Yazar "Bayazit A.K." seçeneğine göre listele
Listeleniyor 1 - 4 / 4
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Active vitamin D is cardioprotective in experimental uraemia but not in children with CKD Stages 3-5(NLM (Medline), 2021) Schön A.; Leifheit-Nestler M.; Deppe J.; Fischer D.-C.; Bayazit A.K.; Obrycki L.; Mir S.BACKGROUND: Uraemic cardiac remodelling is associated with vitamin D and Klotho deficiency, elevated fibroblast growth factor 23 (FGF23) and activation of the renin-angiotensin system (RAS). The cardioprotective properties of active vitamin D analogues in this setting are unclear. METHODS: In rats with 5/6 nephrectomy (5/6Nx) treated with calcitriol, the cardiac phenotype and local RAS activation were investigated compared with controls. A nested case-control study was performed within the Cardiovascular Comorbidity in Children with Chronic Kidney Disease (4C) study, including children with chronic kidney disease (CKD) Stages 3-5 [estimated glomerular filtration rate (eGFR) 25?mL/min/1.73?m2] treated with and without active vitamin D. Echocardiograms, plasma FGF23 and soluble Klotho (sKlotho) were assessed at baseline and after 9?months. RESULTS: In rats with 5/6Nx, left ventricular (LV) hypertrophy, LV fibrosis and upregulated cardiac RAS were dose-dependently attenuated by calcitriol. Calcitriol further stimulated FGF23 synthesis in bone but not in the heart, and normalized suppressed renal Klotho expression. In the 4C study cohort, treatment over a mean period of 9?months with active vitamin D was associated with increased FGF23 and phosphate and decreased sKlotho and eGFR compared with vitamin D naïve controls, whereas LV mass index did not differ between groups. CONCLUSIONS: Active vitamin D ameliorates cardiac remodelling and normalizes renal Klotho expression in 5/6Nx rats but does not improve the cardiac phenotype in children with CKD Stages 3-5. This discrepancy may be due to further enhancement of circulating FGF23 and faster progression of CKD associated with reduced sKlotho and higher serum phosphate in vitamin D-treated patients. © The Author(s) 2020. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.Öğe Carotid artery intima-media thickness and distensibility in children and adolescents: Reference values and role of body dimensions(2013) Doyon A.; Kracht D.; Bayazit A.K.; Deveci M.; Duzova A.; Krmar R.T.; Litwin M.; Niemirska A.; Oguz B.; Schmidt B.M.W.; Sözeri B.; Querfeld U.; Melk A.; Schaefer F.; Wühl E.Carotid intima-media thickness (cIMT) and carotid artery distensibility are reliable screening methods for vascular alterations and the assessment of cardiovascular risk in adult and pediatric cohorts. We sought to establish an international reference data set for the childhood and adolescence period and explore the impact of developmental changes in body dimensions and blood pressure (BP) on carotid wall thickness and elasticity. cIMT, the distensibility coefficient, the incremental modulus of elasticity, and the stiffness index ß were assessed in 1155 children aged 6 to 18 years and sex-specific reference charts normalized to age or height were constructed from 1051 nonobese and nonhypertensive children. The role of body dimensions, BP, and family history, as well as the association between cIMT and distensibility, was investigated. cIMT increased and distensibility decreased with age, height, body mass index, and BP. A significant sex difference was apparent from the age of 15 years. Age- and height-normalized cIMT and distensibility values differed in children who are short or tall for their age. By stepwise multivariate analysis, standardized systolic BP and body mass index were independently positively associated with cIMT SD scores (SDS). Systolic BP SDS independently predicted all distensibility measures. Distensibility coefficient SDS was negatively and ß SDS positively associated with cIMT SDS, whereas incremental modulus of elasticity was independent of cIMT. Morphological and functional aspects of the common carotid artery are particularly influenced by age, body dimensions, and BP. The reference charts established in this study allow to accurately compare vascular phenotypes of children with chronic conditions with those of healthy children. © 2013 American Heart Association, Inc.Öğe Response to intima-media thickness in children-need for more parameters(Lippincott Williams and Wilkins, 2014) Doyon A.; Kracht D.; Bayazit A.K.; Deveci M.; Duzova A.; Krmar R.T.; Litwin M.; Niemirska A.; Oguz B.; Schmidt B.M.W.; Sözeri B.; Querfeld U.; Melk A.; Schaefer F.; Wühl E.[No abstract available]Öğe Timing and Modality of Kidney Replacement Therapy in Children and Adolescents(Elsevier Inc., 2024) Thumfart J.; Wagner S.; Kirchner M.; Azukaitis K.; Bayazit A.K.; Obrycki L.; Canpolat N.Introduction: The choice and timing of kidney replacement therapy (KRT) is influenced by clinical factors, laboratory features, feasibility issues, family preferences, and clinicians' attitudes. We analyzed the factors associated with KRT modality and timing in a multicenter, multinational prospective pediatric cohort study. Methods: A total of 695 pediatric patients with chronic kidney disease (CKD) enrolled into the Cardiovascular Comorbidity in Children with CKD (4C) study at age 6 to 17 years with estimated glomerular filtration rate (eGFR) of 10 to 60 ml/min per 1.73 m2 were investigated. Competing risk regression was performed to identify factors associated with initiation of dialysis or preemptive transplantation (Tx), including primary renal diagnosis, demographics, anthropometrics, and laboratory parameters. Results: During the 8-year observation period, 342 patients (49%) started KRT. Of these, 200 patients started dialysis, whereas 142 patients underwent preemptive Tx. A lower eGFR at enrolment (Hazard ratio [HR]: 0.76 [95% confidence interval: 0.74–0.78]), a steeper eGFR slope (HR: 0.90 [0.85–0.95], and a higher systolic blood pressure SD score (SDS) (HR: 2.07 [1.49–2.87]) increased the likelihood of KRT initiation. Patients with glomerulopathies were more likely to start dialysis than children with congenital anomalies of the kidneys and urinary tracts (CAKUT) (HR: 3.81 [2.52–5.76]). Lower body mass index (BMI) SDS (HR: 0.73 [0.6–0.89]) and lower hemoglobin (HR: 0.8 [0.72–0.9]) were associated with higher likelihood of dialysis. A significant center effect was observed, accounting for 6.8% (dialysis) to 8.7% (preemptive Tx) of explained variation. Conclusion: The timing and choice of KRT in pediatric patients is influenced by the rate of kidney function loss, the underlying kidney disease, nutritional status, blood pressure, anemia and center-specific factors. © 2024