Hyponatremia: Is it related to the seasons?

BACKGROUND: Hyponatremia is a common electrolyte disorder in inpatients related to morbidity and mortality. In this study, we aimed to examine whether there is a relationship between the incidence of hyponatremia and the seasons among the patients hospitalized in our nephrology department. METHODS: The inpatients in our Nephrology Department between 2012 and 2015 were retrospectively analyzed. The patients with serum sodium levels below 135 mmol/L were included in the study. Hyponatremia incidence was calculated as the proportion of inpatients with low sodium levels in a season to the total number of inpatients in the same season. RESULTS: Out of 1950 inpatients in four years, 509 were found to have hyponatremia (26.1%). The mean serum sodium level of the patients was 129.7±4.7 mmol/L. Hyponatremia incidences in autumn, winter, spring, and summer were found to be 28.7%, 15.4%, 20.4%, and 36.6%, respectively. Upon comparing the incidence of hyponatremia in patients hospitalized in winter and summer seasons, there was a significantly higher incidence of hyponatremia in summer (p<0.001). We found a positive correlation between hyponatremia incidence and temperature (r=0.867, p=0.001). However, there was a negative correlation between hyponatremia incidence and relative humidity (r=-0.735, p=0.001). CONCLUSIONS: The highest hyponatremia incidence was observed in summer in a four-year period. Loss of sodium by perspiration, along with increased temperature and/or excessive hypotonic fluid intake, might contribute to the development of hyponatremia.

Telomerase activity in patients with stage 2-5D chronic kidney disease.

BACKGROUND: Molecular mechanisms of increased cardiovascular mortality in chronic kidney disease (CKD) associated with biological age are not well understood. Recent studies support the hypothesis that common factors responsible for this phenomenon are cellular aging and telomere dysfunction. OBJECTIVES: The purpose of this study was to investigate the relation between telomerase activity and CKD stages. METHODS: The study included 120 patients who were followed-up for CKD stage 2-5D, composed of 30 patients of each stage and 30 healthy volunteers without any known disease who were admitted to our hospital for routine check-ups. Telomerase activity in peripheral blood mononuclear cells (PBMC) was measured using the TRAP assay. RESULTS: A significant difference was observed for telomerase activity in PBMC between groups. The detected levels were lowest in the healthy control group (0.15±0.02), and highest in CKD stage 5D patients (0.23±0.04). In CKD patients, telomerase activity in PBMC was positively correlated with the CKD stage, serum creatinine, potassium and parathormone levels, and negatively correlated with estimated glomerular filtration rate (eGFR), body mass index (BMI), platelet count and serum calcium levels. According to the linear regression analysis, independent predictors for high telomerase activity in CKD patients were eGFR and BMI. CONCLUSION: Telomerase activity in PBMC increases with advancing CKD stage in CKD patients. Increased telomerase activity in PBMC is associated with eGFR and BMI.

Manganese superoxide dismutase, glutathione peroxidase and catalase gene polymorphisms and clinical outcomes in acute kidney injury.

INTRODUCTION: The aim of this study was to evaluate the potential association of single gene polymorphisms of manganese superoxide dismutase (MnSOD), glutathione peroxidase 1 (GPX1) and catalase (CAT) with clinical outcomes of acute kidney injury (AKI). MATERIALS AND METHODS: Ninety AKI patients and 101 healthy volunteers were included in the study. Determination of MnSOD rs4880, GPX1 rs1050450 and CAT rs769217 polymorphisms was performed using real-time polymerase chain reaction amplification. The duration of hospitalization of AKI patients, dialysis and intensive care requirements, sepsis, oliguria and in-hospital mortality rates were assessed. RESULTS: The MnSOD, GPX1 and CAT genotypes and allele frequencies of AKI patients did not differ significantly from those of healthy controls. In patients with a T allele in the ninth exon of the CAT gene, intensive care requirements were greater than those of patients with the CC genotype (p = 0.04). In addition, sepsis and in-hospital mortality were observed significantly more frequently in patients with a T allele in the ninth exon of the CAT gene (p = 0.03). Logistic regression analysis determined that bearing a T allele was the primary determinant of intensive care requirements and in-hospital mortality, independent of patient age, gender, presence of diabetes and dialysis requirements (OR 6.10, 95% CI 1.34-27.81, p = 0.02 and OR 10.25, 95% CI 1.13-92.80, p = 0.04, respectively). CONCLUSION: Among AKI patients in the Turkish population, hospital morbidity and mortality were found to be more frequent in patients bearing a T allele of the rs769217 polymorphism of the CAT gene.

Protective Effects of Caffeic Acid Phenethyl Ester on Cyclophosphamide-Induced Hemorrhagic Cystitis in Rats.

We investigated the protective effect of caffeic acid phenethyl ester (CAPE) on cyclophosphamide-induced hemorrhagic cystitis in rats in comparison with 2-mercaptoethane sulfonate (MESNA). Forty male rats were randomized into four groups: group 1 (control), group 2 (cyclophosphamide), group 3 (cyclophosphamide + MESNA), group 4 (cyclophosphamide + CAPE). Cyclophosphamide injection increased malondialdehyde levels indicating oxidative stress, whereas CAPE and MESNA ameliorated malondialdehyde levels in the bladder (p < 0.05). Only catalase activities were decreased significantly in both groups (cyclophosphamide + MESNA and cyclophosphamide + CAPE, p < 0.05). Pretreatment with CAPE (p < 0.01) resulted in a significant decrease in nitric oxide levels when compared with the cyclophosphamide group. When we consider the studies that show the critical importance of increased nitric oxide levels in pathogenesis of cyclophosphamide-induced hemorrhagic cystitis, we suggest that it would be more beneficial to use MESNA with CAPE to prevent histological damage.

Effect of cholecalciferol replacement on vascular calcification and left ventricular mass index in dialysis patients.

OBJECTIVE: The aim of this study was to determine the effect of oral cholecalciferol treatment on vascular calcification, left ventricular mass index (LVMI) and other cardiac functions in dialysis patients. DESIGN AND METHODS: A six-month course of oral cholecalciferol treatment was recommended to dialysis patients with vitamin D insufficiency. While 26 patients were given cholecalciferol treatment, 17 patients who could not tolerate to therapy received standard therapy. Initial biochemical parameters were measured, and they were measured again after 6 months of treatment. Echocardiographic measurements were also performed, and the vascular calcification score (VCS) was calculated at baseline and at the 6th month. RESULTS: The cholecalciferol replacement group showed no significant change in LVMI and VCS values (p > 0.05). However, while LVMI was similar between groups at initial evaluation, it was lower in the cholecalciferol group at the 6th month when compared to the standard treatment group (141.8 ± 40.2 g/m(2) vs. 166.3 ± 31.4 g/m(2); p = 0.04). Likewise, left ventricular diastolic diameters (48.8 ± 5.1 mm vs. 47.5 ± 4.6 mm; p = 0.023) and left atrial diameters (41.2 ± 8.9 mm vs. 38.9 ± 8.1 mm; p = 0.006) decreased in the cholecalciferol group. Additionally, significant increases were observed in serum 25-hydroxyvitamin D (25(OH)D) and albumin levels, with a significant decrease in serum C-reactive protein levels. CONCLUSION: A lesser increase in left ventricular mass and better diastolic functions was observed in dialysis patients after 6 months of cholecalciferol treatment.

Sexual dysfunction in dialysis patients: does vitamin D deficiency have a role?

INTRODUCTION: Sexual dysfunction and vitamin D deficiency are highly prevalent in dialysis patients. Low levels of vitamin D have been linked to many diseases. To the best of our knowledge, the relationship between vitamin D and sexual dysfunction in dialysis patients has not been previously reported in the literature. MATERIALS AND METHODS: Cholecalciferol, 50,000 IU/week, was orally administered to 37 dialysis patients with vitamin D insufficiency for 3 months followed by dosage of 10,000 IU every other week for 3 months. The Arizona Sexual Experiences Scale (ASEX), Hospital Anxiety and Depression Scale and Pittsburgh Sleep Quality Index questionnaires were filled out by all patients at baseline and at the sixth month of the study. RESULTS: Sexual dysfunction, poor sleep quality, anxiety and depression rates were 83.7%, 45.9%, 18.9% and 48.6%, respectively in all patients. ASEX total score was found to be positively correlated with age and was negatively correlated with serum 25(OH)D level and serum albumin level. After cholecalciferol treatment, 25(OH)D levels increased significantly, however no significant change was observed in any of the parameters. In multivariate linear regression analysis, age and 25(OH)D level were found to be independent predictors of ASEX total score. CONCLUSIONS: Vitamin D deficiency seems to contribute to sexual dysfunction in dialysis patients. However, it was observed in this study that; cholecalciferol replacement given to dialysis patients with vitamin D insufficiency did not result in any significant changes in sexual functions.

The effects of allopurinol on metabolic acidosis and endothelial functions in chronic kidney disease patients.

BACKGROUND: Hyperuricemia and metabolic acidosis have emerged as important risk factors for progression of kidney disease. In this study, we aimed to investigate the effects of allopurinol on metabolic acidosis and endothelial functions in hyperuricemic stage 2-4 chronic kidney disease (CKD) patients. METHODS: Thirty patients with stage 2-4 CKD and serum uric acid levels over 5.5 mg/dl were included in the study group. They were prescribed 300 mg/day per oral allopurinol treatment for three months. Age- and gender-matched CKD patients (n = 30) with similar clinical characteristics were taken as the control group and were not given allopurinol treatment. Endothelial functions were measured via flow-mediated dilatation (∆FMD %) over the forearm. pH and HCO3 levels in venous blood, Cr clearance and proteinuria levels were calculated in all patients at baseline and in the third month. RESULTS: Serum uric acid levels significantly decreased in the study group from 7.9 ± 1.6 to 6.4 ± 1.7 (p < 0.001). Cr clearance (from 43.4 ± 20.1 to 51.4 ± 24.9, p = 0.011), serum bicarbonate levels (from 21.4 ± 3.4 to 23.0 ± 3.4, p = 0.007) and ΔFMD % values (from 5.8 ± 2.5 to 6.2 ± 2.7, p = 0.006) increased significantly in the allopurinol group. There were no significant changes except for ∆FMD % values (decreased from 6.27 ± 1.62 to 5.71 ± 1.90, p = 0.005) in the control group. ∆FMD % variations within the two groups were clearly significant in the repeated ANOVA general linear model. CONCLUSION: We assume that decreasing uric acid levels with allopurinol treatment seems to be helpful in restoring endothelial functions, preventing metabolic acidosis and slowing down the progression of CKD.

Caffeic acid phenethyl ester protects against amphotericin B induced nephrotoxicity in rat model.

The present study was conducted to investigate whether caffeic acid phenethyl ester (CAPE), an active component of propolis extract, has a protective effect on amphotericin B induced nephrotoxicity in rat models. Male Wistar-Albino rats were randomly divided into four groups: (I) control group (n = 10), (II) CAPE group (n = 9) which received 10 µmol/kg CAPE intraperitoneally (i.p.), (III) amphotericin B group (n = 7) which received one dose of 50 mg/kg amphotericin B, and (IV) amphotericin B plus CAPE group (n = 7) which received 10 µmol/kg CAPE i.p. and one dose of 50 mg/kg amphotericin B. The left kidney was evaluated histopathologically for nephrotoxicity. Levels of malondialdehyde (MDA), nitric oxide (NO), enzyme activities including catalase (CAT), and superoxide dismutase (SOD) were measured in the right kidney. Histopathological damage was prominent in the amphotericin B group compared to controls, and the severity of damage was lowered by CAPE administration. The activity of SOD, MDA, and NO levels increased and catalase activity decreased in the amphotericin B group compared to the control group (P = 0.0001, P = 0.003, P = 0.0001, and P = 0.0001, resp.). Amphotericin B plus CAPE treatment caused a significant decrease in MDA, NO levels, and SOD activity (P = 0.04, P = 0.02, and P = 0.0001, resp.) and caused an increase in CAT activity compared with amphotericin B treatment alone (P = 0.005). CAPE treatment seems to be an effective adjuvant agent for the prevention of amphotericin B nephrotoxicity in rat models.

The effect of biocompatible peritoneal dialysis solutions on neutrophil to lymphocyte ratio.

INTRODUCTION: Long-term exposure to dialysis solutions is an important contributor to the ongoing inflammatory process in peritoneal dialysis (PD) patients. Some studies have shown amelioration of this adverse effect with biocompatible solutions. We aimed to compare the neutrophil-to-lymphocyte (N/L) ratio in PD patients using biocompatible and standard solutions and to find out the association between N/L ratio and peritonitis indices. MATERIALS AND METHODS: This was a cross-sectional, multicenter study involving 120 prevalent PD patients. Seventy-one patients (59%) were using biocompatible solutions and 49 patients (41%) were using standard solutions. From blood samples, N/L ratio and platelet-to-lymphocyte ratio were calculated and mean platelet volume, erythrocyte sedimentation rate and hs-CRP values were detected. Data regarding the peritonitis rate and time to first peritonitis episode were also recorded. RESULTS: Biocompatible and standard groups were similar regarding age and gender. N/L ratio and hs-CRP levels have been found significantly higher in patients using biocompatible solutions (3.75 ± 1.50 vs. 3.27 ± 1.3, p = 0.04 and 3.2 ± 2.5 vs. 1.8 ± 2.0, p < 0.01, respectively). Peritonitis rates and time to the first peritonitis episode were found similar in patients using both types of solutions (0.23 ± 0.35 vs. 0.27 ± 0.32, p = 0.36 and 32.8 ± 35.8 vs. 21.5 ± 26.9 months, p = 0.16, respectively). DISCUSSION: N/L ratio was significantly higher in biocompatible solution users in parallel to hs-CRP levels, so biocompatible solutions seem to be related with increased inflammation in PD patients. Although we cannot make a certain explanation, we assume that there may be an association between acidity of the peritoneal content and virulence of microorganisms.

Associations between serum hepcidin level, FGF-21 level and oxidative stress with arterial stiffness in CAPD patients.

BACKGROUND: Patients on continuous ambulatory peritoneal dialysis (CAPD) and hemodialysis have accelerated atherosclerosis associated with an increase in cardiovascular morbidity and mortality. Atherosclerosis is associated with increased arterial stiffness (AS), endothelial dysfunction and elevated oxidative stress (OS) and inflammation. We aimed to investigate the relationship between oxidative stress status, arterial stiffness, hepcidin and fibroblast growth factor-21 (FGF-21) levels in CAPD patients. METHODS: As a prospective observational study, we analyzed 56 CAPD patients, aged between 30 and 63 years. Serum hepcidin, FGF-21 levels, OS status and AS were determined. Arterial stiffness was measured by flow-mediated dilatation (FMD). Oxidative stress status was determined by total antioxidant status, total oxidant status (TOS) and oxidative stress index (OSI). RESULTS: FMD was negatively correlated with TOS, OSI, hepcidin and FGF-21 (r: -0.313, p: 0.020; r: -0.0331, p: 0.014; r: -0.498, p < 0.001; r: -0.403, p: 0.002, respectively). OSI was positively correlated with hepcidin, parathormone and negatively correlated with FMD (r: 0.278, p: 0.040; r: 0.462, p < 0.001; r: -0.0331, p: 0.014, respectively). CONCLUSION: There are many factors affecting arterial stiffness in CAPD patients. In our study, higher levels of OS status, hepcidin and FGF-21 were independent determinants of arterial stiffness in PD patients. Therefore, definition and improvement of these new parameters will be helpful to reduce the cardiovascular disease risk and mortality in CAPD patients.

Utility of serum creatinine/cystatin C ratio in diagnosis of postrenal acute kidney injury.

BACKGROUND: In obstructive uropathy, despite a severe increase in the serum creatinine (Cr) levels, only a mild cystatin C (CysC) increase was previously reported. Therefore, we aimed to determine the availability of serum Cr/CysC ratio in predicting postrenal acute kidney injury (AKI). MATERIALS AND METHODS: This was a cross-sectional study involving 61-adult patients with heterogeneous AKI cases. Patients with bilateral pelvicalyceal dilatation in renal sonography were considered as postrenal AKI group (n = 15) and others were intrinsic AKI group (n = 46). Venous blood sampling for blood urea nitrogen, Cr and CysC measurements were performed on admission. RESULTS: The mean age of study population was 66.3 ± 15.5 years; 38 (62%) of which were male. Two groups were similar regarding age, gender, and comorbidities. Cr/CysC ratio was significantly higher in postrenal AKI group (6.9 ± 3.1 vs. 4.4 ± 2.1, P = 0.007). CONCLUSION: We suggest that serum Cr/CysC ratio seems to be a useful diagnostic tool for detection of postrenal AKI cases, especially for the cases without definite hydronephrosis.

Malnutrition-inflammation score and endothelial dysfunction in hemodialysis patients.

OBJECTIVE: The aim of this study was to find out the relationship between Malnutrition-Inflammation score (MIS) and the endothelial function parameters, including measurements of flow-mediated vasodilatation (FMD) in the brachial artery and serum vascular cell adhesion molecule-1 (VCAM-1). Furthermore, predictors of FMD were also assessed. MATERIALS AND METHODS: A total of 70 anuric hemodialysis patients were enrolled in this cross-sectional study. Measurements of FMD, serum VCAM-1, oxidized low density lipoprotein cholesterol (oxLDL) were done before the mid-week dialysis session from all participants at the time of MIS calculation. Patients were divided into 3 groups according to MIS (the MIS was ≤4 in group I, 4< and ≤7 in group II, and >7 in group III) and compared for above parameters. RESULTS: Patients with higher MIS had higher serum high sensitive C-reactive protein, oxLDL and VCAM-1 levels whereas these patients had lower serum albumin, hemoglobin levels, and FMD rates. MIS was positively correlated with high sensitive C-reactive protein, oxLDL and VCAM-1 levels. However, there was a negative correlation between MIS and FMD. MIS and oxLDL were found as an independent significant predictors of FMD (P = .014 and P = .018, respectively) in a multivariate analysis. CONCLUSIONS: MIS is a useful tool in prediction of the severity of endothelial dysfunction. Furthermore, decrease in MIS by the modifiable parameters and also treatment of oxLDL could be expected to improve endothelial dysfunction in hemodialysis patients.