beta-carotene and Kidney-Failure--Chronic

Oxidative stress may contribute to the progression of chronic renal failure. In this study, cats with spontaneous renal insufficiency were fed a dry cat food supplemented with the antioxidants vitamins E and C, and beta-carotene for 4 weeks. When compared with healthy cats, cats with renal insufficiency had a tendency to oxidative stress. The antioxidant supplements significantly reduced DNA damage in cats with renal insufficiency as evidenced by reduced serum 8-OHdG and comet assay parameters. Therefore, supplements of vitamins E and C and beta-carotene as antioxidants may be beneficial to cats with renal disease.

Topics: Animal Feed; Animals; Antioxidants; Ascorbic Acid; beta Carotene; Biomarkers; Blood Urea Nitrogen; Cat Diseases; Cats; Creatinine; Cross-Over Studies; Dietary Supplements; Female; Kidney Failure, Chronic; Male; Oxidative Stress; Phosphorus; Vitamin E

Establish and compare the safety and tolerance of three medical nutritional products when used as sole sources of nutrition in stable hemodialysis patients.. Prospectively randomized, controlled, single blind, parallel design.. Three outpatient hemodialysis clinics.. Seventy-nine normally nourished, stable, anuric, adequately dialyzed, adult outpatients with end-stage renal disease (ESRD) and requiring thrice weekly hemodialysis.. A 3-week trial was conducted. During the first week, baseline medical history and physical examination, gastrointestinal symptom, urea kinetic, bowel habit, and biochemical data were collected while participants ingested their usual diet. During the last 2 weeks, the same data were collected while participants orally ingested 35 kcal/kg actual weight/d of one of three medical nutritional products as a sole source of nutrition. Products were a standard medical nutritional (EN-9527) and two renal nutritionals (EN-9528 and EN-9529). The latter product was a reformulation of EN-9528 and contained added beta-carotene and fructooligosaccharides.. Gastrointestinal symptoms, bowel habits (stool frequency and consistency), routine blood chemistries, urea kinetics, and normalized protein catabolic rate (nPCR) RESULTS: All three groups achieved a mean energy and protein intake of approximately 35 kcal/kg/d and 1.25 g protein/kg/d during the last 10 days of the sole source feeding period. Adherence with the formula ingestion targets was assessed using both a patient-completed product consumption log and nPCR. By intent to treat analysis, there were no changes in number or severity of gastrointestinal symptoms, stool frequency or stool consistency, or urea kinetics between the baseline week and during product consumption. In comparison to the standard formulation, the disease-specific formulations resulted in improved serum phosphorus and calcium-phosphorus product. Patients receiving the fructooligosaccharide-containing product (EN-9529), by Chi-squared analysis, had less constipation than for the comparable product without oligosaccharides (EN-9528) or the standard medical nutritional (EN-9527).. Use of enteral nutritionals as a sole source of nutrition is both possible and well tolerated in hemodialyzed patients. Selection of a disease-specific formulation offered advantages over a standard formulation in the management of biochemical complications of renal disease when the products were used as a sole source of nutrition.

Topics: beta Carotene; Blood Urea Nitrogen; Calcium; Dietary Proteins; Energy Intake; Enteral Nutrition; Female; Food, Formulated; Fructose; Gastrointestinal Diseases; Humans; Kidney Failure, Chronic; Male; Middle Aged; Oligosaccharides; Phosphorus; Prospective Studies; Proteins; Renal Dialysis

Several small clinical studies have reported that serum vitamin A levels were higher but serum vitamin C levels were lower among patients with end-stage renal disease. However, the relationship of antioxidant vitamins to renal function has not been studied in the general population. We examined the relationship of serum antioxidant vitamin levels to serum creatinine levels and risk for hypercreatininemia in a representative sample of 6,629 non-Hispanic whites, 4,411 non-Hispanic blacks, and 4,480 Mexican Americans aged 18 years or older who participated in the Third National Health and Nutrition Examination Survey. Serum antioxidant vitamins were measured by isocratic high-performance liquid chromatography, and serum creatinine levels, by the modified kinetic Jaffé method. Serum vitamin A level was positively and significantly associated with serum creatinine level, whereas serum vitamin C level was inversely and significantly associated with serum creatinine level. A one-SD higher level of serum vitamin A (16.9 microg/dL) was associated with a 2.53-fold (95% confidence interval, 1.96 to 3.27; P < 0.001), 2.07-fold (95% confidence interval, 1.84 to 2.33; P < 0.001), and 2.76-fold (95% confidence interval, 1.74 to 4.37; P < 0.001) greater risk for hypercreatininemia among non-Hispanic whites, non-Hispanic blacks, and Mexican Americans, respectively. A one-SD higher serum vitamin C level (0.45 mg/dL) was associated with a 22% (95% confidence interval, 0.06 to 0.35; P = 0.01) and 42% (95% confidence interval, 0.08 to 0.62; P = 0.02) lower risk for hypercreatininemia in non-Hispanic whites and Mexican Americans. Our study provides useful information to support the hypothesis that antioxidant vitamins may have an important role in the pathogenesis of chronic renal failure.

Topics: Adult; Antioxidants; Ascorbic Acid; beta Carotene; Creatinine; Cross-Sectional Studies; Ethnicity; Female; Humans; Kidney Failure, Chronic; Male; Middle Aged; Odds Ratio; Population Surveillance; Regression Analysis; Risk Factors; United States; Vitamin A; Vitamin E; Vitamins

Topics: beta Carotene; Coenzymes; Creatinine; Humans; Kidney Failure, Chronic; Malondialdehyde; Oxidative Stress; Ubiquinone; Vitamin E

Recent evidence suggests that HDL can directly inhibit LDL oxidation, a key early stage in atherogenesis. Patients with chronic renal failure are at increased cardiovascular risk, have reduced HDL levels and altered HDL composition. We have therefore investigated whether compositional changes in HDL lead to decreased HDL antioxidant capacity in these patients. In comparison to control subject HDL, patient HDL contained less total cholesterol, cholesterol esters, phospholipids and alpha-tocopherol. LDL, HDL and LDL + HDL were standardised for protein and oxidised in the presence of Cu2+. The rate of propagation during HDL oxidation was reduced in the patient group (3.28+/-0.65 x 10(-5) vs. 4.60+/-0.97 x 10(-5) abs. U/min, P < 0.01). Lipid peroxide generation in patient HDL was decreased: 6.56+4.4 versus 13.42+/-7.0 nmol malondialdehyde (MDA)/mg HDL protein after 90 min and 14.45+/-3.8 versus 20.11+/-7.8 nmol MDA/mg HDL protein after 180 min. This is attributable to reduced HDL polyunsaturated fatty acid content in patients (0.53+/-0.12 vs. 0.72+/-0.16 mmol/g HDL, P < 0.01). The inhibitory effect of HDL on LDL oxidation was similar: 71 and 33% for patient HDL compared to 68 and 31% for control HDL, after 90 and 180 min, respectively. Compositional changes of HDL in patients on haemodialysis did not affect the antioxidant capacity of HDL after standardisation for HDL protein. However, reduced HDL levels in vivo may result in reduced HDL antioxidant capacity in these patients.

Topics: 1-Alkyl-2-acetylglycerophosphocholine Esterase; Antioxidants; Arteriosclerosis; Aryldialkylphosphatase; beta Carotene; Carotenoids; Cholesterol; Cholesterol Esters; Cholesterol, HDL; Cholesterol, LDL; Esterases; Fatty Acids; Female; Humans; Kidney Failure, Chronic; Lipid Peroxidation; Lycopene; Male; Middle Aged; Oxidation-Reduction; Phospholipases A; Phospholipids; Platelet Activating Factor; Renal Dialysis; Risk Factors; Vitamin E

An oxidative stress has been reported in patients with chronic renal failure (CRF) treated by haemodialysis. To our knowledge, only scant information is available concerning CRF patients treated by continuous ambulatory peritoneal dialysis (CAPD) with regard to their redox and nutritional status.. The oxidative stress and the biological nutritional status were evaluated in 20 elderly CRF patients treated by CAPD, compared with a control group of 30 elderly non-CRF patients. Plasma peroxidation products were assayed as thiobarbituric acid-reactive substances (TBARS), and two enzymatic antioxidant systems were determined: erythrocyte superoxide dismutase (SOD), glutathione peroxidase activity in plasma (P-GSH-Px) and in erythrocytes (E-GSH-Px). Selenium, vitamin E, beta-carotene and vitamin A were evaluated as plasma non-enzymatic antioxidants. Nutritional status and iron status were assessed by determining serum albumin, prealbumin, iron, ferritin and transferrin concentrations.. Plasma TBARS concentration was high in both groups (CAPD: 1.37 +/- 0.06 mumol/l versus non-CRF: 1.41 +/- 0.06 mumol/l; P = NS), compared with usual values (0.60 to 1.20 mumol/l), on account of the patients' ages. SOD and E-GSH-Px activities were normal in both groups. A significant lowering in P-GSH-Px activity was observed only in CAPD patients (211 +/- 14 U/l, usual values: 480 to 650 U/l). Plasma selenium concentration, decreased in both groups, was significantly lower in CAPD than in non-CRF patients (P < 0.01). Plasma vitamin E, beta-carotene and vitamin A concentrations were significantly enhanced only in CAPD patients (P < 0.0001, P < 0.005 and P < 0.0001, respectively. Biological nutritional markers were similar in both groups and within usual values.. This study demonstrated the existence of an oxidative stress in CAPD-treated elderly CRF patients, evidenced by a decrease in plasma selenium levels and in P-GSH-Px activity. However, plasma TBARS were not higher in CAPD patients than in age-matched non-CRF control subjects, probably on account on the patients' ages.

Topics: Aged; Aged, 80 and over; Antioxidants; beta Carotene; Female; Glutathione Peroxidase; Humans; Kidney Failure, Chronic; Male; Peritoneal Dialysis, Continuous Ambulatory; Retinol-Binding Proteins; Retinol-Binding Proteins, Plasma; Vitamin E

In 57 patients with chronic renal failure (CRF) [44 patients on regular dialysis treatment (RDT), 33 renal transplant patients (RT) and 26 normal patients (NP)] and in a further 11 patients with CRF (8 patients on RDT and 17 patients without any renal disease in the post mortem) the vitamin A content of the serum obtained from the tissue of the liver, the stomach, the subcutaneous adipose tissue and the bone were analyzed. The vitamin A content of the serum was increased significantly for all groups of patients in comparison with the control group, but hypervitaminotic ranges were not reached in any case. The vitamin A content decreased depending on the time of dialysis treatment and the period after kidney transplantation. The retinol-binding protein accumulated even more than vitamin A in CRF and RDT. This statement is not in conformity with that of a hypervitaminosis A, of which normal respectively decreased RBP levels are characteristic. The serum prealbumin concentration was near the upper limit of the normal range in all groups of patients. The serum content of beta-carotene in patients with CRF and RDT was raised in comparison with NP and RT patients. As to the vitamin A content of the organs, a distinctive decrease appeared in the liver, so that a marginal supply must be assumed. In the stomach and the subcutaneous adipose tissue no changes, in comparison with the control patients, resulted. Due to renal insufficiency the results indicated an unphysiological situation in the vitamin A metabolism. Connections with disturbances of the fat-household could not be set up.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; beta Carotene; Carotenoids; Cholesterol; Female; Humans; Hyperparathyroidism; Kidney Failure, Chronic; Kidney Transplantation; Male; Middle Aged; Osteomalacia; Prealbumin; Renal Dialysis; Retinol-Binding Proteins; Tissue Distribution; Triglycerides; Vitamin A

The serum and cutaneous concentrations of beta-carotene and vitamin A and the serum concentrations of retinal-binding protein (RBP) and prealbumin were investigated in ten patients with chronic renal failure. The serum beta-carotene concentration was lower in the patients 1.3 +/- 0.7 mumol/l) than in the twenty-two healthy controls (2.4 +/- 0.9; P less than 0.01). The skin carotene concentration was also lower in patients than in controls (18.7 +/- 5.5 v. 24.6 +/- 9.9 nmol/g protein; P less than 0.05). By contrast, the patients' mean concentration of vitamin A in the skin was twice that of the healthy controls (11.0 +/- 4.8 v. 5.9 +/- 1.4 nmol/g protein; P less than 0.005) and in serum 3 times that of the controls (4.8 +/- 1.7 v. 1.8 +/- 0.3 mumol/l; P less than 0.001). The increase of serum vitamin A was accompanied by a rise in the RBP concentration, but the concentrations of vitamin A-esters and prealbumin remained in the normal range. It is suggested that vitamin A may accumulate in the skin as a result of an increased transfer of the vitamin by RBP. A possible relationship between high skin levels of vitamin A and uraemic skin symptoms is discussed.

Topics: Adult; beta Carotene; Carotenoids; Female; Humans; Kidney Failure, Chronic; Male; Middle Aged; Prealbumin; Retinol-Binding Proteins; Retinol-Binding Proteins, Plasma; Skin; Skin Manifestations; Vitamin A