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Permanent URI for this collectionhttps://hdl.handle.net/20.500.14288/3
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Publication Metadata only The role of uric acid in mineral bone disorders in chronic kidney disease(Springer, 2019) Afsar, Baris; Sag, Alan A.; Kuwabara, Masanari; Cozzolino, Mario; Covic, Adrian; N/A; Öztosun, Çınar; Kanbay, Mehmet; Undergraduate Student; Faculty Member; School of Medicine; School of Medicine; N/A; 110580Increasing survival in the chronic kidney disease (CKD) population exposes the bone to the cumulative detrimental sequelae of CKD, now defined physiologically and histopathologically as chronic kidney disease mineral bone disorder (CKD-BMD). This disorder is increasingly recognized as a "nontraditional" driver of morbidity and mortality and presents an opportunity to improve CKD outcomes via research. However, recent advances in the literature on this topic have not yet been collected into a single review. Therefore, this report aims to discuss the disordered renal-bone axis in CKD-BMD, molecular and hormonal drivers, novel treatment strategies, and forthcoming research in a clinician-directed format. A key novel topic will be the unique impact of uric acid on CKD-BMD, which is poised to apply extensive existing research in the uric acid domain to benefit the CKD-BMD population.Publication Metadata only Intravenous fluid therapy in accordance with kidney injury risk: when to prescribe what volume of which solution(Oxford University Press (OUP), 2023) Ortiz, Alberto; Soler, Maria Jose; N/A; Kanbay, Mehmet; Çöpür, Sidar; Mızrak, Berk; Faculty Member; Researcher; Undergraduate Student; School of Medicine; School of Medicine; School of Medicine; 110580; 368625; N/AAcute kidney injury (AKI) is common in hospitalized patients while common risk factors for the development of AKI include postoperative settings, patients with baseline chronic kidney disease (CKD) or congestive heart failure. Intravenous (IV) fluid therapy is a crucial component of care for prevention and treatment of AKI. In this narrative review, we update the approach to IV fluid therapy in hospitalized patients including the timing of fluid prescription, and the choice of fluid type, amount and infusion rate along with the potential adverse effects of various crystalloid and colloid solutions, addressing specifically their use in patients with acute kidney disease, CKD or heart failure, and their potential impact on the risk of hospital-acquired AKI.Publication Metadata only Global perspective on kidney transplantation: Turkey(Amer Soc Nephrology, 2021) Aki, Fazil Tuncay; N/A; Andaçoğlu, Oya Münevver; Doctor; N/A; Koç University Hospital; N/AN/APublication Metadata only Therapeutic implications of shared mechanisms in non-alcoholic fatty liver disease and chronic kidney disease(Springer, 2021) Afsar, Baris; Sag, Alan A.; Siriopol, Dimitrie; Kuwabara, Masanari; Badarau, Silvia; Covic, Adrian; Ortiz, Alberto; N/A; Kanbay, Mehmet; Çöpür, Sidar; Bülbül, Mustafa Cem; Faculty Member; Researcher; Researcher; School of Medicine; School of Medicine; School of Medicine; 110580; 368625; 327626The most common cause of liver disease worldwide is now non-alcoholic fatty liver disease (NAFLD). NAFLD refers to a spectrum of disease ranging from steatosis to non-alcoholic steatohepatitis, causing cirrhosis, and ultimately hepatocellular carcinoma. However, the impact of NAFLD is not limited to the liver. NAFLD has extra-hepatic consequences, most notably, cardiovascular and renal disease. NAFLD and chronic kidney disease share pathogenic mechanisms including insulin resistance, lipotoxicity, inflammation and oxidative stress. Not surprisingly, there has been a recent surge in efforts to manage NAFLD in an integrated way that not only protects the liver but also delays comorbidities such as chronic kidney disease. This concept of simultaneously addressing the main disease target and comorbidities is key to improve outcomes, as recently demonstrated by clinical trials of SGLT2 inhibitors and GLP1 receptor agonists in diabetes. HIF activators, already marketed in China, also have the potential to protect both liver and kidney, as suggested by preclinical data. This review concisely discusses efforts at identifying common pathogenic pathways between NAFLD and chronic kidney disease with an emphasis on potential paradigm shifts in diagnostic workup and therapeutic management.Publication Metadata only Abdominal compartment syndrome: an often overlooked cause of acute kidney injury(Springer Heidelberg, 2022) Basile, Carlo; N/A; N/A; N/A; N/A; Çöpür, Sidar; Berkkan, Metehan; Hasbal, Nuri Barış; Kanbay, Mehmet; Resercher; Undergraduate Student; Faculty Member; Faculty Member; School of Medicine; School of Medicine; School of Medicine; School of Medicine; 368625; N/A; 143778; 110580Abdominal compartment syndrome (ACS) is defined as any organ dysfunction caused by intra-abdominal hypertension (IAH), referred as intra-abdominal pressure (IAP) >= 12 mm Hg according to the World Society of Abdominal Compartment Syndrome. Abdominal compartment syndrome develops in most cases when IAP rises above 20 mmHg Abdominal compartment syndrome, while being a treatable and even preventable condition if detected early in the stage of intra-abdominal hypertension, is associated with high rates of morbidity and mortality if diagnosis is delayed: therefore, early detection is essential. Acute kidney injury (AKI) is a common comorbidity, affecting approximately one in every five hospitalized patients, with a higher incidence in surgical patients. AKI in response to intra-abdominal hypertension develops as a result of a decline in cardiac output and compression of the renal vasculature and renal parenchyma. In spite of the high incidence of intra-abdominal hypertension, especially in surgical patients, its potential role in the pathophysiology of AKI has been investigated in very few clinical studies and is commonly overlooked in clinical practice despite being potentially treatable and reversible. Aim of the present review is to illustrate the current evidence on the pathophysiology, diagnosis and therapy of intra-abdominal hypertension and abdominal compartment syndrome in the context of AKI. [GRAPHICS] .Publication Metadata only Renalase: another puzzle piece between hypertension and simple renal cysts?(Springer, 2015) Elcioglu, Omer Celal; Afsar, Baris; Takir, Mumtaz; Toprak, Aybala Erek; Bakan, Ali; Bakan, Sibel; Kostek, Osman; Oral, Alihan; Erman, Hayriye; Covic, Adrian; N/A; Kanbay, Mehmet; Faculty Member; School of Medicine; 110580Since renalase is mostly expressed in kidney tubules, simple renal cyst (SRC) originates from the kidney tubules, and both conditions are related to hypertension, it may be possible that SRC is associated with increased renalase levels. Therefore, in the current study we aimed to confirm the relation between renalase and epinephrine levels, the association between SRC and renalase levels and the association between renalase, blood pressure levels and endothelial dysfunction. We made a cross-sectional study including 75 patients with SRC, and 51 controls were included to the study. Flow-mediated dilatation (FMD) was assessed, and serum renalase and epinephrine levels were determined. Patient with SRC had lower renalase, higher epinephrine and lower FMD levels when compared to patients without SRC (p < 0.05). Log renalase was correlated with log epinephrine (r = -0.302, p = 0.001) and log FMD (r = 0.642, p < 0.0001). There was no correlation between renalase and urine albumin/creatinine ratio and glomerular filtration rate. In univariate analysis, age, glomerular filtration rate, renalase and FMD were associated with the presence of SRC. Multivariate regression analysis of factors which are statistically significant in univariate analysis showed that age and renalase was associated with the presence of SRC. We have demonstrated that renalase levels were associated with the presence of SRC and endothelial dysfunction. Further research is necessary to highlight underlying mechanisms.Publication Metadata only Effects of serum uric acid on estimated GFR in cardiac surgery patients: a pilot study(Karger Publishers, 2015) Ejaz, A. Ahsan; Alquadan, Kawther F.; Dass, Bhagwan; Shimada, Michiko; Johnson, Richard J.; N/A; Kanbay, Mehmet; Faculty Member; School of Medicine; 110580Background: The aim of the study was to investigate the effects of serum uric acid (SUA) on acute kidney injury (AKI) in patients undergoing cardiac surgery. Methods: Prospectively collected data from a previous study were analyzed to investigate the relationship between SUA and AKI as assessed by neutrophil gelatinase-associated lipocalin (NGAL), serum creatinine (SCr) and kinetic estimated glomerular filtration rate (KeGFR). Results: Patients undergoing cardiovascular surgery (n = 37) were included. SUA was measured at postoperative 1 h. Statistically significant correlations were present between SUA and NGAL measured at postoperative 1 h (r = 0.39, p = 0.008), 6 h (r = 0.31, p = 0.029) and 24 h (r = 0.31, p < 0.001), respectively. Significant correlations were also noted between SUA and SCr measured on postoperative day 1 (r = 0.41, p = 0.006), day 2 (r = 0.29, p = 0.042) and day 3 (r = 0.42, p = 0.009). Negative correlations were demonstrated between SUA and day 1 (r = -0.44, p = 0.007), day 2 (r = -0.43, p = 0.007), day 3 (r = -0.44, p = 0.006 and day 4 KeGFR (r = -0.35, p = 0.035). The inverse relationship of SUA and KeGFR was also demonstrated with a different method (Jelliffe) of measurement. Conclusions: A reduction in glomerular filtration rate (GFR) can lead to a rise in SUA. However, in this study, we are able to show that SUA at 1 h (maximal dilution time) effectively predicts subsequent changes in urinary NGAL, SCr, KeGFR, and the development of AKI. Thus, these findings suggest that uric acid precedes and predicts acute changes in renal function and cannot be ascribed to a simple relationship in which a reduced GFR raises SUA.Publication Metadata only Association between elevated serum uric acid and vitamin D insufficiency among the middle-aged and elderly population(Buluş Design, 2016) Takir, Mumtaz; Solak, Yalçın; Erek, Aybala; Kostek, Osman; Oral, Alihan; Elcioglu, Omer Celal; Bakan, Ali; Afsar, Baris; Ozkok, Abdullak; Jalal, Diana; Johnson, Richard J.; Aydin Bahat, Kubra; Odabas, Ali Riza; N/A; Kanbay, Mehmet; Faculty Member; School of Medicine; 110580OBJECTIVE: Vitamin D insufficiency might have a role in numerous diseases including autoimmune disease, cancer, diabetes mellitus, hypertension and heart diseases. The relationship between vitamin D insufficiency and hyperuricemia has been shown previously but there are conflicting results in studies. MATERIAL and METHODS: A total of 1562 patients who had serum uric acid and vitamin D levels measured at the same time were enrolled. Patients who were on vitamin D replacement therapy, receiving calcium and/or allopurinol, or had gout and chronic kidney disease were excluded. RESULTS: Hyperuricemic patients had significantly lower levels of serum vitamin D level compared with normouricemic patients (p<0.001) whereas there was no difference between the groups in terms of serum calcium, phosphorus, parathormone and alkaline phosphatase. Severe deficiency (25(OH) vitamin D <10) was significantly more common among patients with hyperuricemia (p<0.001). When vitamin D levels were analyzed according to age, a significant inverse correlation between vitamin D and serum uric acid level was found in decades 7 and 8. Age, eGFR and vitamin D level below 20 appeared as independent associates of serum uric acid levels. CONCLUSION: These data suggest that hyperuricemia associates with vitamin D deficiency. Further studies are needed to understand the mechanism underlying this association and its potential clinical implications. / AMAÇ: D vitamini eksikliği başta otoimmünite, kanser, diyabetes mellitus, hipertansiyon ve kalp hastalıkları olmak üzere birçok hastalıkla ilişkili olabilir. D vitamini eksikliği ile hiperürisemi arasında çelişkili sonuçlar daha önceki çalışmalarda gösterilmiştir. GEREÇ ve YÖNTEMLER: Serum D vitamini ve ürik asit değerleri eş zamanlı bakılan hastalar çalışmaya dahil edildi. D vitamini replasman tedavisi alanlar, kalsiyum ve/veya allopurinol kullananlar, gut ve kronik böbrek yetmezliği (glomeruler filtrasyon hızı <60 ml/min) olan hastalar çalışmaya dahil edilmedi. BULGULAR: Hiperürisemik hastaların serum vitamin D düzeyleri normoürisemik hastalara göre daha düşük olduğu görülmesine (p<0.001) karşın, gruplar serum kalsiyum, fosfor, parathormon ve alkalen fosfataz düzeyleri bakımından benzerdi. D vitamini düzeylerine göre değerlendirildiğinde ağır (vitamin D <10) düzeyde eksikliği olan hastaların daha çok hiperürisemik (p<0.001) grupta olduğu görüldü. Yaşa göre serum D vitamini ve ürik asit düzeyleri arasında anlamlı derecede negatif korelasyonun 7.ve 8. dekatlarda olduğu görüldü. Yaş, serum D vitamini düzeyinin <20 olması ve eGFR düzeyleri, serumürik asit düzeyi ile anlamlı korelasyon gösterdiği görüldü. SONUÇ: Çalışmamızda, hiperüriseminin D vitamini eksikliği ile ilişkili olduğu saptanmıştır. Bu ilişkiyi açıklayabilecek mekanizma ve bunun klinik açıdan etkilerine yönelik daha ileri çalışmalara ihtiyaç vardır.Publication Metadata only The impact of exercise on physical function, cardiovascular outcomes and quality of life in chronic kidney disease patients: a systematic review(Springer, 2018) Afsar, Baris; Siriopol, Dimitrie; Kanbay, Asiye; Burlacu, Alexandru; Covic, Adrian; N/A; N/A; N/A; N/A; N/A; Aslan, Gamze; Eren, Özgür Can; Kılıç, Uğur; Dağel, Tuncay; Kanbay, Mehmet; Doctor; Researcher; Other; Doctor; Faculty Member; School of Medicine; School of Medicine; N/A; N/A; School of Medicine; Koç University Hospital; N/A; N/A; N/A; N/A; 110580The prevalence of chronic kidney disease (CKD) and end-stage renal disease (ESRD) is increasing steadily. CKD does not only relate to morbidity and mortality but also has impact on quality of life, depression and malnutrition. Such patients often have significantly decreased physical activity. Recent evidence suggests that low physical activity is associated with morbidity, mortality, muscle atrophy, quality of life impairment, cardiovascular outcomes and depression. Based on this, it is now recommended to regularly improve the physical activity of these patients. Furthermore, studies have shown the beneficial effects of various exercise programs with respect to outcomes such as low physical activity muscle atrophy, quality of life, cardiovascular outcomes and depression. Despite these encouraging findings, the subject is still under debate, with various aspects still unknown. In this review, we tried to critically summarize the existing studies, to explore mechanisms and describe future perspectives regarding physical activity in CKD/ESRD patients.Publication Metadata only What is the best vascular access site for continuous renal replacement therapy during neonatal period?(Springer, 2015) Büyükpastırmacı, Müge; Karacabey, Burçin Nazlı; Aygün, Fatih.; Zeybek, Çiğdem Ayşe; N/A; Demirkol, Demet; Faculty Member; School of Medicine; 108964N/A