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Introduction: End-stage renal disease (ESRD) is a growing disease worldwide, including Korea. This is an important condition that affects patient outcome. To provide optimal management for mineral disturbance, vascular calcification, and bone disease in ESRD patients, the Korean dialysis cohort for mineral, vascular calcification, and fracture (ORCHESTRA) study was conducted by enrolling Korean dialysis patients. Methods: Sixteen university-affiliated hospitals and one Veterans' Health Service Medical Center participated in this study. This prospective cohort study enrolled approximately 900 consecutive patients on dialysis between May 2019 and January 2021. Enrolled subjects were evaluated at baseline for demographic information, laboratory tests, radiologic imaging, and bone mineral densitometry (BMD) scans. After enrollment, regular assessments of the patients were performed, and their biospecimens were collected according to the study protocol. The primary outcomes were the occurrence of major adverse cardiovascular events, invasive treatment for peripheral artery disease, and osteoporotic fractures. The secondary outcomes were hospitalization for cerebrovascular disease or progression of abdominal aortic calcification. Participants will be assessed for up to 3 years to determine whether primary or secondary outcomes occur. Results: Between May 2019 and January 2021, all participating centers recruited 900 consecutive dialysis patients, including 786 undergoing hemodialysis (HD) and 114 undergoing peritoneal dialysis (PD). The mean age of the subjects was 60.4 ± 12.3 years. Males accounted for 57.7% of the total population. The mean dialysis vintage was 6.1 ± 6.0 years. The HD group was significantly older, had a longer dialysis vintage, and more comorbidities. Overall, the severity of vascular calcification was higher and the level of BMD was lower in the HD group than in the PD group. Conclusion: This nationwide, multicenter, prospective cohort study focused on chronic kidney disease-mineral and bone disorder and aimed to provide clinical evidence to establish optimal treatment guidelines for Asian dialysis patients. [ABSTRACT FROM AUTHOR]

Background: Urine osmolality indicates the ability of the kidney to concentrate the urine and reflects the antidiuretic action of vasopressin. However, results about the association between urine osmolality and adverse renal outcomes in chronic kidney disease (CKD) are conflicting. We investigated the association between urine osmolality and adverse renal outcomes in a nationwide prospective CKD cohort. Methods: A total of 1,999 CKD patients were categorized into 3 groups according to their urine osmolality tertiles. Primary outcome was a composite of 50% decline in the estimated glomerular filtration rate (eGFR), initiation of dialysis, or kidney transplantation. Results: During a mean follow-up of 35.2 ± 19.0 months, primary outcome occurred in 432 (21.6%) patients; 240 (36.4%), 162 (24.3%), and 30 (4.5%) in the lowest, middle, and highest tertiles, respectively. Low urine osmolality was independently associated with a greater risk of CKD progression (hazard ratio [HR], 1.71; 95% confidence interval [CI], 1.12–2.59). This association was particularly evident in patients with CKD stages 3–4 (per 10 mosm/kg decrease; HR, 1.02; 95% CI, 1.00–1.03). Adding urine osmolality to a base model with conventional factors significantly increased the ability to predict CKD progression (C-statistics, 0.86; integrated discrimination improvement [IDI], 0.021; both p < 0.001). However, adding both urine osmolality and eGFR did not further improve the predictive ability compared with the addition of eGFR only (C-statistics, p = 0.29; IDI, p = 0.09). Conclusions: Low urine osmolality was an independent risk factor for adverse renal outcomes in CKD patients, but its predictive ability did not surpass eGFR. Thus, kidney function should be considered while interpreting the clinical significance of urine osmolality. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background/Aims: This study aimed to investigate the potential beneficial anti-proteinuric effect of an add-on aldosterone blockade and the impact of the aldosterone escape phenomenon. Methods: We retrospectively analyzed data of 304 patients with persistent proteinuria, who were administered spironolactone (25 mg/day) after treatment with angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) for >3 months. Patients were divided according to their aldosterone levels during ACEI/ARB treatment into an escape group (plasma aldosterone >80 pg/mL, N=95, 31.5%) and a non-escape group (plasma aldosterone ≤80 pg/mL, N=209, 68.5%) and according to their urine albumin-to-creatinine ratio (UACR) and estimated glomerular filtration rate (eGFR). Results: After 12 months, the UACR decreased significantly in patients with 1≤UACR<3.5 g/g Cr, UACR ≥3.5 g/g Cr, and eGFR ≥60 mL/min/1.73 m2, and in the non-escape group. Severe hyperkalemia (K≥7.0 mEq/L) developed in 9 of 137 patients with eGFR<60 mL/min/1.73 m2 (6.5%) and in none of the 167 patients with eGFR≥60 mL/min/1.73 m2. Conclusions: Proteinuria decreased significantly after add-on spironolactone treatment in patients with 1≤UACR<3.5 g/g Cr, UACR ≥3.5 g/g Cr, and eGFR ≥60 mL/min/1.73 m2, and in the non-escape group. The anti-proteinuric effect of spironolactone may vary according to the degree of albuminuria, impaired eGFR, and aldosterone escape. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background/Aims: Blood pressure (BP) variability is known as a poor prognostic factor for cardiovascular outcomes. This study assessed the prognostic significance of BP variability in association with increasing age in hemodialysis patients. Methods: We retrospectively analyzed 2,174 patients on hemodialysis from March 2005 to December 2012. The impact of intradialytic and interdialytic BP variability on all-cause mortality according to age groups was analyzed. Results: Kaplan-Meier survival curves for 5-year cumulative mortality showed higher mortality in patients with higher intradialytic systolic and diastolic BP variability as well as interdialytic systolic and diastolic BP variability (log-rank p=0.006, <0.001, 0.018 and < 0.001) in patients aged <55 years, but not in older age groups. Cox proportional analysis revealed that 5-year mortality was associated with intradialytic diastolic BP variability in patients aged <55 years (HR, 2.03 CI, 1.24-3.32). Conclusion: The overall mortality was associated with BP variability in patients aged <55 years, but not in older ages. This result suggests that younger hemodialysis patients with BP variability require further medical attention and intervention to reduce BP variability. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Inhibition of histone deacetylase (HDAC) was reported to suppress cardiac hypertrophy and fibrosis in various hypertrophic animal models. However, the HDAC expression profile and HDAC enzyme activity have not yet been investigated in DOCA-salt hypertensive rats. Methods: Unilaterally nephrectomized rats were implanted with DOCA strips. DOCA-salt rats then received a control diet with vehicle or valproate. We measured the expression of cardiac hypertrophic markers, class I HDACs, class II HDACs, fibrosis, and HDAC enzyme activity. Results: Here we report that sodium valproate inhibits the cardiac hypertrophy accompanied by fibrosis in the heart of chronic hypertensive rats. We show that expression of GATA6 and HDAC6 is upregulated in DOCA-salt hypertension. In addition, HDAC6 and HDAC8 enzyme activity is attenuated by sodium valproate. Conclusion: These results suggest that a novel HDAC6- and HDAC8-selective inhibitor is needed to treat or prevent pathological cardiac hypertrophy. © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background/Aims: Sildenafil, the first selective phosphodiesterase-5 (PDE5) inhibitor to be widely used for treating erectile dysfunction, has been investigated with regard to its cardioand renoprotective effects in animal models. This study further investigated the renoprotective effects of sildenafil and their molecular mechanisms in deoxycorticosterone acetate (DOCA)-salt hypertensive (DSH) rats. Methods: DOCA strips (200 mg/kg) were implanted in rats 1 week after unilateral nephrectomy. These rats were fed on a control diet, with or without sildenafil (50 mg·kg-1day-1), for 2 weeks. Systolic blood pressure (SBP) was measured by the tail cuff method, and the urinary albumin-to-creatinine ratio (ACR) was calculated. The extent of glomerulosclerosis and tubulointerstitial fibrosis was determined by Masson's trichrome stain. Renal expression of ED-1, transforming growth factor-β1 (TGF-β1), Bax, and Bcl-2 were determined by semiquantitative immunoblotting, polymerase chain reaction (PCR), and immunohistochemistry. TUNEL staining was used for detecting apoptotic cells. Results: The increased SBP in DSH rats was not attenuated by sildenafil treatment. The decreased creatinine clearance and increased ACR in DSH rats, compared with control animals, were attenuated by sildenafil treatment. Further, sildenafil treatment attenuated glomerulosclerosis and tubulointerstitial fibrosis in DSH rats and counteracted the increased expression of ED-1, TGF-β1, and Bax and the decreased expression of Bcl-2 in the kidneys of these rats. The increase in the number of apoptotic cells in DSH rats was attenuated by sildenafil treatment. Conclusion: Sildenafil effectively prevented the progression of renal injury in DSH rats via its anti-inflammatory, antifibrotic, and antiapoptotic effects. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]