Basol Canbakan

Serum fibroblast growth factor-23 (FGF-23) levels are independently associated with left ventricular mass and myocardial performance index in maintenance haemodialysis patients

BACKGROUND Fibroblast growth factor-23 (FGF-23) is a phosphorus-regulating substance. Circulating FGF-23 levels increase markedly in dialysis patients and are independently associated with increased risk of mortality. Given the fact that cardiovascular disease is the leading cause of death in dialysis patients, the aim of this study was to test if elevated FGF-23 levels might be associated with left ventricular mass index (LVMI) and left ventricular index of myocardial performance (MPI) in maintenance haemodialysis patients. METHODS In this cross-sectional study, plasma FGF-23 concentrations were measured using a C-terminal human enzyme-linked immunosorbent assay kit, and echocardiography was performed in 128 maintenance haemodialysis patients (65 women and 63 men, mean age: 55.5 ± 13 years, mean haemodialysis vintage: 52 ± 10 months, all patients are on haemodialysis thrice a week) and 40 control subjects (21 women and 19 men; mean age: 54 ± 11 years) with normal kidney function (eGFR > 90 mL/min/1.73 m(2)). RESULTS Serum FGF-23 levels were elevated when compared with age- and gender-matched controls with preserved kidney function [(median 958 RU/mL; interquartile range 106-1894 RU/mL) vs (median 27 RU/mL; interquartile range 11-35), P < 0.0001]. Patients with a history of coronary artery disease and aortic valve calcifications had higher levels of log FGF-23 than those without (3.00 ± 0.22 vs 2.82 ± 0.26, P = 0.002; and 3.06 ± 0.19 vs 2.83 ± 0.26, P = 0.0001, respectively). Patients with MPI > 0.47 had higher serum FGF-23 levels than those with MPI < 0.47 [(median 1156 RU/mL; interquartile range 396-1894 RU/mL) vs (median 657 RU/mL; interquartile range 106-1102 RU/mL), P = 0.0001]. Significant correlations were recorded between log FGF-23 levels and LVMI (r = 0.281, P = 0,007) and MPI (r = 0.555, P = 0.0001). Multivariable-adjusted regression analyses revealed that increased log FGF-23 concentrations were independently associated with increased left ventricular mass index (30% increase per 1-SD increase in log FGF-23 concentration, P = 0.002) and increased MPI (28.5% increase per 1-SD increase in log FGF-23 concentration, P = 0.001). CONCLUSIONS Plasma FGF-23 concentration is independently associated with LVMI and MPI in maintenance haemodialysis patients. Further prospective studies are needed to clarify whether increased serum FGF-23 level is a marker or a potential mechanism for left ventricular involvement in patients with end-stage renal disease.

Lessons learned from the catastrophic Marmara earthquake: factors influencing the final outcome of renal victims.

BACKGROUND During catastrophic earthquakes, crush syndrome is the second most frequent cause of death after the direct impact of trauma. The Marmara earthquake, which struck Northwestern Turkey in August 1999, was characterized by 639 crush syndrome victims with acute renal problems. The factors influencing their final outcome have been the subject of this study. PATIENTS/METHODS Within the first week of the disaster questionnaires asking about 63 clinical and laboratory variables were sent to 35 reference hospitals that treated the victims. Information obtained by means of these questionnaires, including the factors with a potential influence on outcome, was submitted to analysis. RESULTS Overall mortality rate was 15.2%. In univariate analysis, nonsurvivors were older (p = 0.048); the highest mortality rates were observed among the victims coming from the closest cities to the reference hospitals. Admission within the first 3 days of the disaster (p = 0.016), with oliguria (p = 0.042), lower figures for blood pressure (p < 0.001), platelets (p = 0.004) and serum albumin (p = 0.005) were associated with mortality. Also, higher body temperature (p = 0.013) and serum potassium (p < 0.001) as well as suffering from thoracic or abdominal traumas, extremity amputations and medical complications other than renal failure (for all 4: p < 0.0001) in addition to need of dialysis support (p = 0.015) and mechanical ventilation (p < 0.0001) indicated higher risk of death. In the multivariate analysis, age (p = 0.030, OR = 1.02), presence of disseminated intravascular coagulation (p = 0.001, OR = 4.49), abdominal trauma (p = 0.012, OR = 4.05) and amputations (p = 0.010, OR = 2.81) were predictors of mortality. Dialyzed patients were characterized by higher mortality rates than nondialyzed victims (17.2% versus 9.3%, p = 0.015). CONCLUSION Outcome of the renal victims of catastrophic earthquakes is influenced by the type of trauma, comorbid events and complications observed during the clinical course as well as epidemiological features such as age, distance to reference hospitals and time lapse between disaster and admission to reference hospitals.

The impact of daily sodium intake on posttransplant hypertension in kidney allograft recipients

BACKGROUND Hypertension (HT) is a common problem, observed frequently after kidney transplantation due to several causes. Posttransplantation HT increases the incidence of both cardiovascular diseases and allograft failure. Although a low sodium diet is strongly advised, the relationship between it and posttransplantation HT has not been well studied in transplant patients. METHODS Thirty-eight kidney transplant patients with stable allograft function ≥ 6 months after transplantation with a history of blood pressures ≥ 120/80 mm Hg despite antihypertensive therapy were included in this study. Office and ambulatory blood pressure monitoring (ABPM) were performed before the study. We measured serum biochemistries, hemograms, as well as 24-hour urinary excretions of sodium, potassium, calcium, magnesium, creatinine, and protein levels. After injection of low sodium diet of ≤ 80 mmol/d arranged by a dietician for 14 days, we repeated the measurements to compare the results. RESULTS After 14 days, the low sodium diet decreased the office systolic (from 132.4 ± 18.8 to 123.7 ± 13.4 mm Hg; P < .001) and diastolic (from 87.3 ± 10.8 to 81.3 ± 7.0 mm Hg; P < .001) blood pressures with decreased sodium excretion (from 177.2 ± 72.7 to 85.3 ± 37.7 mmol/L; P < .001) in the 24-hour urine. It also decreased the average systolic (from 125.3 ± 11.1 to 120.5 ± 9.1 mm Hg) and diastolic (from 80.7 ± 8.3 to 76.9 ± 6.6 mm Hg, P < .001) blood pressures in the 24-hour ABPM. Nighttime systolic (from 120.7 ± 10.9 to 113.9 ± 19.7 mm Hg) and diastolic (from 77.0 ± 9.4 to 74.1 ± 7.8 mm Hg) blood pressures by 24-hour ABPM were significantly decreased (P < .01; P < .05). The low sodium diet had no effect on dipper versus nondipper HT development. Although sodium, calcium, and magnesium excretions in the 24-hour urine were decreased, there was no change in potassium and protein excretion levels. CONCLUSIONS Daily sodium intake was extremely higher than recommended levels among kidney allograft recipients with HT. A low dietary sodium intake (80 mmol/d) combined with antihypertensive treatment controlled blood pressure efficiently by office and 24-hour ABPM readings.

Pulmonary and peritoneal tuberculosis in a CAPD patient

Patients with chronic renal failure have an increased incidence of tuberculosis due to decreased cellular immunity. More than half of the tuberculosis infection in these patients presented with extrapulmonary involvement. Tuberculous peritonitis is an important problem in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Simultaneous pulmonary and peritoneal tuberculosis is a very rare condition. We describe a 39-year-old man with culture negative CAPD peritonitis. In spite of conventional antimicrobial therapy the patient had persistent fever, weight loss, and night sweats. Approximately after one month from starting treatment, both sputum specimen and peritoneal fluid were positive for mycobacterium. Quadruple therapy for tuberculosis has been started. The response to treatment was promptly. He is still on treatment for six months and receiving CAPD. Tuberculous peritonitis should always be considered when patients on CAPD develop culture negative peritonitis treated with conventional antibiotics without improvement. In addition, the existence of extraperitoneal tuberculosis, especially pulmonary disease must be investigated.

Is hepcidin‐25 a predictor of atherosclerosis in hemodialysis patients?

Atherosclerotic cardiovascular disease is an important cause of mortality and morbidity in hemodialysis patients. Iron accumulation in arterial wall macrophages is increased in atherosclerotic lesions. Hepcidin is a key hepatic hormone regulating iron balance. It inhibits iron release from macrophages and iron absorption from enterocytes by binding and inactivating the cellular iron exporter ferroportin. The aim of this study is to investigate the relation of hepcidin‐25, iron parameters, and atherosclerosis measured by carotid intima media thickness (CIMT) in hemodialysis patients. Eighty‐two hemodialysis patients were enrolled in this cross‐sectional study. Predialysis blood samples were centrifuged at 1500 g and 4°C for 10 minutes and stored at −80°C for the measurement of hepcidin‐25. DRG hepcidin enzyme‐linked immunosorbent assay kit was used for the measurement of hepcidin‐25. Ultrasonographical B‐mode imaging of bilateral carotid arteries was performed with a high‐resolution real‐time ultrasonography (Mindray DC7). Mean age of the study population was 57.90 ± 16.08 years and 43.9% were men. Total study population was grouped into two according to median value of hepcidin‐25. There was no difference between groups with respect to age, dialysis vintage, and C‐reactive protein. CIMT was found to be statistically significantly higher in low hepcidin‐25 group. In correlation analysis, CIMT was found to be correlated with age (P < 0.01, R = 0.33) and hepcidin‐25 (P < 0.01, R = 0.46). In linear regression analysis, age (β = 0.31) and hepcidin‐25 (β = 0.44) were found to be the determinants of CIMT in hemodialysis patients. Our results implicate that hepcidin may take part in pathophysiology of atherosclerosis and cardiovascular disease in hemodialysis patients.

Acute renal infarction in a heavy smoker

Renal infarction is a rare cause of acute abdominal and flank pain. Whether it occurs due to thrombosis or embolism, the occlusion of the renal arteries always results in renal infarction. Cigarette smoking is a known risk factor for arterial thrombosis. Both vasoconstrictor and pro-thrombotic effects of smoking lead to arterial thrombosis. Herein, we report a case of acute renal infarction in a heavy smoker. The definite diagnosis was made by contrast-enhanced abdominal computerized tomography and renal arteriography.

Tamoxifen in the treatment of idiopathic retroperitoneal fibrosis.

Idiopathic retroperitoneal fibrosis (RF) is a histologically benign, nonspecific inflammatory process of the fibroadipose tissue in the retroperitoneum with an unknown etiology. It may be complicated due to encasement and obstruction of the retroperitoneal structures. Tamoxifen has been known to be an effective agent in regression of desmoid tumors which include similar mesenchymal elements to those seen in RF. Herein, we reported a case of RF presented with ureteral obstruction and acute renal failure. The patient was successfully treated with tamoxifen.

Increased serum renalase in hemodialysis patients: is it related to left ventricular hypertrophy?

Abstract Introduction: Left ventricular hypertrophy (LVH) is one of the most common cardiac abnormalities in patients with end stage renal disease (ESRD). Hypertension, diabetes, increased body mass index, gender, age, anemia, and hyperparathyroidism have been described as risk factors for LVH in patients on dialysis. However, there may be other risk factors which have not been described yet. Recent studies show that renalase is associated with cardiovascular events. The aim of this study was to reveal the relation between renalase, LVH in patients under hemodialysis (HD) treatment. Methods: The study included 50 HD patients and 35 healthy controls. Serum renalase levels and left ventricle mass index (LVMI) were measured in all participants and the relation between these variables was examined. Findings: LVMI was positively correlated with dialysis vintage and C-reactive protein (CRP) (r = 0.387, p = 0.005 and r = 0.597, p < 0.001, respectively) and was negatively correlated with residual diuresis and hemoglobin levels (r = −0.324, p = 0.022 and r = −0.499, p < 0.001, respectively). There was no significant association of renalase with LVMI in the HD patients (r = 0.263, p = 0.065). Serum renalase levels were significantly higher in HD patients (212 ± 127 ng/mL) compared to controls (116 ± 67 ng/mL) (p < 0.001). Renalase was positively correlated with serum creatinine and dialysis vintage (r = 0.677, p < 0.001 and r = 0.625, p < 0.001, respectively). Discussion: In our study, LVMI was correlated with dialysis vintage, residual diuresis, CRP, and hemoglobin. LVMI tends to correlate with renalase and this correlation may be significant in studies with more patient numbers. The main parameters affecting renalase levels are dialysis vintage and serum creatinine.

Increased serum renalase in peritoneal dialysis patients: Is it related to cardiovascular disease risk?

BACKGROUND Renalase, with possible monoamine oxidase activity, is implicated in degradation of catecholamines; which suggests novel mechanisms of cardiovascular complications in patients with chronic kidney diseases. Epicardial adipose tissue (EAT) has been found to correlate with cardiovascular diseases (CVD) in dialysis patients. The present study aimed to evaluate the association of serum renalase levels with EAT thickness and other CVD risk factors in peritoneal dialysis (PD) patients. METHODS The study included 40 PD patients and 40 healthy controls. All subjects underwent blood pressure and anthropometric measurements. Serum renalase was assessed by using a commercially available assay. Transthoracic echocardiography was used to measure EAT thickness and left ventricular mass index (LVMI) in all subjects. RESULTS The median serum renalase level was significantly higher in the PD patients than in the control group [176.5 (100-278.3) vs 122 (53.3-170.0)ng/ml] (p=0.001). Renalase was positively correlated with C-reactive protein (r=0.705, p<0.001) and negatively correlated with RRF (r=-0.511, p=0.021). No correlation was observed between renalase and EAT thickness or LVMI. There was a strong correlation between EAT thickness and LVMI in both the PD patients and the controls (r=0.848, p<0.001 and r=0.640, p<0.001 respectively). CONCLUSIONS This study indicates that renalase is associated with CRP and residual renal function but not with EAT thickness as CVD risk factors in PD patients.

Fibroblast growth factor is associated to left ventricular mass index, anemia and low values of transferrin saturation

BACKGROUND Fibroblast growth factor 23 (FGF-23) is a phosphorus-regulating hormone. In chronic kidney disease (CKD), circulating FGF-23 levels are markedly elevated and independently associated with mortality. Left ventricular hypertrophy (LVH) is a potent risk factor for mortality in CKD, and FGFs have been implicated in the pathogenesis of myocardial hypertrophy. In addition, the effect of anemia on CV disease and LVH is well known in CKD. A relation between iron and FGF-23 metabolism is mentioned in a few studies. The aim of this study was to test the association of FGF-23 levels with echocardiographic (ECHO) and iron parameters in peritoneal dialysis patients (PD). METHODS In this cross-sectional study, 61 subjects with PD (29 women and 32 men, mean age: 46.9±13.3 years, mean PD vintage: 69.5±39 months) underwent echocardiograms to assess left ventricular mass index (LVMI). Medical treatments and average values of the basic laboratory results of the last 6 months for all patients were recorded. Serum FGF-23 concentrations were measured using intact FGF-23 (iFGF-23) human enzyme-linked immunosorbent assay (ELİSA) kit. According to the median levels of serum FGF-23 the patients were grouped into two (FGF-23 high and low groups). RESULTS Significant positive correlation was recorded between serum FGF-23 levels and LVMI (P=0.023). There was also significant difference in terms of hemoglobin (12.1±2 versus 11.0±2, P=0.017), transferrin saturation (TSAT) (24.9±16.8 versus 19.5±10.8, P=0.042) between low and high FGF-23 group. Also in linear regression analysis the negative relation between FGF-23 and hemoglobin is persisted (r=0.199, P=0.045). CONCLUSIONS FGF-23 is associated with LVMI, anemia and low TSAT in patients with PD. Whether increased FGF-23 is a marker or a potential mechanism of myocardial hypertrophy and anemia in patients with end-stage renal disease (ESRD) requires further study.