Renal Function Effect on the Association Between Body Mass Index and Mortality Risk After Acute Myocardial Infarction

Background: Body mass index (BMI) is a critical determinant of mortality after acute myocardial infarction (AMI), and higher BMI is associated with survival benefit in patients with renal impairment. However, there are no studies investigating the interactive effects of BMI and renal function on mortality risk after AMI occurrence. Methods: We enrolled 12,647 AMI patients from Korea Acute Myocardial Infarction Registry between November 2011 and December 2015. Patients were categorized based on estimated Glomerular Filtration Rate (eGFR) and BMI. The primary endpoint was all-cause mortality after AMI treatment. Results: Within each renal function category, the absolute mortality rate was decreased in patients with higher BMI. However, the adjusted hazard ratio (HR) of all-cause mortality for higher BMI was decreased as renal function worsened [adjusted HR (95% confidence interval) at BMI ≥ 25 kg/m²: 0.63 (0.41-0.99), 0.76 (0.59-0.97), and 0.84 (0.65-1.08) for patients with eGFR ≥ 90, 90-45, and <45 mL/min/1.73 m², respectively]. There was a significant interaction between BMI and renal function (P for interaction = 0.010). The protective effect of higher BMI was preserved against non-cardiac death and it was also decreased with lowering eGFR in competing risks models [adjusted HR at BMI ≥25 kg/m²: 0.38 (0.18-0.83), 0.76 (0.59-0.97), and 0.84 (0.65-1.08) for patients with eGFR ≥ 90, 90-45, and <45 mL/min/1.73 m², respectively; P for interaction = 0.03]. However, renal function did not significantly affect the association between BMI and risk of cardiac death (P for interaction = 0.20). Conclusions: The effect of BMI on the mortality risk after AMI was dependent on renal function. The association between greater BMI and survival benefit was weakened as renal function was decreased. In addition, the negative effect of renal function on the BMI - mortality association was pronounced in the non-cardiac death.

Vascular Calcification in Chronic Kidney Disease: Distinct Features of Pathogenesis and Clinical Implication

Vascular calcification (VC) is highly prevalent in patients with chronic kidney disease (CKD) and leads to increased cardiovascular morbidity and mortality. In patients with CKD, traditional factors do not fully explain the high prevalence of VC. This suggests that a CKD-specific pathobiology is involved in the development of VC and mounting evidence indicates that VC in CKD patients has distinct features of clinical presentation and that clinical implications are changed compared to those in the general population. In this review, we discuss the mechanism, diagnostic imaging modalities, clinical features and implications, and management of VC in patients with CKD.

Chronic kidney disease (CKD) is associated with a higher prevalence of vascular calcification (VC) and cardiovascular disease. VC in CKD patients showed different pathophysiological features from those of the general population. The pathogenesis of VC in CKD is a highly organized process, and prior studies have suggested that patients with CKD have their own specific contributors to the phenotypic change of vascular smooth muscle cells (VSMCs), including uremic toxins, CKD-mineral and bone disease (CKD-MBD), inflammation, and oxidative stress. For the diagnosis and monitoring of VC in CKD, several imaging modalities, including plain radiography, ultrasound, and computed tomography have been utilized. VC in CKD patients has distinct clinical features and implications. CKD patients revealed a more intense and more prevalent calcification on the intimal and medial layers, whereas intimal calcification is predominantly observed in the general population. While a higher VC score is clearly associated with a higher risk of all-cause mortality and cardiovascular events, a greater VC score in CKD patients does not fully reflect the burden of atherosclerosis, because they have more calcification at equal volumes of atheromatous plaques. The primary goal of VC treatment in CKD is the prevention of VC progression, and the main management is to control the biochemical components of CKD-MBD. Cinacalcet and non-calcium-containing phosphate binders are the mainstay of VC prevention in CKD-MBD management. VC in patients with CKD is an ongoing area of research and is expected to advance soon.

Circulating Vascular Adhesion Protein-1 Level Predicts the Risk of Cardiovascular Events and Mortality in Hemodialysis Patients

Background: Vascular adhesion protein-1 (VAP-1) is an oxidative enzyme of primary amines that facilitates the transmigration of inflammatory cells. Its oxidative and inflammatory effects are prominently increased in pathological conditions, such as metabolic, atherosclerotic, and cardiac diseases. However, the clinical significance of circulating VAP-1 levels in hemodialysis (HD) patients is unclear.

Methods: A total of 434 HD patients were enrolled in a prospective multicenter cohort study between June 2016 and April 2019. Plasma VAP-1 levels were measured at the time of data entry, and the primary endpoint was defined as a composite of cardiovascular (CV) and cardiac events.

Results: Circulating VAP-1 levels were positively correlated with plasma levels of cardiac remodeling markers, including brain natriuretic peptide, galectin-3, and matrix metalloproteinase-2. Multivariable logistic regression analysis revealed that patients with higher circulating VAP-1 levels were more likely to have left ventricular diastolic dysfunction [odds ratio, 1.40; 95% confidence interval [CI], 1.04–1.88]. The cumulative event rate of the composite of CV events was significantly greater in VAP-1 tertile 3 than in VAP-1 tertiles 1 and 2 (P = 0.009). Patients in tertile 3 were also associated with an increased cumulative event rate of cardiac events (P = 0.015), with a 2.06-fold higher risk each for CV (95% CI, 1.10–3.85) and cardiac (95% CI, 1.03–4.12) events after adjusting for multiple variables.

Conclusions: Plasma VAP-1 levels were positively associated with left ventricular diastolic dysfunction and the risk of incident CV and cardiac events in HD patients. Our results indicate that VAP-1 may aid clinicians in identifying HD patients at a high risk of CV events.

COVID-19 and Sirolimus Treatment in a Kidney Transplant Recipient

One year after COVID-19 was declared a pandemic, the management of the disease in kidney transplant patients remains uncertain. The interruption of immunosuppressive therapy is frequently suggested in kidney transplant recipients with COVID-19; however, such an interruption potentially increases the risk of allograft rejection and hyperimmune response. We here report the successful treatment of COVID-19 pneumonia in a kidney transplant recipient who received a sirolimus-based regimen. The course of COVID-19 management was favorable for maintaining sirolimus treatment. Nevertheless, the patient showed signs of extreme overexposure to sirolimus because of drug interaction with antiviral treatment. This case illustrates the advantages and related adverse events of sirolimus-based immunosuppression in the management of COVID-19 in kidney transplant recipients.

Circulating Neprilysin Level Predicts the Risk of Cardiovascular Events in Hemodialysis Patients

Background: Neprilysin inhibition has demonstrated impressive benefits in heart failure treatment, and is the current focus of interest in cardiovascular (CV) and kidney diseases. However, the role of circulating neprilysin as a biomarker for CV events is unclear in hemodialysis (HD) patients.

Methods: A total of 439 HD patients from the K-cohort were enrolled from June 2016 to April 2019. The plasma neprilysin level and echocardiographic findings at baseline were examined. The patients were prospectively followed up to assess the primary endpoint (composite of CV events and cardiac events).

Results: Plasma neprilysin level was positively correlated with left ventricular (LV) mass index, LV end-systolic volume, and LV end-diastolic volume. Multivariate linear regression analysis revealed that neprilysin level was negatively correlated with LV ejection fraction (β = −2.14; p = 0.013). The cumulative event rate of the composite of CV events was significantly greater in neprilysin tertile 3 (p = 0.049). Neprilysin tertile 3 was also associated with an increased cumulative event rate of cardiac events (p = 0.016). In Cox regression analysis, neprilysin tertile 3 was associated with a 2.61-fold risk for the composite of CV events [95% confidence interval (CI), 1.37–4.97] and a 2.72-fold risk for cardiac events (95% CI, 1.33–5.56) after adjustment for multiple variables.

Conclusions: Higher circulating neprilysin levels independently predicted the composite of CV events and cardiac events in HD patients. The results of this study suggest the importance of future studies on the effect of neprilysin inhibition in reducing CV events.

Comparison of joint degeneration and pain in male and female mice in DMM model of osteoarthritis

OBJECTIVE

While the prevalence of radiographic and symptomatic osteoarthritis (OA) is higher in women, male mice are more frequently used in animal experiments to explore its pathogenesis or drug efficacy. In this study, we examined whether sexual dimorphism affects pain and joint degeneration in destabilization of the medial meniscus (DMM) mouse model.

METHODS

DMM or sham surgery was performed on the knee of male and female C57BL/6 mice. Joint damage was assessed by safranin O staining and scored using the Osteoarthritis Research Society International (OARSI) scoring system. Von Frey hair, incapacitance, and rotarod tests were conducted to measure joint pain. The analgesic effect of capsazepine (CPZ), a TRPV1 antagonist, was compared between male and female mice.

RESULTS

Histology and OARSI scoring analysis showed that cartilage degeneration developed, and progressed in both male and female DMM groups, however, damage was less severe in females at the late stage of OA. Pain behavior, as measured by mechanical allodynia, was displayed for longer in male DMM mice compared to females. Incapacitance data showed that CPZ significantly reduced DMM-induced pain in male mice but not in female mice. Immunofluorescence microscopy analysis demonstrated that DMM surgery increased the expression of TRPV1 in both female and male dorsal root ganglion (DRG). Injection of CPZ significantly suppressed TRPV1 expression in the DRG of male mice only.

CONCLUSION

Joint damage develops comparably in both female and male mice after DMM although it progresses less in females. There was a subtle sex difference in pain behaviors and analgesic efficacy of a TRPV1 antagonist, which was accompanied by a differential regulation of TPRV1.

Urinary mRNA Signatures as Predictors of Renal Function Decline in Patients With Biopsy-Proven Diabetic Kidney Disease

The clinical manifestations of diabetic kidney disease (DKD) are more heterogeneous than those previously reported, and these observations mandate the need for the recruitment of patients with biopsy-proven DKD in biomarker research. In this study, using the public gene expression omnibus (GEO) repository, we aimed to identify urinary mRNA biomarkers that can predict histological severity and disease progression in patients with DKD in whom the diagnosis and histologic grade has been confirmed by kidney biopsy. We identified 30 DKD-specific mRNA candidates based on the analysis of the GEO datasets. Among these, there were significant alterations in the urinary levels of 17 mRNAs in patients with DKD, compared with healthy controls. Four urinary mRNAs-LYZ, C3, FKBP5, and G6PC-reflected tubulointerstitial inflammation and fibrosis in kidney biopsy and could predict rapid progression to end-stage kidney disease independently of the baseline eGFR (tertile 1 vs. tertile 3; adjusted hazard ratio of 9.68 and 95% confidence interval of 2.85-32.87, p < 0.001). In conclusion, we demonstrated that urinary mRNA signatures have a potential to indicate the pathologic status and predict adverse renal outcomes in patients with DKD.

Epidemiology, risk factors, and clinical impact of early post-transplant infection in older kidney transplant recipients: the Korean organ transplantation registry study

Background

As in younger recipients, post-transplant infection is a frequent and devastating complication after kidney transplantation (KT) in older recipients. However, few studies have analyzed characteristics of post-transplant infection in older kidney recipients. In this study of a nation-wide cohort of older kidney recipients, we investigated the current epidemiology, risk factors, and clinical impacts of early post-transplant infection, which was defined as infectious complications requiring hospitalization within the first 6 months after KT.

Methods

Three thousand seven hundred thirty-eight kidney recipients registered in the Korean Organ Transplantation Registry between 2014 and 2017 were enrolled. Recipients were divided into two groups, younger (n = 3081) and older (n = 657), with a cutoff age of 60 years. We observed characteristics of early post-transplant infection, and investigated risk factors for the development of infection. We also analyzed the association of early post-transplant infection with clinical outcomes including cardiac events, rejection, graft loss, and all-cause mortality.

Results

The incidence of early post-transplant infection was more frequent in older recipients (16.9% in younger group and 22.7% in older group). Bacteria were the most common causative pathogens of early post-transplant infection, and the most frequent site of infection was the urinary tract in both older and younger recipients. Older recipients experienced more mycobacterial infections, co-infections, and multiple site infections compared with younger recipients. In older recipients, female sex (HR 1.398, 95% CI 1.199–1.631), older donor age (HR 1.010, 95% CI 1.004–1.016), longer hospitalization after KT (HR 1.010, 95% CI 1.006–1.014), and experience of acute rejection (HR 2.907, 95% CI 2.471–3.419) were independent risk factors for the development of early post-transplant infection. Experiencing infection significantly increases the incidence of rejection, graft loss, and all-cause mortality.

Conclusion

Our results illustrate current trends, risk factors, and clinical impacts of early post-transplant infection after KT in older recipients. Considering the poor outcomes associated with early post-transplant infection, careful screening of recipients at high risk for infection and monitoring of recipients who experience infection are advised. In addition, since older recipients exhibit different clinical characteristics than younger recipients, further studies are needed to establish effective strategies for treating older recipients.

Supplementary Information

Supplementary information accompanies this paper at 10.1186/s12877-020-01859-3.

Rhabdomyolysis-Induced AKI Was Ameliorated in NLRP3 KO Mice via Alleviation of Mitochondrial Lipid Peroxidation in Renal Tubular Cells

Introduction: A recent study showed that early renal tubular injury is ameliorated in Nod-like receptor pyrin domain-containing protein 3 (NLRP3) KO mice with rhabdomyolysis-induced acute kidney injury (RIAKI). However, the precise mechanism has not been determined. Therefore, we investigated the role of NLRP3 in renal tubular cells in RIAKI. Methods: Glycerol-mediated RIAKI was induced in NLRP3 KO and wild-type (WT) mice. The mice were euthanized 24 h after glycerol injection, and both kidneys and plasma were collected. HKC-8 cells were treated with ferrous myoglobin to mimic a rhabdomyolytic environment. Results: Glycerol injection led to increase serum creatinine, aspartate aminotransferase (AST), and renal kidney injury molecule-1 (KIM-1) level; renal tubular necrosis; and apoptosis. Renal injury was attenuated in NLRP3 KO mice, while muscle damage and renal neutrophil recruitment did not differ between NLRP3 KO mice and WT mice. Following glycerin injection, increases in cleaved caspase-3, poly (ADP-ribose) polymerase (PARP), and a decrease in the glutathione peroxidase 4 (GPX-4) level were observed in the kidneys of mice with RIAKI, and these changes were alleviated in the kidneys of NLRP3 KO mice. NLRP3 was upregulated, and cell viability was suppressed in HKC-8 cells treated with ferrous myoglobin. Myoglobin-induced apoptosis and lipid peroxidation were significantly decreased in siNLRP3-treated HKC-8 cells compared to ferrous myoglobin-treated HKC-8 cells. Myoglobin reduced the mitochondrial membrane potential and increased mitochondrial fission and reactive oxygen species (ROS) and lipid peroxidation levels, which were restored to normal levels in NLRP3-depleted HKC-8 cells. Conclusions: NLRP3 depletion ameliorated renal tubular injury in a murine glycerol-induced acute kidney injury (AKI) model. A lack of NLRP3 improved tubular cell viability via attenuation of myoglobin-induced mitochondrial injury and lipid peroxidation, which might be the critical factor in protecting the kidney.

Renal dysfunction is associated with decline of cognitive function in community-dwelling older adults: Korean frailty and aging cohort study

Background

Cognitive decline is common in older adults. Similarly, the prevalence of renal dysfunction is also increased in the elderly population. We conducted this study to clarify the relationship between renal dysfunction and decline of cognitive function in community-dwelling elderly population.

Methods

A cross-sectional analysis was performed using data from the Korean Frailty and Aging Cohort Study, a nationwide cohort study. Total 2847 (1333 men, 1514 women) eligible participants were enrolled for this study. The estimated glomerular filtration rate (eGFR, mL/min/1.73m²) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. Global cognitive function was assessed with the Mini-mental State Examination-Korean version. Other domains of cognitive function were tested with the Consortium to Establish a Registry for Alzheimer’s disease and the Frontal Assessment Battery.

Results

The mean age of all participants was 76.0 ± 3.9 years and eGFR (all in mL/min/1.73 m²) was 77.5 ± 14.3. And the mean eGFR was 91.7 ± 3.2 in quartile 1, 84.9 ± 1.8 in quartile 2, 76.1 ± 3.7 in quartile 3, and 57.2 ± 10.8 in quartile 4. In baseline characteristics, participants with lower eGFR tend to have lower cognitive function scores than participant with higher eGFR. In linear regression analysis, eGFR was correlated with the word list memory (β = 0.53, P = 0.005), word list recall (β = 0.86, P < 0.001), and word list recognition (β = 0.43, P = 0.030) after adjustment of confounding variables. Moreover, after multivariate adjustment the association with cognitive impairment in quartile 2 was stronger (adjusted OR: 1.535, 95% CI: 1.111–2.120, P = 0.009), and the ORs of cognitive impairment were 1.501 (95% CI: 1.084–2.079, P = 0.014) in quartile 3 and 1.423 (95% CI: 1.022–1.983, P = 0.037) in quartile 4.

Conclusion

In older adults, the immediate, recent memory, and recognition domains were significantly related to renal function. Also, the mild renal dysfunction was independently associated with impairment of global cognitive function. These results suggest that the early stages of renal dysfunction could be an effective target to prevent worsening of cognitive impairment. Therefore, regular monitoring and early detection of mild renal dysfunction in elderly population might be needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-020-01862-8.

Vaginal compared with intramuscular progestogen for preventing preterm birth in high-risk pregnant women (VICTORIA study): a multicentre, open-label randomised trial and meta-analysis

OBJECTIVE

To compare the efficacy of two types of progestogen therapy for preventing preterm birth (PTB) and to review the relevant literature.

DESIGN

A multicentre, randomised, open-label, equivalence trial and a meta-analysis.

SETTING

Tertiary referral hospitals in South Korea.

POPULATION

Pregnant women with a history of spontaneous PTB or short cervical length (<25 mm).

METHODS

Eligible women were screened and randomised at 16-22 weeks of gestation to receive either 200 mg of vaginal micronised progesterone daily (vaginal group) or an intramuscular injection of 250 mg 17α-hydroxyprogesterone caproate weekly (IM group). Stratified randomisation was carried out according to participating centres and indications for progestogen therapy. This trial was registered at ClinicalTrials.gov (NCT02304237).

MAIN OUTCOME MEASURE

Preterm birth (PTB) before 37 weeks of gestation.

RESULTS

A total of 266 women were randomly assigned and a total of 247 women (119 and 128 women in the vaginal and IM groups, respectively) were available for the intention-to-treat analysis. Risks of PTB before 37 weeks of gestation did not significantly differ between the two groups (22.7 versus 25.8%, P = 0.571). The difference in PTB risk between the two groups was 3.1% (95% CI -7.6 to 13.8%), which was within the equivalence margin of 15%. The meta-analysis results showed no significant differences in the risk of PTB between the vaginal and IM progestogen treatments.

CONCLUSION

Compared with vaginal progesterone, treatment with intramuscular progestin might increase the risk of PTB before 37 weeks of gestation by as much as 13.8%, or reduce the risk by as much as 7.6%, in women with a history of spontaneous PTB or with short cervical length.

TWEETABLE ABSTRACT

Vaginal and intramuscular progestogen showed equivalent efficacy for preventing preterm birth before 37 weeks of gestation.

SO085CIRCULATING PCSK9 LEVEL PREDICTS RISK OF CARDIOVASCULAR EVENTS AND DEATH IN HEMODIALYSIS PATIENTS

Background and Aims

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a promising new target for prevention of cardiovascular (CV) events. However, the clinical significance of circulating PCSK9 is unclear in hemodialysis (HD) patients.

Method

A total of 353 HD patients were prospectively enrolled from June 2016 to May 2018 in a K-cohort. Plasma PCSK9 level was measured at the time of study enrollment. Patients were classified into three groups based on PCSK9 tertile. The primary endpoint was defined as composite of CV event and death from any cause.

Results

Plasma PCSK9 level was positively correlated with total cholesterol level in patients with statin treatment. However, PCSK9 was not related to plasma inflammatory (high-sensitivity C-reactive peptide, monocyte chemoattractant protein-1, interleukin-6) or calcification-related markers (osteoprotegerin and receptor activator of nuclear factor kappa-Β ligand). Multivariate linear regression analysis revealed that baseline statin treatment and serum glucose, albumin, and total cholesterol were independent determinants of circulating PCSK9 levels. In Cox-regression analysis, PCSK9 tertile 3 was associated with a 1.99-fold risk for composite events (95% CI, 1.08–3.66), and it was associated with a 2.26-fold risk for CV events (95% CI, 1.11–4.62) after adjustment for multiple variables. PCSK9 tertile 3 provides additional prognostic power to predict composite events in subgroups with higher levels of high-sensitivity C-reactive peptide and LDL.

Conclusion

In conclusion, higher circulating PCSK9 level independently predicted CV events and death in HD patients. These results suggest the importance of future studies regarding the effect of PCSK9 inhibition on reduction of CV events.

P1490AGAIT SPEED AND HANDGRIP STRENGTH AS PREDICTORS OF ALL-CAUSE MORTALITY AND CARDIOVASCULAR EVENTS IN HEMODIALYSIS PATIENTS

Background and Aims

Low physical performance in patients undergoing maintenance hemodialysis is associated with a high mortality rate. We investigated the clinical relevance of gait speed and handgrip strength, the two most commonly used methods to assess physical performance.

Method

We obtained data regarding gait speed and handgrip strength from 277 hemodialysis patients and evaluated their relationship with baseline parameters, mental health, plasma inflammatory markers, and major adverse clinical outcomes. Low physical performance was defined by the recommendations suggested by the Asian Working Group on Sarcopenia.

Results

The prevalence of low gait speed and handgrip strength were 28.2% and 44.8%, respectively. Old age, low serum albumin levels, high comorbidity index, and impaired cognitive functions were associated with low physical performance. Patients with isolated low gait speed exhibited a general trend for worse quality of life than those with isolated low handgrip strength. Gait speed and handgrip strength showed very weak correlations with had different determinant factors (older age, the presence of diabetes, and lower serum albumin for low gait speed, and lower body mass index, and the presence of previous cardiovascular events for low handgrip strength). Patients with low gait speed and handgrip strength had elevated levels of plasma endocan and matrix metalloproteinase-7 and the highest risk of all-cause mortality and cardiovascular events among the groups (adjusted hazard ratio of 2.72, p = 0.024).

Conclusion

Gait speed and handgrip strength reflected distinctive aspects of patient characteristics and that their combination improved the prediction of adverse clinical outcomes in hemodialysis patients. Gait speed seems to be a better indicator for poor patient outcomes compared with handgrip strength.

P0798ASSOCIATION BETWEEN RENAL DYSFUNCTION AND GENERAL COGNITIVE FUNCTION IN COMMUNITY DWELLING OLDER ADULTS: KOREAN FRAILTY AND AGING COHORT STUDY

Background and Aims

Cognitive impairment is common in older adults. Similarly, the prevalence of renal dysfunction is also increased in the elderly. We conducted this study to clarify the relationship between the renal function and cognitive impairment in community dwelling older adults in Korea.

Method

A cross-sectional analysis was performed on the data of the Korean Frailty and Aging Cohort Study (KFACS), a nationwide cohort study that began in 2016. Of the 3014 participants assessed in the first and second year, 2847 participants (1333 men, 1514 women) who completed baseline assessments were enrolled. The estimated glomerular filtration rate (eGFR, mL/min/1.73m2) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Renal function of the participants was classified into four groups by eGFR quartile. General cognitive function was accessed with mini-mental state exam in the Korean version (MMSE-KC). Participants who had MMSE-KC score less than 1.5 standard deviation by age, gender, and education level were regarded as the cognitive impairment. Multivariate logistic regression model was used to examine the relationship between renal function and cognitive impairment. In addition, we investigated to find the point of eGFR interval at which the odds ratio begins to increase.

Results

The mean eGFR in quartile 1 was 91.7 ± 3.22 ml/min/1.73m2, and 84.9 ± 1.81 in quartile 2, 76.1 ± 3.66 in quartile 3, and 57.2 ± 10.75 in quartile 4. In baseline characteristics, participants with lower eGFR had lower MMSE-KC scores. And the prevalence of cognitive impairment was 10.8% in quartile 1, 15.9% in quartile 2, 15.2% in quartile 3, 14.9% in quartile 4. After multivariate adjustment, the odds ratio (OR) of cognitive impairment in quartile 2 [adjusted OR: 1.569, 95% confidence intervals (CI): 1.141 - 2.158, p = 0.006] compared with quartile 1. And the odd ratios of cognitive impairment were 1.539 (95% CI: 1.113 - 2.127, p = 0.009) in quartile 3, 1.475 (95% CI: 1.062 - 2.049, p = 0.020) in quartile 4 compared with quartile 1, respectively. Among the participants with eGFR above 60 ml/min/1.73m2, the renal function was grouped by 5 ml/min/1.73m2 interval. The risk of cognitive impairment started to increase from eGFR between 80 and 85 ml/min/1.73m2 (adjusted OR: 1.667, 95% CI: 1.128 - 2.463, p = 0.010).

Conclusion

Renal dysfunction was associated with lower global cognitive function in older adults. And the risk of cognitive impairment increased from quartile 2, especially, eGFR between 80 and 85 ml/min/1.73m2 in this population. These results suggest that mild decline of kidney function is also a risk factor of cognitive decline in the elderly.

P0826OBESITY AND RISK FOR CHRONIC KIDNEY DISEASE IN THE HEALTHY MIDDLE-AGED KOREAN POPULATION

Background and Aims

Although obesity is a well-known risk factor for chronic kidney disease (CKD), previous epidemiologic studies have produced mixed results. This study was purposed to investigate the relationship between obesity and CKD occurrence in the healthy middle-aged Korean population.

Method

We used a prospective, longitudinal data from the Korean Genome and Epidemiology Study (KoGES), a population-based, epidemiology study in South Korea (2001-2014). A total of 6,678 participants aged 40-69 who were free of diabetes, hypertension, and CKD at baseline were followed-up biennially. CKD was defined as at least two-time occurrence of estimated glomerular filtration rate &lt; 60 mL/min/1.73m2 using CKD-EPI equation during the follow-up period.

Results

A total of 433 participants (6.5%) developed CKD. We divided the participants into 5 groups by BMI: underweight (BMI &lt; 18.5), normal-weight (BMI 18.5-22.0), overweight 1 (BMI 23.0-24.9), overweight 2 (BMD 25-29.9), and obesity (BMI &gt;30). Compared to the normal-weight group, hazard ratio of CKD occurrence was elevated in overweight 2 (HR=1.43, p=0.01) and obesity (HR=1.73, p=0.03) in multivariate-adjusted regression analysis (variates: age, newly developed hypertension, newly developed diabetes, fasting glucose &gt; 126mg/dL, 2hours glucose &gt; 200mg/dL, systolic blood pressure &gt; 140mmHg, physical activity, alcohol consumption, smoking). When dividing the participants into three age groups: the 40s, 50s, and 60s, only the 60s group showed a significant correlation of BMI with CKD occurrence (overweight 2: HR=1.93, p=0.05, obesity: HR=3.94, p=0.03).

Conclusion

The risk of CKD was significantly high for those in their 60s who were overweight or obese despite free of underlying diseases in the Korean population.

P0151SEXUAL DIMORPHISM IN HYPERTENSION ACCORDING TO THE CHANGE OF URINE SODIUM AND VOLUME EXCRETION BY SEX OR MENOPAUSE

Background and Aims

A recent study demonstrated female rats more rapidly excreted urine sodium and water under saline bolus infusion than male rats, and suggested sexual dimorphisms in renal transporters. However, the sexual differences in renal salt and water excretion was not yet investigated with human data. We purposed to clarify whether the sexual difference of natriuretic and diuretic ability exists, and it contributes to decreasing blood pressure (BP) in nondiabetic chronic kidney disease (CKD) patients.

Method

This is a secondary analysis of an open-label, randomized, controlled study determining the effect of intensive low-salt diet education on BP and albuminuria in nondiabetic CKD patients. A total of 235 patients had stopped all renin-angiotensin blocking agents or diuretics during a run-in period for eight weeks (0w). After the run-in period, they received olmesartan (40mg daily) for eight weeks (8w), and then maintained the same medicine with low-salt diet education for an additional eight weeks (16w).

Results

Mean age of premenopausal women (n=50), same-aged young men (n=76), postmenopausal women (n=68), and same-aged older men (n=41) was 40.7, 40.2, 59.0, and 69.9 years old, respectively. Their MDRD eGFR was 76.2, 71.6, 59.8, and 58.8 mL/min/1.73m2, respectively. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) was lower in premenopausal women (129/79 mmHg) than in young men (134/83 mmHg). Daily salt intake decreased in 16w in premenopausal women (1839 → 1288mg, p=0.008) and young men (2494 → 1552mg, p=0.001) compared with them in 0w, while there was no significant change in postmenopausal women (2443 → 2171mg, p=0.610) and older men (2870 → 2366mg, p=0.458). Except for the premenopausal women (136 (0w) → 133 (16w) mEq/day, p=0.749), urine sodium excretion for 24 hours significantly decreased in 16w compared with that in 0w or 8w (young men: 154 (8w) → 137 (16w)mEq/day p=0.042, postmenopausal women: 152 (0w) → 128m (16w)Eq/day p=0.016, older men: 181 (0w) → 145 (16w)mEq/day p=0.019). Also, urine volume was significantly larger in the premenopausal women than in young men in 8w and 16w (8w: 1009 vs. 980mL p=0.002, 16w: 1004 vs. 978mL, p=0.006), while it was not different between postmenopausal women and older men (8w: 1002 vs. 990 p=0.347, 16w: 1003 vs. 1001 p=0.895). The urine volume was positively correlated with BP in the premenopausal women, while it was negatively associated with BP in young men in 16w.

Conclusion

Although sodium intake was similarly decreased in premenopausal women and young men, urine sodium excretion did not fall, and urine volume increased in premenopausal women. This phenomenon disappeared in postmenopausal women. Augmented natriuretic and diuretic potency might contribute to lower BP in premenopausal women with nondiabetic CKD.

Gait speed and handgrip strength as predictors of all-cause mortality and cardiovascular events in hemodialysis patients

Background

Low physical performance in patients undergoing maintenance hemodialysis is associated with a high mortality rate. We investigated the clinical relevance of gait speed and handgrip strength, the two most commonly used methods of assessing physical performance.

Methods

We obtained data regarding gait speed and handgrip strength from 277 hemodialysis patients and evaluated their relationships with baseline parameters, mental health, plasma inflammatory markers, and major adverse clinical outcomes. Low physical performance was defined by the recommendations suggested by the Asian Working Group on Sarcopenia.

Results

The prevalence of low gait speed and handgrip strength was 28.2 and 44.8%, respectively. Old age, low serum albumin levels, high comorbidity index score, and impaired cognitive functions were associated with low physical performance. Patients with isolated low gait speed exhibited a general trend for worse quality of life than those with isolated low handgrip strength. Gait speed and handgrip strength showed very weak correlations with different determining factors (older age, the presence of diabetes, and lower serum albumin level for low gait speed, and lower body mass index and the presence of previous cardiovascular events for low handgrip strength). Patients with low gait speed and handgrip strength had elevated levels of plasma endocan and matrix metalloproteinase-7 and the highest risks for all-cause mortality and cardiovascular events among the groups (adjusted hazard ratio of 2.72, p = 0.024). Elderly patients with low gait speed and handgrip strength were at the highest risk for poor clinical outcomes.

Conclusion

Gait speed and handgrip strength reflected distinctive aspects of patient characteristics and the use of both factors improved the prediction of adverse clinical outcomes in hemodialysis patients. Gait speed seems to be a better indicator of poor patient outcomes than is handgrip strength.

Effects of online hemodiafiltration on anemia and nutritional status in chronic hemodialysis patients

Background

Online hemodiafiltration (OL-HDF) offers considerable advantages in clearance of molecules of various sizes. However, evidence of clinical effects of OL-HDF is scarce in Korea. In this study, we investigated changes in laboratory values over more than 12 months after switching to OL-HDF.

Methods

Adult patients with end-stage renal disease undergoing hemodialysis (HD) were prospectively enrolled in a K-cohort (CRIS no. KCT0003281) from 6 tertiary hospitals in South Korea. We recruited 435 patients, 339 of whom were on HD at enrollment. One hundred eighty-two patients were followed for more than 24 months. Among them, 44 were switched to OL-HDF for more than 12 months without conversion to HD. We used a paired t test to compare baseline and 24-month follow-up results.

Results

The mean age of the subjects was 61.2 ± 12.2 years, and 62.6% were male. The baseline hemoglobin level was not significantly different between HD and OL-HDF group (10.61 ± 1.15 vs. 10.46 ± 1.03 g/dL, P = 0.437). However, the baseline serum protein and albumin levels were significantly lower in the OL-HDF group (6.82 ± 0.49 vs. 6.59 ± 0.48 g/dL, P = 0.006; 3.93 ± 0.28 vs. 3.73 ± 0.29 g/dL, P < 0.001). In patients switched to OL-HDF, levels of hemoglobin and serum albumin significantly increased (10.46 ± 1.03 vs. 11.08 ± 0.82 g/dL, P = 0.001; 3.73 ± 0.29 vs. 3.87 ± 0.30 g/dL, P = 0.001). The normalized protein catabolic rate decreased after 24 months, but the change was not significant (1.07 ± 0.25 vs. 1.03 ± 0.21 g/kg/day, P = 0.433). Although the dose of erythropoiesis-stimulating agent was lower in patients who converted to HDF, it was not significantly different (-115.7 ± 189.7 vs. -170.5 ± 257.1 P = 0.206).

Conclusion

OL-HDF treatment over more than 12 months was associated with no harmful effects on anemia and nutritional status.

Circulating PCSK9 Level and Risk of Cardiovascular Events and Death in Hemodialysis Patients

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a promising new target for the prevention of cardiovascular (CV) events. However, the clinical significance of circulating PCSK9 is unclear in hemodialysis (HD) patients. A total of 353 HD patients were prospectively enrolled from June 2016 to August 2019 in a K-cohort. Plasma PCSK9 level was measured at the time of study enrollment. The primary endpoint was defined as a composite of CV event and death. Plasma PCSK9 level was positively correlated with total cholesterol level in patients with statin treatment. Multivariate linear regression analysis revealed that baseline serum glucose, albumin, total cholesterol, and statin treatment were independent determinants of circulating PCSK9 levels. Cumulative rates of composite and CV events were significantly higher in patients with tertile 3 PCSK9 (p = 0.017 and p = 0.010, respectively). In multivariate Cox-regression analysis, PCSK9 tertile 3 was associated with a 1.97-fold risk of composite events (95% CI, 1.13–3.45), and it was associated with a 2.31-fold risk of CV events (95% CI, 1.17–4.59). In conclusion, a higher circulating PCSK9 level was independently associated with incident CV events and death in HD patients. These results suggest the importance of future studies regarding the effect of PCSK9 inhibition.

Baseline High Blood Pressure is Associated with Clinico-Pathologic Findings and Later Renal Progression in Chronic Glomerulonephritis

Background

Several factors had been suggested to contribute to the development of hypertension in chronic glomerulonephritis (GN). This study was conducted to find the association of baseline blood pressure (BP) with pathophysiologic findings and later renal progression in chronic GN.

Methods

Clinico-pathological findings including serum creatinine (Cr), proteinuria, pathological findings, and urinary Na excretion were analyzed in a total of 233 patients with IgA nephropathy from The Kyung-Hee Cohort of GN. Glomerular surface area (GSA) was measured by imaging analysis and urine angiotensinogen (AGT) concentrations by human ELISA kits.

Results

Systolic BP was ≥130mmHg in 124 patients (53%). Systolic BP was negatively correlated with follow-up eGFR (r=−0.32, p<0.0001) and positively serum uric acid concentrations, while it had no significant relationships with initial serum Cr and eGFR. As compared with patients with systolic BP<130 mmHg, those with ≥130 mmHg were older and showed higher serum Cr, proteinuria, 24 hr urinary Na excretion, mean GSA, and T-I fibrosis, lower follow-up eGFR, and steeper decline in slope of eGFR. The results in patients with normal serum Cr concentrations were comparable to those in whole group. Systolic BP was positively correlated with age, baseline and follow-up proteinuria, serum uric acid concentrations and IgM deposit and negatively with follow-up eGFR. In subgroup analysis, systolic BP was also positively correlated with mean GSA and urinary AGT concentrations.

Conclusion

This study showed that baseline systolic BP is related to urinary Na excretion, glomerulomegaly, T-I fibrosis and later renal progression in patients with IgA nephropathy.

Long-term Trends in the Clinicopathologic Features of Kidney Transplant Recipients With Graft Dysfunction

BACKGROUND

Graft biopsy is the gold standard for the differential diagnosis of graft dysfunction. The time interval between transplant surgery and biopsy often provides clinicians with diagnostic clues. However, the clinicopathologic features of late graft biopsy, especially those obtained at more than 5 years after kidney transplant, are not well understood.

MATERIALS AND METHODS

We retrospectively collected graft biopsy tissues obtained from kidney transplant recipients who underwent indication biopsy between February 2012 and March 2017. Patients were divided according to their post-transplant period, and their clinical characteristics, pathologic diagnosis, and Banff scores were compared across groups.

RESULTS

A total of 410 indication biopsy specimens obtained from 321 kidney transplant recipients were analyzed in this study. Overall, the incidence of T cell-mediated rejection, borderline rejection, and BK virus-associated nephropathy decreased while that of antibody-mediated rejection, nonspecific interstitial fibrosis and tubular atrophy, and glomerulonephritis increased over time. Most samples obtained over 5 years after kidney transplant exhibited chronic glomerular and tubulointerstitial injuries irrespective of their pathologic diagnosis. In patients whose post-transplant period was less than 5 years, urine protein-to-creatinine ratio was significantly elevated in the glomerulonephritis and chronic active antibody-mediated rejection groups only. In contrast, patients who underwent graft biopsy more than 5 years after kidney transplant showed significantly high levels of proteinuria irrespective of the pathologic diagnosis, and there was no statistical difference between groups.

CONCLUSION

We demonstrated that the etiology of graft dysfunction is largely influenced by the biopsy time point.

P5989Effect of neprilysin inhibitor for ischemic mitral regurgitation after myocardial injury

Background

After myocardial infarction (MI), mitral valve (MV) tethering and fibrosis stimulate functional mitral regurgitation (MR), resulting in high morbidity of heart failure and cardiac mortality. However, pharmacological treatment has not been proven effective in reducing ischemic MR. MV change post-MI is associated with an excessive endothelial-to-mesenchymal transition (EMT) by transforming growth factor (TGF)-β overexpression and also with left ventricular (LV) remodeling. In a recent clinical study using echocardiography, angiotensin receptor neprilysin inhibitor (ARNI) reduced functional MR to a greater extent than did valsartan, but the mechanism was not revealed.

Purpose

This study tested the hypothesis that treatment of neprilysin inhibitor attenuates functional MR after MI by facilitating LV reverse remodeling and suppressing EMT which mitigates inadequate leaflet adaptation.

Methods

In male Sprague-Dawley rats (n=31), functional MR was induced by occluding the left circumflex coronary artery. Two weeks after MI, MR and LV dilatation were confirmed by echocardiography and magnetic resonance imaging (MRI). Rats were randomly assigned to LCZ696 treatment (ARNI, 60 mg/kg/d, n=10), valsartan treatment (30mg/kg/d, n=10), or corn oil only (MR control group; n=11). After 6 weeks, LV volumes, functions and MR extent were quantified by using echocardiography, cardiac MRI and pressure-volume loop analysis. Also, excised mitral leaflets and LV were analyzed by histopathology and primary cultured valvular endothelial cells (VECs) were evaluated focusing on molecular changes.

Results

LCZ696 significantly attenuated post-MI LV dilatation after 6 weeks when compared with the control group (LV end-diastolic volume (EDV), 461.3±41.3 uL versus 525.1±78.2 uL; p<0.05), while valsartan did not (LV EDV, 471.2±26.8 uL; p>0.05 to control). There were no significant differences in the change of arterial pressure and ejection fraction between the treatment groups, however, dP/dt was greater in the LCZ696 group than in the MR control group (8203±286 mmHg/s for LCZ696 versus 6936±555 mmHg/s for MR control; p=0.01). MR extent and LA volume were significantly decreased in the LCZ696 group compared with the valsartan group. Pathological analysis showed that fibrosis was more prominent in the MR control than in the LCZ696 group. LCZ696 strongly reduced leaflet thickness, TGF-β, and downstream phosphorylated extracellular-signal-regulated kinase and EMT (25.4±11.8% vs. 53.4±12.6% α-smooth muscle actin-positive VECs; p<0.05). Leaflet area increased comparably (5%) in the LCZ696 group compared with the valsartan group.

Conclusions

Neprilysin inhibitor has positive effects on LV reverse remodeling and also directly modulates profibrotic changes of MV leaflets post-MI without eliminating adaptive growth. Understanding the mechanisms could provide new opportunities to ARNI reducing ischemic MR.

Acknowledgement/Funding

This work was supported by the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2014R1A6A3A04056205). It was also

Clinical outcomes and effects of treatment in older patients with idiopathic membranous nephropathy

BACKGROUND/AIMS

Membranous nephropathy (MN) is the most common primary glomerular disease diagnosed in older patients. Few reports describe the clinical outcomes in older patients with idiopathic MN.

METHODS

The outcomes of 135 patients with histologically proven MN were analyzed. 'Older' was defined as 60 years of age or older at the time of the renal biopsy. The rates of complete remission (CR), progression to end-stage renal disease (ESRD) and infection were compared between older and younger patients.

RESULTS

The cumulative event rate for achieving CR was inferior (p = 0.012) and that for requiring renal replacement was higher (p = 0.015) in older patients, and they had a greater risk of infection (p = 0.005). Older age was a significant predictor of a lower rate of CR (adjusted odds ratio [OR], 0.51; 95% confidence interval [CI], 0.26 to 0.98), and was a robust predictor of infection (adjusted OR, 5.27; 95% CI, 1.31 to 21.20). Conservative treatment was associated with a lower remission rate (p = 0.036) and corticosteroid treatment was less effective in achieving CR (p = 0.014), in preventing progression to ESRD (p = 0.013) and in reducing infection (p = 0.033) in older patients. Cyclosporine treatment had similar clinical outcomes with regard to CR, ESRD progression, and infection in older patients.

CONCLUSION

Older age was independently associated with inferior rates of CR and greater risk of infection. Treatment modalities affected the outcomes of older patients differently in that cyclosporine treatment is predicted to be more useful than corticosteroids.

Cilastatin protects against tacrolimus-induced nephrotoxicity via anti-oxidative and anti-apoptotic properties

BACKGROUND

Cilastatin (CL) is an inhibitor of dehydropeptidase-I, which is safely used in clinical practice to prevent nephrotoxicity of antibiotics. Tacrolimus (TAC) is the most important immunosuppressant in renal transplantation, but it causes considerable nephrotoxicity. We evaluated the protective effects of CL against chronic TAC-induced nephropathy.

METHODS

Chronic nephropathy was induced by administering TAC (1.5 mg/kg/ day, subcutaneous injection) to rats on a low-salt diet for 4 weeks. CL (75 or 150 mg/kg/day, intraperitoneal injection) was concomitantly treated with TAC. Human proximal tubular cells were exposed to TAC (50 μg/mL) with or without CL (250 μg/mL). We investigated the effects of CL on TAC-induced injury in terms of renal function, tubulointerstitial fibrosis, and inflammation. The effects of CL on oxidative stress and apoptosis were evaluated in both in vivo and in vitro models of TAC nephrotoxicity.

RESULTS

CL treatment improved TAC-induced renal dysfunction and decreased renal interstitial fibrosis (reduced expression of e-cadherin and TGFβ-1) and interstitial inflammation (decreased infiltration of ED-1-positive and osteopontin-positive cells). Compared to TAC treatment alone, CL co-treatment reduced oxidative stress (serum 8-OHdG level and immunoreactivity of 8-OHdG and 4-HHE in renal tissue) and increased renal expression of anti-oxidant enzyme, manganese superoxide dismutase. CL treatment decreased apoptotic cell death (decreased TUNEL-positive cells and reduced expression of active caspase-3) in TAC-treated kidney. In vitro CL treatment prevented tubular cell death from TAC treatment and decreased number of annexin V-positive cells were observed in cilastatin-cotreated cells.

CONCLUSION

CL has protective effects against chronic TAC-induced nephrotoxicity owing to its anti-oxidative and anti-apoptotic properties.