Ozkan Gungor

Endogenous Testosterone and Mortality in Male Hemodialysis Patients: Is It the Result of Aging?

BACKGROUND AND OBJECTIVES Low serum testosterone levels in hemodialysis (HD) patients have recently been associated with cardiovascular risk factors and increased mortality. To confirm this observation, we investigated the predictive role of serum total testosterone levels on mortality in a large group of male HD patients from Turkey. DESIGN, SETTINGS, PARTICIPANTS, & MEASUREMENTS A total of 420 prevalent male HD patients were sampled in March 2005 and followed up for all-cause mortality. Serum total testosterone levels were measured by ELISA at baseline and studied in relation to mortality and cardiovascular risk profile. RESULTS Mean testosterone level was 8.69 ± 4.10 (0.17 to 27.40) nmol/L. A large proportion of patients (66%) had testosterone deficiency (<10 nmol/L). In univariate analysis, serum testosterone levels were positively correlated with creatinine and inversely correlated with age, body mass index, and lipid parameters. During an average follow-up of 32 months, 104 (24.8%) patients died. The overall survival rate was significantly lower in patients within the low testosterone tertile (<6.8 nmol/L) compared with those within the high tertile (>10.1 nmol/L; 64 versus 81%; P = 0.004). A 1-nmol/L increase in serum testosterone level was associated with a 7% decrease in overall mortality (hazard ratio 0.93; 95% confidence interval 0.89 to 0.98; P = 0.01); however, this association was dependent on age and other risk factors in adjusted Cox regression analyses. CONCLUSIONS Testosterone deficiency is common in male HD patients. Although testosterone levels, per se, predicted mortality in this population, this association was largely dependent on age.

Nutritional State Alters the Association between Free Triiodothyronine Levels and Mortality in Hemodialysis Patients

Background: Serum free triiodothyronine (fT3) level is suggested to be a risk factor for mortality in unselected dialysis patients. We investigated the prognostic value of serum fT3 levels and also low-T3 syndrome on overall survival in a large cohort of hemodialysis (HD) patients with normal thyroid-stimulating hormone levels. Methods: A total of 669 prevalent HD patients were enrolled in the study. Serum fT3 level was measured by enzyme immune assay in frozen sera samples at the time of enrollment. Overall mortality was assessed during 48 months of follow-up. Results: Baseline fT3 was 1.47 ± 0.43 (0.01–2.98) pg/ml, and low-T3 syndrome was present in 71.7% of the cases. During a mean follow-up of 34 ± 16 months, 165 (24.7%) patients died. fT3 level was a strong predictor for mortality in crude and adjusted Cox models including albumin or high-sensitivity C-reactive protein (hs-CRP). Further adjustment for both albumin and hs-CRP made the impact of fT3 on mortality disappear. The presence of low-T3 syndrome was associated with mortality in only the unadjusted model. Conclusions: Low-T3 syndrome is a frequent finding among HD patients, but it does not predict outcome. However, serum fT3 level is a strong and inverse mortality predictor, in part explained by its underlying association with nutritional state and inflammation.

Plasmapheresis Therapy in Renal Transplant Patients: Five-Year Experience

INTRODUCTION Plasma exchange (PE) and double-filtration plasmapheresis (DFPP) have been used successfully in renal transplant patients as well as those with various other diseases over the last decade. In this retrospective study, we sought to explore the outcomes of plasmapheresis in renal transplant patients. PATIENTS AND METHODS We investigated 58 patients who received PE or DFPP therapy between 2005 and 2010. PE was performed using a Fresenius AS.TEC 204 device and DFPP, by an INFOMED HF 440 device. Indications for therapy, biopsy findings, number of PE/DFPP sessions, laboratory data, medications, complications as well as graft and patient survivals were recorded. RESULTS Overall mean age of subjects was 34.1 ± 8.8 years and 55% were female. Sixteen patients underwent 95 DFPP sessions and 42 underwent 215 PE sessions. Indications for therapy were acute humoral rejection (n = 39), recurrent focal segmental glomerulosclerosis (FSGS; n = 8), thrombotic microangiopathy (n = 6), and chronic humoral rejection (n = 5). Responses to therapy were 24/39 for acute humoral rejection, 1/5 for chronic rejection, 4/8 for FSGS, and 3/6 for thrombotic microangiography. No complication was observed in any patient. CONCLUSION PE/DFPP is a safe and successful method for treatment of acute humaral rejection as less so for recurrent FSGS and thrombotic microangiopathy. The outcomes among subjects with chronic humoral rejection were not satisfactory.

The effect of oral supplementation with a combination of beta-hydroxy-beta-methylbutyrate, arginine and glutamine on wound healing: a retrospective analysis of diabetic haemodialysis patients.

BackgroundDiabetes is an important reason for end-stage renal failure and diabetic foot wounds worsen the life qualities of these patients. Protein and amino acid support accelerates the wound healing. The purpose of this retrospective study is to examine the effect of beta-hydroxy-beta-methylbutyrate, arginine and glutamine (Abound®) supplementation on the wound healing.MethodsA total of 11 diabetic dialysis patients were included in this retrospective study aiming to evaluate the effect of the diet support with beta-hydroxy-beta-methylbutyrate, arginine and glutamine on wound healing in diabetic dialysis patients. Pre-treatment and post-treatment wound depth and wound appearance were scored in accordance with the “Bates-Jensen” wound assessment tool. The results of 4-week treatment with beta-hydroxy-beta-methylbutyrate, arginine and glutamine (Abound®) support were evaluated in terms of wound healing.ResultsThe mean age of patients was 66 (SD: 10, range: 51-81) and 9 (81.8%) of them were males. After the 4-week treatment, in accordance with the Bates-Jensen scoring, healing was observed on the wound depth score of 7(63.6%) patients and on wound appearance score of 8(72.7%) patients out of 11. While the wound depth score of 4(36.4%) cases and wound appearance score of 3(27.3%) cases remained the same, no deterioration was observed on any cases throughout the follow-up period.ConclusionIn conclusion, our findings revealed that Abound treatment makes a positive contribution to the wound healing in diabetic dialysis patients.

The effect of immunosuppressive treatment on arterial stiffness and matrix Gla protein levels in renal transplant recipients

INTRODUCTION Arterial stiffness is a risk marker for cardiovascular events. In this study we aimed to compare the effect on calcineurin inhibitors (CNI) and mammalian Target of Rapamycine inhibitors (mTORi) on arterial stiffness in renal transplant patients. PATIENTS AND METHODS 81 renal transplant patients under CNI-based or mTORi-based protocol for at least 6 months were included in the study. Arterial stiffness was measured by using the SphygmoCor device (AtCor Medical, Sydney, Australia). Vitamin K-dependent, calcification inhibitor matrix Gla protein (MGP) concentrations were quantified by ELISA methods (Biomedica, Vienna, Austria). RESULTS 34 patients were on mTORi-based and 47 on CNI-based immunosuppression. Mean age was 37.9 ± 10.8 (18 - 71) years and 45% were female. Age, gender, graft functions and follow-up period of the groups were similar. Augmentation index was 15.2 ± 12.6% in CNI and 18.8 ± 14.0% in mTORi groups (p > 0.05). There was no difference regarding carotid-femoral pulse wave velocity between groups. Arterial stiffness was positively correlated with age, total cholesterol, LDL cholesterol, mean arterial pressure (MAP) and proteinuria. MGP levels were higher in the mTORi group but were not predictors for carotid-femoral pulse wave velocity. CONCLUSION Rather than specific immunosuppressive drug effects, conventional risk factors, blood pressure and proteinuria are the most important predictors for arterial stiffness in renal transplant patients.

The Relationships between Serum sTWEAK, FGF-23 Levels, and Carotid Atherosclerosis in Renal Transplant Patients

Background: Cardiovascular disease is the main cause of mortality after renal transplantation. Soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) and fibroblast growth factor-23 (FGF-23) are two novel molecules that have been associated with atherosclerosis in different populations. In this cross-sectional study, we investigated the associations between sTWEAK, FGF-23, and carotid artery intima-media thickness (CA-IMT) in renal transplant patients. Methods: A total of 117 renal transplant patients were studied. CA-IMT was determined by B-mode Doppler ultrasonography. Serum sTWEAK and FGF-23 were measured by a commercially available enzyme-linked immunosorbent assay (ELISA). Results: Mean age was 39.6 ± 9.6 years and 51% of the patients were male. Mean sTWEAK level was 595 ± 225 pg/mL (158–1140), FGF-23 level was 92 ± 123 RU/mL (9.6–1006), and CA-IMT level was 0.62 ± 0.11 mm (0.40–0.98). sTWEAK level was positively correlated with CA-IMT. There was no association between sTWEAK and FGF-23 levels. FGF-23 was also associated with CA-IMT. In adjusted models using linear regression analysis, only age and serum TWEAK levels were predictors for CA-IMT. Conclusion: There is a positive correlation between CA-IMT and sTWEAK, but not with FGF-23 levels in renal transplant patients.

Renal tubular acidosis in renal transplant patients: the effect of immunosuppressive drugs.

BACKGROUND Renal tubular acidosis (RTA) is a non-anion gap metabolic acidosis and is generally mild and asymptomatic in kidney recipients. Calcineurine inhibitors (CNIs) increase the frequency of RTA but the frequency of RTA development in kidney transplant recipients receiving mammalian target of rapamycin inhibitors (mTORi) treatment remains unclear. In this study, we aimed to investigate the frequency of RTA in kidney transplant recipients on mTORi and CNI treatment and to compare both groups. MATERIAL AND METHODS We enrolled 137 adult renal transplant patients - 82 patients on mTORi and 55 patients on CNI who had similar age, sex, posttransplant follow-up period, and graft functions. We recorded the parameters of venous blood gas analysis, including serum pH value, serum bicarbonate (HCO3) concentration, presence of metabolic acidosis defined as low HCO3 (<22 mEq/L), and serum pH value (<7.35), as well as base excess and urine pH at last follow-up. RTA was defined to be metabolic acidosis with normal serum anion gap and positive urine anion gap. RESULTS The mean age of our study population was 41.2±11.3 years. RTA frequency was 35% in the mTORi group and 41% in the CNI group. mTORi and CNI groups did not differ significantly in terms of the development of metabolic and renal tubular acidosis. Type I RTA was common in both groups. RTA was affected by duration of time since transplantation and graft functions in both groups. CONCLUSIONS The rates of RTA development in patients on long-term CNI and mTORi treatment were similar.

Paraoxonase 1, atherosclerosis and arterial stiffness in renal patients

Atherosclerosis is an important contributor to increased cardiovascular burden in populations with and without renal disease. Paraoxonases (PON) are a group of enzymes that hydrolyse organophosphates. Recent evidence indicates a protective role for PON in patients with coronary artery disease and atherosclerosis. Although data are limited, the low enzyme activity found in patients with chronic kidney disease and renal transplants has been linked to atherosclerosis and arterial stiffness. In this paper, we review the emerging role of PON1 in the pathophysiology of atherosclerosis and arterial stiffness in patients with chronic kidney disease.

Can strict volume control be the key for treatment and prevention of posterior reversible encephalopathy syndrome in hemodialysis patients

Posterior reversible encephalopathy syndrome (PRES) is a rare but if diagnosed late an irreversible disease. The majority of the patients present with severe hypertension, and effective blood pressure control is the mainstay of therapy. In this case report, we present three cases with PRES, treated successfully with strict volume control policy and propose that strict volume control policy may be a key element for the treatment of PRES.

Nephrosclerosis and carotid atherosclerosis: Lessons from kidney donor histology

Aim:  Carotid artery intima media thickness (CA‐IMT) measurement has been shown to be a safe and reproducible method to assess severity of atherosclerosis. The association between nephrosclerosis and systemic atherosclerosis is not clear. In this study, we investigated the association between CA‐IMT and nephrosclerosis in a group of kidney transplant donors.