Relationship between urinary potassium excretion, serum potassium levels and cardiac injury in non-dialysis chronic kidney disease: KoreaN cohort study for Outcome in patients With Chronic Kidney Disease (KNOW-CKD).

Although the cardiovascular benefits of an increased urinary potassium excretion have been suggested, little is known about the potential cardiac association of urinary potassium excretion in patients with chronic kidney disease. In addition, whether the cardiac association of urinary potassium excretion was mediated by serum potassium levels has not been studied yet. We reviewed the data of 1633 patients from a large-scale multicentre prospective Korean study (2011-2016). Spot urinary potassium to creatinine ratio was used as a surrogate for urinary potassium excretion. Cardiac injury was defined as a high-sensitivity troponin T ≥ 14 ng/l. OR and 95 % (CI for cardiac injury were calculated using logistic regression analyses. Of 1633 patients, the mean spot urinary potassium to creatinine ratio was 49·5 (sd 22·6) mmol/g Cr and the overall prevalence of cardiac injury was 33·9 %. Although serum potassium levels were not associated with cardiac injury, per 10 mmol/g Cr increase in the spot urinary potassium to creatinine ratio was associated with decreased odds of cardiac injury: OR 0·917 (95 % CI 0·841, 0·998), P = 0·047) in multivariate logistic regression analysis. In mediation analysis, approximately 6·4 % of the relationship between spot urinary potassium to creatinine ratio and cardiac injury was mediated by serum potassium levels, which was not statistically significant (P = 0·368). Higher urinary potassium excretion was associated with lower odds of cardiac injury, which was not mediated by serum potassium levels.

Low-density lipoprotein cholesterol levels and adverse clinical outcomes in chronic kidney disease: Results from the KNOW-CKD.

BACKGROUND AND AIMS: The optimal low-density lipoprotein cholesterol (LDL-C) level to prevent cardiovascular disease in chronic kidney disease (CKD) patients remains unknown. This study aimed to explore the association of LDL-C levels with adverse cardiovascular and kidney outcomes in Korean CKD patients and determine the validity of "the lower, the better" strategy for statin intake. METHODS AND RESULTS: A total of 1886 patients from the KoreaN cohort study for Outcome in patients With CKD (KNOW-CKD) were included. Patients were classified into four LDL-C categories: <70, 70-99, 100-129, and ≥130 mg/dL. The primary outcome was extended major adverse cardiovascular events (eMACEs). Secondary outcomes included all-cause mortality, and CKD progression. During the follow-up period, the primary outcome events occurred in 136 (7.2%) patients (16.9 per 1000 person-years). There was a graded association between LDL-C and the risk of eMACEs. The hazard ratios (95% confidence intervals) for LDL-C categories of 70-99, 100-129, and ≥130 mg/dL were 2.06 (1.14-3.73), 2.79 (1.18-6.58), and 4.10 (1.17-14.3), respectively, compared to LDL-C <70 mg/dL. Time-varying analysis showed consistent findings. The predictive performance of LDL-C for eMACEs was affected by kidney function. Higher LDL-C levels were also associated with significantly higher risks of CKD progression. However, LDL-C level was not associated with all-cause mortality. CONCLUSIONS: This study showed a graded relationship between LDL-C and the risk of adverse cardiovascular outcome in CKD patients. The lowest risk was observed with LDL-C <70 mg/dL, suggesting that a lower LDL-C target may be acceptable.

Urinary chloride concentration and progression of chronic kidney disease: results from the KoreaN cohort study for Outcomes in patients With Chronic Kidney Disease.

BACKGROUND: Urinary chloride is regulated by kidney transport channels, and high urinary chloride concentration in the distal tubules can trigger tubuloglomerular feedback. However, little attention has been paid to urinary chloride as a biomarker of clinical outcomes. Here, we studied the relationship between urinary chloride concentration and chronic kidney disease (CKD) progression. METHODS: We included 2086 participants with CKD from the KoreaN cohort study for Outcomes in patients With Chronic Kidney Disease. Patients were categorized into three groups, according to baseline urinary chloride concentration tertiles. The study endpoint was a composite of ≥50% decrease in estimated glomerular filtration rate from baseline values, or end-stage kidney disease. RESULTS: During a median follow-up period of 3.4 years (7452 person-years), 565 participants reached the primary endpoint. There was a higher rate of CKD progression events in the lowest and middle tertiles than in the highest tertile. Compared with the lowest tertile, the highest tertile was associated with 33% [95% confidence interval (CI) 0.49-0.90] lower risk for the primary outcome in a cause-specific hazard model after adjustment for confounding variables. In addition, for every 25 mEq/L increase in urinary chloride concentration, there was 11% (95% CI 0.83-0.96) lower risk for CKD progression. This association was consistent in a time-varying model. Urinary chloride concentration correlated well with tubule function and kidney injury markers, and its predictive performance for CKD progression was comparable to that of these markers. CONCLUSIONS: In this hypothesis-generating study, low urinary chloride concentration was associated with a higher risk for CKD progression.

Measured sodium excretion is associated with CKD progression: results from the KNOW-CKD study.

BACKGROUND: Diet is a modifiable factor of chronic kidney disease (CKD) progression. However, the effect of dietary salt intake on CKD progression remains unclear. Therefore, we analyzed the effect of dietary salt intake on renal outcome in Korean patients with CKD. METHODS: We measured 24-h urinary sodium (Na) excretion as a marker of dietary salt intake in the prospective, multi-center, longitudinal KoreaN cohort study for Outcome in patients With CKD (KNOW-CKD). Data were analyzed from CKD patients at Stages G3a to G5 (n = 1254). We investigated the association between dietary salt intake and CKD progression. Patients were divided into four quartiles of dietary salt intake, which was assessed using measured 24-h urinary Na excretion. The study endpoint was composite renal outcome, which was defined as either halving the estimated glomerular filtration rate or developing end-stage renal disease. RESULTS: During a median (interquartile range) follow-up of 4.3 (2.8-5.8) years, 480 (38.7%) patients developed the composite renal event. Compared with the reference group (Q2, urinary Na excretion: 104.2 ≤ Na excretion < 145.1 mEq/day), the highest quartile of measured 24-h urinary Na excretion was associated with risk of composite renal outcome [Q4, urinary Na excretion ≥192.9 mEq/day, hazard ratio 1.8 (95% confidence interval 1.12-2.88); P = 0.015] in a multivariable hazards model. Subgroup analyses showed that high-salt intake was particularly associated with a higher risk of composite renal outcome in women, in patients <60 years of age, in those with uncontrolled hypertension and in those with obesity. CONCLUSIONS: High salt intake was associated with increased risk of progression in CKD.

Polypharmacy and the Progression of Chronic Kidney Disease: Korean Cohort Study for Outcome in Patients with Chronic Kidney Disease.

INTRODUCTION: The renal hazard of polypharmacy has never been evaluated in predialysis chronic kidney disease (CKD) patients. OBJECTIVE: We aimed to analyze the renal hazard of polypharmacy in predialysis CKD patients with stage 1-5. METHOD: The data of 2,238 patients from a large-scale multicenter prospective Korean study (2011-2016), excluding 325 patients with various missing data, were reviewed. Polypharmacy was defined as taking 6 or more medications at the time of enrollment; renal events were defined as a ≥50% decrease in kidney function from baseline values, doubling of the serum creatinine levels, or initiation of renal replacement treatment. Hazard ratio (HR) and 95% confidence interval (CI) were calculated using Cox proportional-hazard regression analysis. RESULTS: Of the 1,913 patients, the mean estimated glomerular filtration rate was 53.6 mL/min/1.73 m2. The mean medication count was 4.1, and the prevalence of polypharmacy was 27.1%. During the average period of 3.6 years, 520 patients developed renal events (27.2%). Although increased medication counts were associated with increased renal hazard with HR (95% CI) of 1.056 (1.007-1.107, p = 0.025), even after adjusting for various confounders, adding comorbidity score and kidney function nullified the statistical significance. In mediation analysis, 55.6% (p = 0.016) of renal hazard in increased medication counts was mediated by the kidney function, and there was no direct effect of medication counts on renal event development. In subgroup analysis, the renal hazard of the medication counts was evident only in stage 1-3 of CKD patients (p for interaction = 0.014). CONCLUSIONS: We cannot identify the direct renal hazard of multiple medications, and most of the potential renal hazard was derived from intimate relationship with disease burden and kidney function.

Rapid Weight Change Over Time Is a Risk Factor for Adverse Outcomes in Patients With Predialysis Chronic Kidney Disease: A Prospective Cohort Study.

OBJECTIVE: Both obesity and being underweight are risk factors for adverse outcomes in chronic kidney disease (CKD) patients. However, the effects of longitudinal weight changes on patients with predialysis CKD have not yet been studied. In this study, we analyzed the effects of weight change over time on the adverse outcomes in predialysis CKD population. METHODS: Longitudinal data from a multicenter prospective cohort study (KNOW-CKD) were analyzed. In a total of 2,022 patients, the percent weight change per year were calculated using regression analysis and the study subjects were classified into five categories: group 1, ≤ -5%/year; group 2, -5< to ≤ -2.5%/year; group 3, -2.5< to <2.5%/year; group 4, 2.5≤ < 5%/year; and group 5, ≥5%/year. The incidences of end-stage renal disease (ESRD) and the composite outcome of cardiovascular disease (CVD) and death were calculated in each group and compared to group 3 as reference. RESULTS: During a median 4.4 years of follow-up, 414 ESRD, and 188 composite of CVD and mortality events occurred. Both weight gain and loss were independent risk factors for adverse outcomes. There was a U-shaped correlation between the degree of longitudinal weight change and ESRD (hazard ratio 3.61, 2.15, 1.86 and 3.66, for group 1, 2, 4 and 5, respectively) and composite of CVD and death (hazard ratio 2.92, 2.15, 1.73 and 2.54, respectively), when compared to the reference group 3. The U-shape correlation was most prominent in the subgroup of estimated glomerular filtration rate <45 mL/min/1.73 m2. CONCLUSION: Both rapid weight gain and weight loss are associated with high risk of adverse outcomes, particularly in the advanced CKD.

Hepcidin, iron indices and bone mineral metabolism in non-dialysis chronic kidney disease.

BACKGROUND: Few studies have examined the association between hepcidin, iron indices and bone mineral metabolism in non-dialysis chronic kidney disease (CKD) patients. METHODS: We reviewed the data of 2238 patients from a large-scale multicenter prospective Korean study (2011-16) and excluded 214 patients with missing data on markers and related medications of iron and bone mineral metabolism, hemoglobin, blood pressure and causes of CKD. Multivariate linear regression analysis was used to identify the association between iron and bone mineral metabolism. RESULTS: The proportion of CKD Stages 1-5 were 16.2, 18.7, 37.1, 21.6 and 6.4%, respectively. Per each 10% increase in transferrin saturation (TSAT), there was a 0.013 mmol/L decrease in phosphorus [95% confidence interval (CI) -0.021 to -0.004; P = 0.003] and a 0.022 nmol/L increase in logarithmic 25-hydroxyvitamin D (Ln-25OHD) levels (95% CI 0.005-0.040; P = 0.019). A 1 pmol/L increase in Ln-ferritin was associated with a 0.080 ng/L decrease in Ln-intact parathyroid hormone (Ln-iPTH; 95% CI -0.122 to -0.039; P < 0.001). Meanwhile, beta (95% CI) per 1 unit increase in phosphorus, Ln-25OHD and Ln-iPTH for the square root of the serum hepcidin were 0.594 (0.257-0.932; P = 0.001), -0.270 (-0.431 to -0.108; P = 0.001) and 0.115 (0.004-0.226; P = 0.042), respectively. In subgroup analysis, the relationship between phosphorus, 25OHD and hepcidin was strongest in the positive-inflammation group. CONCLUSIONS: Markers of bone mineral metabolism and iron status, including hepcidin, were closely correlated to each other. Potential mechanisms of the relationship warrant further studies.

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.

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 ).

High serum adiponectin is associated with anemia development in chronic kidney disease: The results from the KNOW-CKD study.

BACKGROUND: Adiponectin is an adipokine secreted by adipocytes. A low adiponectin level is a significant risk factor of diabetes mellitus and cardiovascular disease. Recent studies have shown that adiponectin is negatively associated with hematopoiesis and predicts the development of anemia in the general population. In chronic kidney disease (CKD) patients, circulating adiponectin level is paradoxically elevated and the role of adiponectin is complex. Therefore, we evaluated the relationship between adiponectin and anemia in these patients. METHODS: This prospective longitudinal study included 2113 patients from the KNOW-CKD study (KoreaN cohort study for Outcome in patients With CKD), after excluding 125 without data on adiponectin levels. Hemoglobin levels were measured yearly during a mean follow-up period of 23.7 months. Anemia was defined as hemoglobin levels of <13.0 and 12.0 g/dL for men and women, respectively. RESULTS: Mean patient age was 53.6 ±â€¯12.2 years, and 1289 (61%) were men. The mean estimated glomerular filtration rate (eGFR) was 50.4 ±â€¯30.2 mL min-1 1.73 m-2. Serum adiponectin level was inversely associated with body mass index, eGFR, log-transformed C-reactive protein, and positively with Charlson comorbidity index, urine protein to creatinine ratio, and high density lipoprotein cholesterol. In addition, serum adiponectin level was also negatively correlated with hemoglobin level and reticulocyte production index in both men and women. In multivariable linear regression analysis after adjustment of multiple confounders, adiponectin was negatively associated with hemoglobin (men, ß = -0.219, P < .001; women, ß = -0.09, P = .025). Among 1227 patients without anemia at baseline, 307 newly developed anemia during the follow-up period. In multivariable Cox regression analysis after adjustment of confounders, high adiponectin level was significantly associated with an increased risk of incident anemia (per 1 µg/mL increase, hazard ratio, 1.02; 95% confidence interval 1.01-1.04; P = .001). CONCLUSIONS: A high serum adiponectin level is independently associated with a low hemoglobin level and predicts the development of anemia in patients with CKD. These findings reveal the potential role of adiponectin in CKD-related anemia.

Serum Hepcidin and Iron Indices Affect Anemia Status Differently According to the Kidney Function of Non-Dialysis Chronic Kidney Disease Patients: Korean Cohort Study For Outcome in Patients with Chronic Kidney Disease (KNOW-CKD).

BACKGROUND/AIMS: No studies have examined the association among serum hepcidin, iron indices, or anemia status based on the kidney function of non-dialysis chronic kidney disease (CKD) patients. METHODS: We reviewed data of 2238 patients from a large-scale multicenter prospective Korean study (2011-2016) and excluded 198 patients with missing data regarding serum hepcidin, hemoglobin, transferrin saturation (TSAT), ferritin, and usage of erythropoiesis-stimulating agents (ESA) or supplemental iron and 363 patients using ESA or supplemental iron. Finally, 1677 patients were included. RESULTS: The mean patient age was 53.5 years, and 65.4% were men. TSAT and serum hepcidin were significantly associated with anemia status, whereas serum ferritin was not, regardless of anemia severity. For patients with an estimated glomerular filtration rate (eGFR) ≥45 mL/min/1.73 m2, a 10% increase of TSAT was associated with hemoglobin <13 g/dL (odds ratio [OR], 0.628; 95% confidence interval [CI], 0.515-0.765; P<0.001) and hemoglobin <11.5 g/dL (OR, 0.672; 95% CI, 0.476-0.950; P=0.024), whereas a 10-ng/mL increase of serum hepcidin was associated with hemoglobin <11.5 g/dL (OR, 1.379; 95% CI, 1.173-1.620; P<0.001) and hemoglobin <10.0 g/dL (OR, 1.360; 95% CI, 1.115-1.659; P=0.002) for patients with eGFR <45 mL/min/1.73 m2 according to multivariate logistic analysis. CONCLUSIONS: TSAT was associated with less severe anemia in early CKD patients. Serum hepcidin was associated with more severe anemia in advanced CKD patients.

Association between Urine Creatinine Excretion and Arterial Stiffness in Chronic Kidney Disease: Data from the KNOW-CKD Study.

BACKGROUND/AIMS: Previous studies have shown that low muscle mass is associated with arterial stiffness, as measured by pulse wave velocity (PWV), in a population without chronic kidney disease (CKD). This link between low muscle mass and arterial stiffness may explain why patients with CKD have poor cardiovascular outcomes. However, the association between muscle mass and arterial stiffness in CKD patients is not well known. METHODS: Between 2011 and 2013, 1,529 CKD patients were enrolled in the prospective Korean Cohort Study for Outcome in Patients With Chronic Kidney Disease (KNOW-CKD). We analyzed 888 participants from this cohort who underwent measurements of 24-hr urinary creatinine excretion (UCr) and brachial-ankle PWV (baPWV) at baseline examination. The mean of the right and left baPWV (mPWV) was used as a marker of arterial stiffness. RESULTS: The baPWV values varied according to the UCr quartile (1,630±412, 1,544±387, 1,527±282 and 1,406±246 for the 1st to 4th quartiles of UCr, respectively, P<0.001). For each 100 mg/d increase in UCr, baPWV decreased by 6m/sec in a multivariable linear regression model fully adjusted for traditional and renal cardiovascular risk factors. The odds ratio of the 1st quartile for high baPWV (highest quintile of mPWV) compared with the 4th quartile was 2.62 (1.24-5.54, P=0.011) in a logistic model fully adjusted for traditional and renal cardiovascular risk factors. CONCLUSION: Low muscle mass estimated by low UCr was associated high baPWV in pre-dialysis CKD patients in Korea. Further studies are needed to confirm the causal relationship between UCR and baPWV, and the role of muscle mass in the development of cardiovascular disease in CKD.

Successful pregnancy in a patient with autosomal dominant polycystic kidney disease on long-term hemodialysis.

Recent advances in dialysis and a multidisciplinary approach to pregnant patients with advanced chronic kidney disease provide a better outcome. A 38-yr-old female with autosomal dominant polycystic kidney disease (ADPKD) became pregnant. She was undergoing hemodialysis (HD) and her kidneys were massively enlarged, posing a risk of intrauterine fetal growth restriction. By means of intensive HD and optimal management of anemia, pregnancy was successfully maintained until vaginal delivery at 34.5 weeks of gestation. We discuss the special considerations involved in managing our patient with regard to the underlying ADPKD and its influence on pregnancy.

Glycemic Control and Adverse Clinical Outcomes in Patients with Chronic Kidney Disease and Type 2 Diabetes Mellitus: Results from KNOW-CKD.

BACKGRUOUND: The optimal level of glycosylated hemoglobin (HbA1c) to prevent adverse clinical outcomes is unknown in patients with chronic kidney disease (CKD) and type 2 diabetes mellitus (T2DM). METHODS: We analyzed 707 patients with CKD G1-G5 without kidney replacement therapy and T2DM from the KoreaN Cohort Study for Outcome in Patients With Chronic Kidney Disease (KNOW-CKD), a nationwide prospective cohort study. The main predictor was time-varying HbA1c level at each visit. The primary outcome was a composite of development of major adverse cardiovascular events (MACEs) or all-cause mortality. Secondary outcomes included the individual endpoint of MACEs, all-cause mortality, and CKD progression. CKD progression was defined as a ≥50% decline in the estimated glomerular filtration rate from baseline or the onset of end-stage kidney disease. RESULTS: During a median follow-up of 4.8 years, the primary outcome occurred in 129 (18.2%) patients. In time-varying Cox model, the adjusted hazard ratios (aHRs) for the primary outcome were 1.59 (95% confidence interval [CI], 1.01 to 2.49) and 1.99 (95% CI, 1.24 to 3.19) for HbA1c levels of 7.0%-7.9% and ≥8.0%, respectively, compared with <7.0%. Additional analysis of baseline HbA1c levels yielded a similar graded association. In secondary outcome analyses, the aHRs for the corresponding HbA1c categories were 2.17 (95% CI, 1.20 to 3.95) and 2.26 (95% CI, 1.17 to 4.37) for MACE, and 1.36 (95% CI, 0.68 to 2.72) and 2.08 (95% CI, 1.06 to 4.05) for all-cause mortality. However, the risk of CKD progression did not differ between the three groups. CONCLUSION: This study showed that higher HbA1c levels were associated with an increased risk of MACE and mortality in patients with CKD and T2DM.

Systolic blood pressure, low-density lipoprotein cholesterol levels, and adverse kidney outcome: results from KNOW-CKD.

It is unknown whether intensive control of blood pressure (BP) and lipids can delay the progression of chronic kidney disease (CKD). This study examined the combined association of strict targets of systolic BP (SBP) and low-density lipoprotein cholesterol (LDL-C) levels with adverse kidney outcomes. In total, 2012 patients from the KoreaN Cohort Study for Outcomes in Patients With CKD (KNOW-CKD) were classified into four groups according to SBP of 120 mmHg and LDL-C of 70 mg/dl: group 1, <120 and <70; group 2, <120 and ≥70; group 3, ≥120 and <70; group 4, ≥120 and ≥70. We constructed time-varying models treating two variables as time-varying exposures. The primary outcome was the progression of CKD, defined as a ≥50% decrease in estimated glomerular filtration rate from the baseline or the onset of kidney failure requiring replacement therapy. The primary outcome events occurred in 27.9%, 26.7%, 40.3%, and 39.1% from groups 1 to 4. In the time-varying model, the hazard ratios (95% confidence intervals) for the primary outcome were 0.48 (0.33-0.69), 0.78 (0.63-0.96), and 0.96 (0.74-1.23) for groups 1 to 3, respectively, compared with group 4. When less stringent cut-offs of SBP of 130 mmHg and LDL-C of 100 mg/dl were used, this graded association was lost, while only SBP was associated with adverse kidney outcomes. In this study, the lower targets of SBP of <120 mmHg and LDL-C < 70 mg/dl were synergistically associated with a lower risk of adverse kidney outcomes.

Comparison of outcomes of chronic kidney disease based on etiology: a prospective cohort study from KNOW-CKD.

The causes of chronic kidney disease (CKD) affects its outcomes. However, the relative risks for adverse outcomes according to specific causes of CKD is not well established. In a prospective cohort study from KNOW-CKD, a cohort was analyzed using overlap propensity score weighting methods. Patients were grouped into four categories according to the cause of CKD: glomerulonephritis (GN), diabetic nephropathy (DN), hypertensive nephropathy (HTN), or polycystic kidney disease (PKD). From a total of 2070 patients, the hazard ratio of kidney failure, the composite of cardiovascular disease (CVD) and mortality, and the slope of the estimated glomerular filtration rate (eGFR) decline according to the cause of CKD were compared between causative groups in a pairwise manner. There were 565 cases of kidney failure and 259 cases of composite CVD and death over 6.0 years of follow-up. Patients with PKD had a significantly increased risk for kidney failure compared to those with GN [Hazard ratio (HR) 1.82], HTN (HR 2.23), and DN (HR 1.73). For the composite outcome of CVD and death, the DN group had increased risks compared to the GN (HR 2.07), and HTN (HR 1.73) groups but not to the PKD group. The adjusted annual eGFR change for the DN and PKD groups were - 3.07 and - 3.37 mL/min/1.73 m2 per year, respectively, and all of these values were significantly different than those of the GN and HTN groups (- 2.16 and - 1.42 mL/min/1.73 m2 per year, respectively). In summary, the risk of kidney disease progression was relatively higher in patients with PKD compared to other causes of CKD. However, the composite of CVD and death was relatively higher in patients with DN-related CKD than in those with GN- and HTN-related CKD.

Proteinuria Modifies the Relationship Between Urinary Sodium Excretion and Adverse Kidney Outcomes: Findings From KNOW-CKD.

Introduction: High sodium intake is associated with increased proteinuria. Herein, we investigated whether proteinuria could modify the association between urinary sodium excretion and adverse kidney outcomes in patients with chronic kidney disease (CKD). Methods: In this prospective observational cohort study, we included 967 participants with CKD stages G1 to G5 between 2011 and 2016, who measured 24-hour urinary sodium and protein excretion at baseline. The main predictors were urinary sodium and protein excretion levels. The primary outcome was CKD progression, which was defined as a ≥50% decline in the estimated glomerular filtration rate (eGFR) or the onset of kidney replacement therapy. Results: During a median follow-up period of 4.1 years, the primary outcome events occurred in 287 participants (29.7%). There was a significant interaction between proteinuria and sodium excretion for the primary outcome (P = 0.006). In patients with proteinuria of <0.5 g/d, sodium excretion was not associated with the primary outcome. However, in patients with proteinuria of ≥0.5 g/d, a 1.0 g/d increase in sodium excretion was associated with a 29% higher risk of adverse kidney outcomes. Moreover, in patients with proteinuria of ≥0.5 g/d, the hazard ratios (HRs) (95% confidence intervals[CIs]) for sodium excretion of <3.4 and ≥3.4 g/d were 2.32 (1.50-3.58) and 5.71 (3.58-9.11), respectively, compared with HRs for patients with proteinuria of <0.5 g/d and sodium excretion of <3.4 g/d. In sensitivity analysis with 2 averaged values of sodium and protein excretion at baseline and third year, the results were similar. Conclusion: Higher urinary sodium excretion was more strongly associated with an increased risk of adverse kidney outcomes in patients with higher proteinuria levels.

A rare case of primary hyperparathyroidism associated with primary aldosteronism, Hürthle cell thyroid cancer and meningioma.

Multiple endocrine neoplasia type 1 (MEN1) syndrome includes varying combinations of endocrine and non-endocrine tumors. There are also a considerable number of atypical MEN1 syndrome. In this case, a 68-yr-old woman was referred to the Department of Endocrinology for hypercalcemia. Five years ago, she had diagnosed as primary hyperaldosteronism and now newly diagnosed as parathyroid hyperplasia with laboratory and pathologic findings. Hürthle-cell thyroid cancer was also resected during the parathyroid exploration and small meningioma was found on brain MRI. Her general condition has markedly improved and her adrenal mass and meningioma are being closely observed now. We could find the loss of heterozygosity of the MEN1 locus in parathyroid glands, suggesting a MEN1-related tumor, but not a germline mutation. Considering a variety of phenotypic expression and a limitation of current molecular analysis, periodic follow up will be needed in patients with a MEN1-like phenotype.

Quality of life in patients with diabetic nephropathy: findings from the KNOW-CKD (Korean Cohort Study for Outcomes in Patients with Chronic Kidney Disease) cohort.

BACKGROUND: Diabetic nephropathy (DN) can affect quality of life (QoL) because it requires arduous lifelong management. This study analyzed QoL differences between DN patients and patients with other chronic kidney diseases (CKDs). METHODS: The analysis included subjects (n = 1,766) from the KNOW-CKD (Korean Cohort Study for Outcomes in Patients with Chronic Kidney Disease) cohort who completed the Kidney Disease Quality of Life Short Form questionnaire. After implementing propensity score matching (PSM) using factors that affect the QoL of DN patients, QoL differences between DN and non-DN participants were examined. RESULTS: Among all DN patients (n = 390), higher QoL scores were found for taller subjects, and lower scores were found for those who were unemployed or unmarried, received Medical Aid, had lower economic status, had higher platelet counts or alkaline phosphatase levels, or used clopidogrel or insulin. After PSM, the 239 matched DN subjects reported significantly lower patient satisfaction (59.9 vs. 64.5, p = 0.02) and general health (35.3 vs. 39.1, p = 0.04) than the 239 non-DN subjects. Scores decreased in both groups during the 5-year follow-up, and the scores in the work status, sexual function, and role-physical domains were lower among DN patients than non-DN patients, though those differences were not statistically significant. CONCLUSION: Socioeconomic factors of DN were strong risk factors for impaired QoL, as were high platelet, alkaline phosphatase, and clopidogrel and insulin use. Clinicians should keep in mind that the QoL of DN patients might decrease in some domains compared with non-DN CKDs.

Sphingosine-1-phosphate reduces hepatic ischaemia/reperfusion-induced acute kidney injury through attenuation of endothelial injury in mice.

AIM: Hepatic ischaemia/reperfusion injury (IRI) frequently complicates acute kidney injury (AKI) during the perioperative period. This study was to determine whether hepatic IRI causes AKI and the effect of the sphingosine-1-phosphate (S1P) on AKI. METHODS: S1P and vehicle were given to mice before ischaemia and mice were subjected to hepatic IRI. Plasma creatinine (PCr), alanine transaminase (ALT), urinary neutrophil gelatinase-associated lipocalin (NGAL) and renal histological changes were determined. As a marker of endothelial injury, vascular permeability was measured. The effect of VPC 23019, a S1P(1) receptor antagonist, was also assessed. RESULTS: Hepatic IRI resulted in liver injury (increased ALT) and systemic inflammation. Kidneys showed elevated inflammatory cytokines, leucocyte infiltration, increased vascular permeability, tubular cell apoptosis and increased urinary NGAL, although PCr did not increase. Pretreatment with S1P resulted in an attenuation of systemic inflammation and kidney injury without any effect on plasma ALT or peripheral lymphocytes. The protective effect of S1P was partially reversed by VPC 23019, suggesting the important contribution of the S1P/S1P(1) pathway to protect against hepatic IRI-induced AKI. CONCLUSION: The study data demonstrate the important contribution of systemic inflammation and endothelial injury to AKI following hepatic IRI. Modulation of the S1P/S1P(1) receptor pathway might have some therapeutic potential in hepatic IRI-induced kidney injury.