-1,443). Patients with an FGF-23 level > 423.8 pg/mL significantly had a lower proportion of RKF (39.2% vs. 60.1%, P < 0.001) and a higher proportion of LV diastolic dysfunction (54. 1% vs. 29.1%, P < 0.001) than those with an iFGF-23 level ≤ 423.8 pg/mL. The odds ratio (OR) for LV diastolic dysfunction was significantly higher in patients with RFK (OR per one-unit increase in the natural log-transformed iFGF-23 levels, 1.80; 95% confidence interval [CI]: 1.11-2.93) than in patients without RKF (OR per one-unit increase in the natural log-transformed iFGF-23 levels: 1.42; 95% CI: 1.01-1.99) in multivariate analysis (p < 0.001). During the follow-up period, 55 patients experienced CVD. The hazard ratio (HR) for CVD development was also significantly higher in patients with RKF (HR per one-unit increase in the natural log-transformed iFGF-23 levels, 2.64; 95% CI: 1.29-5.40) than those without RKF (HR per one-unit increase in the natural log-transformed iFGF-23 levels: 1.44; 95% CI: 1.04-1.99) in multivariate analysis (p = 0.05). Conclusions: Increased iFGF-23 levels were associated with LV diastolic dysfunction and CVD development in patients undergoing prevalent hemodialysis; however, the loss of RKF attenuated the magnitude of these associations. Therefore, in these patients, RKF strongly influenced the detrimental role of iFGF-23 in the development of CVD.

Urinary Retinol-Binding Protein 4 is Associated With Renal Function and Rapid Renal Function Decline in Kidney Transplant Recipients.

BACKGROUND: Urinary retinol-binding protein 4 (RBP4) has been known as a biomarker of chronic kidney disease. In this study, we evaluated the association of urinary RBP4 with renal function and progression of renal function in kidney transplant recipients (KTRs). METHODS: A total 50 KTRs were included in this study. Proteomic analysis with liquid chromatography-mass spectrometry and tandem mass spectrometry was performed to discover potential urinary biomarkers. Several urinary proteins including RBP4 were identified and then validated by enzyme-linked immunosorbent assay. Rapid renal function decline was defined as estimated glomerular filtration rate (eGFR) decline of >3 mL/min/1.73 m2/year or initiation of dialysis, and 19 (38%) were included in rapid renal function decline group. RESULTS: Urinary RBP4/creatinine was inversely correlated with allograft function (r = -0.54, P < .001 with eGFR, and r = 0.49, P < .001 with serum creatinine, respectively). Urinary RBP4/creatinine was higher in rapid renal function decline group than in stable renal function group (184.9 ± 156.7 vs 83.1 ± 99.9, P = .017). Log-transformed urinary RBP4/creatinine was significantly associated with rapid renal function decline in univariate logistic regression analysis (Odds ratio [OR] 7.59, confidence interval [CI] 2.04-36.70, P = .005). In multivariate logistic regression adjusted with recipient age and sex, donor age, number of HLA mismatch, and acute rejection episode, urinary RBP4/creatinine remained a significant factor for rapid renal function decline (OR 9.43, CI 1.99-65.65, P = .010). Receiver operating characteristic analysis showed that the area under the curve of urinary RBP4/creatinine was 0.747 (CI 0.608-0.886, P < .001) for rapid renal function decline. CONCLUSIONS: Urinary RBP4 levels are associated with renal function and might be used to predict rapid renal function decline in KTRs.

Hypochromic red cells as predictors of anemia in patients undergoing hemodialysis: an observational retrospective study.

The percentage of hypochromic red blood cells (%HRC) estimates the availability of iron by evaluating the degree of hemoglobinization. We investigated whether %HRC was a predictor of anemia in patients undergoing hemodialysis. We recruited 142 patients undergoing routine hemodialysis between 2017 and 2019. Delta hemoglobin level (ΔHb)1mo-baseline was calculated as the difference between the hemoglobin level at 1 month after study enrollment and that at the time of study enrollment. Development of anemia was defined as hemoglobin level ≤ 15% of baseline. The median %HRC was 3.1%. There was a significant negative correlation between (ΔHb)1mo- baseline and %HRC (r = - 0.63, P < 0.001). The incidence of anemia was significantly higher in patients with %HRC > 3.1% than in those with %HRC ≤ 3.1%. In the multivariate logistic regression analysis, %HRC was significantly related to the development of anemia (odds ratio 2.57, 95% confidence interval [CI] 1.72-3.85, P < 0.001). The best cutoff value for %HRC to predict the development of anemia was 4.3%, with a sensitivity and specificity of 67.74 (95% CI, 54.7-79.1) and 97.50 (95% CI, 91.3- 99.7), respectively. %HRC is an independent predictor of anemia in patients undergoing hemodialysis. %HRC ≤ 4.3% is an early marker to consider changing the anemia treatment.

Effect of Extracorporeal Shock Wave Therapy on Muscle Mass and Function in Patients Undergoing Maintenance Hemodialysis: A Randomized Controlled Pilot Study.

Patients undergoing maintenance hemodialysis (MHD) are susceptible to muscle wasting and decreased muscle function, resulting in shorter survival time. This study was aimed at evaluating the effect of radial extracorporeal shock wave therapy (rESWT) on muscle mass and function in patients on MHD. This single blind controlled study was conducted on patients on MHD from September 2018 to December 2019. Eighteen patients were enrolled in the rESWT and control groups. rESWT was performed once a week for 12 wk in both quadriceps femoris muscles of the ESWT group. Finally, 15 patients were assessed for body composition, handgrip strength, physical performance and blood chemistry before rESWT, after rESWT and at a 12-wk follow-up. Leg lean mass and appendicular skeletal muscle mass index increased significantly in the ESWT group compared with the control group (p = 0.001 and p = 0.017). The timed up-and-go test and sit-to-stand tests revealed greater significant improvement in the ESWT group (p = 0.023 and p = 0.046). This study is the first to report that rESWT can improve muscle mass and function in MHD patients. A subsequent study will be conducted to validate the clinical effects of rESWT in a larger sample of patients undergoing MHD.

Comparison of Different Types of Oral Adsorbent Therapy in Patients with Chronic Kidney Disease: A Multicenter, Randomized, Phase IV Clinical Trial.

PURPOSE: Oral adsorbents delay disease progression and improve uremic symptoms in patients with chronic kidney disease (CKD). DW-7202 is a newly developed oral adsorbent with high adsorptive selectivity for uremic toxins. We evaluated patient preference for and adherence to DW-7202 versus AST-120 therapy and compared treatment efficacy and safety in patients with pre-dialysis CKD. MATERIALS AND METHODS: A seven-center, randomized, open-label, two-way crossover, active-controlled, phase IV clinical trial was conducted. Patients with stable CKD were randomly assigned to receive DW-7202 (capsule type) or AST-120 (granule type) for 12 weeks. The groups then switched to the other adsorbent and took it for the next 12 weeks. Patient preference was the primary outcome. Secondary outcomes included changes in estimated glomerular filtration rate (eGFR) and serum creatinine, cystatin C, and indoxyl sulfate (IS) levels. RESULTS: Significantly more patients preferred DW-7202 than AST-120 (p<0.001). Patient adherence improved after switching from AST-120 to DW-7202; there was no apparent change in adherence after switching from DW-7202 to AST-120. Changes in eGFR and serum creatinine, cystatin C, and IS levels were not significantly different according to adsorbent type. There was also no significant difference in the incidences of adverse events during treatment with DW-7202 and AST-120. CONCLUSION: DW-7202 can be considered as an alternative to AST-120 in patients who cannot tolerate or show poor adherence to granule type adsorbents. Further studies to evaluate factors affecting patient preferences and improved adherence are warranted (Clinical trial registration No. NCT02681952).

Dyschloremia is associated with failure to restore renal function in survivors with acute kidney injury: an observation retrospective study.

Dyschloremia is common in critically ill patients. However, little is known about the effects of dyschloremia on renal function in patients with acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT). A total of 483 patients who received CRRT for AKI were selected and divided into three groups according to their serum chloride concentrations at the time of CRRT initiation. At 90 days after initiating CRRT, renal outcome, i.e., non-complete renal recovery, or renal failure, was assessed in the three groups. The hypochloremia group (serum chloride concentrations < 96 mEq/L, n = 60), the normochloremia group (serum chloride concentrations, 96-111 mEq/L, n = 345), and the hyperchloremia group (serum chloride concentrations > 111 mEq/L, n = 78) were classified. The simplified acute physiology score III was higher in the hyperchloremia and hypochloremia groups than in the normochloremia group. Multivariate logistic regression analyses showed that hypochloremia (odds ratio, 5.12; 95% confidence interval [CI], 2.56-10.23; P < 0.001) and hyperchloremia (odds ratio, 2.53; 95% CI, 1.25-5.13; P = 0.01) were significantly associated with non-complete renal recovery. Similar trends were observed for renal failure. This study showed that dyschloremia was independently associated with failure in restoring renal function following AKI.

Sex differences in the blood pressure level associated with increased risks of cardiovascular events: a Korean nationwide population-based cohort study.

Hypertension is a leading risk factor for cardiovascular events and death. Despite differences in clinical implications of hypertension between men and women, guidelines establishing optimal blood pressure (BP) targets are still debated. The aim of this study was to investigate sex differences in the BP level associated with increased risks of major adverse cardiac and cerebral events (MACCEs) among antihypertensive-treated patients. Using data from the Korean National Health Insurance Service-National Sample Cohort, we enrolled antihypertensive-treated patients and divided them into four categories: Group 1: SBP < 120 and DBP < 80 mm Hg; Group 2: 120 ≤ SBP < 130 and DBP < 80 mm Hg; Group 3: 130 ≤ SBP < 140 or 80 ≤ DBP < 90 mm Hg; and Group 4: SBP ≥ 140 or DBP ≥ 90 mm Hg. We performed time-dependent cox regression analysis to investigate sex differences in the BP levels that increased the risk of MACCEs. Most of the 98 267 patients fell into Group 3 (53.2% men and 52.8% women) and Group 4 (30.5% men and 28.1% women). During 8.34 ± 2.07 years, there were 8,813 MACCEs and 791 deaths. The incidences of MACCEs and death tended to increase as the BP increased in both sexes. Compared to Group 1, the risk of MACCEs significantly increased only in Group 4 for men, while it significantly increased in Groups 3 and 4 for women. This study shows that there are sex differences in the BP level at which the risk of MACCEs increases. Our finding suggests that sex should be significantly considered when determining the optimal BP target in patients undergoing hypertension treatment.

High-protein diet with renal hyperfiltration is associated with rapid decline rate of renal function: a community-based prospective cohort study.

BACKGROUND: The effect of a high-protein diet with renal hyperfiltration (RHF) on decline of kidney function has rarely been explored. We investigated the association between a high-protein diet, RHF and declining kidney function. METHODS: A total of 9226 subjects from the Korean Genome and Epidemiology Study, a community-based prospective study (2001-14), were enrolled and classified into quartiles according to daily amount of protein intake based on food frequency questionnaires. RHF was defined as estimated glomerular filtration rate (eGFR) with residuals of >95th percentile after adjustment for age, sex, history of hypertension or diabetes, height and weight. Rapid decline of renal function was defined as decline rate of eGFR >3 mL/min/1.73 m2/year. RESULTS: The relative risk of RHF was 3.48-fold higher in the highest than in the lowest protein intake quartile after adjustment for confounding factors [95% confidence interval (CI) 1.39-8.71]. The mean eGFR decline rate was faster as quartiles of protein intake increased. Furthermore, the highest quartile was associated with 1.32-fold increased risk of rapid eGFR decline (95% CI 1.02-1.73). When subjects were divided into two groups with or without RHF, the highest quartile was associated with a rapid decline in renal function only in RHF subjects (odds ratio 3.35; 95% CI 1.07-10.51). The sensitivity analysis using the Korean National Health and Nutrition Examination Survey (2008-15) data with 40 113 subjects showed that higher quartile was associated with increased risk for RHF. CONCLUSIONS: A high-protein diet increases the risk of RHF and a rapid renal function decline in the general population. These findings suggest that a high-protein diet has a deleterious effect on renal function in the general population.

The interactive effects of input and output on managing fluid balance in patients with acute kidney injury requiring continuous renal replacement therapy.

BACKGROUND: The interactive effect of cumulative input and output on achieving optimal fluid balance has not been well elucidated in patients with acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT). This study evaluated the interrelation of fluid components with mortality in patients with AKI requiring CRRT. METHODS: This is a retrospective observational study conducted with a total of 258 patients who were treated with CRRT due to AKI between 2016 and 2018 in the intensive care unit of Ewha Womans University Mokdong Hospital. The amounts of fluid input and output were assessed at 24-h and 72-h from the initiation of CRRT. The study endpoints were 7- and 28-day all-cause mortality. RESULTS: The mean patient age was 64.7 ± 15.8 years, and 165 (64.0%) patients were male. During the follow-up, 7- and 28-day mortalities were observed in 120 (46.5%) and 157 (60.9%) cases. The patients were stratified into two groups (28-day survivors vs. non-survivors), and the cumulative fluid balances (CFBs) at 24 h and 72 h were significantly higher in the 28-day non-survivors compared with the survivors. The increase in 24-h and 72-h CFB was significantly associated with an increase in 7- and 28-day mortality risks. To examine the interactive effect of cumulative input or output on the impact of CFB on mortality, we also stratified patients into three groups based on the tertile of 24-h and 72-h cumulative input or output. The increases in 24-h and 72-h CFBs were still significantly related to the increases in 7-day and 28-day mortality, irrespective of the cumulative input. However, we did not find significant associations between increase in 24-h and 72-h CFB and increase in mortality risk in the groups according to cumulative output tertile. CONCLUSIONS: The impact of cumulative fluid balance on mortality might be more dependent on cumulative output. The physicians need to decrease the cumulative fluid balance of CRRT patients as much as possible and consider increasing patient removal.

The Association of Glomerular Glucocorticoid Receptor Expression with Responsiveness to Corticosteroid Treatment in IgA Nephropathy.

BACKGROUND: Corticosteroids can be used to treat IgA nephropathy (IgAN). However, responsiveness to these drugs is highly variable and unpredictable. Corticosteroids act by binding glucocorticoid receptors (GCRs). Therefore, we evaluated the association between GCR expression and responsiveness to corticosteroid treatment in IgAN. METHODS: We screened 78 IgAN patients receiving steroid treatment between 2010 and 2016. Of these, 33 patients met study inclusion criteria. Glomerular GCR expression was assessed by real-time polymerase chain reaction. Complete remission (CR) and partial remission (PR) were defined as a spot urine protein-to-creatinine ratio (UPCR) of <0.3 g/g and a ≥50% reduction of proteinuria from baseline along with UPCR of ≥0.3 g/g, respectively. Disease progression was defined as a ≥30% decrease in estimated glomerular filtration rate (eGFR) from baseline. RESULTS: The mean age of study patients was 43.9 ± 11.6 years (25 males and 8 females). All 33 patients responded to steroid treatment; CR and PR occurred in 14 (42.4%) and 18 (54.5%) patients, respectively. One patient did not achieve PR, but proteinuria was decreased after treatment. There were no significant differences in baseline eGFR and proteinuria between CR and non-CR groups. GCR mRNA expression was significantly higher in the CR group compared to that in the non-CR group. Immunohistochemistry confirmed higher GCR expression in the CR group. During a median follow-up of 20.6 months, 1 (7.1%) patient in the CR group had disease progression, as compared to 8 (42.1%) patients in non-CR group (p = 0.03). CONCLUSION: This study suggests that responsiveness to corticosteroid may differ depending on the degree of glomerular GCR expression in IgAN.

A Diet Rich in Vegetables and Fruit and Incident CKD: A Community-Based Prospective Cohort Study.

RATIONALE & OBJECTIVE: A diet rich in vegetables and fruit can lower blood pressure and may reduce cardiovascular risk. However, the association between this dietary pattern and incident chronic kidney disease in the general population is unknown. STUDY DESIGN: A community-based prospective cohort study. SETTING & PARTICIPANTS: 9,229 study participants with normal kidney function from the Korean Genome and Epidemiology Study database. PREDICTORS: Daily consumption of nonfermented and fermented vegetables and fruit classified into tertiles based on a validated semiquantitative food-frequency questionnaire. OUTCOMES: Incident occurrence of estimated glomerular filtration rate (eGFR) < 60mL/min/1.73m2, incident proteinuria (≥1+ by dipstick test), and repeated measures of estimated net endogenous acid production. ANALYTICAL APPROACH: Multivariable cause-specific hazards model to assess the association of vegetable and fruit intake with incident chronic kidney disease. RESULTS: During a mean follow-up of 8.2 years, 1,741 (21.9/1,000 person-years [PY]) participants developed eGFRs < 60mL/min/1.73m2. Incident eGFR < 60mL/min/1.73m2 occurred less frequently with higher intake of nonfermented vegetables, occurring at rates of 22.8/1,000 PY, 22.7/1,000 PY, and 20.1/1,000 PY for the lowest, middle, and highest tertiles, respectively; P for trend < 0.001. The incidence of proteinuria was also lower in the middle and highest tertiles. In a multivariable cause-specific hazards model, the highest tertile of nonfermented vegetable intake was associated with 14% lower risk for incident eGFR < 60mL/min/1.73m2 than the lowest tertile. The highest tertile was also associated with 32% lower risk for proteinuria than the lowest tertile. There were no associations of fermented vegetable and fruit intake with incidence of eGFR < 60mL/min/1.73m2. However, the highest tertiles of both fermented vegetable and fruit intake were associated with 14% and 45% lower risks for incident proteinuria compared with the lowest tertiles (both P < 0.001). During follow-up, estimated net endogenous acid production increased in the lowest tertile of intake of nonfermented or fermented vegetables and fruit, whereas it decreased in the highest tertile. LIMITATIONS: Self-reported dietary intake, single ethnicity population. CONCLUSIONS: A diet rich in vegetables and fruit may reduce the risk for kidney disease.

Incidence of and risk factors for delayed acute kidney injury in patients undergoing colorectal surgery.

BACKGROUND: The risk of delayed AKI (AKI development beyond the perioperative period) in patients undergoing colorectal surgery is greater than that in patients undergoing other major operations. However, the characteristics of and risk factors for delayed AKI are unclear. METHODS: We investigated 683 patients who underwent colorectal surgery with intestinal resection at a single tertiary hospital. All patients were followed-up for a year postoperatively. The primary outcome was the development of AKI during follow-up. RESULTS: AKI occurred in 177 (25.9%) during the first postoperative year. Patients who developed AKI were significantly older, showed a lower body mass index, and significantly lower preoperative hemoglobin and serum albumin levels. AKI occurred most commonly during the first 3 months postoperatively. However, AKI occurred persistently even after this initial period. Older age, lower preoperative serum albumin levels, and late ostomy closure were independently associated with a higher risk of delayed AKI. CONCLUSION: AKI commonly occurs beyond the perioperative period. Careful risk stratification and modification of risk factors may prevent delayed AKI in patients undergoing colorectal cancer surgery.

Secondhand Smoke and CKD.

BACKGROUND AND OBJECTIVES: Active smoking is associated with higher risk of various diseases. However, the risk of CKD development in nonsmokers exposed to secondhand smoke is not well elucidated. We aimed to investigate the association between secondhand smoke exposure and the risk of CKD development among never-smokers. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A total of 131,196 never-smokers with normal kidney function, who participated in the Korean Genome and Epidemiology Study from 2001 to 2014, were analyzed. The participants were classified into three groups on the basis of frequency of secondhand smoke exposure, assessed with survey questionnaires; no exposure, <3 days per week, and ≥3 days per week. The association between secondhand smoke and CKD, defined as eGFR<60 ml/min per 1.73 m2, was examined in the cross-sectional analysis. In addition, the risk of incident CKD development was analyzed in a longitudinal cohort of 1948 participants without CKD at baseline, which was a subset of the main cohort. RESULTS: The mean age of participants was 53 years, and 75% were women. Prevalent CKD was observed in 231 (1.8%), 64 (1.7%), and 2280 (2.0%) participants in the ≥3 days per week, <3 days per week, and no exposure groups. The odds ratio (OR) of prevalent CKD was significantly higher in the groups exposed to secondhand smoke than the no exposure group (<3 days per week: OR, 1.72; 95% confidence interval [95% CI], 1.30 to 2.27; and ≥3 days per week: OR, 1.44; 95% CI, 1.22 to 1.70). During a mean follow-up of 104 months, CKD occurred in 319 (16%) participants. Multivariable Cox analysis revealed that the risk for CKD development was higher in participants exposed to secondhand smoke than the no exposure group (<3 days per week: hazard ratio, 1.59; 95% CI, 0.96 to 2.65; and ≥3 days per week: hazard ratio, 1.66; 95% CI, 1.03 to 2.67). CONCLUSIONS: Exposure to secondhand smoke was associated with a higher prevalence of CKD as well as development of incident CKD.

Differential effects of arterial stiffness and fluid overload on blood pressure according to renal function in patients at risk for cardiovascular disease.

The pathogenesis of hypertension is multifactorial in patients with chronic kidney disease (CKD). We explored the relative contribution of arterial stiffness and fluid overload to blood pressure (BP) in these patients. We evaluated 1531 patients from a prospective observational cohort study of high-risk patients with cardiovascular disease. BP, arterial stiffness, and volume status expressed as the extracellular water/total body water ratio (ECW/TBW) were measured by 24-h BP monitoring, pulse-wave velocity (PWV), and bioelectrical impedance analysis, respectively. Multiple linear regression analysis showed that both PWV and ECW/TBW of the patients with CKD were significantly associated with 24-h systolic BP (SBP). The areas under the receiver-operating characteristic curve (AUCs) for predicting 24-h SBP ≥130 mm Hg significantly increased after PWV was added to conventional factors regardless of CKD status. However, the AUCs did not increase in the ECW/TBW-based models. When a cut-off 24-h SBP level of 140 mm Hg was used, the predictability of ECW/TBW for elevated BP significantly improved in patients with CKD (0.718 vs. 0.683, P = 0.034) but not in those without. Notably, a significant impact of arterial stiffness on high BP was consistently observed regardless of CKD status. This association was further confirmed by the net reclassification and integrated discriminant improvements, root mean squared error with adjusted R2, and interaction effects. As kidney function declines, fluid overload is significantly associated with high BP. The impact of fluid overload on BP is only observed in more severe hypertension in patients with CKD.

Severe vitamin D deficiency is a risk factor for renal hyperfiltration.

Background: Vitamin D deficiency is associated with renal progression in chronic kidney disease. Moreover, improvement of clinical outcomes after vitamin D supplementation has been reported in the diabetic and chronic kidney disease population. Objective: We investigated the association between renal hyperfiltration (RHF) and vitamin D status in a relatively healthy population. Design: Data were retrieved from the Korean NHANES, a nationwide population-based cross-sectional study from 2008 to 2015. Overall, 33,210 subjects with normal renal function were included in the final analysis. Severe vitamin D deficiency was defined as serum 25-hydroxyvitamin D concentration <10 ng/mL. RHF was defined as estimated glomerular filtration rate with residual in the >95th percentile after adjustment for age, sex, height, weight, and history of hypertension or diabetes. Results: The mean ± SD age of subjects was 48.1 ± 15.9 y, and the number of women was 18,779 (56.5%). Estimated glomerular filtration rate was negatively associated with serum 25-hydroxyvitamin D concentrations in multivariable linear regression analysis (ß: -0.02; 95% CI: -0.02, -0.01; P < 0.001). Furthermore, 1637 (4.9%) subjects were categorized into the RHF group, and the prevalence of RHF was significantly higher in the severe vitamin D deficiency group than in the sufficiency group (5.8% compared with 5.0%, P < 0.001). In a multivariable logistic regression model, severe vitamin D deficiency was a significant risk factor for RHF (OR: 2.41; 95% CI, 1.72, 3.43; P < 0.001). Conclusions: Severe vitamin D deficiency is significantly associated with increasing prevalence of RHF in a relatively healthy adult population.

Factors Associated with Early Mortality in Critically Ill Patients Following the Initiation of Continuous Renal Replacement Therapy.

Continuous renal replacement therapy (CRRT) is an important modality to support critically ill patients, and the need for CRRT treatment has been increasing. However, CRRT management is costly, and the associated resources are limited. Thus, it remains challenging to identify patients that are likely to have a poor outcome, despite active treatment with CRRT. We sought to elucidate the factors associated with early mortality after CRRT initiation. We analyzed 240 patients who initiated CRRT at an academic medical center between September 2016 and January 2018. We compared baseline characteristics between patients who died within seven days of initiating CRRT (early mortality), and those that survived more than seven days beyond the initiation of CRRT. Of the patients assessed, 130 (54.2%) died within seven days of CRRT initiation. Multivariate logistic regression models revealed that low mean arterial pressure, low arterial pH, and high Sequential Organ Failure Assessment score before CRRT initiation were significantly associated with increased early mortality in patients requiring CRRT. In conclusion, the mortality within seven days following CRRT initiation was very high in this study. We identified several factors that are associated with early mortality in patients undergoing CRRT, which may be useful in predicting early outcomes, despite active treatment with CRRT.