Prognostic role of the neutrophil-to-lymphocyte ratio in patients with chronic kidney disease

BACKGROUND/AIMS

The neutrophil-to-lymphocyte ratio (NLR) has a prognostic value in cardiovascular disease, infection, inflammatory disease, and several malignancies. Therefore, the NLR has a possible predictive value in patients with chronic kidney disease (CKD), but this predictive value has not been validated. Here, we aimed to investigate the possibility of NLR as a predictor of CKD progression.

METHODS

This retrospective observational study included 141 patients with non-dialysis CKD. The participants were divided into terciles (T1, T2, and T3) according to NLR. The primary outcome was defined as a composite kidney event, which included a decline in the estimated glomerular filtration rate (eGFR) of at least 50% or initiation of renal replacement therapy during the follow-up period.

RESULTS

The mean follow-up duration was 5.45 ± 2.11 years. The mean NLRs were 1.35 ± 0.05 in T1 (n = 47), 2.16 ± 0.04 in T2 (n = 47), and 4.29 ± 0.73 in T3 (n = 47). The group with the highest NLR (T3) had higher baseline CKD and serum creatinine and lower eGFR levels than the group with the lowest NLR (T1). The cumulative incidence rate of composite kidney events was significantly higher in T3 compared with T1 (p < 0.001, log-rank test). Cox regression analysis revealed that high NLR was associated with the risk of composite kidney events (adjusted hazard ratio, 3.33; 95% confidence interval, 1.43-7.76).

CONCLUSION

A higher NLR reflects the more advanced stage of CKD and suggests a role for NLR as a biomarker for predicting CKD progression.

Underweight status and development of end-stage kidney disease: A nationwide population-based study

BACKGROUND

Underweight status increases the risk of cardiovascular disease and mortality in the general population. However, whether underweight status is associated with an increased risk of developing end-stage kidney disease is unknown.

METHODS

A total of 9 845 420 participants aged ≥20 years who underwent health checkups were identified from the Korean National Health Insurance Service database and analysed. Individuals with underweight (body mass index [BMI] < 18.5 kg/m² ) and obesity (BMI ≥ 25 kg/m² ) were categorized according to the World Health Organization recommendations for Asian populations.

RESULTS

During a mean follow-up period of 9.2 ± 1.1 years, 26 406 participants were diagnosed with end-stage kidney disease. After fully adjusting for other potential predictors, the moderate to severe underweight group (<17 kg/m² ) had a significantly higher risk of end-stage kidney disease than that of the reference (normal) weight group (adjusted hazard ratio, 1.563; 95% confidence interval, 1.337-1.828), and competing risk analysis to address the competing risk of death also showed the similar results (adjusted hazard ratio, 1.228; 95% confidence interval, 1.042-1.448). Compared with that of the reference BMI group (24-25 kg/m² ), the adjusted hazard ratios for end-stage kidney disease increased as the BMI decreased by 1 kg/m² . In the sensitivity analysis, sustained underweight status or progression to underweight status over two repeated health checkups, when compared with normal weight status, had a higher hazard ratio for end-stage kidney disease.

CONCLUSIONS

Underweight status is associated with an increased risk of end-stage kidney disease, and this association gradually strengthens as BMI decreases.

Uncontrolled hypertension is associated with increased risk of graft failure in kidney transplant recipients: a nationwide population-based study

Backgroud

Hypertension is highly prevalent in patients with kidney transplantation caused by transplantation-related immunologic or non-immunologic risk factors. However, whether a strict definition of hypertension (≥130/80 mmHg) and subdivided blood pressure (BP) groups are associated with an increased risk of graft failure after kidney transplantation using a nationwide large cohort study are still unknown.

Methods

Using Korean National Health Insurance Service data, we included 14,249 patients who underwent kidney transplantation from 2002 to 2016. Patients were categorized into five BP groups according to the 2021 Kidney Disease: Improving Global Outcomes practice guidelines for BP management: normal BP (<120/80 mmHg), elevated BP (120-129/ < 80 mmHg), incident hypertension (≥130/80 mmHg), and controlled or uncontrolled hypertension with anti-hypertensive medications.

Results

The primary outcome was graft failure, which occurred in 1934 (13.6%) participants during the 6-year follow-up. After adjusting for covariates, hypertension was associated with a higher risk of graft failure [Adjusted hazard ratio (AHR), 1.70; 95% confidence interval (CI), 1.48-1.96)] than no-hypertension. The AHR for graft failure was the highest in patients with uncontrolled hypertension (AHR, 2.13; 95% CI, 1.80-2.52). The risk of graft failure had a linear relationship with systolic and diastolic BP, and pulse pressure.

Conclusions

In this nationwide population-based study, hypertension ≥130/80 mmHg based on the 2021 KDIGO BP guidelines in kidney transplantion recipients, and elevated systolic and diastolic BP, and pulse pressure were associated with the risk of developing graft failure in kidney transplant recipients.

Comparison of the medium cutoff dialyzer and postdilution hemodiafiltration on the removal of small and middle molecule uremic toxins

Background

The medium cutoff (MCO) dialyzer increases the removal of several middle molecules more effectively than high-flux hemodialysis (HD). However, comparative data addressing the efficacy and safety of MCO dialyzers vs. postdilution hemodiafiltration (HDF) in Korean patients are lacking.

Methods

Nine patients with chronic HD were included in this pre-post study. Patients underwent HD with an MCO dialyzer for 4 weeks, followed by a 2-week washout period using a high-flux dialyzer to minimize carryover effects, and then turned over to postdilution HDF for 4 weeks. Reduction ratios and differences in the uremic toxins before and after dialysis were calculated from the MCO dialysis, postdilution HDF, and high-flux HD. In the in vitro study, EA.hy926 cells were incubated with dialyzed serum.

Results

Compared to postdilution HDF, the MCO dialyzer achieved significantly higher reduction ratios for larger middle molecules (myoglobin, kappa free light chain [κFLC], and lambda FLC [λFLC]). Similarly, the differences in myoglobin, κFLC, and λFLC concentrations before and after the last dialysis session were significantly greater in MCO dialysis than in postdilution HDF. The expression of Bax and nuclear factor κB was decreased in the serum after dialysis with the MCO dialyzer than with HDF.

Conclusion

Compared with high-volume postdilution HDF, MCO dialysis did not provide greater removal of molecules below 12,000 Da, whereas it was superior in the removal of larger uremic middle molecule toxins in patients with kidney failure. Moreover, these results may be expected to have an anti-apoptotic effect on the human endothelium.

Role of APE1/Ref-1 in hydrogen peroxide-induced apoptosis in human renal HK-2 cells

Background

Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a multipotent protein that plays essential roles in cellular responses to oxidative stress. However, the role of APE1/Ref-1 for kidney injuries has yet to be identified.

Methods

To examine the role of APE1/Ref-1 in ischemia-reperfusion (I/R) injuries and hydrogen peroxide (H2O2)-induced renal tubular apoptosis, we studied male C57BL6 mice and human proximal tubular epithelial (HK-2) cells treated with H2O2 at different concentrations. The colocalization of APE1/Ref-1 in the proximal tubule, distal tubule, thick ascending limb, and collecting duct was observed with confocal microscopy. The overexpression of APE1/Ref-1 with knockdown cell lines using an APE1/Ref-1-specific DNA or small interfering RNA (siRNA) was used for the apoptosis assay. The promotor activity of nuclear factor kappa B (NF-κB) was assessed and electrophoretic mobility shift assay was conducted.

Results

APE1/Ref-1 was predominantly localized to the renal tubule nucleus. In renal I/R injuries, the levels of APE1/Ref-1 protein were increased compared with those in kidneys subjected to sham operations. The overexpression of APE1/Ref-1 in HK-2 cells enhanced the Bax/Bcl-2 ratio as a marker of apoptosis. Conversely, the suppression of APE1/Ref-1 expression by siRNA in 1-mM H2O2-treated HK-2 cells decreased the Bax/Bcl-2 ratio, the phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, p38, c-Jun N-terminal kinase (JNK) 1/2, and NF-κB. In HK-2 cells, the promoter activity of NF-κB increased following H2O2 exposure, and this effect was further enhanced by APE1/Ref-1 transfection.

Conclusion

The inhibition of APE1/Ref-1 with siRNA attenuated H2O2-induced apoptosis through the modulation of mitogen-activated protein kinase pathways mediated by ERK, JNK, and p38 and the nuclear activation of NF-κB and proapoptotic factors.

Urinary Phosphorus Excretion and Cardiovascular Outcomes in Patients with Pre-Dialysis Chronic Kidney Disease: The KNOW-CKD Study

The relationship between 24-h urinary phosphorus excretion (24 h UPE) and cardiovascular disease in patients with pre-dialysis chronic kidney disease (CKD) has rarely been studied, despite the fact that the relationship between serum phosphorus level and the risk of a cardiovascular event is well established. A total of 1701 patients with pre-dialysis CKD were finally included for the analyses and were divided into tertiles by 24 h UPE (first tertile (T1, 349.557 (mean) ± 88.413 (standard deviation)), second tertile (T2, 557.530 ± 50.738), and third tertile (T3, 851.695 ± 171.593). The study outcome was a six-point major adverse cardiac event (MACE). The median follow-up duration was 7.992 years. Kaplan-Meier curve analysis visualized that the cumulative incidences of a six-point MACE (p = 0.029) significantly differed from 24 h UPE levels, as the incidence rate of the study outcomes was highest in T1 and lowest in T3. Cox proportional hazard models unveiled that, compared to T1, the risk of a six-point MACE was significantly decreased in T3 (adjusted hazard ratio (HR) 0.376, 95% confidence interval (CI) 0.207 to 0.683). The restricted cubic spline curve analysis visualized an inverted S-shaped association between 24 h UPE level and the risk of a six-point MACE, indicating a significantly increased risk of a six-point MACE in patients with a low 24 h UPE level. In conclusion, low 24 h UPE is associated with adverse cardiovascular outcomes in patients with CKD. Our finding emphasizes that low 24 h UPE should not be a reliable marker for dietary restriction of phosphorus that essentially leads to better outcomes in patients with CKD.

The effects of socioeconomic status on major adverse cardiovascular events: a nationwide population-based cohort study

Background: Although multiple factors influence the risk of major adverse cardiovascular events (MACE), the effects of socioeconomic status on MACE in the presence and absence of renal dysfunction (RD) have not been comprehensively explored in Korea. Methods: We examined the effects of socioeconomic status on MACE in individuals with and without RD. The data of 44,473 Koreans from 2008 to 2017 were obtained from the Health Care Big Data Platform of the Ministry of Health and Welfare in Korea. Their socioeconomic status was assessed using a socioeconomic score (SES) based on marital status, education, household income, and occupation. The incidence of myocardial infarction (MI), stroke, and death was compared according to SES level (0–4). Multiple linear regression analysis was used to evaluate the hazard ratios and 95% confidence intervals for outcomes based on participant SES. Results: MI risk was only affected by education level. The participants’ income, education, and SES affected their stroke risk, whereas death was associated with all four socioeconomic factors. The incidence of stroke and death increased as SES worsened (from 0 to 4). SES was positively related to risk of stroke and death in participants without RD. SES did not affect MI, stroke, or death in participants with RD. Conclusion: A low socioeconomic status is associated with risk of stroke and death, especially in individuals without RD.

Association between urinary chloride excretion and progression of coronary artery calcification in patients with nondialysis chronic kidney disease: results from the KNOW-CKD study

BACKGROUND

Urine chloride has recently been suggested as a biomarker of renal tubule function in patients with nondialysis chronic kidney disease (CKD), as low urinary chloride concentration is associated with an increased risk of CKD progression. We investigate the association between urinary chloride excretion and the progression of coronary artery calcification (CAC).

METHODS

A total of 1,065 patients with nondialysis CKD were divided into tertiles by spot urine chloride-to-creatinine ratios. The 1st, 2nd, and 3rd tertiles were defined as low, moderate, and high urinary chloride excretion, respectively. The study outcome was CAC progression, which was defined as an increase in coronary artery calcium score of more than 200 Agatston units during the 4-year follow-up period.

RESULTS

Compared to moderate urinary chloride excretion, high urinary chloride excretion was associated with decreased risk of CAC progression (adjusted odds ratio, 0.379; 95% confidence interval, 0.190-0.757), whereas low urinary chloride excretion was not associated with risk of CAC progression. Restricted cubic spine depicted an inverted J-shaped curve, with a significant reduction in the risk of CAC progression in subjects with high spot urine chloride-to-creatinine ratios.

CONCLUSION

High urinary chloride excretion is associated with decreased risk of CAC progression in patients with nondialysis CKD.

Bone Mineral Density and All-Cause Mortality in Patients with Nondialysis Chronic Kidney Disease: Results from KNOW-CKD Study

Despite the clear association between low BMD and all-cause mortality in the general population, the association has not been validated in patients with nondialysis CKD. To investigate the association of low BMD with all-cause mortality in this population, a total of 2089 patients with nondialysis CKD at stages 1 to predialysis 5 were categorized into normal BMD (T-score ≥ -1.0), osteopenia (-2.5 < T-score < -1.0), and osteoporosis (T-score ≤ - 2.5) by the BMD at femoral neck. The study outcome was all-cause mortality. Kaplan-Meier curve depicted a significantly increased number of all-cause death events in the subjects with osteopenia or osteoporosis during the follow-up period compared with subjects with normal BMD. Cox regression models demonstrated that osteoporosis, but not osteopenia, was significantly associated with an increased risk of all-cause mortality (adjusted hazard ratio 2.963, 95% confidence interval 1.655 to 5.307). Smoothing curve fitting model visualized a clear inverse correlation between BMD T-score and the risk of all-cause mortality. Even after recategorizing the subjects by BMD T-scores at total hip or lumbar spine, the result was similar to the primary analyses. Subgroup analyses revealed that the association was not significantly modified by clinical contexts, such as age, gender, body mass index, estimated glomerular filtration rate, and albuminuria. In conclusion, low BMD is associated with an increased risk of all-cause mortality in patients with nondialysis CKD. This emphasizes that the routine measurement of BMD by DXA may confer an additional benefit beyond the prediction of fracture risk in this population.

Rheumatoid arthritis and the risk of end-stage renal disease: A nationwide, population-based study

Introduction

Despite the risk of incident chronic kidney disease among the patients with rheumatoid arthritis (RA), the association of RA and the risk of end-stage renal disease (ESRD) has not been clearly elucidated. We aimed to investigate the association of RA and the risk of ESRD.

Materials and methods

A total of 929,982 subjects with (n = 154,997) or without (n = 774,985) RA from the National Health Insurance Service (NHIS) database in Koreas (corresponding to the period between 2009 and 2017) were retrospectively analyzed. RA was defined by the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM), codes plus any dispensing of disease-modifying anti-rheumatic drugs. The primary outcome was incident ESRD, identified by a combination of the ICD-10-CM codes and a special code assigned to patients receiving maintenance dialysis for ≥ 3 months or those with a transplant kidney.

Results

Compared to the subjects without RA, the subjects with RA resulted in an increased incidence of ESRD (incidence rates of 0.374 versus 0.810 cases per 1,000 person-years). Accordingly, compared to the subjects without RA, the risk of ESRD was significantly increased among the subjects with RA (adjusted hazard ratio 2.095, 95% confidence interval 1.902-2.308). Subgroup analyses revealed that the risk of ESRD imposed by RA is relatively higher in relatively young and healthy individuals.

Conclusion

Rheumatoid arthritis (RA) increase the risk of ESRD. As the risk of ESRD imposed by RA is relatively higher in relatively young and healthy individuals, kidney-protective treatment, such as biologic agents, should be preferentially considered among these patients with RA.

Weight change and risk of depression in patients with diabetic kidney disease: a nationwide population-based study

BACKGROUND

Several studies have reported that depression is prevalent in patients with diabetes or chronic kidney disease. However, the relationship between weight changes and the risk of depression has not been elucidated in patients with diabetic kidney disease (DKD).

METHODS

From the Korean National Health Insurance Service database, we selected 67,866 patients with DKD and body weight data from two consecutive health examinations with a 2-year interval between 2009 and 2012. Weight change over 2 years was categorized into five groups: ≥-10%, &lt;-10% to ≥-5%, &lt;-5% to &lt;5%, ≥5% to &lt;10%, and ≥10%. The occurrence of depression was monitored via the codes of International Statistical Classification of Diseases, 10th revision through the end of 2018.

RESULTS

During the 5.24-year follow-up, 17,023 patients with DKD developed depression. Weight change and the risk of depression had a U-shaped relationship: patients with ≥-10% weight change (hazard ratio [HR], 1.12) and those with ≥10% weight change (HR, 1.11) showed higher HRs for depression than those with &lt;-5% to &lt;5% weight change, even after adjusting for several confounding factors. In the subgroup analyses, the risk of depression tended to increase as weight gain or weight loss increased in all subgroups.

CONCLUSION

Both weight loss and weight gain increased the risk of depression in patients with DKD.

Serum triglycerides level is independently associated with renal outcomes in patients with non-dialysis chronic kidney disease: Results from KNOW-CKD study

To investigate whether high serum triglycerides (TG) level is associated with adverse renal outcomes in patients with non-dialysis chronic kidney disease (CKD), a total of 2,158 subjects from a prospective cohort study (Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease) were divided into the quartile by serum TG level. The primary outcomes were composite renal events, which is defined as a composite of decline of kidney function (the first occurrence of > 50% decline of estimated glomerular filtration rate or doubling of serum creatinine from the baseline) or onset of end-stage renal disease (initiation of dialysis or kidney transplantation). During the median follow-up of 6.940 years, the cumulative incidence of composite renal event was significantly differed by serum TG level in Kaplan-Meier curve analysis (P < 0.001, by Log-rank test). Cox regression analysis demonstrated that, compared to that of the 1st quartile, the risk of composite renal event was significantly higher in the 4th quartile (adjusted hazard ratio 1.433, 95% confidence interval 1.046 to 1.964). The association between high serum TG level and adverse renal outcome remained consistent in the cause-specific hazard model. Subgroup analyses revealed that the association is modified by age, estimated glomerular filtration rate, and spot urine albumin-to-creatinine ratio. In conclusion, high serum TG level is independently associated with adverse renal outcomes in patients with non-dialysis CKD. Interventional studies are warranted to determine whether lowering serum TG levels may alter the natural course of CKD.

Effects of Blood Pressure According to Age on End-Stage Renal Disease Development in Patients With Diabetes: A Nationwide Population-Based Cohort Study

Background:

Recent hypertension guidelines have recommended lower blood pressure (BP) targets in high-risk patients. However, there are no specific guidelines based on age or systolic and diastolic blood pressure (SBP and DBP, respectively). We aimed to assess the effects of age-related BP on development of end-stage renal disease (ESRD) in patients with diabetes.

Methods:

A total of 2 563 870 patients with diabetes aged >20 years were selected from the Korean National Health Screening Program from 2009 to 2012 and followed up until the end of 2019. Participants were categorized into age and BP groups, and the hazard ratios for ESRD were calculated.

Results:

During a median follow-up of 7.15 years, the incidence rates of ESRD increased with increasing SBP and DBP. The hazard ratio for ESRD was the highest in patients younger than 40 years of age with DBP≥100 mm Hg. The effect of SBP and DBP on ESRD development was attenuated with age (interaction P was <0.0001 for age and SBP, and 0.0022 for age and DBP). The subgroup analysis for sex, antihypertension medication, and history of chronic kidney disease showed higher hazard ratios for ESRD among males, younger than 40 years, not taking antihypertension medications and chronic kidney disease compared to those among females, older than 40 years, antihypertension medication, and nonchronic kidney disease groups.

Conclusions:

Higher SBP and DBP increase the risk of developing ESRD in patients with diabetes, and in particular, younger individuals face greater risk. Therefore, intensive BP management is warranted in younger patients to prevent ESRD.

Weight change and fracture risk in patients with diabetic kidney disease: A nationwide population-based study

Background

The increased risk of fracture has been associated with weight loss in patients with diabetes or chronic kidney disease. However, the relationship between weight changes over time and fracture risk in patients with diabetic kidney disease is still unknown.

Methods

A total number of 78,922 patients with diabetic kidney disease, aged ≥ 40 years, were selected using the Korean National Health Insurance Service database, between 2009 and 2012. They were followed up until the end of 2018. Weight change was defined as the difference in body weight from the index year to 2 years later. Weight changes were then divided into five categories, ranging from weight loss of ≥10% to weight gain of ≥10%.

Results

Fractures were identified in 9,847 patients with diabetic kidney disease, over a median follow-up of 5.2 years. The risk of composite fracture of the vertebral, hip, or other sites increased as the weight change increased. Specifically, patients with ≥10% weight loss (hazard ratio [HR], 1.286; 95% confidence interval [CI], 1.184–1.398) and ≥10% weight gain (HR, 1.198; 95% CI, 1.080–1.330) showed a higher HR compared to those with ≤ 5% weight change after adjusting for several confounding factors. Higher HR of vertebral and hip fractures was also seen with increased weight loss or gain. In particular, patients with ≥10% weight loss showed the highest HR for hip fractures (HR, 1.738; 95% CI, 1.489–2.028).

Conclusions

Both weight loss and weight gain increase the risk of fracture in patients with diabetic kidney disease. Therefore, patients with diabetic kidney disease who experience weight changes should be made aware of the risk of fracture.

MO489: Weight Change and Risk of Depression in Patients With Diabetic Kidney Disease: A Nationwide Population-Based Study

BACKGROUND AND AIMS

Several studies have reported that depression has a high prevalence in patients with diabetes or chronic kidney disease. However, the relationship between weight changes and the risk of depression has not been elucidated in patients with diabetic kidney disease (DKD).

METHOD

From the Korean National Health Insurance Service database, we selected 67 866 patients with DKD with body weight data from two consecutive health examinations with a 2-year interval between 2009 and 2012. The weight change &gt;2 years was categorized into five groups: ≥10% weight loss, 5%–10% weight loss, &lt;5% weight change, 5%–10% weight gain and ≥10% weight gain. The occurrence of depression was monitored through the end of 2018 by the ICD-10 codes.

RESULTS

During the 5.24-year follow-up, 17 023 patients with DKD developed depression. The weight change and the risk of depression showed a U-shaped relationship: patients with ≥10% weight loss [hazard ratio (HR): 1.116] and those with ≥10% weight gain (HR: 1.114) showed higher HRs than those with ≤5% weight change, even after adjusting for several confounding factors. In subgroup analyses, the risk of depression tended to increase as weight gain or weight loss increased in all subgroups.

CONCLUSION

Both weight loss and weight gain increased the risk of depression in patients with DKD

Low waist circumference prior to percutaneous coronary intervention predict the risk for end-stage renal disease: a nationwide Korean population based-cohort study

BACKGROUND/AIMS

The obesity paradox has been known in end-stage renal disease (ESRD). However, the effect of body mass index (BMI) or waist circumference (WC) prior to percutaneous coronary intervention (PCI) on the development of ESRD is not clear.

METHODS

Using nationally representative data from the Korean National Health Insurance System, we enrolled 140,164 subjects without ESRD at enrolment who underwent PCI between 2010 and 2015, and were followed-up until 2017. Patients were stratified into five levels based on their baseline BMI and six levels based on their WC with 5-cm increments. BMI and WC were measured at least 2 years prior to PCI. The primary outcome was the development of ESRD.

RESULTS

During a median follow-up of 5.4 years, 2,082 (1.49%) participants developed ESRD. The underweight group (hazard ratio [HR], 1.331; 95% confidence interval [CI], 0.955 to 1.856) and low WC (< 80/< 75) (HR, 1.589; 95% CI, 1.379 to 1.831) showed the highest ESRD risk and the BMI 25 to 30 group showed the lowest ESRD risk (HR, 0.604; 95% CI, 0542 to 0.673) in all participants after adjusting for all covariates. In the subgroup analysis for diabetes mellitus (DM) duration, WC < 85/80 cm (men/women) increased ESRD risk in only the DM group (DM < 5 years and DM ≥ 5 years) compared to the reference group (85-90/80-85 of WC), but not the normal or impaired fasting glucose group.

CONCLUSION

Low WC prior to PCI showed an increased ESRD risk in patients with DM undergoing PCI as compared to those without DM.