Allopurinol Lowers Serum Urate but Does Not Reduce Oxidative Stress in CKD.
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ABSTRACT:
SUBMITTER: Sun M
PROVIDER: S-EPMC9312025 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Oxidative stress has been implicated as a core contributor to the initiation and progression of multiple neurological diseases. Genetic and environmental factors can produce oxidative stress through mitochondrial dysfunction leading to the degeneration of dopaminergic and other neurons underlying Parkinson disease (PD). Although clinical trials of antioxidants have thus far failed to demonstrate slowed progression of PD, oxidative stress remains a compelling target. Rather than prompting abandonment of antioxidant strategies, these failures have raised the bar for justifying drug and dosing selections and for improving study designs to test for disease modification by antioxidants. Urate, the main antioxidant found in plasma as well as the end product of purine metabolism in humans, has emerged as a promising potential neuroprotectant with advantages that distinguish it from previously tested antioxidant agents. Uniquely, higher urate levels in plasma or cerebrospinal fluid (CSF) have been linked to both a lower risk of developing PD and to a slower rate of its subsequent progression in numerous large prospective epidemiological and clinical cohorts. Laboratory evidence that urate confers neuroprotection in cellular and animal models of PD, possibly via the Nrf2 antioxidant response pathway, further strengthened its candidacy for rapid clinical translation. An early phase trial of the urate precursor inosine demonstrated its capacity to safely produce well tolerated, long-term elevation of plasma and CSF urate in early PD, supporting a phase 3 trial now underway to determine whether oral inosine dosed to elevate urate to concentrations predictive of favorable prognosis in PD slows clinical decline in people with recently diagnosed, dopamine transporter-deficient PD.
| S-EPMC5693633 | biostudies-literature
Project description:BackgroundHigher serum urate levels are associated with an increased risk of diabetic kidney disease. Lowering of the serum urate level with allopurinol may slow the decrease in the glomerular filtration rate (GFR) in persons with type 1 diabetes and early-to-moderate diabetic kidney disease.MethodsIn a double-blind trial, we randomly assigned participants with type 1 diabetes, a serum urate level of at least 4.5 mg per deciliter, an estimated GFR of 40.0 to 99.9 ml per minute per 1.73 m2 of body-surface area, and evidence of diabetic kidney disease to receive allopurinol or placebo. The primary outcome was the baseline-adjusted GFR, as measured with iohexol, after 3 years plus a 2-month washout period. Secondary outcomes included the decrease in the iohexol-based GFR per year and the urinary albumin excretion rate after washout. Safety was also assessed.ResultsA total of 267 patients were assigned to receive allopurinol and 263 to receive placebo. The mean age was 51.1 years, the mean duration of diabetes 34.6 years, and the mean glycated hemoglobin level 8.2%. The mean baseline iohexol-based GFR was 68.7 ml per minute per 1.73 m2 in the allopurinol group and 67.3 ml per minute per 1.73 m2 in the placebo group. During the intervention period, the mean serum urate level decreased from 6.1 to 3.9 mg per deciliter with allopurinol and remained at 6.1 mg per deciliter with placebo. After washout, the between-group difference in the mean iohexol-based GFR was 0.001 ml per minute per 1.73 m2 (95% confidence interval [CI], -1.9 to 1.9; P?=?0.99). The mean decrease in the iohexol-based GFR was -3.0 ml per minute per 1.73 m2 per year with allopurinol and -2.5 ml per minute per 1.73 m2 per year with placebo (between-group difference, -0.6 ml per minute per 1.73 m2 per year; 95% CI, -1.5 to 0.4). The mean urinary albumin excretion rate after washout was 40% (95% CI, 0 to 80) higher with allopurinol than with placebo. The frequency of serious adverse events was similar in the two groups.ConclusionsWe found no evidence of clinically meaningful benefits of serum urate reduction with allopurinol on kidney outcomes among patients with type 1 diabetes and early-to-moderate diabetic kidney disease. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; PERL ClinicalTrials.gov number, NCT02017171.).
| S-EPMC7375708 | biostudies-literature
Project description:Study of Oxidative stress Markers (F2 Isoprostanes for lipid peroxidation, Carbonyl groups for protein peroxidation, 3 Nitrotyrosine for damage by nitrogens, and 8-Hydroxyguanosine for RNA peroxidation)in patients with colorectal cancer undergo surgical treatment (preoperatively during the intervention and postoperatively) and controls.
| 2115584 | ecrin-mdr-crc
Project description:Therapy to slow the relentless expansion of interstitial extracellular matrix that leads to renal functional decline in patients with CKD is currently lacking. Because chronic kidney injury increases tissue oxidative stress, we evaluated the antifibrotic efficacy of cysteamine bitartrate, an antioxidant therapy for patients with nephropathic cystinosis, in a mouse model of unilateral ureteral obstruction. Fresh cysteamine (600 mg/kg) was added to drinking water daily beginning on the day of surgery, and outcomes were assessed on days 7, 14, and 21 after surgery. Plasma cysteamine levels showed diurnal variation, with peak levels similar to those observed in patients with cystinosis. In cysteamine-treated mice, fibrosis severity decreased significantly at 14 and 21 days after unilateral ureteral obstruction, and renal oxidized protein levels decreased at each time point, suggesting reduced oxidative stress. Consistent with these results, treatment of cultured macrophages with cysteamine reduced cellular generation of reactive oxygen species. Furthermore, treatment with cysteamine reduced ?-smooth muscle actin-positive interstitial myofibroblast proliferation and mRNA levels of extracellular matrix proteins in mice and attenuated myofibroblast differentiation and proliferation in vitro, but did not augment TGF-? signaling. In a study of renal ischemia reperfusion, cysteamine therapy initiated 10 days after injury and continued for 14 days decreased renal fibrosis by 40%. Taken together, these data suggest previously unrecognized antifibrotic actions of cysteamine via TGF-?-independent mechanisms that include oxidative stress reduction and attenuation of the myofibroblast response to kidney injury and support further investigation into the potential benefit of cysteamine therapy in the treatment of CKD.
| S-EPMC3871767 | biostudies-literature
Project description:BACKGROUND:Primary open-angle glaucoma (POAG) is a multifactorial pathology involving a variety of pathogenic mechanisms, including oxidative/nitrosative stress. This latter is the consequence of the imbalance between excessive formation and insufficient protection against reactive oxygen/nitrogen species. OBJECTIVE:Our main goal is to gather molecular information to better managing pathologic variants that may determine the individual susceptibility to oxidative/nitrosative stress (OS/NS) and POAG. METHOD:An extensive search of the scientific literature was conducted using PUBMED, the Web of Science, the Cochrane Library, and other references on the topic of POAG and OS/NS from human and animal model studies published between 2010 and 2017. Finally, 152 works containing relevant information that may help understanding the role of antioxidants, essential fatty acids, natural compounds and other similar strategies for counteracting OS/NS in POAG were considered. RESULTS:A wide variety of studies have proven that antioxidants, among them vitamins B3, C and E, Coenzyme Q10 or melatonin, ?-3/?-6 fatty acids and other natural compounds (such as coffee, green tea, bear bile, gingko biloba, coleus, tropical fruits, etc.,) may help regulating the intraocular pressure as well as protecting the retinal neurons against OS/NS in POAG. CONCLUSION:Based on the impact of antioxidants and ?-3/?-6 fatty acids at the molecular level in the glaucomatous anterior and posterior eye segments, further studies are needed by integrating all issues involved in glaucoma pathogenesis, endogenous and exogenous risk factors and their interactions that will allow us to reach newer effective biotherapies for preventing glaucomatous irreversible blindness.
| S-EPMC6120109 | biostudies-literature
Project description:There are several mechanisms, including inflammation, oxidative stress and abnormal calcium homeostasis, involved in the pathogenesis of atrial fibrillation. In diabetes mellitus (DM), increased oxidative stress may be attributable to higher xanthine oxidase activity. In this study, we examined the relationship between oxidative stress and atrial electrical and structural remodeling, and calcium handling abnormalities, and the potential beneficial effects of the xanthine oxidase inhibitor allopurinol upon these pathological changes.Ninety rabbits were randomly and equally divided into 3 groups: control, DM, and allopurinol-treated DM group. Echocardiographic and hemodynamic assessments were performed in vivo. Serum and tissue markers of oxidative stress and atrial fibrosis, including the protein expression were examined. Atrial interstitial fibrosis was evaluated by Masson trichrome staining. ICaL was measured from isolated left atrial cardiomyocytes using voltage-clamp techniques. Confocal microscopy was used to detect intracellular calcium transients. The Ca2+ handling protein expression was analyzed by Western blotting. Mitochondrial-related proteins were analyzed as markers of mitochondrial function. Compared with the control group, rabbits with DM showed left ventricular hypertrophy, increased atrial interstitial fibrosis, oxidative stress and fibrosis markers, ICaL and intracellular calcium transient, and atrial fibrillation inducibility. These abnormalities were alleviated by allopurinol treatment.Allopurinol, via its antioxidant effects, reduces atrial mechanical, structural, ion channel remodeling and mitochondrial synthesis abnormalities induced by DM-related increases in oxidative stress.
| S-EPMC6015332 | biostudies-other
Project description:BackgroundGout gives rise to increased risk of cardiovascular events. Gout attacks can be effectively prevented with urate lowering drugs, and allopurinol potentially reduces cardiovascular risk. What target level of urate is required to reduce cardiovascular risk is not known.ObjectivesTo investigate the effect of achieving target plasma urate with allopurinol on cardiovascular outcomes in a case-control study nested within long-term users of allopurinol.MethodsWe identified long-term users of allopurinol in Funen County, Denmark. Among these, we identified all cases of cardiovascular events and sampled 4 controls to each case from the same population. The cases and controls were compared with respect to whether they reached a urate target below 0.36 mmol/l on allopurinol. The derived odds ratios were controlled for potential confounders available from data on prescriptions, laboratory values and in- and outpatient contacts.ResultsNo association between treatment-to-target urate level and cardiovascular events were found (adjusted odds ratio of 1.01, 95% confidence interval 0.79-1.28). No significant effect was seen in any subgroup defined by age, gender, renal function, allopurinol dose or the achieved urate level. Overall, the doses of allopurinol used in this study were low (mean ≈ 140 mg/day).ConclusionWe were unable to demonstrate a link between achieved urate level in patients treated with allopurinol and risk of cardiovascular events. Possible explanations include that allopurinol doses higher than those used in this study are required to achieve cardiovascular risk reduction or that the cardiovascular effect of allopurinol is not mediated through low urate levels. It remains to be seen whether allopurinol has a dose-response relationship with cardiovascular events at higher doses.
| S-EPMC4709004 | biostudies-literature
Project description:Uremic cardiomyopathy is a clinically highly relevant cause of cardiovascular events in patients with chronic kidney disease (CKD). This study aimed at a comprehensive analysis of cardiac function and cardiac pathological characteristics in adenine-induced CKD in 129/Sv mice. This included the analysis of kidney function and morphology, heart function as well as cardiac hypertrophy, fibrosis and calcification. Also, cardiac RNA-sequencing was performed. Although overall, no cardiac dysfunction, hypertrophy or fibrosis could be observed, prolonged moderate CKD in this mouse model enhanced cardiac oxidative stress markers. In line, cardiac RNA-sequencing revealed an increase in oxidative stress-inducing signaling in CKD as well as anti-inflammatory feedback responses. This suggests a maladaptive preconditioning of the heart in CKD, which could increase the risk of enhanced cardiovascular damage upon additional cardiovascular risk factors and/or events.
2022-09-21 | GSE191122 | GEO
Project description:ObjectiveTo investigate whether serum urate levels, number of gout flares, and tophi burden are related to death from cardiovascular (CV) causes after treatment with febuxostat or allopurinol in patients with gout from the Cardiovascular Safety of Febuxostat or Allopurinol in Patients With Gout and Cardiovascular Comorbidities (CARES) trial.MethodsPatients were randomly assigned to receive febuxostat (40 mg or 80 mg once daily, according to serum urate levels at week 2) or allopurinol titrated in 100-mg increments from 200-400 mg or 300-600 mg (with dose determined according to kidney function). Changes from baseline in serum urate level, gout flares, and tophus resolution were key exploratory efficacy parameters in the overall population and in subgroups of patients who died and those who did not die from a CV-related cause. The latter subgroup included patients who died due to non-CV causes and those who did not die due to any cause.ResultsPatients received treatment with febuxostat (n = 3,098) or allopurinol (n = 3,092) for a median follow-up period of 32 months (for a maximum of 85 months). In the overall population, mean serum urate levels were lower in those receiving febuxostat compared with those receiving allopurinol at most study visits. There were no associations between serum urate levels and death from CV causes with febuxostat. The number of gout flares requiring treatment was higher within 1 year of treatment with febuxostat compared with allopurinol (mean incidence of gout flares per patient-years of exposure 1.33 versus 1.20), but was comparable thereafter and decreased overall throughout the study period (mean incidence of gout flares per patient-years of exposure 0.35 versus 0.34 after 1 year of treatment; overall mean incidence 0.68 versus 0.63) irrespective of whether the patient died from a CV-related cause. Overall, 20.8% of patients had ≥1 tophus at baseline; tophus resolution rates were similar between treatment groups, with cumulative resolution rates of >50%.ConclusionIn the CARES trial, febuxostat and allopurinol (≤600 mg doses) had comparable efficacy in patients with gout and CV disease, and there was no evidence of a relationship between death from CV causes and serum urate levels, number of gout flares, or tophus resolution among the patients receiving febuxostat.
| S-EPMC9541704 | biostudies-literature
Project description:BackgroundPrevious studies have noted significant variation in serum urate (sUA) levels, and it is unknown how this influences the accuracy of hyperuricemia classification based on single data points. Despite this known variability, hyperuricemic patients are often used as a control group in gout studies. Our objective was to determine the accuracy of hyperuricemia classifications based on single data points versus multiple data points given the degree of variability observed with serial measurements of sUA.MethodsData was analyzed from a cross-over clinical trial of urate-lowering therapy in young adults without a gout diagnosis. In the control phase, sUA levels used for this analysis were collected at 2-4 week intervals. Mean coefficient of variation for sUA was determined, as were rates of conversion between normouricemia (sUA ≤6.8 mg/dL) and hyperuricemia (sUA > 6.8 mg/dL).ResultsMean study participant (n = 85) age was 27.8 ± 7.0 years, with 39% female participants and 41% African-American participants. Mean sUA coefficient of variation was 8.5% ± 4.9% (1 to 23%). There was no significant difference in variation between men and women, or between participants initially normouricemic and those who were initially hyperuricemic. Among those initially normouricemic (n = 72), 21% converted to hyperuricemia during at least one subsequent measurement. The subgroup with initial sUA < 6.0 (n = 54) was much less likely to have future values in the range of hyperuricemia compared to the group with screening sUA values between 6.0-6.8 (n = 18) (7% vs 39%, p = 0.0037). Of the participants initially hyperuricemic (n = 13), 46% were later normouricemic during at least one measurement.ConclusionSingle sUA measurements were unreliable in hyperuricemia classification due to spontaneous variation. Knowing this, if a single measurement must be used in classification, it is worth noting that those with an sUA of < 6.0 mg/dL were less likely to demonstrate future hyperuricemic measurements and this could be considered a safer threshold to rule out intermittent hyperuricemia based on a single measurement point.Trial registrationData from parent study ClinicalTrials.gov Identifier: NCT02038179 .
| S-EPMC8425059 | biostudies-literature