SARS-CoV-2 vaccine effectiveness and clinical outcomes in hemodialysis patients: the NHIS-COVID-19 cohort study in South Korea.

Background: Patients undergoing hemodialysis (HD) have a high risk of novel coronavirus disease 2019 (COVID-19) and poor clinical outcomes. This study aimed to investigate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine effectiveness against infection and deaths in the South Korean population undergoing HD. Methods: We conducted a retrospective cohort study to compare the incidence of COVID-19 and post-diagnosis mortality between patients who were either never vaccinated or fully or partially vaccinated. The Korean nationwide COVID-19 registry and the Korean National Health Insurance Service databases were used. Adult patients without a history of COVID-19 were included between October 8, 2020, and December 31, 2021. The study outcomes were COVID-19 diagnosis, severe clinical COVID-19-related events, and post-diagnosis death. Results: Eighty-five thousand eighteen patients undergoing HD were included, of whom 69,601 were fully vaccinated, 2,213 were partially vaccinated and 13,204 were unvaccinated. Compared with the unvaccinated group, the risk of being diagnosed with COVID-19 in patients who were fully vaccinated decreased during the study period (adjusted odds ratio [aOR] = 0.147; 95% confidence interval [CI] = 0.135-0.159). There were 1,140 (1.3%) patients diagnosed with COVID-19. After diagnosis, fully vaccinated patients were significantly less likely to die than unvaccinated patients (aOR = 0.940; 95% CI = 0.901-0.980) and to experience severe clinical events (aOR = 0.952; 95% CI = 0.916-0.988). Conclusion: Full vaccination against COVID-19 was associated with a reduced risk of both infection and severe clinical outcomes in the South Korean population undergoing HD. These findings support the use of vaccination against SARS-CoV-2 among patients undergoing HD.

Geriatric Nutritional Risk Index and First-Year Mortality in Incident Hemodialysis Patients.

OBJECTIVE: The Geriatric Nutritional Risk Index is a simple nutritional screening method, and this study aimed to investigate the association between the initial Geriatric Nutritional Risk Index and all-cause mortality in incident patients in the first year after the initiation of hemodialysis. MATERIALS AND METHODS: This study is a retrospective cohort study and used the Korean Renal Data System database. Patients who were eligible for Geriatric Nutritional Risk Index assessment and underwent hemodialysis from January 2016 to December 2019 were included. The primary outcome was all-cause mortality, and outcome evaluation was performed in December 2020. A Cox proportional hazard model was used to analyze the association between the Geriatric Nutritional Risk Index and mortality. RESULTS: A total of 10,545 patients were included, and the mean age was 63.9 ± 3.7 years. The patients were divided into four groups by the quartile of the Geriatric Nutritional Risk Index with a mean value of 96.2 ± 8.2. During the study period, 545 (5.2%) deaths occurred. The surviving patients had higher Geriatric Nutritional Risk Index values than ones who died in the first year of hemodialysis initiation (96.6 ± 7.5 vs. 88.2 ± 9.3, p < 0.001). Quartile 1 (Geriatric Nutritional Risk Index < 91.8) showed a significantly increased risk of all-cause (Hazard Ratio: 2.56; 95% Confidence Interval: 2.13-3.09; p < 0.001) and cardiovascular mortality (Hazard Ratio: 22.29; 95% Confidence Interval: 1.71- 3.08; p < 0.001) at the first year in comparison with Quartile 4 (Geriatric Nutritional Risk Index ≥ 101.3). In areas under the receiver-operating characteristic curves of all-cause mortality, the Geriatric Nutritional Risk Index model improved predictive values, compared to the baseline model. The area with the Geriatric Nutritional Risk Index model was significantly higher than the one with a model including albumin or body mass index (p < 0.001). CONCLUSIONS: These findings suggest that a low Geriatric Nutritional Risk Index (<91.8) is associated with first-year all-cause and cardiovascular mortality in patients who start hemodialysis and may be a useful and reproducible tool for assessing prognoses in this population.

Remaining life expectancy of Korean hemodialysis patients: how much longer can they live?

Background: Hemodialysis (HD) patients have a higher mortality rate compared to the general population. However, no study has investigated life expectancy in Korean HD patients so far. Therefore, this study aimed to calculate the remaining life expectancy among Korean maintenance HD patients and compare it to those of the general population as well as HD patients from other countries. Methods: Baseline data were retrieved from HD quality assessment data from 2015. Among the patients over 30 years old who were alive at the beginning of 2016 (20,304 males and 14,264 females), a total of 22,078 (12,621 males and 9,457 females) were still alive at the end of 2021 while 12,490 (7,683 males and 4,807 females) were deceased during 6 years of follow-up. We used the life table method to calculate the expected remaining years of life in 2-year increments. Results: The remaining life expectancies for 60-year-old patients were 11.64 years for males and 14.64 years for females. The average remaining lifetimes of the HD population were only about half of the general population. Diabetic patients demonstrated shorter life expectancy compared to patients with hypertension or glomerulonephritis. The remaining life expectancy of Korean HD patients was similar to that of Japanese and was almost double that of HD patients in Western countries such as Europe and the United States. Conclusion: The HD population shows shorter life expectancy compared to the general population. Longitudinal analysis should be warranted to analyze the effect of advanced dialysis technology on improved survival rates among the HD population.

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.

Geriatric Nutritional Risk Index as a Prognostic Factor for Renal Progression in Patients with Type 2 Diabetes Mellitus.

The aim of this study was to evaluate whether the geriatric nutritional risk index (GNRI) is associated with chronic kidney disease (CKD) progression in patients with type 2 diabetes mellitus (DM). In total, 1100 patients with type 2 DM with a follow-up duration > 1 year were included in this longitudinal study. The risk of CKD progression was assessed according to GNRI quartiles. Patients in the lowest GNRI quartile exhibited a significantly lower estimated glomerular filtration rate (eGFR), compared with those in quartile four. Moreover, these patients had poorer glycemic control and lower hemoglobin levels, body mass index, and albumin levels. Additionally, they exhibited a greater annual decline in eGFR. Multivariate logistic regression analysis showed that old age (>60 years), baseline eGFR, the presence of proteinuria, the use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and low GNRI were significantly associated with CKD progression. GNRI may serve as a valuable predictive tool for identifying the risk of adverse renal outcomes in patients with type 2 DM. It may potentially serve as a more feasible measure for assessing the nutritional status of these patients, as well as for predicting their clinical outcomes.

Regular laboratory testing and patient survival among patients undergoing maintenance hemodialysis: a Korean nationwide cohort study.

Routine laboratory tests are regularly performed in patients undergoing maintenance hemodialysis (HD) to detect anemia, chronic kidney disease-mineral bone disorders, and cardiovascular disease. More frequent laboratory tests may be associated with better outcomes. However, there is little evidence supporting a specific monitoring interval. This study evaluated the impact of regular laboratory testing on mortality in Korean patients undergoing maintenance HD. We used HD quality assessments, and National Health Insurance Service claims data from October to December 2015. In HD quality assessment, 22 tests are recommended every 1-6 months. A total of 34,950 patients were divided into two groups based on the regularity of laboratory testing. A Cox proportional hazards model was used to assess the effects of regular laboratory tests on patient mortality during a mean follow-up duration of 53.7 months. The proportion of patients with and without regular laboratory testing was 85.6% (n = 29,914) and 14.4% (n = 5036), respectively. Patients who underwent regular laboratory testing had a longer dialysis duration, lower serum phosphorus levels and diastolic blood pressure, and higher hemoglobin and single-pool Kt/V levels than those who did not. After adjusting for demographic and clinical parameters, regular laboratory testing independently reduced mortality risk (hazard ratio, 0.90; 95% confidence interval 0.85-0.95; P < 0.001). Regular laboratory testing was associated with a decreased mortality risk among patients undergoing HD. Management of end-stage kidney disease-related complications based on laboratory tests can improve survival.

The Geriatric Nutritional Risk Index Is an Optimal Evaluation Parameter for Predicting Mortality in Adult All Ages Hemodialysis Patients: A Korean Population-Based Study.

The Geriatric Nutritional Risk Index (GNRI) is a nutritional screening tool used for predicting mortality in patients undergoing hemodialysis (HD). This study investigated the cutoff values for the GNRI for predicting mortality in HD patients using Korean HD quality assessment data from 2015. To identify the optimal GNRI cutoff value, we used Harrell's C-index with multivariate Cox regression models. The highest value of C-index was identified as the cutoff value of GNRI for all-cause mortality in this population. In total, 34,933 patients were included; 90.8 of GNRI was the highest value of C-index, and it was used as a cutoff value to predict mortality; 3311 patients (9.5%) had GNRI values < 90.8, and there were 12,499 deaths during the study period. The mean follow-up period was 53.7 months. The crude mortality rates in patients with GNRI values < 90.8 and ≥ 90.8 were 160.4/1000 and 73.2/1000 person-years respectively. In the fully adjusted Cox model, patients with a GNRI < 90.8 had a 1.78 times higher risk of mortality than those with a GNRI ≥ 90.8. These findings suggest that the optimal GNRI cutoff value is 90.8 for predicting mortality in maintenance HD patients.

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.

Mortality and Risk Factors in Very Elderly Patients Who Start Hemodialysis: Korean Renal Data System, 2016-2020.

INTRODUCTION: The number of elderly patients with end-stage renal disease (ESRD) is increasing worldwide. However, decision-making about elderly patients with ESRD remains complex because of the lack of studies, especially in very elderly patients (≥75 years). We examined the characteristics of very elderly patients starting hemodialysis (HD) and the associated mortality and prognostic factors. METHODS: Data were analyzed retrospectively using a nationwide cohort registry, the Korean Renal Data System. Patients who started HD between January 2016 and December 2020 were included and divided into three groups according to age at HD initiation (<65, 65-74, and ≥75 years). The primary outcome was all-cause mortality during the study period. Risk factors for mortality were analyzed using Cox proportional hazard models. RESULTS: In total, 22,024 incident patients were included with 10,006, 5,668, and 6,350 in each group (<65, 65-74, and ≥75 years, respectively). Among the very elderly group, women had a higher cumulative survival rate than men. The survival rate was lower in patients with vascular access via a catheter than in those with an arteriovenous fistula or graft. Very elderly patients with more comorbid diseases had a significantly lower survival rate than those with fewer comorbidities. In the multivariate Cox models, old age, cancer presence, catheter use, low body mass index, low Kt/V, low albumin concentration, and capable status of partial self-care were associated with high risk of mortality. CONCLUSION: Preparation of an arteriovenous fistula or graft when starting HD should be considered in very elderly patients with fewer comorbid diseases.

Dialysis specialist care and patient survival in hemodialysis facilities: a Korean nationwide cohort study.

BACKGROUND: It is important for the dialysis specialist to provide essential and safe care to hemodialysis (HD) patients. However, little is known about the actual effect of dialysis specialist care on the survival of HD patients. We therefore investigated the influence of dialysis specialist care on patient mortality in a nationwide Korean dialysis cohort. METHODS: We used an HD quality assessment and National Health Insurance Service claims data from October to December 2015. A total of 34,408 patients were divided into two groups according to the proportion of dialysis specialists in their HD unit, as follows: 0%, no dialysis specialist care group, and ≥50%, dialysis specialist care group. We analyzed the mortality risk of these groups using the Cox proportional hazards model after matching propensity scores. RESULTS: After propensity score matching, 18,344 patients were enrolled. The ratio of patients from the groups with and without dialysis specialist care was 86.7% to 13.3%. The dialysis specialist care group showed a shorter dialysis vintage, higher levels of hemoglobin, higher single-pool Kt/V values, lower levels of phosphorus, and lower systolic and diastolic blood pressures than the no dialysis specialist care group. After adjusting demographic and clinical parameters, the absence of dialysis specialist care was a significant independent risk factor for all-cause mortality (hazard ratio, 1.10; 95% confidence interval, 1.03-1.18; p = 0.004). CONCLUSION: Dialysis specialist care is an important determinant of overall patient survival among HD patients. Appropriate care given by dialysis specialists may improve clinical outcomes of patients undergoing HD.

Impact of needle type on substitution volume during online hemodiafiltration: plastic cannulae versus metal needles.

BACKGROUND: Plastic cannulae have attracted increasing interest as an alternative to traditional metal needles with the aim of reducing cannulation-related complications. We investigated whether the substitution volumes during hemodiafiltration differ using these two types of needles in dialysis patients. METHODS: An intervention study involving 26 hemodialysis patients was conducted in Korea between March and September in 2021. Patients first received online hemodiafiltration using traditional metal needles, and thereafter plastic cannulae were used in a stepwise protocol. Repeated-measures design and linear mixed-effect models were used to compare substitution volumes between the two needle types with the same inner diameter. RESULTS: The mean patient age was 62.7 years, and their mean dialysis vintage was 95.2 months. Most patients (92.3%) had an arteriovenous fistula as the vascular access. The substitution volume increased as blood flow and needle size increased for both plastic cannulae and metal needles. The substitution volume was significantly higher with 17-gauge (G) plastic cannulae than with 16-G metal needles at blood flow rates of 280, 300, and 330 mL/min. Similar results were obtained for 15-G metal needles and 16-G plastic cannulae at a blood flow rate of 330 mL/min. However, the patient ratings of pain on a visual analogue scale were higher for plastic cannulae. CONCLUSION: Higher substitution volumes were obtained at the same prescribed blood flow rate with plastic cannulae than with metal needles during online hemodiafiltration. Plastic cannulae are an option for achieving high-volume hemodiafiltration for patients with low blood flow rates.

Hemodialysis facility star rating affects mortality in chronic hemodialysis patients: a longitudinal observational cohort study.

BACKGROUND: Many countries have their own hemodialysis (HD) quality assurance programs and star rating systems for HD facilities. However, the effects of HD quality assurance programs on patient mortality are not well understood. Therefore, in the present study, the effects of the Korean HD facility star rating on patient mortality in maintenance HD patients were evaluated. METHODS: This longitudinal, observational cohort study included 35,271 patients receiving HD treatment from 741 facilities. The fivestar ratings of HD facilities were determined based on HD quality assessment data from 2015, which includes 12 quality measures in structural, procedural, and outcome domains. The patients were grouped into high (three to five stars) and low (one or two stars) groups based on HD facility star rating. Cox proportional hazards model was used to evaluate the effects of star rating on patient mortality during the mean follow-up duration of 3 years. RESULTS: The patient ratio between high and low HD facility star rating groups was 82.0% vs. 18.0%. The patients in the low star rating group showed lower single-pool Kt/V and higher calcium and phosphorus levels compared with subjects in the high star rating group. After adjusting for sociodemographic and clinical parameters, the HD facility star rating independently increased the mortality risk (hazard ratio, 1.11; 95% confidence interval, 1.04-1.18; p = 0.002). CONCLUSION: The HD facilities with low star rating showed higher patient mortality.

The change in Geriatric Nutritional Risk Index is associated with mortality in patients who start hemodialysis: Korean Renal Data Registry, 2016-2018.

Malnutrition is common in patients undergoing hemodialysis (HD) and is associated with mortality. This study aimed to investigate the association between changes in nutrition status measured by the Geriatric Nutritional Risk Index (GNRI) and all-cause mortality in patients who started HD. A nationwide retrospective cohort study was conducted based on the Korean Renal Data System database. Patients who started HD from January 2016 to December 2018, and were eligible for GNRI and GNRI trend were included. GNRI trend was a longitudinal change of GNRI, assessed by random slope in a mixed-effect model. Positive and negative random slopes in each patient were assigned to positive and negative GNRI trends. A total of 2313 patients were included and median follow-up period was 3.1 (2.6-3.7) years. GNRI values decreased over time (estimate - 1.212, 95% confidence interval (CI) - 1.116-0.692) and positive GNRI trend was associated with survival benefit (hazard ratio 0.55, 95% CI 0.36-0.84) after multivariate adjustment. These findings show that serial GNRI assessment, besides GNRI, is a useful prognostic factor for mortality in patients who start HD.

Effect of once-weekly dulaglutide on renal function in patients with chronic kidney disease.

BACKGROUND: Dulaglutide is associated with improved cardiovascular and kidney outcomes and can be a good therapeutic option for patients with type 2 diabetes with chronic kidney disease (CKD). In this study, the effects of dulaglutide on glucose-lowering efficacy and changes in renal function were analyzed. METHODS: This retrospective study involved 197 patients with type 2 diabetes with mild-to-severe CKD treated with dulaglutide for at least 3 months between January 2017 and December 2020 at two tertiary hospitals in Korea. Changes in the creatinine-based estimated glomerular filtration rate (eGFR) and HbA1c were compared before and after the use of dulaglutide in each patient. RESULTS: The number of patients and mean eGFR (mL/min/1.73 m2) in CKD 2, 3a, 3b, and 4 were 94 (75.0 ± 8.5), 46 (54.8 ± 6.3), 31 (38.8 ± 4.4), and 26 (22.5 ± 5.4), respectively. Mean HbA1c level and body mass index (BMI) at the initiation of dulaglutide were 8.9% ± 1.4% and 29.1 ± 3.6 kg/m2, the median duration of the use of dulaglutide was 16 months. The use of dulaglutide was associated with a mean decrease in HbA1c by 0.9% ± 1.5% and the glucose-lowering efficacy was similar across all stages of CKD. Also, it was associated with a reduced decline in the eGFR; the mean eGFR change after the use of dulaglutide was -0.76 mL/min/1.73 m2 per year, whereas it was -2.41 mL/min/1.73 m2 before use (paired t-test, P = 0.003). The difference was more pronounced in patients with an eGFR < 60 mL/min/1.73 m2. Subgroup analysis showed that the renal protective effect was better in patients with proteinuria, age ≤ 65 years, and HbA1c < 9.0%, but showed no association with BMI. CONCLUSIONS: The use of dulaglutide provided adequate glycemic control irrespective of CKD stage and was associated with a reduced decline in the eGFR in the CKD population.

COVID-19-related clinical outcomes among Korean hemodialysis patients.

BACKGROUND: Hemodialysis (HD) patients are more vulnerable to viral epidemics, experiencing higher mortality rates compared to individuals without chronic kidney disease (CKD). This retrospective cohort study sought to demonstrate clinical outcomes and associated factors among coronavirus disease 2019 (COVID-19) confirmed Korean HD patients. METHODS: From February 2020 to November 2021, the COVID-19 Task Force Team collected clinical data for HD patients with confirmed COVID-19 via a self-report survey of nephrologists. The composite outcome included in-hospital mortality, admission to the intensive care unit (ICU), and use of mechanical ventilation. Risk factors associated with clinical outcomes were analyzed among HD patients and compared to those of individuals without CKD using the COVID-19 database from the Korea Disease Control and Prevention Agency. RESULTS: A total of 380 HD patients from 206 facilities were diagnosed with COVID-19. Fever (49.5%) and cough (25.7%) were the two most common initial symptoms. The overall in-hospital fatality rate was 22.4% and even higher among ICU admission cases (64.7%). Non-survivors were older, more frequently developed shortness of breath, and were more likely to come from a nursing hospital. Compared to the age- and sex-matched non-CKD population, HD patients showed greater risk of in-hospital mortality (hazard ratio, 2.07; 95% confidence interval, 1.56-2.75; p < 0.001) and composite outcome (hazard ratio, 3.50; 95% confidence interval, 2.56-4.77; p < 0.001). CONCLUSION: HD patients have a greater risk of in-hospital mortality and morbidity from COVID-19. Special attention should be paid to COVID-19 HD patients when they are older or present with symptoms.

Geriatric nutritional risk index is associated with retinopathy in patients with type 2 diabetes.

The geriatric nutritional risk index (GNRI) is a nutrition-related risk assessment tool and has been used in various clinical settings. The relationship between body mass index (BMI) and the associated risk of diabetic retinopathy (DR) remains inconclusive. We aimed to evaluate the association between GNRI and DR in patients with type 2 diabetes. We included a total of 1359 patients with type 2 diabetes who followed up in our diabetes clinic and underwent fundus photographic examinations from August 2006 to February 2014. DR was assessed by retinal ophthalmologists using comprehensive ophthalmologic examinations. Patients were divided into tertiles according to their GNRI category. Patients in a lower GNRI tertile tended to have a higher proportion of nonproliferative DR (NPDR) and proliferative DR (PDR) compared with those in the other tertiles. The risk of PDR was higher in patients included in GNRI tertile 1 (Odds ratio (OR) 2.252, 95% Confidence Interval (CI) 1.080-4.823, P = 0.033) and GNRI tertile 2 (OR 2.602, 95% CI 1.323-5.336, P = 0.007) compared with those in GNRI tertile 3. In patients with lower GNRIs, the prevalence of DR was higher than in those with higher GNRIs. When GNRI was compared with BMI using the area under the curve, overall accuracy was high in GNRI. The risk of PDR was high in patients with low GNRI and there is an inverse association between GNRI scores and prevalence of DR. GNRI might be a useful tool to predict DR in patients with type 2 diabetes.

Nurse Caseload and Patient Survival in Hemodialysis Units: A Korean Nationwide Cohort Study.

INTRODUCTION: The patient-to-nurse ratio is highly variable among dialysis facilities. However, there is little known about the association between nurse caseload and hemodialysis (HD) patient outcomes. We evaluated the association between patient-to-nurse ratio and mortality in the Korean patients undergoing HD. METHODS: We used HD quality assessment data and National Health Insurance Service claim data from the year of 2013 for collecting demographic and clinical data. Altogether, 21,817 patients who participated in the HD quality assessment in 2013 were included in the study. Nurse caseload was defined as the number of HD sessions performed by a nurse per working day. The patients were divided into two groups according to the nurse caseload as follows: low nurse caseload group (≤6.0) and high nurse caseload group (>6.0). We analyzed mortality risk based on nurse caseload using the Cox proportional hazard model. RESULTS: The mean age was 59.1 years, and males accounted for 58.5%. The mean hemoglobin was 10.6 g/dL and albumin was 3.99 g/dL. At the mean follow-up duration of 51.7 (20.6) months, the ratio between low and high groups was 69.6% (15,184 patients) versus 30.4% (6,633 patients). The patients in the high nurse caseload group were older and showed lower levels of hemoglobin, albumin, calcium, and iron saturation and higher levels of phosphorus than those in the low nurse caseload group. A high nurse caseload was associated with a lower survival rate. In the adjusted Cox analysis, a high nurse caseload was an independent risk factor for all-cause mortality (hazard ratio 1.08; 95% confidence interval, 1.02-1.14; p = 0.01). CONCLUSION: High nurse caseload was associated with an increased mortality risk among the patients undergoing HD. Further prospective studies are needed to determine whether a caseload of nursing staff can improve the prognosis of HD patients.

High cortisol levels are associated with oxidative stress and mortality in maintenance hemodialysis patients.

BACKGROUND: Chronic stimulation of the mineralocorticoid receptor has been suggested as one of the potential causes of cardiovascular events and death in patients with end-stage renal disease. This observational cohort study was performed to demonstrate that serum cortisol might be a predictive marker for patient mortality and to evaluate its association with oxidized low-density lipoprotein (oxLDL) in hemodialysis (HD) patients. METHODS: Patients receiving HD three times a week were screened for enrollment at two institutions. Baseline cortisol levels were measured before each HD session, and the patients were divided into two groups according to the median value of serum cortisol before analysis. The baseline characteristics and laboratory values of the high and low cortisol groups were compared. Serum cortisol, adrenocorticotropic hormone, renin, aldosterone, and oxLDL were measured in 52 patients to evaluate the effect of oxidative stress on serum cortisol levels. RESULTS: A total of 133 HD patients were enrolled in this cohort study. Compared to the patients with low serum cortisol levels, the patients with high serum cortisol levels (baseline cortisol ≥ 10 µg/dL) showed higher rates of cardiovascular disease (59.7% vs. 39.4%, P=0.019) and left ventricular systolic dysfunction (LVSD) (25.9% vs. 8.0%, P=0.016). The patients in the high cortisol group demonstrated higher all-cause mortality than those in the low cortisol group. The serum cortisol level was an independent risk factor for patient mortality (hazard ratio 1.234, 95% confidence interval 1.022-1.49, P=0.029). Among the 52 patients with oxLDL measurements, oxLDL was an independent risk factor for elevated serum cortisol levels (Exp(B) 1.114, P=0.013) and LVSD (Exp(B) 12.308, P=0.045). However, plasma aldosterone levels did not affect serum cortisol levels. CONCLUSIONS: Serum cortisol is a useful predictive marker for all-cause death among patients receiving HD. OxLDL is an independent marker for elevated serum cortisol among HD patients.

The paradoxical effect of aldosterone on cardiovascular outcome in maintenance hemodialysis patients.

BACKGROUND: Patients with end-stage kidney disease face increased risk of cardiovascular events, and left ventricular diastolic dysfunction (LVDD) contributes to the high occurrence of cardiovascular mortality (CM). Although a high serum aldosterone (sALD) level is involved in the development of cardiovascular complications in the general population, this association is unclear in patients undergoing hemodialysis. We aimed to determine the impact of sALD on LVDD and CM among hemodialysis patients (HDPs). METHODS: We performed a prospective cohort study of maintenance HDPs without cardiovascular disease. The patients were divided into two groups according to the median level of sALD. All patients underwent baseline echocardiography to evaluate diastolic dysfunction (E/e' ratio > 15). The LVDD and CM rates were compared between the high and low aldosterone groups. RESULTS: We enrolled a total of 60 adult patients (mean age, 57.9 ± 12.1 years; males, 30.0%). The low aldosterone group had an increased left ventricular diastolic dimension compared with the high aldosterone group (52.2 ± 8.4 mm vs. 50.3 ± 5.2 mm, respectively; p = 0.03). Low log-aldosterone (odds ratio [OR], 0.40; 95% confidence interval [CI], 0.19-0.86) and large left atrial dimension (OR, 1.31; 95% CI, 1.11-1.54) were independent risk factors for LVDD at baseline. In addition, Cox regression analysis demonstrated that low sALD was an independent predictor of CM in HDPs (hazard ratio, 0.46; 95% CI, 0.25-0.85; p = 0.01) during follow-up. CONCLUSION: Low sALD was not only associated with LVDD but was also an independent predictor of CM among HDPs regardless of their interdialytic weight gain.

Chronic Kidney Disease on Health-Related Quality of Life in Patients with Diabetes Mellitus: A National Representative Study.

IMPORTANCE: With an increasing prevalence of diabetes mellitus (DM) and comorbid chronic kidney disease (CKD), health-related quality of life (HRQoL) in patients with DM and CKD needs to be better understood. OBJECTIVE: To investigate the association between the severity of CKD on HRQoL in DM patients. DESIGN: A cross-sectional study of a nationally representative population-based survey, the Korea National Health and Nutrition Examination Survey (KNHANES). SETTING: Data collected between 2007 and 2018 from the KNHANES. PARTICIPANTS: Adult participants with DM who completed the self-administered European Quality of Life Questionnaire Five Dimension (EQ-5D) questionnaire (n = 7243). Exposures: CKD stages defined by the Kidney Disease Improving Global System (KDIGO) staging system. Main Outcomes and Measures: We estimated the odds ratios (ORs) and 95% confidence intervals (CIs) of the presence of having problems in the 5 dimensions (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression) of EQ-5D by CKD stage after adjusting for socio-demographic parameters and comorbid conditions. In addition, the EQ-5D index, reflecting the overall health status, was compared across CKD stages. RESULTS: Among 7243 participants (mean (standard error) age 58.2 (0.2) 56.9% male), 24.0% (n = 1768) had CKD and 8.6% (n = 775) had stage 3-5 CKD. Pain/discomfort was the most common problem (30.5%) among patients with DM. Participants with more advanced CKD were more likely to experience problems in all dimensions of EQ-5D except the anxiety/depression dimension. In particular, compared to those without CKD, the adjusted ORs (95% CI) for any problem in the usual activities dimension was 1.65 (1.30, 2.10) in CKD stage 3 and 4.23 (2.07, 8.67) in CKD stage 4-5. Moreover, participants with stage 3 (-0.016 (-0.029, -0.003)) and stage 4-5 CKD (-0.088 (-0.129, -0.048)) had significantly lower EQ-5D index than those without CKD. However, compared with no CKD, CKD stage 1-2 was not significantly associated with having any problem in any dimensions. CONCLUSIONS AND RELEVANCE: In this nationally representative study, patients with DM had a high prevalence of self-reported poor HRQoL and the prevalence increased with more advanced stages of CKD. Therefore, assessment of HRQoL and interventions are necessary at early stages of CKD in DM patients.