Digital coincidence counting with 4πβ(PPC)-γ for the standardization of 60Co

A 4πβ(PPC)-γ coincidence system has been made at KRISS based on a digital DAQ. 60Co sources were measured to verify the system. The maximum detection efficiency for beta particles was estimated to be 96.7 %. Massic activities for sample sources had 0.005 % of the sample variability error, which was well within the expanded standard uncertainty of 0.54 % (k = 2).

Circulating osteoprotegerin levels and cardiovascular outcomes in patients with pre-dialysis chronic kidney disease: results from the KNOW-CKD study

While the relationship between circulating osteoprotegerin (OPG) and cardiovascular events is well-established in the general population, its association with cardiovascular risks in chronic kidney disease (CKD) patients remains less robust. This study hypothesized that elevated circulating OPG levels might be associated with an increased risk of major adverse cardiac events (MACE) in CKD patients, a total of 2,109 patients with CKD stages 1 through pre-dialysis 5 from the KNOW-CKD cohort were categorized into quartiles based on serum OPG levels. The primary outcome of the study was 3-point MACE, defined as a composite of nonfatal myocardial infarction, nonfatal stroke, or cardiac death. The median follow-up duration was 7.9 years. The cumulative incidence of 3-point MACE significantly varied across serum OPG levels in Kaplan-Meier curve analysis (P < 0.001, log-rank test), with the highest incidence observed in the 4th quartile. Cox regression analysis indicated that, relative to the 1st quartile, the risk of 3-point MACE was significantly higher in the 3rd (adjusted hazard ratio 2.901, 95% confidence interval 1.009 to 8.341) and the 4th quartiles (adjusted hazard ratio 4.347, 95% confidence interval 1.410 to 13.395). In conclusion, elevated circulating OPG levels are associated with adverse cardiovascular outcomes in pre-dialysis CKD patients.

A simplified cranial cavity model to understand the relationship between intracranial pressure and dural sinus pressure

Although accurate intracranial pressure (ICP) monitoring is essential for the diagnosis and treatment of severe brain diseases, current methods are performed invasively. Therefore, a safe and less invasive ICP measurement is required. The purpose of our study was to develop a simplified cranial cavity model for a better understanding of the relationship between the ICP and the pressure measurement within the dural venous sinus (DVS) to support the validity of using sinus pressure as the surrogate of the ICP. The in-house cranial cavity model had three components: the brain part, the DVS part, and the subarachnoid space (SAS) part. Pressure in other parts was measured when the pressure in the SAS part and, separately, brain part was increased from 0 (baseline) to 50 mmHg at intervals of 10 mmHg. When the pressure in the SAS part was increased from 10 to 50 mmHg at 10 mmHg interval, pressures of both the brain and DVS parts increased without significant difference (all P > 0.05). However, pressures in both the SAS and DVS parts differed while the pressure in the brain part was increased. The pressures in both parts showed about 70% of the increase in the brain part. Nevertheless, the pressures in the SAS and DVS parts were not significantly different (P > 0.05). A simplified in-house cranial cavity model was developed consisting of three compartments to represent the actual intracranial spaces. The pressure measurement within the DVS was feasible to use as a surrogate for the ICP measurement.

Factors Associated With the Development and Severity of Polycystic Liver in Patients With Autosomal Dominant Polycystic Kidney Disease

BACKGROUND

Factors related to the development and severity of polycystic liver disease (PLD) have not been well established. We aimed to evaluate the genetic and epidemiologic risk factors of PLD in patients with autosomal dominant polycystic kidney disease (ADPKD).

METHODS

Adult patients with inherited cystic kidney disease were enrolled from May 2019 to May 2021. Demographic, clinical, and laboratory data were collected at the initial study visit. The severity of PLD was graded based on the height-adjusted total liver volume: < 1,000 mL/m (Gr1), 1,000-1,800 mL/m (Gr2), and > 1,800 mL/m (Gr3). Targeted exome sequencing was done by a gene panel including 89 ciliopathy-related genes. We searched out the relative factors to the presence and the severity of PLD using logistic regression analysis.

RESULTS

Of 602 patients with typical ADPKD, 461 (76.6%) patients had PLD. The patients with PLD showed female predominance and a higher frequency of other ADPKD-related complications. The genetic variants with truncating mutation of PKD1 (PKD1-protein-truncating [PT]) or PKD2 commonly affected the development and severity of PLD. An older age, female sex, and higher kidney volume with Mayo classification 1C-1E was significantly associated with the development of PLD, but not with the severity of PLD. On the other hand, higher body mass index, lower hemoglobin, and higher alkaline phosphatase (ALP) were the significant risk factors of severe PLD (≥ Gr2).

CONCLUSION

Hepatic involvement in ADPKD could be related to kidney manifestations and genetic variants including PKD1-PT or PKD2. Monitoring hemoglobin and ALP and evaluating the genetic variants might help predict severe PLD.

TRIAL REGISTRATION

Clinical Research Information Service Identifier: KCT0005580.

Baseline characteristics of the Korean genetic cohort of inherited cystic kidney disease

BACKGROUND

Identifying genetic mutations in individuals with inherited cystic kidney disease is necessary for precise treatment. We aimed to elucidate the genetic characteristics of cystic kidney disease in the Korean population.

METHODS

We conducted a 3-year prospective, multicenter cohort study at eight hospitals from May 2019 to May 2022. Patients with more than three renal cysts were enrolled and classified into two categories, typical autosomal dominant polycystic kidney disease (ADPKD) and atypical PKD. We identified the clinical characteristics and performed a genetic analysis using a targeted gene panel.

RESULTS

A total of 725 adult patients were included in the study, of which 560 (77.2%) were diagnosed with typical ADPKD and 165 (22.8%) had atypical PKD. Among the typical ADPKD cases, the Mayo imaging classification was as follows: 1A (55, 9.9%), 1B (149, 26.6%), 1C (198, 35.8%), 1D (90, 16.3%), and 1E (61, 11.0%). The atypical PKD cases were classified as bilateral cystic with bilateral atrophic (31, 37.3%), lopsided (27, 32.5%), unilateral (nine, 10.8%), segmental (eight, 9.6%), bilateral cystic with unilateral atrophic (seven, 8.4%), and asymmetric (one, 1.2%). Pathogenic variants were found in 64.3% of the patients using the ciliopathy-related targeted gene panel. The typical ADPKD group demonstrated a higher discovery rate (62.3%) than the atypical PKD group (41.8%).

CONCLUSION

We present a nationwide genetic cohort's baseline clinical and genetic characteristics for Korean cystic kidney disease.

Measurement of Direct-Photon Cross Section and Double-Helicity Asymmetry at sqrt[s]=510 GeV in p[over →]+p[over →] Collisions

We present measurements of the cross section and double-helicity asymmetry A_{LL} of direct-photon production in p[over →]+p[over →] collisions at sqrt[s]=510  GeV. The measurements have been performed at midrapidity (|η|<0.25) with the PHENIX detector at the Relativistic Heavy Ion Collider. At relativistic energies, direct photons are dominantly produced from the initial quark-gluon hard scattering and do not interact via the strong force at leading order. Therefore, at sqrt[s]=510  GeV, where leading-order-effects dominate, these measurements provide clean and direct access to the gluon helicity in the polarized proton in the gluon-momentum-fraction range 0.02<x<0.08, with direct sensitivity to the sign of the gluon contribution.

Risk of CKD Following Detection of Microscopic Hematuria: A Retrospective Cohort Study

RATIONALE & OBJECTIVE

Microscopic hematuria is an uncertain risk factor for chronic kidney disease (CKD). We investigated the association between persistent or single episodes of microscopic hematuria and the development of incident CKD, overall and separately among men and women.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

A total of 232,220 Korean adults without CKD at baseline who underwent repeated regular health examinations at Kangbuk Samsung Health Study formed the study cohort.

EXPOSURE

Microscopic hematuria was defined by≥5 red blood cells per high-power field. Participants were categorized into 1 of 4 groups according to the presence of hematuria at 2 consecutive examinations: (1) no hematuria at both examinations (reference group); (2) hematuria followed by no hematuria (regressed hematuria group); (3) no hematuria followed by hematuria (developed hematuria group); and (4) hematuria at both examinations (persistent hematuria group).

OUTCOME

CKD was defined as an estimated glomerular filtration rate<60mL/min/1.73m² or proteinuria (1+or more on dipstick examination).

ANALYTICAL APPROACH

Semiparametric proportional hazards models were used to estimate hazard ratios.

RESULTS

During a 4.8-year median follow-up period, 2,392 participants developed CKD. Multivariable-adjusted hazard ratios for incident CKD, comparing the regressed, developed, and persistent hematuria groups to the no-hematuria group were 1.85 (95% CI, 1.35-2.53), 3.18 (95% CI, 2.54-3.98), and 5.23 (95% CI, 4.15-6.59), respectively. The association between persistent hematuria and incident CKD was stronger in men than women (P for interaction<0.001), although a statistically significant association was observed in both sexes.

LIMITATIONS

Lack of albuminuria and inability to consider specific glomerular diseases.

CONCLUSIONS

Men and women with microscopic hematuria, especially persistent hematuria, may be at increased risk of CKD.

Nutritional status is associated with preserved kidney function in patients with autosomal dominant polycystic kidney disease

OBJECTIVE

Malnutrition is a common complication in autosomal dominant polycystic kidney disease (ADPKD). We examined whether nutritional status is associated with the preservation of kidney function, using a cohort of typical ADPKD.

METHODS

We enrolled ambulatory ADPKD patients in nine tertiary medical centers in Korea from May 2019 to December 2021. We excluded patients who were aged less than 18 years, who had known end-stage kidney disease at the time of enrollment, who had a diagnosis of atypical ADPKD, and who were Tolvaptan users. The primary outcome was an estimated glomerular filtration rate (eGFR) decline >3 mL/min/1.73m², based on nutritional status assessed by subjective global assessment (SGA). We also evaluated an eGFR decline >1 mL/min/1.73m², an increase in urine protein-creatinine ratio (UPCR) >0, and an increase in UPCR >0.3 as secondary outcomes, based on SGA after the one-year follow-up. A logistic regression (LR) model was used to calculate the odds ratio (OR) for the primary outcome. Because there were differences in several baseline variables, such as Mayo classification, serum hemoglobin, serum creatinine, and UPCR between SGA groups, we matched propensity scores.

RESULTS

In total, 805 patients were prospectively enrolled in nine tertiary medical centers in Korea from May 2019 to December 2021. Among them, 236 patients who had one-year follow-up data and typical imaging findings were analyzed to evaluate the effect of nutritional status on kidney function. SGA was used to assess the nutritional status. The mean age was 45.0 ± 13.3 years, and 49.6% of the patients were female. The mean eGFR was 81.9 ml/min/1.73m². Among the 236 patients, 91 (38.6%) experienced a one-year eGFR decline >3 mL/min/1.73m². When a multivariable LR was applied, SGA 3-6 was identified as a significant factor related to a one-year eGFR decline >3 mL/min/1.73m² (adjusted OR = 1.22 [1.04-1.43]; P = 0.017). Despite matching propensity scores, the one-year eGFR decline >3 mL/min/1.73m² was still higher in the SGA 3-6 group regardless of proteinuria.

CONCLUSION

Good nutritional status is associated with better-preserved kidney function in non-obese typical ADPKD patients who do not take Tolvaptan.

Three-dimensional navigation-guided percutaneous trans-symphyseal screw for mechanically unstable pubic symphysis diastasis

Minimally invasive trans-symphyseal screw (TSS) for pubic symphysis diastasis was recently advocated, and its feasibility and reproducibility under 3D-navigation guidance are explored. Fifteen cases between 2016 and 2021 with a background of pubic symphysis diastasis are reviewed in this case series. Twenty-two TSS were inserted with an average Injury Severity Score of 35.3. Sixty percent received a one-stage procedure including fracture reduction, intra-operative 3D imaging, and planning followed by execution. The mean operative time and blood loss were 132 minutes and 160 ml, respectively. Average fracture healing was 5.8 months with two delayed unions at 9 months. The pubic symphysis distance was maintained in all cases at 6 months post-op. The average Marjeed score, Multicenter Study Group Pelvic Outcome Score, and Numeric pain rating scale were 60.2, 6.5, and 2.7, respectively. We conclude that 3D-navigation-guided percutaneous TSS restores pelvic stability and provides satisfactory pain control, and thus a safe and effective alternative to open reduction internal fixation.

Serum creatinine to cystatin C ratio and clinical outcomes in adults with non-dialysis chronic kidney disease

Background

Studies have suggested that the serum creatinine/cystatin C (Cr/CysC) ratio is a surrogate marker for muscle wasting is associated with adverse outcomes in several disease conditions. To clarify the utility of the Cr/CysC ratio as a prognostic marker in chronic kidney disease (CKD) we evaluated the association between the Cr/CysC ratio clinical outcomes in patients with non-dialysis CKD.

Methods

This prospective observational cohort study included 1,966 participants of the KoreaN cohort study Outcomes in patients With CKD (KNOW-CKD). We evaluated associated factors with the serum Cr/CysC ratio and association between the serum Cr/CysC ratio and composite outcomes of all-cause death and cardiovascular events (CVEs).

Results

The mean age was 54 ± 12 (SD) years and 61% were men. The mean serum Cr/CysC ratio was 10.97 ± 1.94 in men and 9.10 ± 1.77 in women. The Cr/CysC ratio correlated positively with urinary creatinine excretion, a marker of muscle mass. In the fully adjusted Cox proportional hazard model, the Cr/CysC ratio was associated with the occurrence of adverse outcomes through a median follow-up of 5.9 years [hazard ratio (HR) = 0.92, 95% confidence interval (CI) = 0.85–0.99 for the composite outcomes, HR = 0.87, 95% CI, 0.78 − 0.97 for all-cause death, and HR = 0.93; 95% CI, 0.84–1.04 for CVEs]. In subgroup analyses, there were interactions of the Cr/CysC ratio with age and sex for risk of the clinical outcomes, but not eGFR group.

Conclusion

A higher Cr/CysC ratio is associated with a lower risk of the composite outcomes, especially all-cause mortality, even after adjusting for eGFR. These suggest that the Cr/CysC ratio is a useful prognostic marker in CKD.

Coronary artery calcium and risk of chronic kidney disease in young and middle-aged adults

Background

The role of coronary artery calcium score (CACS) in incident chronic kidney disease (CKD) in asymptomatic young populations remains unclear. The aim of this study was to evaluate the association between CACS and CKD development in adults.

Methods

A cohort study of 113 171 Korean adults (mean age, 40.6 years) without CKD and proteinuria at baseline, who underwent a cardiac tomography estimation of CACS during health screening examinations, was performed (median follow-up: 4.2 years). The outcome was CKD, defined as an estimated glomerular filtration rate (eGFR) &lt;60 ml/min/1.73 m2 and/or the presence of proteinuria. Hazard ratios (HRs) and 95% confidence intervals (CIs) for CKD were estimated using Cox proportional hazards regression analyses.

Results

A higher CACS was moderately associated with an increased risk of CKD in a dose-dependent manner. The multivariable-adjusted HRs (95% CIs) for CKD comparing CACS 1–100, 101–300, and &gt; 300 with CACS = 0 were 1.15 (1.05–1.25), 1.37 (1.13–1.66), and 1.71 (1.32–2.22), respectively (P for trend &lt; 0.001). When CKD was defined using low eGFR and proteinuria separately, corresponding HRs (95% CIs) for low eGFR were 1.31 (1.05–1.62), 1.41 (0.95–2.11), and 1.86 (1.16–3.00), respectively (P for trend = 0.003), while HR (95% CIs) for proteinuria were 1.11 (1.02–1.21), 1.32 (1.07–1.64), and 1.57 (1.16–2.12), respectively.

Conclusions

A higher CACS was progressively associated with an increased risk of CKD, even at low levels of CACS. Individuals with CACS &gt; 0 appear to have an increased risk of CKD and may benefit from preventive measures to reduce CKD risk.

Coronary Artery Calcification Score and the Progression of Chronic Kidney Disease

BACKGROUND

An elevated coronary artery calcification score (CACS) is associated with increased cardiovascular disease risk in patients with CKD. However, the relationship between CACS and CKD progression has not been elucidated.

METHODS

We studied 1936 participants with CKD (stages G1-G5 without kidney replacement therapy) enrolled in the KoreaN Cohort Study for Outcome in Patients With CKD. The main predictor was Agatston CACS categories at baseline (0 AU, 1-100 AU, and >100 AU). The primary outcome was CKD progression, defined as a ≥50% decline in eGFR or the onset of kidney failure with replacement therapy.

RESULTS

During 8130 person-years of follow-up, the primary outcome occurred in 584 (30.2%) patients. In the adjusted cause-specific hazard model, CACS of 1-100 AU (hazard ratio [HR], 1.29; 95% confidence interval [CI], 1.04 to 1.61) and CACS >100 AU (HR, 1.42; 95% CI, 1.10 to 1.82) were associated with a significantly higher risk of the primary outcome. The HR associated with per 1-SD log of CACS was 1.13 (95% CI, 1.03 to 1.24). When nonfatal cardiovascular events were treated as a time-varying covariate, CACS of 1-100 AU (HR, 1.31; 95% CI, 1.07 to 1.60) and CACS >100 AU (HR, 1.46; 95% CI, 1.16 to 1.85) were also associated with a higher risk of CKD progression. The association was stronger in older patients, in those with type 2 diabetes, and in those not using antiplatelet drugs. Furthermore, patients with higher CACS had a significantly larger eGFR decline rate.

CONCLUSION

Our findings suggest that a high CACS is associated with significantly increased risk of adverse kidney outcomes and CKD progression.

Left Ventricular Diastolic Dysfunction and Progression of Chronic Kidney Disease: Analysis of KNOW-CKD Data

Background Few studies have examined the association between the early diastolic mitral inflow velocity/early diastolic mitral annulus velocity ratio (E/e') and chronic kidney disease progression. Methods and Results We reviewed data from 2238 patients with nondialysis chronic kidney disease from the KNOW-CKD (Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease); data from 163 patients were excluded because of missing content. A >50% decrease in estimated glomerular filtration rate from baseline, doubling of serum creatinine, or dialysis initiation and/or kidney transplantation were considered renal events. At baseline, median (interquartile range) ejection fraction and E/e' were 64.0% (60.0%-68.0%) and 9.1 (7.4-11.9), respectively. Proportions of ejection fraction <50% and E/e' ≥15 were 1.3% and 9.6%, respectively. More than one quarter of patients (27.2%) had an estimated glomerular filtration rate <30 mL/min per 1.73 m². During the mean 59.1-month follow-up period, 724 patients (34.9%) experienced renal events. In multivariable Cox proportional hazard regression analysis, the hazard ratio with 95% CI per 1-unit increase in E/e' was 1.027 (1.005-1.050; P=0.016). Penalized spline curve analysis yielded a suggested threshold of E/e' for renal events of 12; in our data set, the proportion of E/e' ≥12 was 4.1%. Conclusions Increased E/e' was associated with an increased hazard of renal events, suggesting that diastolic heart dysfunction is a novel risk factor for chronic kidney disease progression.

Association Between Left Ventricular Geometry and Renal Outcomes in Patients With Chronic Kidney Disease: Findings From Korean Cohort Study for Outcomes in Patients With Chronic Kidney Disease Study

Background

The impact of left ventricular (LV) geometry on the renal outcomes in patients with chronic kidney disease (CKD) has not been established yet. We aimed to investigate the association of LV geometry with renal outcomes and all-cause mortality in patients with pre-dialysis CKD.

Methods

A total of 2,144 subjects from the Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease (KNOW-CKD) were categorized by LV geometry, which was defined by LV mass index and relative wall thickness [normal geometry, concentric remodeling, eccentric hypertrophy (eLVH), and concentric hypertrophy (cLVH)]. Study outcomes were composite renal events [decline of kidney function (the first occurrence of > 50% decline of eGFR or doubling of serum creatinine from the baseline) and onset of ESRD (initiation of dialysis or kidney transplantation) during follow-up periods)] and all-cause mortality.

Results

Cox regression analysis revealed that eLVH [adjusted hazard ratio (HR) 1.498, 95% confidence interval (CI) 1.197–1.873] and cLVH (adjusted HR 1.289, 95% CI 1.011–1.643) were associated with increased risk of composite renal events, whereas concentric remodeling (adjusted HR 1.881, 95% CI 1.135–3.118) and cLVH (adjusted HR 2.216, 95% CI 1.341–3.664) were associated with increased risk of all-cause mortality. Sensitivity analyses confirmed that concentric remodeling (adjusted HR 1.993, 95% CI 1.197–3.368) and eLVH (adjusted HR 1.588, 95% CI 1.261–2.001) are independently associated with all-cause mortality and composite renal events, respectively.

Conclusion

In conclusion, we report that LV geometry is significantly associated with adverse renal outcomes and all-cause mortality in patients with pre-dialysis CKD. Echocardiographic determination of LV geometry may help the early identification for the patients with high risk of CKD progression.

Association of Body Weight Variability With Progression of Coronary Artery Calcification in Patients With Predialysis Chronic Kidney Disease

Background

We investigated whether high body weight variability (BWV) is associated with a higher prevalence of coronary artery calcification (CAC) or more rapid progression of CAC in patients with predialysis chronic kidney disease (CKD).

Methods

A total of 1,162 subjects from a nationwide prospective cohort of predialysis CKD were analyzed. The subjects were divided into the tertile (T1, T2, and T3) by BWV. CAC was assessed at the baseline and a 4-year follow-up by CT scan. Rapid progression of coronary artery calcification was defined as an increase in coronary artery calcium score (CACS) more than 200 Agatston units during a 4-year follow-up.

Results

One-way ANOVA revealed that CACS change during the follow-up period is significantly higher in the subjects with high BWV, although CACS at the baseline and 4-year follow-up was not different among the tertile groups by BWV. Logistic regression analysis revealed that compared to low BWV (T1), both moderate (T2, adjusted odds ratio (OR) 2.118, 95% CI 1.075–4.175) and high (T3, adjusted OR 2.602, 95% CI 1.304–5.191) BWV was associated with significantly increased risk of rapid progression of CAC. Importantly, the association between BWV and progression of CAC remained robust even among the subjects without significant BW gain or loss during follow-up periods (T2, adjusted OR 2.007, 95% CI 1.011–3.984; T3, adjusted OR 2.054, 95% CI 1.003–4.207).

Conclusion

High BWV is independently associated with rapid progression of CAC in patients with predialysis CKD.

Association of High Serum Adiponectin Level With Adverse Cardiovascular Outcomes and Progression of Coronary Artery Calcification in Patients With Pre-dialysis Chronic Kidney Disease

Background: Serum adiponectin level predicts cardiovascular (CV) outcomes and progression of coronary artery calcification (CAC) in the general population, although the association has not been validated in patients with chronic kidney disease (CKD). In this study, we investigated the association of high serum adiponectin level with the risk of adverse CV outcomes and progression of CAC in patients with pre-dialysis CKD.

Methods: A total of 1,127 patients with pre-dialysis CKD from a nationwide prospective cohort of patients with pre-dialysis CKD in Korea were divided into the tertile by serum adiponectin level at the baseline. CV outcome of interest was fatal and non-fatal CV events and all-cause mortality. Progression of CAC was defined as coronary artery calcium score (CACS) change more than 200 during a 4-year follow-up.

Results: Cox regression analysis revealed that high serum adiponectin is associated with increased risk of fatal and non-fatal CV events (adjusted hazard ratio 2.799, 95% CI 1.348–5.811). In contrast, high serum adiponectin level was not significantly associated with all-cause mortality (adjusted hazard ratio 0.655, 95% CI 0.203–2.113). Binary logistic regression analysis revealed that high serum adiponectin level is also associated with increased risk of progression of CAC (adjusted odds ratio [OR] 2.078, 95% CI 1.014–4.260). Subgroup analyses demonstrated that the association of high serum adiponectin with increased risk of fatal and non-fatal CV events is not modified by age, gender, history of diabetes, estimated glomerular filtration rate (eGFR), or spot urine albumin-to-creatinine ratio (ACR).

Conclusions: High serum adiponectin level is associated with adverse CV outcomes and progression of CAC in patients with pre-dialysis CKD.

Low bone mineral density is associated with coronary arterial calcification progression and incident cardiovascular events in patients with chronic kidney disease

Background

Although it is well known that low bone mineral density (BMD) is associated with an increased risk of cardiovascular disease (CVD) and mortality in the general population, the prognostic role of bone mineral density (BMD) has not been established in the chronic kidney disease (CKD) population. Therefore we aimed to evaluate the association between BMD and the risk of CVD and cardiovascular mortality in patients with predialysis CKD.

Methods

This prospective cohort study was conducted with 1957 patients with predialysis CKD Stages 1–5. BMD was measured using dual-energy X-ray absorptiometry and coronary arterial calcification (CAC) scores were evaluated using coronary computed tomography. The primary outcome was a major adverse cardiovascular event (MACE).

Results

When patients were classified based on total hip BMD T-score tertiles stratified by sex, the lowest BMD tertile was significantly associated with an increased risk of MACE {hazard ratio 2.16 [95% confidence interval (CI) 1.25–3.74]; P = 0.006}. This association was also shown with BMD at the femur neck but not with BMD at lumbar spine. In the subgroup of 977 patients with follow-up CACs at their fourth year, 97 (9.9%) showed accelerated CAC progression (>50/year), and BMD was inversely associated with accelerated CAC progression even after adjusting for the baseline CAC score [odds ratio 0.75 (95% CI 0.58–0.99); P = 0.039]. In addition, baseline CAC was associated with an increased risk of MACEs after adjusting for total hip T-score.

Conclusions

Low BMD was significantly associated with CAC progression and MACEs in patients with predialysis CKD.

Standardization of 129I using the movable 4πβ(LS)-X(NaI(Tl)) system

The ¹²⁹I standardization, using the movable 4πβ(LS)-X(NaI(Tl)) coincidence system, was performed for two ¹²⁹I radioactive sources - one was dissolved in 0.1M NaOH solution and the other in 0.1M HNO₃ solution. The system incorporates three movable PM tubes for a β-counter placed on a plane and a X-ray detector that can be moved up to the bottom of the vial. The β-efficiency depending on the amount of radioactive solution was investigated with 14 liquid scintillation samples prepared by gravimetrically dispensing 4.4-145 mg of ¹²⁹I radioactive solution. The β-efficiencies above 90% were observed at less than 56 mg, but it was at most 70% at 145 mg. This occurred regardless of the activity of the sample or the type of chemical solution used to dissolve ¹²⁹I source. The activity concentration of each ¹²⁹I source was determined by efficiency-extrapolation method for samples with an activity range of 0.28-4.5 kBq. The β-efficiency points were derived over 10 intervals by moving 3-PM tubes in fine steps of about 1 mm from the sample. The highest value for β-efficiency was 95%. The combined uncertainty were 0.25% and 0.26%, respectively. The stated precision obtained using the system is better than that previously reported in the literature obtained by the triple to double coincidence ratio (TDCR) or the CIEMAT/NIST efficiency tracing method.

The difference between cystatin C- and creatinine-based eGFR is associated with adverse cardiovascular outcome in patients with chronic kidney disease

BACKGROUND AND AIMS

Decreased kidney function is an important risk factor for cardiovascular disease (CVD). However, assessing risk of CVD may be difficult when there is a gap between creatinine- and cystatin C-based estimated glomerular filtration rate (eGFR). We studied the association of the difference in eGFRs with major adverse cardiovascular events (MACE) in patients with chronic kidney disease (CKD).

METHODS

This prospective cohort study was conducted in 2076 patients with CKD stages based on the KDIGO guideline (eGFR categories of G1: ≥90; G 2: 60-89; G3: 30-59; G4: 15-29; G5: <15 mL/min/1.73 m² without kidney replacement therapy). The difference in eGFR (eGFR_diff) was calculated by subtracting the cystatin C-based eGFR (eGFR_cys) from the creatinine-based eGFR (eGFR_creat). The primary outcome was MACE, defined as non-fatal acute myocardial infarction and unstable angina, stroke, congestive heart failure, symptomatic arrhythmia, and cardiac death.

RESULTS

During a median follow-up of 4.1 years, MACE occurred in 147 patients (incidence rate, 15.0 per 1000 patient-years). When patients were categorized into baseline eGFR_diff tertiles, the highest tertile was associated with a significantly higher risk of MACE (hazard ratio, 2.12; 95% confidence interval [CI], 1.28-3.51) than the lowest tertile when adjusted for eGFR_creat, eGFR_cys, or eGFR based on both creatinine and cystatin C. Patients in the highest tertile had more baseline coronary artery calcification (CAC) than those in the lowest tertile (odds ratio [OR], 1.38; 95% CI, 1.03-1.86). In addition, 978 patients had data for both baseline and follow-up CAC at year 4. In this subgroup, baseline eGFR_diff was significantly associated with accelerated CAC progression (≥50/year) (OR, 1.03; 95% CI, 1.01-1.05).

CONCLUSIONS

A large positive difference between eGFR_creat and eGFR_cys was associated with a higher risk of MACE and faster CAC progression in patients with CKD. Therefore, careful monitoring of CVD is needed for patients with a higher eGFR_diff.

Persistent Resistant Hypertension Has Worse Renal Outcomes in Chronic Kidney Disease than that Resolved in Two Years: Results from the KNOW-CKD Study

Apparent treatment-resistant hypertension (ATRH) is closely related to chronic kidney disease (CKD); however, the long-term outcomes and the effects of improvement in ATRH in patients with CKD are not well understood. We evaluated the relationship between the persistence of ATRH and the progression of CKD. This cohort study enrolled 1921 patients with CKD. ATRH was defined as blood pressure above 140/90 mmHg and intake of three different types of antihypertensive agents, including diuretics, or intake of four or more different types of antihypertensive agents, regardless of blood pressure. We defined ATRH subgroups according to the ATRH status at the index year and two years later. The prevalence of ATRH at baseline was 14.0%. The presence of ATRH at both time points was an independent risk factor for end-point renal outcome (HR, 1.41; 95% CI, 1.04–1.92; p = 0.027). On the other hand, the presence of ATRH at any one of the time points was not statistically significant. In conclusion, persistent ATRH is more important for the prognosis of renal disease than the initial ATRH status. Continuous follow-up and appropriate treatment are important to improve the renal outcomes.

Moderate-Vigorous Physical Activity and Clinical Outcomes in Adults with Nondialysis Chronic Kidney Disease

The health benefits of physical activity (PA) are well known. However, the association between an adequate amount of moderate-vigorous PA (MVPA) and clinical outcomes has limited evidence in chronic kidney disease (CKD). We assessed PA using a self-administered questionnaire. The amount of MVPA was categorized into four groups: none, low, moderate, and high (0, <7.5, 7.5-14.9, and 15.0-29.9 metabolic equivalent-hours/week, respectively). We analyzed the association between the amount of MVPA and clinical outcomes. Among a total of 1909 adults with CKD, adults with MVPA showed various beneficial outcomes compared to those with no MVPA in a Kaplan-Meier curve followed over a median of 5.9 years. In multivariable-adjusted Cox proportional hazard models, a low and a moderate amount of MVPA was associated with a lower risk of all-cause death. A moderate amount of MVPA was associated with a lower risk of cardiovascular events. A high amount of MVPA was associated with a lower risk of end-stage kidney disease in ESKD in 1324 adults with eGFR <60 mL/min/1.73 m2. Age and sex modified the relationships between MVPA and clinical outcomes. MVPA is associated with various beneficial outcomes across the amount of MVPA. PA plans should be tailored for individual adults with CKD.

Metabolic Acidosis Is an Independent Risk Factor of Renal Progression in Korean Chronic Kidney Disease Patients: The KNOW-CKD Study Results

Background: We aimed to evaluate serum bicarbonate as a risk factor for renal progression, cardiovascular events, and mortality in Korean CKD patients.

Methods: We analyzed 1,808 participants from a Korean CKD cohort whose serum bicarbonate levels were measured at enrollment. Serum bicarbonate levels were categorized as low, lower normal, higher normal, and high (total carbon dioxide <22, 22–26, 26.1–29.9, and ≥30 mmol/L, respectively) groups. Metabolic acidosis was defined as a serum bicarbonate level <22 mmol/L. The primary outcome was renal events defined as doubling of serum creatinine, 50% reduction of eGFR from the baseline values, or development of end-stage kidney disease. The secondary outcome consisted of cardiovascular events and death. In addition, patients whose eGFR values were measured more than three times during the follow-up period were analyzed for eGFR decline. The rapid decline in eGFR was defined as lower than the median value of the eGFR slope.

Results: The mean serum bicarbonate level was 25.7 ± 3.7 mmol/L and 240 (13.2%) patients had metabolic acidosis. During the follow-up period of 55.2 ± 24.1 months, 545 (30.9%) patients developed renal events and 187 (10.6%) patients developed a composite of cardiovascular events and death. After adjustment, the low serum bicarbonate group experienced 1.27 times more renal events than the lower normal bicarbonate group [hazard ratio (HR): 1.27; 95% CI: 1.01–1.60, P = 0.043]. There was no significant association between the bicarbonate groups and the composite outcome of cardiovascular events and death. The low bicarbonate group showed a significantly rapid decline in eGFR [odds ratio (OR): 2.12; 95% CI: 1.39–3.22, P < 0.001] compared to the lower normal bicarbonate group.

Conclusions: Metabolic acidosis was significantly associated with increased renal events and a rapid decline in renal function in Korean predialysis CKD patients.

Low serum adiponectin level is associated with better physical health-related quality of life in chronic kidney disease

Hyperadiponectemia is paradoxically associated with renal disease progression and mortality in chronic kidney disease (CKD). Its association with health-related quality of life (HR-QOL) is unknown. This study aimed to verify the association between adiponectin and HR-QOL in Korean pre-dialysis CKD cohort. This cross-sectional study analyzed 1551 pre-dialysis CKD patients from KNOW-CKD (KoreaN Cohort Study for Outcome in Patients With Chronic Kidney Disease). Participants were categorized into three tertiles (T1–T3) according to adiponectin levels. HR-QOL was assessed using SF-36. High physical component summary (PCS) and mental component summary (MCS) were defined as highest quartile of each score. Multivariate logistic regression was used to analyze odds ratio (OR) and 95% confidence interval (CI) for high PCS and MCS. Prevalence of high PCS were 33.3%, 27.5%, and 17.0% and that of high MCS were 31.7%, 24.8%, and 21.3% for T1, T2, and T3 (both p for trend < 0.001). The adjusted OR [95% CI] of T1 and T2 in reference to T3 were 1.56 [1.09–2.23] and 1.19 [0.85–1.68] for high PCS and 1.19 [0.85–1.68] and 0.94 [0.68–1.29] for high MCS. Serum adiponectin level was inversely associated with physical HR-QOL in Korean pre-dialysis CKD patients. This relationship was independent of various cardiovascular risk factors.

Development of a movable 4πβ(LS)-γ coincidence counting system for activity standardization of β-γ emitters

A new movable 3PM-γ coincidence system, based on 4πβ(LS)-γ coincidence counting, for activity measurement of β-γ emitters has been designed at the Korea Research Institute of Standards and Science (KRISS). The system incorporates 3 PM tubes on the plane and two detectors placed above and below the center of the plane. The 3 PM tubes for β-counters in the plane are movable up to 100 mm from a liquid scintillation vial, thus enabling the variation of β-detection efficiencies by a geometrical technique. A NaI(Tl) γ-counter was set above for the present work. The β-event is determined by counting the logical sum of three double coincidences. All the necessary electronics, i.e., logical sum, adjusting the duration of dead-time of each counting channel and coincidence resolving times, and analyzing coincidence relation, were specially designed to be fabricated in an integrated circuit. Details of the detectors, the electronics, the overall movable 3PM-γ coincidence system are presented, as well as the results of investigations to assess its operating characteristics. Validation measurements have been performed with ⁶⁰Co and ⁵⁷Co sources. The highest β-detection efficiency achieved with ⁶⁰Co and ⁵⁷Co was 97% and 95%, respectively. The activity concentration determined with a new system agreed with calibrated values within the uncertainty range. Further results from validation measurements and the corresponding uncertainty budgets are presented.

Genetic identification of inherited cystic kidney diseases for implementing precision medicine: a study protocol for a 3-year prospective multicenter cohort study

Background

Inherited cystic kidney disease is a spectrum of disorders in which clusters of renal cysts develop as the result of genetic mutation. The exact methods and pipelines for defining genetic mutations of inherited cystic kidney disease are not clear at this point. This 3-year, prospective, multicenter, cohort study was designed to set up a cohort of Korean patients with inherited cystic kidney disease, establish a customized genetic analysis pipeline for each disease subtype, and identify modifying genes associated with the severity of the disease phenotype.

Methods/design

From May 2020 to May 2022, we aim to recruit 800 patients and their family members to identify pathogenic mutations. Patients with more than 3 renal cysts in both kidneys are eligible to be enrolled. Cases of simple renal cysts and acquired cystic kidney disease that involve cyst formation as the result of renal failure will be excluded from this study. Demographic, laboratory, and imaging data as well as family pedigree will be collected at baseline. Renal function and changes in total kidney volume will be monitored during the follow-up period. Genetic identification of each case of inherited cystic kidney disease will be performed using a targeted gene panel of cystogenesis-related genes, whole exome sequencing (WES) and/or family segregation studies. Genotype-phenotype correlation analysis will be performed to elucidate the genetic effect on the severity of the disease phenotype.

Discussion

This is the first nationwide cohort study on patients with inherited cystic kidney disease in Korea. We will build a multicenter cohort to describe the clinical characteristics of Korean patients with inherited cystic kidney disease, elucidate the genotype of each disease, and demonstrate the genetic effects on the severity of the disease phenotype.

Trial registration

This cohort study was retrospectively registered at the Clinical Research Information Service (KCT0005580) operated by the Korean Center for Disease Control and Prevention on November 5th, 2020.

Low High-Sensitivity C-Reactive Protein Level in Korean Patients With Chronic Kidney Disease and Its Predictive Significance for Cardiovascular Events, Mortality, and Adverse Kidney Outcomes: Results From KNOW-CKD

Background Inflammation levels are lower in East Asians than in Western people. We studied the association between high-sensitivity hs-CRP (C-reactive protein) and adverse outcomes in Korean patients with chronic kidney disease. Methods and Results We included 2018 participants from the KNOW-CKD (Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease) between April 2011 and February 2016. The primary outcome was a composite of extended major cardiovascular events (eMACE) or all-cause mortality. The secondary end points were separate outcomes of eMACE, all-cause death, and adverse kidney outcome. We also evaluated predictive ability of hs-CRP for the primary outcome. The median hs-CRP level was 0.60 mg/L. During the mean follow-up of 3.9 years, there were 125 (6.2%) eMACEs and 80 (4.0%) deaths. In multivariable Cox analysis after adjustment of confounders, there was a graded association of hs-CRP with the primary outcome. The hazard ratios for hs-CRPs of 1.0 to 2.99 and ≥3.0 mg/L were 1.33 (95% CI, 0.87-2.03) and 2.08 (95% CI, 1.30-3.33) compared with the hs-CRP of <1.0 mg/L. In secondary outcomes, this association was consistent for eMACE and all-cause death; however, hs-CRP was not associated with adverse kidney outcomes. Finally, prediction models failed to show improvement of predictive performance of hs-CRP compared with conventional factors. Conclusions In Korean patients with chronic kidney disease, the hs-CRP level was low and significantly associated with higher risks of eMACEs and mortality. However, hs-CRP did not associate with adverse kidney outcome, and the predictive performance of hs-CRP was not strong. Registration URL: http://www.clinicaltrials.gov; Unique identifier: NCT01630486.

Erratum: Evolution of π^{0} Suppression in Au+Au Collisions from sqrt[s_{NN}]=39 to 200 GeV [Phys. Rev. Lett. 109, 152301 (2012)]

This corrects the article DOI: 10.1103/PhysRevLett.109.152301.

Association Between Serum High-Density Lipoprotein Cholesterol Levels and Progression of Chronic Kidney Disease: Results From the KNOW-CKD

Background High-density lipoprotein cholesterol ( HDL -C) levels are generally decreased in patients with chronic kidney disease ( CKD ). However, studies on the relationship between HDL -C and CKD progression are scarce. Methods and Results We studied the association between serum HDL -C levels and the risk of CKD progression in 2168 participants of the KNOW - CKD (Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease). The primary outcome was the composite of a 50% decline in estimated glomerular filtration rate from baseline or end-stage renal disease. The secondary outcome was the onset of end-stage renal disease. During a median follow-up of 3.1 (interquartile range, 1.6-4.5) years, the primary outcome occurred in 335 patients (15.5%). In a fully adjusted Cox model, the lowest category with HDL -C of <30 mg/dL (hazard ratio, 2.21; 95% CI, 1.30-3.77) and the highest category with HDL -C of ≥60 mg/dL (hazard ratio, 2.05; 95% CI , 1.35-3.10) were associated with a significantly higher risk of the composite renal outcome, compared with the reference category with HDL -C of 50 to 59 mg/dL. This association remained unaltered in a time-varying Cox analysis. In addition, a fully adjusted cubic spline model with HDL -C being treated as a continuous variable yielded similar results. Furthermore, consistent findings were obtained in a secondary outcome analysis for the development of end-stage renal disease. Conclusions A U-shaped association was observed between serum HDL -C levels and adverse renal outcomes in this large cohort of patients with CKD . Our findings suggest that both low and high serum HDL -C levels may be detrimental to patients with nondialysis CKD .

The KNOW-CKD Study: What we have learned about chronic kidney diseases

As the nation’s largest chronic kidney disease (CKD) cohort, the KoreaN Cohort Study for Outcomes in Patients With Chronic Kidney Disease (KNOW-CKD) was established to investigate the clinical course, risk factors for progression, and adverse outcomes of CKD. From 2011 to 2016, the KNOW-CKD recruited 2,238 adult patients with CKD from stage G1 to G5 who were not receiving renal replacement therapy from nine tertiary care hospitals throughout Korea. As of 2019, the KNOW-CKD has published more than 50 articles in the areas of socio-economics, nutrition, quality of life, health-related habits, CKD progression, cardiovascular comorbidity and outcome, anemia, mineral bone disease, biomarker discovery, and international and inter-ethnic comparisons. The KNOW-CKD will eventually offer a prediction model for long-term consequences of CKD, such as the occurrences of end-stage renal disease, cardiovascular disease, and death, thereby enabling the identification and treatment of at-risk populations that require extra medical attention.

Mediation of the relationship between proteinuria and serum phosphate: Insight from the KNOW-CKD study

Proteinuria and hyperphosphatemia are risk factors for cardiovascular disease in patients with chronic kidney disease (CKD). Although the interaction between proteinuria and the serum phosphate level is well established, the mechanistic link between the two, particularly the extent to which this interaction is mediated by phosphate-regulating factors, remains poorly understood. In this study, we examined the association between proteinuria and the serum phosphate level, as well as potential mediators, including circulating fibroblast growth factor (FGF23)/klotho, the 24-h urinary phosphate excretion rate to glomerular filtration rate ratio (EP/GFR), and the 24-h tubular phosphate reabsorption rate to GFR ratio (TRP/GFR). The analyses were performed with data from 1793 patients in whom 24-h urine protein and phosphate, serum phosphate, FGF23, and klotho levels were measured simultaneously, obtained from the KoreaN cohort study for Outcome in patients With Chronic Kidney Disease (KNOW-CKD). Multivariable linear regression and mediation analyses were performed. Total, direct, and indirect effects were also estimated. Patients with high serum phosphate levels were found to be more likely to exhibit greater proteinuria, higher FGF23 levels, and lower klotho levels. The 24-h EP/GFR increased and the 24-h TRP/GFR decreased with increasing proteinuria and CKD progression. Simple mediation analyses showed that 15.4% and 67.9% of the relationship between proteinuria and the serum phosphate level were mediated by the FGF23/klotho ratio and 24-h EP/GFR, respectively. Together, these two factors accounted for 73.1% of the relationship between serum markers. These findings suggest that proteinuria increases the 24-h EP/GFR via the FGF23/klotho axis as a compensatory mechanism for the increased phosphate burden well before the reduction in renal function is first seen.

The primary system for measurement of beta emitting radioactive gases at KRISS

Korea Research Institute of Standards and Science (KRISS) is developing a length-compensated proportional counting (LCPC) system as a primary system for standardization of beta emitting radioactive gases. The pilot experiment was performed with ⁸⁵Kr and the optimized high voltage and pressure were found to be 1700 V and 0.203 MPa, respectively. The total activity of ⁸⁵Kr was deduced by the length compensation of each count. The expanded uncertainty was estimated to be around 0.8% (k = 2) for the ⁸⁵Kr measurement.

Glycemic Status, Insulin Resistance, and the Risk of Nephrolithiasis: A Cohort Study

RATIONALE & OBJECTIVE

The effect of glycemic status on nephrolithiasis risk remains controversial. This study sought to examine the association of glycemic status and insulin resistance with incident nephrolithiasis.

STUDY DESIGN

A retrospective cohort study.

SETTING & PARTICIPANTS

278,628 Korean adults without nephrolithiasis who underwent a comprehensive health examination between 2011 and 2017.

EXPOSURES

Glucose level, glycated hemoglobin level, and Homeostasis Model Assessment of Insulin Resistance (HOMA-IR).

OUTCOME

Nephrolithiasis ascertained using abdominal ultrasound.

ANALYTICAL APPROACH

A parametric proportional hazard model was used to estimate adjusted HRs and 95% CIs. We explored prespecified potential sex differences in the association of glycemic status and incident nephrolithiasis.

RESULTS

During a median follow-up of 4.2 years, 6,904 participants developed nephrolithiasis. Associations between levels of glycemic status and incident nephrolithiasis were examined separately in men and women (P for interaction = 0.003). Among men, multivariable-adjusted HRs for incident nephrolithiasis comparing glucose levels of 90-99, 100-125, and ≥ 126 mg/dL were 1.10 (95% CI, 1.01-1.19), 1.11 (95% CI, 1.02-1.21), and 1.27 (95% CI, 1.10-1.46), respectively, while HRs for incident nephrolithiasis comparing glycated hemoglobin levels of 5.7%-5.9%, 6.0%-6.4%, and 6.5%-<5.7% were 1.03 (95% CI, 0.96-1.10), 1.18 (95% CI, 1.07-1.31), and 1.20 (95% CI, 1.06-1.37), respectively. The HR for incident nephrolithiasis comparing the highest HOMA-IR quintile to the lowest quintile was 1.18 (95% CI, 1.06-1.31). Among women, no apparent association was found between glycemic status and nephrolithiasis risk.

LIMITATIONS

Glucose tolerance testing and computed tomography assessment for nephrolithiasis were not available.

CONCLUSIONS

Higher glycemic values, even within the normoglycemic range, and HOMA-IR were positively associated with increased risk for nephrolithiasis, associations that were only observed among men. Insulin resistance and hyperglycemia may contribute to the development of nephrolithiasis, particularly among men.

Design of optimal digital filter and digital signal processing for a CdZnTe high resolution gamma-ray system

We have developed an online digital signal processing system based on an FPGA. The system consists of pile-up rejection, baseline restorer, peak detection and pole-zero cancellation for evaluation of deposited energy in the detector. The shaping algorithm employed is a Moving Window Deconvolution (MWD) to shape digitized data into a trapezoidal form. For the purpose of verification, the developed digital system was tested for ¹³⁷Cs gamma rays. The entire system is programmed using the LabVIEW environment.

P0912THE SERUM CREATININE TO CYSTATIN C RATIO AND CLINICAL OUTCOMES IN PATIENTS WITH NON-DIALYSIS CHRONIC KIDNEY DISEASE: THE KNOW-CKD COHORT

Background and Aims

Muscle wasting leads to poor outcomes in patient with chronic kidney disease (CKD). The serum creatinine to cystatin C (Cr/CysC) ratio has been reported as marker for muscle mass and may predict outcomes in chronic diseases. We hypothesized that the Cr/CysC ratio would be a predictor of outcomes in CKD.

Method

We investigated a total of 2142 patients (male 61%, aged 54±12 year) with CKD followed for a median of 3.74 years. We assessed the factors associated with Cr/CysC ratio and the relationship between Cr/CysC ratio and outcomes of end-stage renal disease (ESRD), cardiovascular event (CVE), and mortality.

Results

The Cr/CysC ratio significantly correlated with age (r=-0.18), estimated glomerular filtration rate (eGFR) (r=-0.21), serum albumin (r=0.11), 24-hour urine creatinine (r=0.38), and moderate to vigorous physical activity time (r=0.07). After adjusting for age, sex, eGFR, and log urine albumin creatinine ratio (model 1), the hazard ratios for ESRD, CVE, and mortality were 0.96 (95% CI, 0.86-1.07), 0.78 (95% CI, 0.61-0.99), and 0.72 (95% CI, 0.53-0.97) per 1 standard deviation Cr/CysC increase (0.21), respectively. After full adjustment for model 1 variables plus lifestyle factors, laboratory factors, and comorbidities (model 2), the hazard ratios for ESRD, CVE, and mortality were 0.99 (95% CI, 0.88-1.10), 0.84 (95% CI, 0.65-1.07), and 0.75 (95% CI, 0.55-0.99) per 1 standard deviation Cr/CysC increase (0.24), respectively. In subgroup of the elderly (age&gt;65 year) and early stage CKD (eGFR&gt;60 ml/min/1.73m2), the hazard ratios for CVE were significantly lower in patients with high Cr/CysC ratio.

Conclusion

Cr/CysC ratio correlates with muscle biomarkers and physical activity. A higher Cr/CysC ratio is associated with low CVE and mortality, but not ESRD in CKD.

P0926ASSOCIATION OF HIGH-SENSITIVE C-REACTIVE PROTEIN WITH CARDIOVASCULAR EVENTS, MORTALITY, AND ADVERSE KIDNEY OUTCOMES IN KOREAN PATIENTS WITH CHRONIC KIDNEY DISEASE: RESULTS FROM KNOW-CKD

Background and Aims

High-sensitivity C-reactive protein (hs-CRP) level is lower in East Asians than in the Western people and its clinical significance needs to be further explored. We aimed to investigate whether hs-CRP could function as a biomarker in Korean CKD patients.

Method

We studied the association of hs-CRP with adverse clinical outcomes in 2,018 patients from the KoreaN cohort study for Outcome in patients With Chronic Kidney Disease (KNOW-CKD). The primary outcome was a composite of extended major cardiovascular events (MACE) or all-cause mortality. Extended MACE (eMACE) included non-fatal cardiovascular events, symptomatic arrhythmia, and cardiac death. The secondary endpoints were separate outcome of eMACE, all-cause death, and adverse kidney outcome. We also evaluated predictive ability of hs-CRP for the primary outcome.

Results

The median hs-CRP level was 0.60 mg/L (IQR 0.2-1.7), and the mean eGFR was 53.6 ml/min/1.73 m2. During the mean follow-up of 3.9 years, there were 125 (6.2%) eMACEs and 80 (4.0%) deaths. The primary composite outcome occurred more frequently in patients with higher hs-CRP level than in those with lower hs-CRP level. In multivariable Cox analysis after adjustment of confounders, there was a graded association of hs-CRP with the primary outcome. The HRs (95% CI) for hs-CRP of 1.0 to 2.99, and ≥ 3.0 mg/L were 1.37 (0.89-2.12) and 2.20 (1.36-3.56), compared with

hs-CRP of &lt;1.0 mg/L. In analyses of secondary outcomes, this association was consistent for eMACE and all-cause death; however, hs-CRP was not associated with adverse kidney outcomes. Finally, prediction models failed to show improvement of predictive performance of hs-CRP compared to conventional factors.

Conclusion

In Korean CKD patients, serum hs-CRP level was low and significantly associated with higher risk of eMACEs and mortality. However, a low serum hs-CRP level was not predictive of adverse kidney outcome, and the predictive performance of hs-CRP was not strong.

Alcohol Consumption and Progression of Chronic Kidney Disease: Results From the Korean Cohort Study for Outcome in Patients with Chronic Kidney Disease

OBJECTIVE

To assess the association of alcohol consumption with chronic kidney disease (CKD) progression in patients with CKD.

PATIENTS AND METHODS

The KoreaN cohort study for Outcome in patients with CKD (KNOW-CKD) is a prospective observational study that included detailed questionnaires regarding alcohol consumption. The 1883 individuals with CKD were enrolled from April 1, 2011, through February 28, 2016, and followed until May 31, 2017. Using a questionnaire, alcohol consumption pattern was classified according to the amount of alcohol per occasion (none, moderate, or binge) or drinking frequency (none, occasional, or regular). The primary endpoint was a composite of 50% or greater decline in estimated glomerular filtration rate (eGFR) from the baseline level or end-stage renal disease.

RESULTS

During a follow-up of 5555 person-years (median, 2.95 years), the primary outcome occurred in 419 patients. Unadjusted cause-specific hazards model showed that the risk of the primary outcome was lower in drinkers than in non-drinkers. However, a fully adjusted model including eGFR and proteinuria yielded a reverse association. Compared with non-drinking, regular and occasional binge drinking were associated with a 2.2-fold (95% CI, 1.38-3.46) and a 2.0-fold (95% CI, 1.33-2.98) higher risk of CKD progression, respectively. This association was particularly evident in patients who had decreased kidney function and proteinuria. There was a significant interaction between alcohol consumption and eGFR for CKD progression. The slopes of eGFR decline were steeper in binge drinkers among patients with eGFR less than 60 mL/min/1.73 m².

CONCLUSIONS

Heavy alcohol consumption was associated with faster progression of CKD.

High fibroblast growth factor 23 is associated with coronary calcification in patients with high adiponectin: analysis from the KoreaN cohort study for Outcome in patients With Chronic Kidney Disease (KNOW-CKD) study

Background

The association between fibroblast growth factor 23 (FGF23) and coronary artery calcification (CAC) was inconclusive. Recently it was shown that adiponectin modulates renal handling of calcium and phosphorus. We hypothesized that adiponectin plays a role in the effect of FGF23 on CAC and explored whether the association between FGF23 and CAC is modified by serum adiponectin level in chronic kidney disease (CKD) patients.

Methods

This cross-sectional study analyzed 1435 predialysis CKD patients from the Korean Cohort Study for Outcome in Patients with CKD cohort. Participants were divided into two groups according to their serum adiponectin (upper half and lower half). Each group was further divided into three groups according to their FGF23 levels as follows: low (<5.0 RU/mL), middle (5.0-29.9 RU/mL) and high (≥30.0 RU/mL). The coronary artery calcium score (CACS) was assessed using cardiac computed tomography and CAC was defined as a CACS >100.

Results

The median CACS did not differ between the low and high adiponectin groups {3.2 [interquartile range (IQR) 0.0-98.1] versus 0.5 [0.0-99.5], P = 0.988}. The CACS ratio comparing high FGF23 to low FGF23 was significantly increased in the high adiponectin group, but not in the low adiponectin group [2.35 (IQR 1.14-4.85) versus 1.10 (0.60-2.03)]. The odds ratio for CAC in the high FGF23 group compared with the low group was 1.97 (IQR 1.10-3.53). The association between FGF23 and CAC was modified significantly by adiponectin level (P for interaction = 0.023).

Conclusions

High serum FGF23 was associated with CAC in CKD patients with high adiponectin, but not in those with low adiponectin. Further studies are warranted to verify the role of adiponectin in FGF23-related CAC.

Metabolic acidosis is associated with pulse wave velocity in chronic kidney disease: Results from the KNOW-CKD Study

Metabolic acidosis is common in chronic kidney disease (CKD) and may have various deleterious consequences. Arterial stiffness in CKD patients is associated with poor cardiovascular outcomes. The present study aimed to evaluate the association between serum bicarbonate and arterial stiffness using the baseline cross-sectional data set of a large-scale Korean CKD cohort. 2,238 CKD patients were enrolled in the KoreaN Cohort Study for Outcome in Patients With Chronic Kidney Disease (KNOW-CKD) from 2011 to 2016. The present study was conducted on 1,659 patients included in this cohort with baseline serum bicarbonate and brachial-to-ankle pulse wave velocity (baPWV) data. Metabolic acidosis was defined as a serum bicarbonate level of <22 mmol/L, and baPWV was used as a surrogate of arterial stiffness. Mean serum bicarbonate was 25.8 ± 3.6 mmol/L. 210 (12.7%) patients had metabolic acidosis. baPWV was significantly higher in patients with metabolic acidosis (P < 0.001) and showed a significant inverse correlation with serum bicarbonate (Unstandardized β −16.0 cm/sec; 95% CI −20.5, −11.4; P < 0.001) in an unadjusted model, which was retained after adjustment (Unstandardized β −5.4 cm/sec; 95% CI −9.9, −1.0; P = 0.017). Metabolic acidosis was found to be associated with a high baPWV in pre-dialysis CKD patients.

Association between time to treatment and functional outcomes according to the Diffusion-Weighted Imaging Alberta Stroke Program Early Computed Tomography Score in endovascular stroke therapy

BACKGROUND AND PURPOSE

The rate at which the chance of a good outcome of endovascular stroke therapy (EVT) decays with time when eligible patients are selected by baseline diffusion-weighted magnetic resonance imaging (DWI-MRI) and whether ischaemic core size affects this rate remain to be investigated.

METHODS

This study analyses a prospective multicentre registry of stroke patients treated with EVT based on pretreatment DWI-MRI that was categorized into three groups: small [Diffusion-Weighted Imaging Alberta Stroke Program Early Computed Tomography Score (DWI-ASPECTS)] (8-10), moderate (5-7) and large (<5) cores. The main outcome was a good outcome at 90 days (modified Rankin Scale 0-2). The interaction between onset-to-groin puncture time (OTP) and DWI-ASPECTS categories regarding functional outcomes was investigated.

RESULTS

Ultimately, 985 patients (age 69 ± 11 years; male 55%) were analysed. Potential interaction effects between the DWI-ASPECTS categories and OTP on a good outcome at 90 days were observed (P_interaction  = 0.06). Every 60-min delay in OTP was associated with a 16% reduced likelihood of a good outcome at 90 days amongst patients with large cores, although no associations were observed amongst patients with small to moderate cores. Interestingly, the adjusted rates of a good outcome at 90 days steeply declined between 65 and 213 min of OTP and then remained smooth throughout 24 h of OTP (P_nonlinearity  = 0.15).

CONCLUSIONS

Our study showed that the probability of a good outcome after EVT nonlinearly decreased, with a steeper decline at earlier OTP than at later OTP. Discrepant effects of OTP on functional outcomes by baseline DWI-ASPECTS categories were observed. Thus, different strategies for EVT based on time and ischaemic core size are warranted.

Association Between High-Sensitivity Cardiac Troponin T and Echocardiographic Parameters in Chronic Kidney Disease: Results From the KNOW-CKD Cohort Study

Background

It is unclear whether high‐sensitivity troponin T (hs‐TnT) is associated with subclinical cardiac changes in chronic kidney disease (CKD). We evaluated the relationship between hs‐TnT and left ventricular structure and function in a CKD population, according to estimated glomerular filtration rate.

Methods and Results

We analyzed 2017 patients with CKD stages 1 to 5 (predialysis) in the KNOW‐CKD (Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease) cohort. The predictor was hs‐TnT level measured at baseline, and the outcomes were left ventricular hypertrophy (LVH) and systolic and diastolic dysfunction shown by echocardiography at baseline and after 4 years. Participants were categorized into quartiles according to hs‐TnT levels. The associations between quartiles of hs‐TnT and outcomes were assessed using multivariable logistic regression analysis with confounders including demographics, medical history, and laboratory findings. A receiver operating characteristic curve was used to assess the diagnostic power of hs‐TnT for the outcomes as a continuous variable. For subgroup analysis, patients were stratified based on an estimated glomerular filtration rate of 60 mL/min per 1.73 m². Elevated hs‐TnT was associated with LVH and diastolic dysfunction at baseline in an adjusted model but was not associated with systolic dysfunction. These associations remained significant for both estimated glomerular filtration rate subgroups. Receiver operating characteristic curve analysis showed that hs‐TnT as a continuous variable exhibited fair significance for detection of LVH (area under the curve: 0.689) and diastolic dysfunction (area under the curve: 0.744). Multivariable analysis showed that higher hs‐TnT levels at baseline were related to development of LVH but not diastolic dysfunction (n=864).

Conclusions

In CKD patients, hs‐TnT is strongly associated with alterations of left ventricular structure and diastolic dysfunction for both estimated glomerular filtration rate strata. Baseline hs‐TnT levels are predictive of new LVH on follow‐up.

Beam Energy and Centrality Dependence of Direct-Photon Emission from Ultrarelativistic Heavy-Ion Collisions

The PHENIX collaboration presents first measurements of low-momentum (0.4<p_{T}<3  GeV/c) direct-photon yields from Au+Au collisions at sqrt[s_{NN}]=39 and 62.4 GeV. For both beam energies the direct-photon yields are substantially enhanced with respect to expectations from prompt processes, similar to the yields observed in Au+Au collisions at sqrt[s_{NN}]=200. Analyzing the photon yield as a function of the experimental observable dN_{ch}/dη reveals that the low-momentum (>1  GeV/c) direct-photon yield dN_{γ}^{dir}/dη is a smooth function of dN_{ch}/dη and can be well described as proportional to (dN_{ch}/dη)^{α} with α≈1.25. This scaling behavior holds for a wide range of beam energies at the Relativistic Heavy Ion Collider and the Large Hadron Collider, for centrality selected samples, as well as for different A+A collision systems. At a given beam energy, the scaling also holds for high p_{T} (>5  GeV/c), but when results from different collision energies are compared, an additional sqrt[s_{NN}]-dependent multiplicative factor is needed to describe the integrated-direct-photon yield.

A unified multidisciplinary fragility hip fracture pilot pathway in a trauma centre in Hong Kong: One-year outcome in the acute phase

Introduction:

The growing impact of fragility hip fracture (FHF) on the healthcare system and the society has become a major concern worldwide. A unified multidisciplinary FHF pathway from admission to rehabilitation and back to community was established in 2015. The acute phase of the pathway was put into pilot in our hospital to evaluate the outcome.

Method:

A designated FHF team was established in our centre since January 2015. The FHF pathway was piloted since June 2015. Patients admitted with a hip fracture resulting from fall on standing height were included. Major outcome parameters were compared in three phases: (1) before FHF team and FHF pathway (January to December 2014), (2) after FHF team but before FHF pathway (January to May 2015) and (3) after FHF team and FHF pathway (June 2015 to May 2016).

Result:

In phases 1, 2 and 3, 631, 263 and 634 patients were included, respectively. From phases 1 to 3, the average key performance indicator (KPI) has improved from 49.2% to 65.8% to 70.0% significantly; average acute length of stay (days) has improved from 13.7 to 13.4 to 11.3 significantly; total surgical complication rates have improved from 6.2% to 7.6% to 5.8%. The 30-day mortality rate and the unplanned readmission rate (within 28 days) have remained below 2.7% and 2.2%, respectively.

Conclusions:

Implementation of an FHF pathway can form a multidisciplinary platform that can improve the standard of care and outcome for our FHF patients in terms of KPI and also length of stay.

New knowledge added by this study:

A newly designed and implemented fragility hip fracture pathway in our centre as a pilot with the results evaluated.

Implications for clinical practice or policy:

With the increasing elderly population in Hong Kong and globally, there is a need to design and implement a fragility hip fracture (FHF) pathway to improve the care and effectiveness for FHF patients.

Arterial Stiffness as a Risk Factor for Subclinical Coronary Artery Calcification in Predialysis Chronic Kidney Disease: From the KNOW-CKD Study

BACKGROUND/AIMS

Both arterial stiffness and coronary artery calcification (CAC) are important predictors of cardiovascular disease in the general population and in chronic kidney disease (CKD) patients. Recent studies on arterial stiffness and CAC in subjects with preserved renal function have verified the association between the two. However, the relationship is not well evaluated in CKD patients.

METHODS

This cross-sectional study analyzed 1,385 predialysis CKD patients from the KNOW-CKD cohort. Participants were divided into four groups according to brachial-ankle pulse wave velocity (baPWV) quartile. Coronary artery calcium scores (CACS) were assessed using cardiac computed tomography and CAC was defined as a CACS >100.

RESULTS

CAC prevalence was higher in the higher baPWV groups (6.4, 9.8, 23.7, and 43.8% for the 1st to 4th quartiles of baPWV, respectively, p < 0.001). In Tobit regression analyses that were fully adjusted for traditional and renal cardiovascular risk factors, the CACS ratio comparing the highest and lowest baPWV quartiles was 3.03 (95% CI, 1.59-6.87). Similarly, the OR for CAC in the highest baPWV quartile compared to the lowest quartile was 1.98 (95% CI, 1.09-3.60) in a fully adjusted multivariate logistic model. Results were consistent across analyses with different cutoffs for CAC or with different clinically relevant subgroups.

CONCLUSION

Increased arterial stiffness measured by high baPWV was associated with CAC in a predialysis CKD cohort. Longitudinal studies are needed to determine the effect of arterial stiffness on the development or progression of CAC in CKD.

Solitary kidney and risk of chronic kidney disease

The renal outcome of solitary kidney remains controversial. We examined the longitudinal association of congenital or acquired solitary kidney with the development of chronic kidney disease (CKD). A cohort study was performed involving 271,171 Korean men and women free of CKD at baseline who underwent a health screening program and who were followed annually or biennially for an average of 5.4 years. Solitary kidney was determined based on ultrasonographic findings. CKD was defined as an estimated glomerular filtration rate of < 60 ml/min/1.73 m² and/or the presence of proteinuria in two or more consecutive visits. During 1,472,519.6 person-years of follow-up, 2989 participants developed CKD (incidence rate: 2.0 per 1000 person-years). After adjustment for potential confounders, the aHR (95% CIs) for incident CKD comparing solitary kidney to the control was 3.26 (1.63-6.54). In analyses of cause-specific solitary kidney, aHR (95% CIs) for CKD comparing unilateral nephrectomy and congenital solitary kidney to the control were 6.18 (2.31-16.49) and 2.22 (0.83-5.92), respectively. The association between solitary kidney and CKD was stronger in men. Having a solitary kidney was independently associated with an increased risk of CKD development. Therefore, preventive strategies for reducing the risk of CKD are required in individuals with a solitary kidney.

Bioelectrical impedance analysis as a nutritional assessment tool in Autosomal Dominant Polycystic Kidney Disease

Objective

Autosomal dominant polycystic kidney disease (ADPKD) patients with massive organomegaly suffer from pressure-related complications including malnutrition. In this study, we analyzed the efficacy of segmental bioelectrical impedance analysis (BIA) for objective and quantitative nutritional assessment in ADPKD patients

Design and methods

We conducted a cross-sectional study, to evaluate the clinical utility of segmental BIA for assessing the nutritional status of ADPKD patients. BIA measurements was assessed according to modified subjective global assessment (SGA) scores and were compared with data from a healthy population. The association between BIA measurements and the height adjusted kidney and liver volumes (htTKLV), were analyzed.

Subjects

A total of 288 ADPKD patients, aged ≥ 18 years old, were analyzed

Main outcome measures

Nutritional status was evaluated with SGA and segmental BIA. The htTKLV were measured in each patients using computed tomonography images.

Results

Higher ratios of extracellular water to total body water (ECW/TBW) in the whole-body (ECW/TBW_WB), trunk (ECW/TBW_TR), and lower extremities (ECW/TBW_LE) and lower phase angle of lower extremities (PhA_LE) correlated with lower SGA scores in the ADPKD population and in both gender. The four parameters, ECW/TBW_WB, ECW/TBW_TR, and ECW/TBW_LE of >0.38 and PhA_LE of <5.8 θ were associated with malnutrition in ADPKD patients. These correlations were preserved in the subgroup analysis for chronic kidney disease stages 1-3A. Compared to healthy populations’ data, body fluid parameters and segmental ECW/TBW values, except for the upper extremities (ECW/TBW_UE), were greater in ADPKD patients. Increased htTKLV was an independent risk factor for malnutrition in ADPKD. The highest correlation with htTKLV was observed for the ECW/TBW_TR (r = 0.466), followed by ECW/TBW_WB (r = 0.407), ECW/TBW_LE (r = 0.385), PhA_LE (r = -0.279), and PhA_TR (r = 0.215).

Conclusions

These results demonstrated that segmental BIA parameters of ECW/TBW_WB, ECW/TBW_TR, ECW/TBW_LE and PhA_LE provide useful information on nutritional status including the impact of organomegaly in ADPKD.

Serum klotho is inversely associated with metabolic syndrome in chronic kidney disease: results from the KNOW-CKD study

BACKGROUND

Metabolic syndrome (MS) is prevalent in chronic kidney disease (CKD). Klotho, a protein linked to aging, is closely associated with CKD. Each component of MS and klotho has an association. However, little is known about the association between klotho and MS per se. We investigated the association between serum klotho levels and MS using baseline cross-sectional data obtained from a large Korean CKD cohort.

METHODS

Of the 2238 subjects recruited in the KoreaN Cohort Study for Outcome in Patients With Chronic Kidney Disease (KNOW-CKD) between 2011 and 2016, 484 patients with missing data on serum klotho and extreme klotho values (values lower than the detectable range or > 6000 pg/mL) or with autosomal dominant polycystic kidney disease patients were excluded. The data of the remaining 1754 subjects were included in the present study. MS was defined using the revised National Cholesterol Education Program Adult Treatment Panel (NCEP-ATP) III criteria. Serum klotho levels were measured using an enzyme-linked immunosorbent assay.

RESULTS

Mean patient age was 54.9 ± 12.1 years and 1110 (63.3%) were male. The prevalence of MS among all study subjects was 63.7% (n = 1118). The median serum klotho level was 527 pg/mL (interquartile range [IQR]: 418-656 pg/mL). Serum klotho level was significantly lower in MS patients than patients without MS (Median [IQR]; 521 pg/mL [413, 651] vs. 541 pg/mL [427, 676], respectively; P = 0.012). After adjusting for age, sex, estimated glomerular filtration rate, and overt proteinuria, serum klotho was independently associated with MS (adjusted odds ratio [OR], 0.44; 95% confidence interval, 0.23-0.82; P = 0.010). Furthermore, the adjusted OR for MS was found to be significantly increased at serum klotho levels of < 518 pg/mL (receiver operating characteristic curve cut-off value).

CONCLUSIONS

Serum klotho was inversely associated with the presence of MS in patients with CKD.

TRIAL REGISTRATION

This trial was registered on ClinicalTrials.gov on 26 June 2012 ( https://clinicaltrials.gov;NCT01630486 ).

eGFR and coronary artery calcification in chronic kidney disease

BACKGROUND

The independent association between eGFR and coronary artery calcification (CAC) is complex and not clear. The aim of this study is to investigate the relationship between eGFR calculated from different equations and CAC in predialysis CKD patients in Korea.

METHODS

In this cross-sectional study, we analyzed 1,533 patients from the KNOW-CKD cohort. eGFR was calculated by a four-variable MDRD equation (eGFR_MDRD ), CKD-EPI creatinine equations (eGFR_{C r} ), CKD-EPI Cystatin C equation (eGFR_{C ys} ), and CKD-EPI Creatinine-Cystatin equation (eGFR_{C rC ys} ). Participants were divided into eGFR categories (< 30, 30-59, 60-89, ≥ 90 ml/min/1.73 m² ). CACS (coronary artery calcium score) was measured using cardiac computed tomography. CAC was defined as CACS > 100.

RESULTS

CAC was found in 334 (21.8%) patients, and was more prevalent in the lower eGFR groups (p < 0.001). In multivariate Tobit regression, CACS increased gradually as eGFR_{C rC ys} decreased (p for trend = 0.034). In multivariate logistic regression, there were gradual associations between lower eGFR and CAC when an eGFR_{C ys} or eGFR_{C rC ys} was used. The adjusted OR for CAC in the group with eGFR < 30 ml/min/1.73m² compared to the group with eGFR ≥ 90 ml/min/1.73m² was 2.64 (95% CI, 1.09-3.60) when eGFR_{C rC ys} was used. Of the four eGFR formulas, only adding eGFR_{C rC ys} significantly improved CAC prediction models without eGFR (p = 0.046).

CONCLUSIONS

There was a gradual and independent association between low eGFR and CAC in a predialysis CKD cohort in Korea. eGFR_{C rC ys} predicted CAC better than other equations in this population. This article is protected by copyright. All rights reserved.

Urinary Potassium Excretion and Progression of CKD

BACKGROUND AND OBJECTIVES

Data on whether low or high urinary potassium excretion is associated with poor kidney outcome have been conflicting. The aim of this study was to clarify the association between urinary potassium excretion and CKD progression.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We investigated the relationship between lower urinary potassium excretion and CKD progression and compared three urinary potassium indices among 1821 patients from the Korean Cohort Study for Outcome in Patients with CKD. Urinary potassium excretion was determined using spot urinary potassium-to-creatinine ratio, spot urinary potassium concentration, and 24-hour urinary potassium excretion. Patients were categorized into four groups according to quartiles of each urinary potassium excretion metric. The study end point was a composite of a ≥50% decrease in eGFR from baseline values and ESKD.

RESULTS

During 5326 person-years of follow-up, the primary outcome occurred in 392 (22%) patients. In a multivariable cause-specific hazard model, lower urinary potassium-to-creatinine ratio was associated with higher risk of CKD progression (adjusted hazard ratio, 1.47; 95% confidence interval, 1.01 to 2.12) comparing the lowest quartile with the highest quartile. Sensitivity analyses with other potassium metrics also showed consistent results in 855 patients who completed 24-hour urinary collections: adjusted hazard ratios comparing the lowest quartile with the highest quartile were 3.05 (95% confidence interval, 1.54 to 6.04) for 24-hour urinary potassium excretion, 1.95 (95% confidence interval, 1.05 to 3.62) for spot urinary potassium-to-creatinine ratio, and 3.79 (95% confidence interval, 1.51 to 9.51) for spot urinary potassium concentration.

CONCLUSIONS

Low urinary potassium excretion is associated with progression of CKD.

Abstract P3-03-31: Is sentinel lymph node biopsy necessary in all patients with early breast cancer?

Background and objectives : Since the results of the American College of Surgeons Oncology Group Z0011 published, the criteria for applying axillary lymph node (ALN) dissection was relaxed among early breast cancer patients who were scheduled for breast conserving surgery, adjuvant chemotherapy therapy, and adjuvant radiation therapy. SLNB criteria may be established if pathologic nodal status can be predicted. The aim of this study was to develop a nomogram for preoperative prediction of axillary node metastasis.

Methods: The records of 1650 patients with T1, T2 primary invasive breast cancer who were treated between January 2013 and September 2016 were selected from the medical database of Yonsei University (Seoul, South Korea). Those whom a preoperative diagnosis of axillary node metastases were excluded. Two nomogram that predicted three or more axillary metastasis and one or more axillary metastasis were developed using a binary logistic regression model with a training cohort. Internal validation was carried out adopting bootstrap method by validation cohort 500 times resampling.

Result: A total of 82 (4.8%) patients had three or more ALNs metastasis. Three hundred seventy five (17.4%) patients had one or more ALNs metastasis. Axillary metastasis was associated with Preoperative ALN suspicious image findings, clinical tumor size, Number of neoplastic foci, estrogen receptor status, Ki-67 expression, tumor marker. The nomogram was developed based on the clinical and statistically significant predictors. It had good discrimination performance (AUC 0.79, 95% CI, 0.73–0.85), (AUC 0.71, 95% CI, 0.67–0.74) and calibration fit.

Conclusion:Our nomogram might help predict the ALN metastasis in breast cancer patients. Patients with a low probability of ALN metastasis could be spared SLNB.

Citation Format: Yoon KH, Lee KB, Lee H, Lee J, Kim JY, Park HS, Park S, Kim SI, Cho YU, Park B-W. Is sentinel lymph node biopsy necessary in all patients with early breast cancer? [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-03-31.