ascorbic-acid and Renal-Insufficiency--Chronic

Increasingly, chronic kidney disease (CKD) is becoming an inevitable consequence of obesity, metabolic syndrome, and diabetes. As the disease progresses, and through dialysis, the need for and loss of water-soluble vitamins both increase. This review article looks at the benefits and possible risks of supplementing these vitamins with the treatment of CKD.. Data in the PubMed and Embase databases were analyzed. The keywords "chronic kidney disease", in various combinations, are associated with thiamin, riboflavin, pyridoxine, pantothenic acid, folates, niacin, cobalamin, and vitamin C. This review focuses on the possible use of water-soluble vitamin supplementation to improve pharmacological responses and the overall clinical condition of patients.. The mechanism of supportive supplementation is based on reducing oxidative stress, covering the increased demand and losses resulting from the treatment method. In the initial period of failure (G2-G3a), it does not require intervention, but later, especially in the case of inadequate nutrition, the inclusion of supplementation with folate and cobalamin may bring benefits. Such supplementation seems to be a necessity in patients with stage G4 or G5 (uremia). Conversely, the inclusion of additional B6 supplementation to reduce CV risk may be considered. At stage 3b and beyond (stages 4-5), the inclusion of niacin at a dose of 400-1000 mg, depending on the patient's tolerance, is required to lower the phosphate level. The inclusion of supplementation with thiamine and other water-soluble vitamins, especially in peritoneal dialysis and hemodialysis patients, is necessary for reducing dialysis losses. Allowing hemodialysis patients to take low doses of oral vitamin C effectively reduces erythropoietin dose requirements and improves anemia in functional iron-deficient patients. However, it should be considered that doses of B vitamins that are several times higher than the recommended dietary allowance of consumption may exacerbate left ventricular diastolic dysfunction in CKD patients.. Taking into account the research conducted so far, it seems that the use of vitamin supplementation in CKD patients may have a positive impact on the treatment process and maintaining a disease-free condition.

Topics: Ascorbic Acid; Dietary Supplements; Folic Acid; Humans; Kidney Failure, Chronic; Niacin; Renal Dialysis; Renal Insufficiency, Chronic; Thiamine; Vitamin B 12; Vitamin B Complex; Water

Acute kidney injury (AKI) is common among hospitalized patients with Coronavirus Infectious Disease 2019 (COVID-19), with the occurrence of AKI ranging from 0.5% to 80%. The variability in the occurrence of AKI has been attributed to the difference in geographic locations, race/ethnicity, and severity of illness. AKI among hospitalized patients is associated with increased length of stay and in-hospital deaths. Even patients with AKI who survive to hospital discharge are at risk of developing chronic kidney disease or end-stage kidney disease. An improved knowledge of the pathophysiology of AKI in COVID-19 is crucial to mitigate and manage AKI and to improve the survival of patients who developed AKI during COVID-19. The goal of this article is to provide our current understanding of the etiology and the pathophysiology of AKI in the setting of COVID-19.

Topics: Acute Kidney Injury; Anti-Bacterial Agents; Antiviral Agents; Apolipoprotein L1; Ascorbic Acid; Azotemia; COVID-19; COVID-19 Drug Treatment; Cytokines; Disease Progression; Glomerulonephritis; Glomerulonephritis, Membranous; Hospital Mortality; Humans; Kidney Tubules, Proximal; Length of Stay; Myoglobin; Nephritis, Interstitial; Nephrosis, Lipoid; Renal Insufficiency, Chronic; Rhabdomyolysis; SARS-CoV-2; Severity of Illness Index; Thrombotic Microangiopathies; Vitamins

Restless legs syndrome (RLS) is defined as the spontaneous movement of the limbs (mainly legs) associated with unpleasant, sometimes painful sensation which is relieved by moving the affected limb. Prevalence of RLS among people on dialysis has been estimated between 6.6% and 80%. RLS symptoms contribute to impaired quality of life and people with RLS are shown to have increased cardiovascular morbidity and mortality.Various pharmacological and non-pharmacological interventions have been used to treat primary RLS. However, the evidence for use of these interventions in people with chronic kidney disease (CKD) is not well established. The agents used in the treatment of primary RLS may be limited by the side effects in people with CKD due to increased comorbidity and altered drug pharmacokinetics.. The aim of this review was to critically look at the benefits, efficacy and safety of various treatment options used in the treatment of RLS in people with CKD and those undergoing renal replacement therapy (RRT). We aimed to define different group characteristics based on CKD stage to assess the applicability of a particular intervention to an individual patient.. We searched the Cochrane Kidney and Transplant Specialised Register to 12 January 2016 through contact with the Information Specialist using search terms relevant to this review.. Randomised controlled trials (RCT) and quasi-RCTs that assessed the efficacy of an intervention for RLS in adults with CKD were eligible for inclusion. Studies investigating idiopathic RLS or RLS secondary to other causes were excluded.. Two authors independently assessed studies for eligibility and conducted risk of bias evaluation. Results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) and 95% CI for continuous outcomes.. We included nine studies enrolling 220 dialysis participants. Seven studies were deemed to have moderate to high risk of bias. All studies were small in size and had a short follow-up period (two to six months). Studies evaluated the effects of six different interventions against placebo or standard treatment. The interventions studied included aerobic resistance exercise, gabapentin, ropinirole, levodopa, iron dextran, and vitamins C and E (individually and in combination).Aerobic resistance exercise showed a significant reduction in severity of RLS compared to no exercise (2 studies, 48 participants: MD -7.56, 95% CI -14.20 to -0.93; I. Given the small size of the studies and short follow-up, it can only be concluded that pharmacological interventions and intra-dialytic exercise programs have uncertain effects on RLS in haemodialysis patients. There have been no studies performed in non-dialysis CKD, peritoneal dialysis patients, or kidney transplant recipients. Further studies are warranted before any conclusions can be drawn. Aerobic resistance exercise and ropinirole may be suitable interventions for further evaluation.

Topics: Amines; Anticonvulsants; Ascorbic Acid; Cyclohexanecarboxylic Acids; Dopamine Agonists; Exercise Therapy; Gabapentin; gamma-Aminobutyric Acid; Humans; Indoles; Iron-Dextran Complex; Levodopa; Quality of Life; Randomized Controlled Trials as Topic; Renal Insufficiency, Chronic; Renal Replacement Therapy; Resistance Training; Restless Legs Syndrome; Vitamin E; Vitamins

A 69-year-old woman presented with acute kidney failure of unknown cause that ultimately required dialysis. Kidney biopsy revealed the diagnosis of oxalate nephropathy. In retrospect, the patient had several risk factors for this entity, including excessive vitamin C intake, a remote history of Roux-en-Y gastric bypass for weight loss, and chronic kidney disease. This presentation of multiple risk factors for oxalate nephropathy is especially relevant to patients and physicians considering the increase in the United States of vitamin C supplementation use and gastric bypass surgery. It is important for physicians to maintain an awareness of this diagnosis and its risk factors.

Topics: Acute Kidney Injury; Aged; Ascorbic Acid; Biopsy, Needle; Calcium Oxalate; Dose-Response Relationship, Drug; Emergency Service, Hospital; Female; Follow-Up Studies; Gastric Bypass; Humans; Immunohistochemistry; Kidney Function Tests; Renal Dialysis; Renal Insufficiency, Chronic; Risk Assessment; Treatment Outcome

We investigated the effect of two dosing regimens of oral iron on iron status and hematological parameters in patients with CKD. In this single center, open label, randomized, active controlled clinical trial, stable adult patients with CKD stage G3-4 with percentage transferrin saturation (%TSAT) ≤ 30% and serum ferritin ≤ 500 ng/ml were eligible. Participants were randomized to receive either 100 mg of ferrous ascorbate once daily (OD group) or 100 mg of ferrous ascorbate twice daily (BD group, total daily dose 200 mg). The primary outcome was change in %TSAT between groups over 12 weeks. The secondary outcomes were changes in other iron status and hematological parameters, serum interleukin-6 (IL-6) and hepcidin. 80 participants were enrolled out of which 76 completed the study. Change in %TSAT was not significantly different between groups (β = - 1.43, 95% CI - 3.99 to 1.12, BD group as reference). The rise in serum ferritin was less in the OD group as compared to BD group (β = - 0.36, 95% CI - 0.61 to - 0.10) whereas MCHC increased in the OD group as compared to decrease in the BD group (β = 0.37, 95% CI 0.067-0.67). These observations need exploration to ascertain the impact of different oral iron dosing strategies in CKD.

Topics: Adult; Anemia, Iron-Deficiency; Ascorbic Acid; Ferritins; Humans; Iron; Renal Insufficiency, Chronic

Anemia is one of the most frequent and earliest complications of chronic kidney disease (CKD), which impacts a patient’s quality of life and increases the risk of adverse clinical outcomes. Patients’ inflammatory status is strictly related to the occurrence of functional iron deficiency anemia (IDA) because this causes an increase in hepcidin levels with the consequent inhibition of iron absorption and release from cellular stores into blood circulation. The aim of this study was to evaluate the use of the new oral formulation based on ferric sodium EDTA in combination with vitamin C, folic acid, copper gluconate, zinc gluconate, and selenomethionine (Ferachel Forte®) in patients with moderate CKD and functional IDA, analyzing the inflammatory status in addition to iron blood parameters, in comparison with oral ferrous sulfate and liposomal iron therapies. Sixty-two elderly patients were randomly allocated to one of the following oral treatments for 6 months: ferrous sulfate (Group 1; N = 20), ferric sodium EDTA in combination (Group 2; N = 22), and ferric liposomal formulation (Group 3; N = 20). The evaluated parameters included iron profile parameters of hemoglobin (Hb), sideremia, ferritin, transferrin saturation, C-reactive protein (CRP), and hepcidin. The results showed that in Group 1, there were no improvements. In Group 2, there were statistically significant (p < 0.001) improvements in all evaluated parameters. Finally, in Group 3, there were significant improvements in all evaluated parameters except for hepcidin, which was less than that of Group 2 patients. In conclusion, the findings showed the superior efficacy of the formulation based on ferric sodium EDTA over the other oral iron sources, and that this formulation can contribute to reducing the systemic inflammatory status in patients with CKD.

Topics: Aged; Anemia, Iron-Deficiency; Antioxidants; Ascorbic Acid; Edetic Acid; Folic Acid; Gluconates; Hepcidins; Humans; Iron; Quality of Life; Renal Insufficiency, Chronic; Selenomethionine; Sodium; Vitamins

Combined sodium bicarbonate and ascorbic acid could prevent CIN following catheterization in CKD patients.

Topics: Aged; Aged, 80 and over; Ascorbic Acid; Cardiac Catheterization; Contrast Media; Creatinine; Drug Therapy, Combination; Female; Humans; Male; Middle Aged; Nephrosis; Renal Insufficiency, Chronic; Sodium Bicarbonate

To determine the incidence of contrast-induced nephropathy (CIN) and to assess the effectiveness of ascorbic acid in the prevention of CIN after coronary angiography in patients with chronic renal impairment. CIN is the third most common cause of hospital-acquired renal failure. It is well documented that periprocedural hydration is effective in the prevention of CIN. Little data exist on the effectiveness of ascorbic acid, a vitamin with antioxidative action. Patients with stable serum creatinine level >107 μmol/L (n = 81) undergoing coronary angiography were randomized to receive either ascorbic acid (N = 40) or placebo (N = 41) before the procedure. All patients received intravenous volume expansion with normal saline before the procedure. CIN was defined as an increase of serum creatinine level >25% from baseline measured 3 to 4 days after the procedure. CIN occurred totally in 5/81 patients (6.2%); in two patients (3%) in the ascorbic acid group and in three patients (7.3%) in the placebo group (P = 0.512). Postprocedural worsening of renal function (postprocedural increase of serum creatinine level) was present in 10/81 patients (12.3%) in the ascorbic acid group and in 19/81 patients (23.4%) in the placebo group (P = 0.038). No patient required dialysis treatment. We found no statistically significant impact of ascorbic acid on the incidence of CIN in patients with chronic renal impairment undergoing coronary arteriography or angioplasty. Ascorbic acid may still have some protective role in CIN reflected in lower incidence of worsening of renal function in the treated group.

Topics: Aged; Aged, 80 and over; Antioxidants; Ascorbic Acid; Contrast Media; Coronary Angiography; Creatinine; Double-Blind Method; Female; Follow-Up Studies; Humans; Kidney Diseases; Kidney Function Tests; Male; Middle Aged; Prospective Studies; Renal Insufficiency, Chronic; Treatment Outcome

Both vitamin C deficiency and inflammation are prevalent in maintenance hemodialysis (MHD) patients. In this study, we aimed to elucidate the effect of oral vitamin C supplementation on inflammatory status in MHD patients with low vitamin C level and high hypersensitive C-reactive protein (hs-CRP) level.. A total of 128 patients were recruited in our present study. Patients were divided into two groups. In group 1 (n = 67), patients were orally administered with 200 mg/day vitamin C in the first 3 months, and then the vitamin C supplementation was withdrawn in the next 3 months. In group 2 (n = 61), patients were not given vitamin C in the first 3 months, and then they were orally administered with 200 mg/day in the next 3 months. Levels of hs-CRP, prealbumin, albumin and hemoglobin as well as the EPO resistance index (ERI) were determined at the baseline and every 3 months throughout the study. Plasma vitamin C level was determined by high-performance liquid chromatography with UV detection.. Among the 128 patients, 28 of them dropped out of the study before completion. Consequently, a total of 100 patients (group 1: n = 48; group 2: n = 52) were included in the final analysis. At the baseline, the plasma vitamin C level of all patients was less than 4 μg/mL. However, this proportion was decreased to 20% after the vitamin C supplementation for 3 months. Compared with patients without the vitamin C supplementation, a decreased level of hs-CRP and an increased level of prealbumin were induced by the vitamin C supplementation for 3 months in both groups. However, levels of these biomarkers returned to their original state after the supplementation was withdrawn. Same beneficial effects on plasma albumin, hemoglobin and ERI response to vitamin C supplementation were observed in the two groups without statistical significance.. The inflammatory status in MHD patients with plasma vitamin C deficiency and high levels of inflammatory markers could be partially improved by long-term oral administration of small doses of vitamin C.. The clinical trial number: NCT01356433.

Topics: Administration, Oral; Ascorbic Acid; China; Combined Modality Therapy; Comorbidity; Cross-Over Studies; Dietary Supplements; Female; Humans; Male; Middle Aged; Nephritis; Prevalence; Renal Dialysis; Renal Insufficiency, Chronic; Risk Factors; Treatment Outcome

The relationship between dietary total antioxidant capacity (DTAC) and death risk among CKD populations remains unclear.. Our results showed L-shaped associations of DTAC with all-cause mortality among individuals with CKD stages 1-2 in both cohorts. Compared to the lowest quartile, higher dietary total antioxidant intake was associated with lower all-cause mortality risks among CKD stages 1-2 after adjustment for covariates, with HRs (95%CI) of 1.00, 0.91 (0.71,1.17), 0.69 (0.53,0.90), and 0.70 (0.54,0.91) in VCEAC, and similar respective estimate trends in CDAI. After sensitivity and subgroup analyses, there were no benefits for patients with stage 3-5 CKD or albuminuria. Mediation analysis revealed that the proportions mediated in both cohorts were less consistent.. Moderate dietary total antioxidants intake has potential benefits for early-stage CKD patients. However, further evidence is needed to confirm whether patients with worsening CKD can benefit in the long term.

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Mortality; Nutrition Surveys; Renal Insufficiency, Chronic; Retrospective Studies

Vitamin C deficiency is common in chronic kidney disease (CKD) due to losses through dialysis and dietary intake below requirement. We investigated prevalence of vitamin C deficiency and impact of vitamin C treatment in deficient/insufficient patients.. A prospective cohort study in patients aged 1-18 years with CKD stages 4 and 5D collected demographic data including underlying disease, treatment, and anthropometric assessment. Vitamin C intake was assessed using 24-h dietary recall. Hemoglobin, iron status, serum vitamin C, and serum oxalate were measured at baseline and after treatment. Vitamin C (250 mg/day) was given orally for 3 months to deficient/insufficient patients.. Nineteen patients (mean age 12.00 ± 4.1 years) showed prevalence of 10.6% vitamin C insufficiency and 78.9% deficiency. There were no associations between vitamin C level and daily vitamin C intake (p = 0.64) or nutritional status (p = 0.87). Median serum vitamin C was 1.51 (0.30-1.90) mg/L. In 16 patients receiving treatment, median serum vitamin C increased from 1.30 (0.23-1.78) to 3.22 (1.77-5.96) mg/L (p = 0.008) without increasing serum oxalate (79.92 (56.6-106.84) vs. 80.47 (56.88-102.95) μmol/L, p = 0.82). However, 62.5% failed to achieve normal vitamin C levels. Ordinal regression analysis revealed patients with non-oligoanuric CKD were less likely to achieve normal vitamin C levels (β = - 3.41, p = 0.03).. We describe high prevalence of vitamin C insufficiency/deficiency among pediatric CKD patients. Vitamin C levels could not be solely predicted by nutritional status or daily intake. The treatment regimen raised serum vitamin C without increasing serum oxalate; however, it was largely insufficient to normalize levels, particularly in non-oligoanuric CKD. Graphical abstract .

Topics: Adolescent; Ascorbic Acid; Ascorbic Acid Deficiency; Child; Humans; Oxalates; Prevalence; Prospective Studies; Renal Dialysis; Renal Insufficiency, Chronic; Vitamin D; Vitamin D Deficiency; Vitamins

Malnutrition and anorexia are common in children with chronic kidney disease (CKD) and gastrostomy tubes (GT) as well as nasogastric tubes (NGT) have been recommended to maximize nutritional support. The optimal requirement of vitamin C in children with CKD remains to be defined but oxalate is a breakdown product of vitamin C. Elevated vitamin C intake and bone oxalate were identified in two formula-fed dialyzed children with negative genetic testing for primary hyperoxaluria.. We evaluated the impact of nutritional support on serum ascorbic acid and plasma oxalate levels in 13 dialyzed infants and young children.. All patients were fed by GT or NGT since the first months of life; overall patients were receiving between 145 and 847% of the age-specific DRI for vitamin C. Mean serum ascorbic acid and plasma oxalate levels were elevated (244.7 ± 139.7 μM/L and 44.3 ± 23.1 μM/L, respectively), and values did not differ according to the degree of residual kidney function. Ascorbic acid levels did not correlate with oxalate levels (r = 0.44, p = 0.13).. Excessive vitamin C intake may contribute to oxalate accumulation in dialyzed children.

Topics: Ascorbic Acid; Child; Child, Preschool; Humans; Hyperoxaluria; Infant; Kidney Failure, Chronic; Oxalates; Renal Dialysis; Renal Insufficiency, Chronic; Vitamins

Chronic kidney disease and dialysis brings with it a plethora of complications, including malnutrition. Strict dietary restrictions in hemodialysis (HD) patients further complicate the picture as it increases the risk of deficiency of micronutrients, specifically water-soluble vitamins. Today, there is a lack of concrete guidelines concerning recommendations on vitamin supplementation in HD patients. This lack of data is partly due to our incomplete understanding of handling of vitamins in a uremic state. There is a dire need for more data on the impact of dialysis and uremic state on water-soluble vitamins to facilitate appropriate preventative supplementation. We present a case of scurvy in a HD patient that will contribute toward the understanding of vitamin status in HD. We hope it will aid in screening HD patients for vitamin C deficiency and individualizing supplementation of vitamin C.

Topics: Adult; Ascorbic Acid; Humans; Male; Renal Dialysis; Renal Insufficiency, Chronic; Scurvy

This study was planned to evaluate the effect of short term intravenous ascorbic acid on reducing ferritin and erythropoietin resistance in patients of chronic kidney disease (CKD) on maintenance haemodialysis (MHD).. Forty adult patients [20 patients in group A with increased serum ferritin level (>500 ng/ml), transferrin saturation (TSAT) ≤20% and 20 patients in group B with normal serum ferritin level (<200 ng/ml), TSAT ≤20%] of end stage renal disease (ESRD) with erythropoietin hyporesponsiveness undergoing maintenance hemodialysis were included in the study. Group A was given intravenous (i.v.) ascorbic acid in a dose of 500 mg once a week after each 4 hours session of dialysis for 3 weeks in a month (total 1500 mg/month), for a period of 3 months along with erythropoietin 6000 IU subcutaneous (S/C) twice weekly without iron therapy. Group B was given erythropoietin (6000 IU S/C twice weekly after each hemodialysis) and intravenous (IV) iron 100 mg/week for 3 months. Hematological and renal investigations, erythrocyte sedimentation rate (ESR), high sensitivity C-reactive protein (HsCRP), serum ferritin and TSAT were done at baseline and then one monthly intervals for three months whereas intact parathyroid hormone (iPTH) was measured at the start and end of the study.. At the end of 3 months of study, in group A, Hemoglobin (Hb) and TSAT significantly increased while ferritin, HsCRP and erythropoietin resistance index (ERI) decreased significantly. In group B, the increase in Hb and TSAT were not significant statistically while ferritin increased significantly and fall in HsCRP and ERI were not significant statistically. The mean rise in Hb between subsequent months was higher in group A as compared to group B.. Short term i.v ascorbic acid could be a new successful adjuvant in reducing ferritin and erythropoietin resistance and enhancing Hb and TSAT in CKD patients on MHD.

Topics: Antioxidants; Ascorbic Acid; Drug Resistance; Erythropoietin; Female; Ferritins; Humans; Male; Middle Aged; Renal Dialysis; Renal Insufficiency, Chronic

Chronic kidney disease (CKD) is a group of heterogeneous abnormalities affecting the function and structure of the kidney and mostly further proceeds to cardiovascular damage prior to end stage renal disease (ESRD). The oxidative insult and inflammatory mediators have some undefined role in CKD and cardiovascular complications. It is therefore, aimed at to pin point the predictive factors in the development of cardiovascular disorder in patients with chronic kidney disease.. Fifty patients of CKD experiencing cardiovascular distress and twenty normal individuals having same age and sex acted as control during these observations. Blood samples (Each 5 ml) were drawn and subjected to centrifugation for 10-15 minutes to separate the serum at 4000-5000rpm. The levels of MDA, GSH, SOD, CAT, VIT C, VIT E, IL-1, TNF-alpha, nitric oxide (NO) and advanced oxidation protein products (AOPPs) were estimated and analyzed.. The nitric oxide levels in the CKD patients decreased significantly (13.26±1.25 ng/ml) compared to controls (42.15±5.26 ng/ml). The serum vitamin E and C levels in these patients recorded 2.15±0.25 μg/ml and 0.97±0.09 μg/ml respectively as against their assigned controls which read 6.35±1.22 μg/ml and 3.29±0.25 μg/ml. Furthermore, a significantly higher level of Malondialdehyde (MDA) as1.25±0.07 nmol/ml was observed in CKD patients viz-a-viz relevant control. However, the serum SOD, catalase (CAT) and GSH levels in the same patients registered a significant decline as evident from respective figures 0.07±0.002 μg/dl, 1.22±0.012 μmol/mol, and 3.25±1.05 μg/dl. The control for these was observed as0.99±0.06 μg/dl, 3.19±0.05 μmol/mol, and 8.64±0.03 μg/dL. On the other hand, the IL-1 levels in the CKD patients found quite higher (402.5±18.26 pg/ml). This clearly points to substantial increase in oxidative insult and reduced NO levels leading to the renal and cardiovascular damage.. Observations support the fact that the decrease in anti-oxidative capacity accompanied by higher inflammatory mediators in CKD is indicative of oxidative stress, consequently leading to CKD progression, in all probability to cardiovascular insult. The outcome reiterates that strategies be designed afresh to contain CKD progression to cardiovascular complications and ESRD. One way could be to focus on early detection of stress related to the disease. It requires analyzing the factors related to stress, such as the one reported here. Linking these factors with the symptoms could be a crucial step forward. And further, the disease could be monitored in a more disciplined manner.

Topics: Advanced Oxidation Protein Products; Ascorbic Acid; Biomarkers; Cardiovascular Diseases; Case-Control Studies; Cytokines; Female; Humans; Inflammation Mediators; Male; Malondialdehyde; Nitric Oxide; Oxidation-Reduction; Oxidative Stress; Renal Insufficiency, Chronic; Superoxide Dismutase; Vitamin E

Functional iron deficiency (FID) is a major cause of persistent anemia in dialysis patients and also contributes to a suboptimal response to erythropoietin (Epo) administration. Vitamin C acts as an enzyme cofactor and enhances mobilization of the ferrous form of iron to transferrin thus increasing its bioavailability. High-dose intravenous vitamin C has been shown to decrease the Epo requirement and improve hemoglobin levels in previous studies. This study assessed the effect of low-dose oral vitamin C on possible reduction in Epo dose requirements in stable hemodialysis patients with FID.. This prospective study included 22 stable hemodialysis patients with FID defined as transferrin saturation (T sat) <30 % and ferritin levels of >100 mcg/L with Epo requirement of ≥4000 U/HD session. Patients received oral vitamin C 250 mg daily for 3 months. Hemoglobin, iron and T sat levels were recorded monthly. No one received iron supplementation during the study period.. There was a significant reduction in median Epo dose requirement in the 15 patients who completed the study, from 203.1 U/kg/week (95 % CI 188.4-270.6) to 172.8 U/kg/week (95 % CI 160.2-214.8), (P = 0.01). In the seven responders, there was 33 % reduction in Epo dose from their baseline. Despite adjustment of Epo dose, the mean hemoglobin level was significantly increased from 10.1 ± 0.6 to 10.7 ± 0.6 mg/dL (P = 0.03). No adverse effects of oral vitamin C were observed.. Daily low-dose oral vitamin C supplementation reduced Epo dose requirements in hemodialysis patients with FID. Limitations of this study include a small sample size and the lack of measurements of vitamin C and oxalate levels. Despite concerns regarding oral vitamin C absorption in dialysis patients, this study indicates vitamin C was well tolerated by all participants without reported adverse effect.

Topics: Administration, Oral; Adult; Aged; Ascorbic Acid; Dietary Supplements; Erythropoiesis; Erythropoietin; Female; Ferritins; Hemoglobins; Humans; Iron; Iron Deficiencies; Male; Middle Aged; Prospective Studies; Renal Dialysis; Renal Insufficiency, Chronic; Transferrin; Vitamins

The safety of polyethylene glycol plus ascorbic acid has not been fully investigated in patients with renal insufficiency. High-dose ascorbic acid could induce hyperoxaluria, thereby causing tubule-interstitial nephritis and renal failure. This study aims to evaluate the safety and efficacy of polyethylene glycol plus ascorbic acid in patients with chronic kidney disease.We retrospectively reviewed prospectively collected data on colonoscopy in patients with impaired renal function. Patients were divided into 2 groups: 2 L polyethylene glycol plus ascorbic acid (n = 61) and 4 L polyethylene glycol (n = 80). The safety of the 2 groups was compared by assessing the differences in laboratory findings before and after bowel cleansing.The laboratory findings were not significantly different before and after the administration of 2 L polyethylene glycol plus ascorbic acid or 4 L polyethylene glycol. In both groups, the estimated glomerular filtration rate was not influenced by the administration of the bowel-cleansing agent. Patients' reports on tolerance and acceptability were better in the 2 L polyethylene glycol plus ascorbic acid group than in the 4 L polyethylene glycol group.The 2 L polyethylene glycol plus ascorbic acid solution is a safe choice for bowel preparation before colonoscopy in patients with impaired renal function.

Topics: Aged; Ascorbic Acid; Cathartics; Colonoscopy; Female; Humans; Male; Middle Aged; Polyethylene Glycols; Renal Insufficiency, Chronic; Retrospective Studies

Mesenchymal stem cells (MSCs) have been shown to improve the outcome of acute renal injury models; but whether MSCs can delay renal failure in chronic kidney disease (CKD) remains unclear. In the present study, the were cultured in media containing various concentrations of basic fibroblast growth factor, epidermal growth factor and ascorbic acid 2-phosphate to investigate whether hepatocyte growth factor (HGF) secretion could be increased by the stimulation of these growth factors. Then, TGF-β1-treated renal interstitial fibroblast (NRK-49F), renal proximal tubular cells (NRK-52E) and podocytes were co-cultured with conditioned MSCs in the absence or presence of ascorbic acid 2-phosphate to quantify the protective effects of conditioned MSCs on renal cells. Moreover, male Sprague-Dawley rats were treated with 1 × 10(6) conditioned MSCs immediately after 5/6 nephrectomy and every other week through the tail vein for 14 weeks. It was found that basic fibroblast growth factor, epidermal growth factor and ascorbic acid 2-phosphate promoted HGF secretion in MSCs. Besides, conditioned MSCs were found to be protective against TGF-β1 induced epithelial-to-mesenchymal transition of NRK-52E and activation of NRK-49F cells. Furthermore, conditioned MSCs protected podocytes from TGF-β1-induced loss of synaptopodin, fibronectin induction, cell death and apoptosis. Rats transplanted with conditioned human MSCs had a significantly increase in creatinine clearance rate, decrease in glomerulosclerosis, interstitial fibrosis and increase in CD4(+)CD25(+)Foxp3(+) regulatory T cells counts in splenocytes. Together, our studies indicated that conditioned MSCs preserve renal function by their anti-fibrotic and anti-inflammatory effects. Transplantation of conditioned MSCs may be useful in treating CKD.

Topics: Animals; Apoptosis; Ascorbic Acid; CD4-Positive T-Lymphocytes; Cells, Cultured; Coculture Techniques; Creatinine; Disease Progression; Epidermal Growth Factor; Epithelial-Mesenchymal Transition; Female; Fibroblast Growth Factor 2; Fibronectins; Fibrosis; Glomerulosclerosis, Focal Segmental; Hepatocyte Growth Factor; Humans; Kidney; Kidney Tubules, Proximal; Lymphocyte Count; Male; Mesenchymal Stem Cell Transplantation; Mesenchymal Stem Cells; Microfilament Proteins; Middle Aged; Nephrectomy; Podocytes; Rats; Rats, Sprague-Dawley; Renal Insufficiency, Chronic; Transforming Growth Factor beta1; Young Adult

A decreased plasma level of vitamin C has been reported to be associated with an increased risk of cardiovascular morbidity and mortality. Here, we sought to determine the vitamin C status of patients with chronic kidney disease and the pathophysiological role of vitamin C in these patients.. We studied 58 patients and evaluated the relationship between renal function and plasma vitamin C concentration, as well as the effect of diabetes on this relationship. Endothelium-dependent flow-mediated dilation of brachial artery was measured to assess the endothelial function. Serum malondialdehyde low-density lipoprotein was measured as a marker for oxidative stress.. Plasma vitamin C concentration had a positive linear relationship with eGFR in both diabetic and non-diabetic patients (P = 0.006 and P = 0.004, respectively). When vitamin C concentration and eGFR relationships were compared in the two groups, vitamin C concentration was significantly lower in diabetic patients at every eGFR (P = 0.006). Flow-mediated vasodilatation of the brachial artery was positively correlated with vitamin C concentration in non-diabetic patients (P = 0.047) but not in diabetic patients. There was a negative correlation between serum malondialdehyde low-density lipoprotein and vitamin C concentration in non-diabetic patients (P = 0.044) but not in diabetic patients.. Renal dysfunction was associated with a decrease in plasma vitamin C level. Moreover, decreased vitamin C may cause endothelial dysfunction via an increase in oxidative stress in non-diabetic chronic kidney disease patients.

Topics: Aged; Aged, 80 and over; Antioxidants; Ascorbic Acid; Ascorbic Acid Deficiency; Diabetes Mellitus, Type 2; Female; Humans; Kidney Function Tests; Male; Middle Aged; Prognosis; Renal Insufficiency, Chronic

We sought to determine whether oxidative stress or a relative deficit of l-arginine plays a role in reducing cutaneous vasodilation in response to local heating in chronic kidney disease (CKD). Eight patients with stage 3-4 CKD and eight age- and sex-matched healthy control (HC) subjects were instrumented with four microdialysis (MD) fibers for the local delivery of 1) Ringers solution (R), 2) 20 mM ascorbic acid (AA), 3) 10 mM l-arginine (l-Arg), and 4) 10 mM N(G)-nitro-l-arginine methyl ester (l-NAME). Red blood cell (RBC) flux was measured via laser Doppler flowmetry. A standardized nonpainful local heating protocol (42°C) was used. Cutaneous vascular conductance (CVC) was calculated as RBC flux/MAP and all data were expressed as a percentage of the maximum CVC at each site (28 mM sodium nitroprusside, T(loc) = 43°C). The plateau %CVC(max) was attenuated in CKD (CKD: 76 ± 4 vs. HC: 91 ± 2%CVC(max); P < 0.05) and the NO contribution to the plateau was lower in CKD (CKD: 39 ± 7, HC: 54 ± 5; P < 0.05). The plateau %CVC(max) in the CKD group was significantly greater at the AA and l-Arg sites compared with R (AA: 89 ± 2; l-Arg: 90 ± 1; R: 76 ± 4; P < 0.05) and did not differ from HC. Initial peak %CVC(max) was also significantly attenuated at the R and l-Arg sites in CKD (P < 0.05) but did not differ at the AA site. These results suggest that cutaneous microvascular function is impaired in stage 3-4 CKD and that oxidative stress and a deficit of l-arginine play a role in this impairment.

Topics: Adult; Arginine; Ascorbic Acid; Case-Control Studies; Female; Hot Temperature; Humans; Male; Microcirculation; Microdialysis; Middle Aged; Nitric Oxide; Oxidative Stress; Renal Insufficiency, Chronic; Skin; Vasodilation

Topics: Arginine; Ascorbic Acid; Body Temperature; Diabetes Mellitus, Type 2; Female; Heat Stress Disorders; Humans; Male; Microcirculation; Nitric Oxide; Renal Insufficiency, Chronic; Skin; Vasodilation

Topics: Adult; Androgens; Anemia; Ascorbic Acid; Blood Cell Count; Blood Transfusion; Carnitine; Contraindications; Erythropoietin; Female; Ferritins; Hemoglobins; Humans; Iron; Male; Recombinant Proteins; Renal Dialysis; Renal Insufficiency, Chronic; Vitamins

Topics: Adolescent; Androgens; Anemia; Ascorbic Acid; Blood Cell Count; Blood Transfusion; Carnitine; Child; Child, Preschool; Contraindications; Erythropoietin; Ferritins; Hemoglobins; Humans; Infant; Infant, Newborn; Iron; Recombinant Proteins; Renal Dialysis; Renal Insufficiency, Chronic; Vitamins