Yasemin Coskun Yavuz

Effect of hemoglobin variability on mortality and some cardiovascular parameters in hemodialysis patients

Abstract Background and objectives: Most hemodialysis patients show hemoglobin fluctuations between low-normal and high levels. This hemoglobin variability may cause left ventricle hypertrophy and may increase mortality as well. Recently, many studies were designed to evaluate the effect of hemoglobin variability on mortality but results were conflicting. We aimed to investigate the effect of hemoglobin variability on mortality and some cardiovascular parameters in hemodialysis population. Design, setting, participants and measurements: Hundred and seventy-five prevalent hemodialysis patients classified into three hemoglobin variability groups according to their hemoglobin levels throughout 24 month observation period: Low-Normal, Low-High, Normal-High. Groups were compared in terms of laboratory, demographical data and mortality rates, initial and the end of 24 month echocardiographic data. Initial and last echocardiographic data were compared within groups in terms of left ventricle mass index increase. Results: Mortality rates and cardiovascular risk factors such as coronary heart disease, diabetes mellitus and hypertension that may affect mortality were same between three groups. There was no significant difference between three groups in terms of echocardiographic and laboratory parameters. Only Low-High group showed significant increase on left ventricle mass index when initial and last echocardiographic parameters were compared. Conclusions: Consistent with previous studies, we found that most of the patients exhibited hemoglobin variability and our study is consistent with some of the studies that did not find any relationship between hemoglobin variability and mortality. Firstly, in this study based on objective data, it was shown that hemoglobin variability has adverse effect on left ventricle geometry independent from anemia.

Is Nebivolol Really Effective in Preventing Contrast Induced Nephropathy

Background/Aims: Contrast induced nephropathy (CIN) has multifactorial etiopatogenesis including oxidative stress and vasoconstriction. Nebivolol is an antioxidant and has vasodilatatory effect via NO release and may prevent CIN development. We have noticed that a few number of studies that have evaluated the effectiveness of nebivolol for the prevention of CIN used serum creatinine (sCr) levels for CIN detection. However, sCr is an insensitive marker for renal damage. Therefore in this study we used serum neutrophil-gelatinase associated lipocalin (NGAL), a more sensitive marker of renal damage, to evaluate preventive role of nebivolol in CIN. Methods: 159 patients undergoing coronary angiography (CAG) who had at least one risk factor for CIN were divided into nebivolol (+) and (-) groups. CIN was defined as a rise in sCr of 0.5mg/dl or a 25% increase from the baseline value. Serum Cr, glomerular filtration rate (eGFR) and NGAL levels were assessed before and 48 h after CAG. Mehran risk scores were calculated for both groups. Results: Both groups were similar in terms of baseline characteristics, Mehran risk scores, and current medications. Clinically, CIN developed at similar rates in both groups. Serum Cr, eGFR and NGAL values were similar in both groups before and after CAG. Serum Cr and NGAL levels increased and eGFR decreased significantly compared to the levels before CAG. Patients who developed CIN were significantly older (p=0.003), and were more likely to have DM (p=0.012), a higher mean contrast agent volume (p<0.001), and a higher Mehran score (p <0.001). We did not observe any favorable effect of Nebivolol in the prevention of CIN in patients undergoing CAG. Conclusion: According to the results of our study Nebivolol does not seem to prevent CIN in patients undergoing CAG. However, further randomised controlled trials with more sensitive renal damage markers are obviously needed to understand the actual effect of nebivolol on CIN especially through oxidative pathways and in high risk patients.

The Affecting Factors and Comparison of Tuberculin Skin Test in Peritoneal Dialysis and Hemodialysis Patients

Compared with the general population, patients with chronic renal failure have increased tuberculosis (TB) prevalence and mortality rates. In this study, we aimed to investigate tuberculin skin test (TST) positivity rates in hemodialysis (HD) and peritoneal dialysis (PD) patients and the factors influencing TST positivity. Ninety-two HD patients and 44 PD patients who had been on HD and PD treatment for at least 3 months were recruited into the study. TST was administered in all patients. Positivity was defined as an induration diameter >10 mm. At least 5 mm of induration following skin testing together with a chest radiography indicating previous infection was defined as latent TB infection. TST positivity rates, diameter of TST indurations, and serum albumin levels in HD patients were higher than the PD patients. TST induration size was not correlated with any other parameters in both HD and PD groups. TST-positive patients had higher albumin levels and lower leukocyte count than the TST-negative patients. In TST-positive patients, albumin level was correlated with the duration of dialysis but TST induration size was not correlated with the lymphocyte count and albumin level. In our study, TST positivity of patients was found in 30.4% of HD patients, 9% of PD patients, and 23.5% of total patients. It is still recommended to use TST for the screening test of TB. We found a significant relationship between TST and albumin level. It should be remembered that TST response may be lower in PD patients, especially in cases in which TB is suspected.

The Efficacy of Cinacalcet in the Treatment of Hyperparathyroidism in Turkish Hemodialysis Patient Population

OBJECTIVE: Cinacalcet reduces parathyroid hormone levels by increasing the sensitivity of the parathyroid gland to calcium. In this study, we firstly aimed to evaluate the efficacy of cinacalcet in Turkish hemodialysis patients. MATERIAL and METHODS: 4483 hemodialysis patients were screened and 469 patients who had used cinacalcet were included in the study. The patients were divided into 4 groups according to drug usage durations (Group 1: 3 months, Group 2: 6 months, Group 3: 9 months and Group 4: 12 months). The patients’ Parathormone, Ca, P and CaxP levels at the 3rd, 6th, 9th and 12th months were compared to the start of treatment and previous months. RESULTS: The levels of Parathormone, Ca, P and CaxP significantly decreased compared to their initial levels in all groups (from 1412 pg/ml to 1222 pg/mL for Parathormone, p<0,001) in the 3rd month. However, this reduction was not continued in the subsequent months (Parathormone: 1381 pg/ ml for the 12th month).