Thiol/Disulfide Ratios, HOMA Score, and Quality of Sleep in Renal Transplant Recipients Without Diabetes.

OBJECTIVES: Thiols play an important role in defense against reactive oxygen species. We aimed to evaluate the relation between oxidative stress, glucose tolerance, and sleep quality in kidney transplant recipients without diabetes. MATERIALS AND METHODS: We enrolled 95 kidney transplant recipients without diabetes from living and deceased donors with stable allograft function and 60 healthy controls. We included recipients who received a kidney from a living donor with a first-degree relation. Insulin resistance was determined using the Homeostasis Model Assessment score. Native thiol, total thiol, and disulfide levels were measured, and disulfide versus native thiol/total thiol ratios were calculated from all patients. We used the Pittsburg Sleep Quality Index to assess sleeping patterns. According to standard cutoff value of the index (≤5 indicates good quality sleep; >5 indicates poor sleep quality), we stratified kidney transplant recipients as group 1 (Pittsburg Sleep Quality Index ≤5; n = 41) and group 2 (Pittsburg Sleep Quality Index >5; n = 54). RESULTS: In correlation analysis, Pittsburg Sleep Quality Index was positively correlated with age, the Homeostasis Model Assessment score, body mass index, serum disulfide levels, disulfide/total thiol ratio, and native/total thiol ratio. The Pittsburgh Sleep Quality Index was negatively correlated with total thiol levels. In subgroup analysis, the Homeostasis Model Assessment score, disulfide levels, and disulfide/total thiol and native/total thiol ratios were significantly lower in group 1; however, total thiol level was significantly higher in this group. In multivariate regression analysis, age, the Homeostasis Model Assessment score, disulfide/total thiol ratio, and renal resistivity index were detected as predictors of sleep quality score. CONCLUSIONS: Sleep quality moderates oxidative stress identified by thiol-disulfide homeostasis and insulin resistance in renal transplant recipients without diabetes.

Effect of Body Composition on Graft Function and Cardiovascular Outcomes in Normotensive Renal Transplant Recipients.

OBJECTIVES: We evaluated the effects of body composition on graft function and cardiovascular outcomes in normotensive renal transplant recipients. MATERIALS AND METHODS: In this cross-sectional study, we analyzed ambulatory blood pressure monitoring data from 136 renal transplant recipients with stable allograft function after living related donor transplant. We enrolled 87 normotensive recipients. We analyzed left ventricular mass index, renal resistive index, and body composition of recipients. We divided recipients into 2 groups according to mean lean body mass, defined by bioimpedance analysis, with 38 in group 1 (lean body mass <47 kg) and 49 in group 2 (lean body mass ≥47 kg). RESULTS: Mean time posttransplant was 35.0 ± 23.3 months. Mean renal resistive index, left ventricular mass index, lean body mass, body mass index, and fat mass were 0.67 ± 0.1, 195.0 ± 118.5 g/m2, 47.3 ± 9.1 kg, 25.9 ± 5.0 kg, and 44.6±10.5 kg,respectively. Lean body mass was positively correlated to sex (r = 0.36, P = .03), body mass index (r = 0.04, P = .416),renalresistive index (r = 0.495, P = .01), and left ventricular mass index (r = 0.713, P = .02) but negatively correlated to serum albumin levels (r=-0.343, P=0.04). Lean body mass was significantly higher in males than in females (P = .03). Patients in group 2 had significantly higher left ventricular mass index (P = .01) and renal resistive index (P = .03). In multiple regression analysis, lean body mass (P = .01) and left ventricular mass index (P = .01) were predictors of renal resistive index. CONCLUSIONS: Lean body mass significantly influences left ventricular mass index and renal resistive index. Hence, body composition analysis could be an early predictor of graft function and cardiovascular outcomes in normotensive renal transplant recipients.

Effect of nutritional support on nutritional status and inflammation in malnourished patients undergoing maintenance hemodialysis.

INTRODUCTION: Protein energy wasting/malnutrition is a strong predictor of morbidity and mortality in patients on maintenance hemodialysis (MHD). We aimed to compare the effects of oral and/or intradialytic parenteral nutrition (IDPN) support on nutritional and inflammatory parameters in malnourished patients with MHD. METHODS: This is an observational study of 56 malnourished patients on MHD. We offered combined oral nutritional support (ONS) and IDPN for 12 months to all patients. Depending on patient choices for treatment, they were classified into four groups: group 1 (ONS only), group 2 (IDPN only), group 3 (both ONS and IDPN), and group 4 (patients who refused artificial nutrition support and only followed dietary advice). Normalized protein catabolic rate (nPCR), malnutrition inflammation score (MIS), and body composition (fat mass [FM], muscle mass [MM]) were assessed monthly. FINDINGS: The mean serum albumin levels of groups 2 and 3 significantly increased with the intervention, whereas that of group 4 significantly decreased. The mean nPCR levels of groups 2 and 3 significantly increased. Group 3 had the most significant positive change in serum albumin and nPCR levels. Mean serum C-reactive protein (CRP) levels of groups 1, 2, and 3 decreased, whereas those of group 4 increased. A ∆ in CRP was only identified in group 3. The MIS of groups 1, 2, and 3 significantly decreased whereas that of group 4 significantly increased. The ∆% in FM was 1.1, 1.9, 9.1, and -2.9 for groups 1, 2, 3, and 4, respectively, and that in MM was -0.6, 4.4, 6.9, and -7.9 for groups 1, 2, 3, and 4, respectively. DISCUSSION: Compared to monotherapy or nutritional counseling, the choice of ONS plus IDPN is associated with improved nutritional status and decreased inflammation in malnourished patients on MHD. Nonetheless, interventional studies must be conducted to confirm these observations.

Hand-Grip Strength Is Associated With Serum Testosterone and Albumin Levels in Male Kidney Transplant Recipients.

OBJECTIVES: In kidney transplant recipients, reduced muscle mass and hand-grip strength are associated with impaired nutritional status. Serum testosterone is highly associated with muscle strength in the general population. Here, we aimed to determine the associations among serum testosterone, hand-grip strength, and nutritional and inflammatory parameters, as well as graft function. MATERIALS AND METHODS: Our study included 144 stable male kidney transplant recipients from our renal transplant outpatient clinic. All patients were evaluated for clinical parameters (age, duration of hemodialysis, and posttransplant time), biochemical parameters (calcium, phosphorus, parathyroid hormone, C-reactive protein, albumin, creatinine), and serum testosterone levels. Body composition was analyzed with the bioimpedance spectroscopy analysis technique using a body composition monitor that estimates body mass index and percent fat. Hand-grip strength was analyzed by using a dynamometer (ProHealthcareProducts.com, Park City, UT, USA). We calculated estimated glomerular filtration rate using the Modification of Diet in Renal Disease-4 equation. RESULTS: Demographic characteristics, duration of dialysis before transplant, biochemical parameters, and estimated glomerular filtration rates were similar among study patients. Mean (standard deviation) serum testosterone was 588.0 (55.5) ng/dL, mean body mass index was 26.8 (0.6) kg/m2, and mean hand-grip strength was 42.2 (1.7) mm2. Serum testosterone levels were positively correlated with hand-grip strength (r = 0.445; P = .033) and serum albumin (r = 0.399; P = .05) and negatively correlated with serum C-reactive protein (r = -0.454; P = .05) and age. In linear multiple regression analysis, serum albumin (P = .033) and testosterone levels (P = .038) were shown to be predictors of hand-grip strength. However, we could not show a significant correlation between graft function and testosterone. CONCLUSIONS: Serum testosterone level is correlated with hand-grip strength and C-reactive protein and albumin levels, which may indicate that testosterone affects nutritional status and inflammation in male renal transplant recipients.

FGF23, NGAL, and Endostatin: the Predictors of Allograft Function in Renal Transplant Recipients.

OBJECTIVES: Increased circulating levels of fibroblast growth factor 23, neutrophil gelatinase-associated lipocalin, and endostatin are independent risk factors for cardiovascular disease. Here, we evaluated correlations among these parameters and graft dysfunction and their relation with arterial stiffness. MATERIALS AND METHODS: This prospective study included 73 maintenance kidney transplant patients with stable allograft function who had received the transplant at least 36 months previously. We calculated the estimated glomerular filtration rate (eGFR). Pulsewave velocity was determined. Serum levels of fibroblast growth factor 23, neutrophil gelatinaseassociated lipocalin, and endostatin were measured by enzyme-linked immunosorbent assay. RESULTS: Demographic characteristics and pulse-wave velocity values were similar in groups 1 and 2 (GFR < 60 and > 60 mL/min, respectively). Mean levels of fibroblast growth factor 23 (P = .036), neutrophil gelatinaseassociated lipocalin (P = .018), and endostatin were significantly higher in group 1. Fibroblast growth factor 23 was negatively correlated with eGFR (r = -0.267, P = .023) and positively correlated with neutrophil gelatinase-associated lipocalin (r = 0.258, P = .036) and endostatin (r = 0.321, P = .006). Serum endostatin levels were positively correlated with pulse-wave velocity (r = 0.276, P = .019). In linear regression analysis, eGFR was detected as the unique predictor of neutrophil gelatinase-associated lipocalin (P = .001). In addition, each 1 mL/min decrease in eGFR resulted in a 0.281 pg/mL increase in fibroblast growth factor 23 (P = .023) and a 0.04 ng/mL increase in neutrophil gelatinase-associated lipocalin (P = .007); each 1 cm/s increase in pulse-wave velocity resulted in a 3648.7 U/L increase of endostatin (P = .019). CONCLUSIONS: All 3 parameters were associated with loss of graft function in kidney transplant recipients. Moreover, endostatin can be used as an independent predictor for cardiovascular morbidity in this population.

Renin-Angiotensin System Blockage and Avoiding High Doses of Calcineurin Inhibitors Prevent Interstitial Fibrosis and Tubular Atrophy in Kidney Transplant Recipients.

OBJECTIVES: Chronic allograft dysfunction is a complex and multifactorial process characterized by progressive interstitial fibrosis and tubular atrophy. The finding of interstitial fibrosis and tubular atrophy is prevalent among kidney transplant patients receiving a calcineurin inhibitor-based immunosuppressive regimen and may be considered as a surrogate of allograft survival. Both immune (acute rejection episodes, sensitization, and HLA incompatibility) and nonimmune (donor age, delayed graft function, calcineurin inhibitor toxicity, infections, and hypertension) mechanisms play a role in chronic allograft dysfunction, and different causes all lead to similar histologic and clinical final pathways, with the end result of graft loss. In our study, we aimed to compare the outcomes of kidney transplant recipients with or without interstitial fibrosis and tubular atrophy in protocol biopsies to determine the conditions that may affect allograft survival. MATERIALS AND METHODS: We divided 192 kidney transplant recipients into 2 groups (96 patients with interstitial fibrosis and tubular atrophy; 96 patients without interstitial fibrosis and tubular atrophy) according to protocol biopsy at 6 months. Patient groups were compared according to their risk factors for chronic allograft dysfunction (cold ischemia time, delayed graft function, donor age, infections, mean blood calcineurin levels, and hypertension). RESULTS: Cold ischemia time, delayed graft function, high 24-hour proteinuria levels, and higher mean blood calcineurin levels were found to be major risk factors for poor graft function in kidney transplant recipients with interstitial fibrosis and tubular atrophy. Renin-angiotensin system blockage with either angiotensin-converting enzyme inhibitors or angiotensin receptor blockers was found to be preventive for interstitial fibrosis and tubular atrophy after kidney transplant. CONCLUSIONS: Preventing prolongation of cold ischemia time, lowering blood cholesterol levels, angiotensin-converting enzyme inhibitors and angiotensin receptor blocker treatment even without existing proteinuria and avoiding higher doses of calcineurin inhibitors should be major approaches in kidney transplant recipients.

Obesity and Loss of Kidney Function: Two Complications to Face for Older Living Kidney Donors.

OBJECTIVES: Although living kidney donors have a minimal lifetime risk of developing end-stage renal disease, long-term complications and physiologic and psychologic sequelae resulting from donation remain unclear because of lack of optimum follow-up after transplant. Here, we evaluated renal function, complications, and physical and mental performance of living kidney donors. MATERIALS AND METHODS: We evaluated 147 patients who donated living kidneys between 1981 and 2012 at Baskent University Hospital. We collected data on donor age, sex, body mass index, smoking status, hypertension before and after nephrectomy, proteinuria, estimated glomerular filtration rate according to the Modification of Diet in Renal Disease formula, and duration after donation. All donors answered the Medical Outcomes Study short-form general health survey; results were evaluated according to answers to 11 questions totaling 22 points. RESULTS: Body mass index of donors showed that 31 (21.1%) were in normal range, 66 (44.9%) had mild obesity (body mass index of 26-30 kg/m²), and 30 (34%) had moderate to high obesity (body mass index > 30 kg/m2). Results from the general health survey showed that 117 donors (80%) had no loss, 13 (9%) had mild loss, 12 (8%) had moderate loss, and 5 (3%) had high loss of ability. When we compared estimated glomerular filtration rates according to donor age, donors who were 18 to 34 years had a mean estimated glomerular filtration rate of 113.5 ± 40, donors 35 to 49 years had a mean rate of 95.01 ± 23.4, donors 50 to 64 years had a mean rate of 87.43 ± 25.4, and donors older than 65 years had a mean rate of 63.76 ± 11.35 mL/min/1.73 m², revealing a statistically significant loss of kidney function with aging (P = .001).. CONCLUSIONS: Careful evaluation of kidney donors before and after donation is essential for the most common risk factors, such as obesity, and for loss of kidney function, especially in older donors.