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Kim AH, Son DH, Moon ME, Jeon S, Lee HS, Lee YJ. Sex differences in the relationship between serum total bilirubin and risk of incident metabolic syndrome in community-dwelling adults: Propensity score analysis using longitudinal cohort data over 16 years. Cardiovasc Diabetol 2024; 23:92. [PMID: 38468265 PMCID: PMC10926637 DOI: 10.1186/s12933-024-02182-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 02/27/2024] [Indexed: 03/13/2024] Open
Abstract
BACKGROUND Research on identifiable risks for metabolic syndrome (MetS) is ongoing, and growing evidence suggests that bilirubin is a potent antioxidant and cytoprotective agent against MetS. However, there have been conflicting results on the association between bilirubin and MetS. Our study aimed to validate the association by separately stratifying data for men and women in a longitudinal prospective study. METHODS Data were derived from the Korean Genome Epidemiology Study provided by the Korea Centers for Disease Control and Prevention. Data from 5,185 adults aged 40-69 years (3,089 men and 2,096 women) without MetS were analyzed. The participants were divided according to sex-specific quartiles of serum total bilirubin levels and followed up biennially for 16 years (until 2018). The log-rank test was used for obtaining the Kaplan-Meier curves of cumulative incidence of MetS according to sex-specific serum total bilirubin quartiles, and the hazard ratios (HRs) with 95% confidence intervals (CIs) for incident metabolic syndrome were analyzed with a multiple Cox proportional hazard regression analysis model, after propensity score matching for removing differences at baseline. RESULTS With increasing serum total bilirubin quartiles, the incidence rate per 1000 person-years proportionally decreased in both men and women. After propensity score matching and adjusting for confounding variables, the HRs (95% CIs) for MetS of the highest quartile in reference to the lowest quartile were 1.00 (0.80-1.24) for men and 0.80 (0.65-0.99) for women. Higher quartiles of serum total bilirubin showed significantly lower cumulative incidence of MetS in women (log-rank test p = 0.009), but not in men (log-rank test p = 0.285). CONCLUSION Serum total bilirubin levels were significantly inversely associated with MetS in women, but there was no significant association observed in men. Sex differences in the effects of serum total bilirubin should be noted when predicting incident MetS by sex in clinical settings.
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Affiliation(s)
- Ae Hee Kim
- Department of Family Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Da-Hye Son
- Department of Family Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Mid-Eum Moon
- Department of Family Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Soyoung Jeon
- Biostatistics Collaboration Unit, Yonsei University College of Medicine, Seoul, Korea
| | - Hye Sun Lee
- Biostatistics Collaboration Unit, Yonsei University College of Medicine, Seoul, Korea
| | - Yong-Jae Lee
- Department of Family Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
- Department of Family Medicine, Yonsei University College of Medicine Gangnam Severance Hospital, 211 Eonju-ro, Gangnam-gu, Seoul, 06273, Korea.
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2
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Mujawar T, Sevelda P, Madea D, Klán P, Švenda J. A Platform for the Synthesis of Oxidation Products of Bilirubin. J Am Chem Soc 2024; 146:1603-1611. [PMID: 38165253 PMCID: PMC10797625 DOI: 10.1021/jacs.3c11778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 11/30/2023] [Accepted: 12/06/2023] [Indexed: 01/03/2024]
Abstract
Bilirubin is the principal product of heme catabolism. High concentrations of the pigment are neurotoxic, yet slightly elevated levels are beneficial. Being a potent antioxidant, oxidative transformations of bilirubin occur in vivo and lead to various oxidized fragments. The mechanisms of their formation, intrinsic biological activities, and potential roles in human pathophysiology are poorly understood. Degradation methods have been used to obtain samples of bilirubin oxidation products for research. Here, we report a complementary, fully synthetic method of preparation. Our strategy leverages repeating substitution patterns in the parent tetracyclic pigment. Functionalized ready-to-couple γ-lactone, γ-lactam, and pyrrole monocyclic building blocks were designed and efficiently synthesized. Subsequent modular combinations, supported by metal-catalyzed borylation and cross-coupling chemistries, translated into the concise assembly of the structurally diverse bilirubin oxidation products (BOXes, propentdyopents, and biopyrrins). The discovery of a new photoisomer of biopyrrin A named lumipyrrin is reported. Synthetic bilirubin oxidation products made available in sufficient purity and quantity will support future in vitro and in vivo investigations.
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Affiliation(s)
- Taufiqueahmed Mujawar
- Department
of Chemistry, Faculty of Science, Masaryk
University, Kamenice 5, Brno 625 00, Czech Republic
| | - Petr Sevelda
- Department
of Chemistry, Faculty of Science, Masaryk
University, Kamenice 5, Brno 625 00, Czech Republic
| | - Dominik Madea
- Department
of Chemistry, Faculty of Science, Masaryk
University, Kamenice 5, Brno 625 00, Czech Republic
- RECETOX,
Faculty of Science, Masaryk University, Kamenice 5, Brno 625 00, Czech Republic
| | - Petr Klán
- Department
of Chemistry, Faculty of Science, Masaryk
University, Kamenice 5, Brno 625 00, Czech Republic
- RECETOX,
Faculty of Science, Masaryk University, Kamenice 5, Brno 625 00, Czech Republic
| | - Jakub Švenda
- Department
of Chemistry, Faculty of Science, Masaryk
University, Kamenice 5, Brno 625 00, Czech Republic
- International
Clinical Research Center, St. Anne’s
University Hospital, Pekařská 53, Brno 656 91, Czech Republic
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3
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Diagnostic methods for neonatal hyperbilirubinemia: benefits, limitations, requirements, and novel developments. Pediatr Res 2021; 90:277-283. [PMID: 33948000 DOI: 10.1038/s41390-021-01546-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 02/20/2021] [Accepted: 04/10/2021] [Indexed: 11/09/2022]
Abstract
Invasive bilirubin measurements remain the gold standard for the diagnosis and treatment of infants with severe neonatal hyperbilirubinemia. The present paper describes different methods currently available to assess hyperbilirubinemia in newborn infants. Novel point-of-care bilirubin measurement methods, such as the BiliSpec and the Bilistick, would benefit many newborn infants, especially in low-income and middle-income countries where the access to costly multi-analyzer in vitro diagnostic instruments is limited. Total serum bilirubin test results should be accurate within permissible limits of measurement uncertainty to be fit for clinical purposes. This implies correct implementation of internationally endorsed reference measurement systems as well as participation in external quality assessment programs. Novel analytic methods may, apart from bilirubin, include the determination of bilirubin photoisomers and bilirubin oxidation products in blood and even in other biological matrices. IMPACT: Key message: Bilirubin measurements in blood remain the gold standard for diagnosis and treatment of severe neonatal hyperbilirubinemia (SNH). External quality assessment (EQA) plays an important role in revealing inaccuracies in diagnostic bilirubin measurements. What does this article add to the existing literature? We provide analytic performance data on total serum bilirubin (TSB) as measured during recent EQA surveys. We review novel diagnostic point-of-care (POC) bilirubin measurement methods and analytic methods for determining bilirubin levels in biological matrices other than blood. Impact: Manufacturers should make TSB test results traceable to the internationally endorsed total bilirubin reference measurement system and should ensure permissible limits of measurement uncertainty.
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4
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Bellarosa C, Bedogni G, Bianco A, Cicolini S, Caroli D, Tiribelli C, Sartorio A. Association of Serum Bilirubin Level with Metabolic Syndrome and Non-Alcoholic Fatty Liver Disease: A Cross-Sectional Study of 1672 Obese Children. J Clin Med 2021; 10:jcm10132812. [PMID: 34202304 PMCID: PMC8268762 DOI: 10.3390/jcm10132812] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/17/2021] [Accepted: 06/21/2021] [Indexed: 12/12/2022] Open
Abstract
As in adults, obesity also plays a central role in the development of metabolic syndrome (MS) in children. Non-alcoholic fatty liver disease (NAFLD) is considered a manifestation of MS. Not only MS but also NAFLD seem to be inversely associated with serum bilirubin concentrations, an important endogenous tissue protector when only mild elevated. The aim of the study was to evaluate the association between serum bilirubin levels and the prevalence of MS and NAFLD in Italian obese children and adolescents. A retrospective cross-sectional study was performed in 1672 patients aged from 5 to 18 years. Clinical and laboratory parameters were assessed. NAFLD was measured by liver ultrasonography. The study was approved by the Ethical Committee of the Istituto Auxologico Italiano (research project code 1C021_2020, acronym BILOB). MS was present in 24% and fatty liver (FL) in 38% of this population. Bilirubin was not associated with FL and MS as a whole, but it was inversely associated only with selected components of MS, i.e., large WC, high blood pressure and high triglycerides. Our data suggest that bilirubin is not protective against MS and NAFLD in the presence of severe obesity.
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Affiliation(s)
- Cristina Bellarosa
- Italian Liver Foundation, 34149 Trieste, Italy; (G.B.); (A.B.); (C.T.)
- Correspondence:
| | - Giorgio Bedogni
- Italian Liver Foundation, 34149 Trieste, Italy; (G.B.); (A.B.); (C.T.)
| | - Annalisa Bianco
- Italian Liver Foundation, 34149 Trieste, Italy; (G.B.); (A.B.); (C.T.)
- Life Science Department, University of Trieste, 34127 Trieste, Italy
| | - Sabrina Cicolini
- Istituto Auxologico Italiano, IRCCS, Experimental Laboratory for Auxo-Endocrinological Research, 28824 Verbania, Italy; (S.C.); (D.C.); (A.S.)
| | - Diana Caroli
- Istituto Auxologico Italiano, IRCCS, Experimental Laboratory for Auxo-Endocrinological Research, 28824 Verbania, Italy; (S.C.); (D.C.); (A.S.)
| | - Claudio Tiribelli
- Italian Liver Foundation, 34149 Trieste, Italy; (G.B.); (A.B.); (C.T.)
| | - Alessandro Sartorio
- Istituto Auxologico Italiano, IRCCS, Experimental Laboratory for Auxo-Endocrinological Research, 28824 Verbania, Italy; (S.C.); (D.C.); (A.S.)
- Istituto Auxologico Italiano, IRCCS, Division of Auxology and Metabolic Diseases, 28824 Verbania, Italy
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Jayanti S, Vítek L, Tiribelli C, Gazzin S. The Role of Bilirubin and the Other "Yellow Players" in Neurodegenerative Diseases. Antioxidants (Basel) 2020; 9:E900. [PMID: 32971784 PMCID: PMC7555389 DOI: 10.3390/antiox9090900] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/16/2020] [Accepted: 09/20/2020] [Indexed: 02/07/2023] Open
Abstract
Bilirubin is a yellow endogenous derivate of the heme catabolism. Since the 1980s, it has been recognized as one of the most potent antioxidants in nature, able to counteract 10,000× higher intracellular concentrations of H2O2. In the recent years, not only bilirubin, but also its precursor biliverdin, and the enzymes involved in their productions (namely heme oxygenase and biliverdin reductase; altogether the "yellow players"-YPs) have been recognized playing a protective role in diseases characterized by a chronic prooxidant status. Based on that, there is an ongoing effort in inducing their activity as a therapeutic option. Nevertheless, the understanding of their specific contributions to pathological conditions of the central nervous system (CNS) and their role in these diseases are limited. In this review, we will focus on the most recent evidence linking the role of the YPs specifically to neurodegenerative and neurological conditions. Both the protective, as well as potentially worsening effects of the YP's activity will be discussed.
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Affiliation(s)
- Sri Jayanti
- Fondazione Italiana Fegato-Onlus, Bldg. Q, AREA Science Park, ss14, Km 163.5, Basovizza, 34149 Trieste, Italy; (S.J.); (C.T.)
- Faculty of Medicine, Universitas Hasanuddin, Makassar 90245, Indonesia
- Molecular Biomedicine Ph.D. Program, University of Trieste, 34127 Trieste, Italy
| | - Libor Vítek
- Institute of Medical Biochemistry and Laboratory Diagnostics, and 4th Department of Internal Medicine, Faculty General Hospital and 1st Faculty of Medicine, Charles University, 12000 Prague, Czech Republic;
| | - Claudio Tiribelli
- Fondazione Italiana Fegato-Onlus, Bldg. Q, AREA Science Park, ss14, Km 163.5, Basovizza, 34149 Trieste, Italy; (S.J.); (C.T.)
| | - Silvia Gazzin
- Fondazione Italiana Fegato-Onlus, Bldg. Q, AREA Science Park, ss14, Km 163.5, Basovizza, 34149 Trieste, Italy; (S.J.); (C.T.)
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6
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YILMAZ N, ÖZ C, EREN E, TEKELİ SÖ. Bilirubin metabolism and its role in atherosclerosis. ARCHIVES OF CLINICAL AND EXPERIMENTAL MEDICINE 2020. [DOI: 10.25000/acem.699424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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7
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Fujiwara R, Haag M, Schaeffeler E, Nies AT, Zanger UM, Schwab M. Systemic regulation of bilirubin homeostasis: Potential benefits of hyperbilirubinemia. Hepatology 2018; 67:1609-1619. [PMID: 29059457 DOI: 10.1002/hep.29599] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 09/11/2017] [Accepted: 10/13/2017] [Indexed: 12/17/2022]
Abstract
Neurotoxic bilirubin is the end product of heme catabolism in mammals. Bilirubin is solely conjugated by uridine diphospho-glucuronosyltransferase 1A1, which is a membrane-bound enzyme that catalyzes the transfer of glucuronic acid. Due to low function of hepatic and intestinal uridine diphospho-glucuronosyltransferase 1A1 during the neonatal period, human neonates develop mild to severe physiological hyperbilirubinemia. Accumulation of bilirubin in the brain leads to the onset of irreversible brain damage, termed kernicterus. Breastfeeding is one of the most significant factors that increase the risk of developing kernicterus in infants. Why does this most natural way of feeding increase the risk of brain damage or even death? This question leads to the hypothesis that breast milk-induced hyperbilirubinemia might bring certain benefits that outweigh those risks. While bilirubin is neurotoxic and cytotoxic, this compound is also a potent antioxidant. There are studies showing improved clinical conditions in patients with hyperbilirubinemia. Accumulating evidence also shows that genetic polymorphisms linked to hyperbilirubinemia are beneficial against various diseases. In this review article, we first introduce the production, metabolism, and transport of bilirubin. We then discuss the potential benefits of neonatal and adult hyperbilirubinemia. Finally, epigenetic factors as well as metabolomic information associated with hyperbilirubinemia are described. This review article advances the understanding of the physiological importance of the paradoxical compound bilirubin. (Hepatology 2018;67:1609-1619).
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Affiliation(s)
- Ryoichi Fujiwara
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany.,Department of Pharmacy and Biochemistry, University of Tuebingen, Tuebingen, Germany.,Department of Pharmaceutics, School of Pharmacy, Kitasato University, Tokyo, Japan
| | - Mathias Haag
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany.,University of Tuebingen, Tuebingen, Germany
| | - Elke Schaeffeler
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany.,University of Tuebingen, Tuebingen, Germany
| | - Anne T Nies
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany.,University of Tuebingen, Tuebingen, Germany
| | - Ulrich M Zanger
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany.,University of Tuebingen, Tuebingen, Germany
| | - Matthias Schwab
- Dr. Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany.,Department of Pharmacy and Biochemistry, University of Tuebingen, Tuebingen, Germany.,Department of Clinical Pharmacology, University Hospital, Tuebingen, Germany.,German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), Heidelberg, Germany
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8
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Conflicting effects of atazanavir therapy on atherosclerotic risk factors in stable HIV patients: A randomized trial of regimen switch to atazanavir. PLoS One 2017; 12:e0181993. [PMID: 29023508 PMCID: PMC5638209 DOI: 10.1371/journal.pone.0181993] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 07/06/2017] [Indexed: 12/29/2022] Open
Abstract
Bilirubin acts as a potent endogenous antioxidant, with higher concentrations associated with lower rates of CVD; the antiretroviral drug atazanavir (ATV) increases bilirubin levels but may also increase von Willebrand factor levels. We tested the hypothesis that increasing endogenous bilirubin using ATV would improve cardiometabolic risk factors and vascular function in older patients with HIV. Ninety participants were enrolled in two study protocols. In protocol 1, we evaluated markers of inflammation, thrombosis, and conduit artery endothelial function in subjects on non-ATV containing regimens. Participants were randomly assigned to continue baseline treatment or switch to an ATV-based regimen. Measurements were made at baseline and 28 days. In the protocol 2, we enrolled 30 subjects who received atazanavir for more than one year and were compared to the aim 1 protocol subjects at baseline. 60 subjects were enrolled in the first protocol (mean age 53, +/- 6 years), with 31 randomized to ATV and 29 continuing baseline treatment. Atazanavir significantly increased serum total bilirubin levels (p<0.001) and acutely but not chronically plasma total antioxidant capacity (p<0.001). An increase in von Willebrand Factor (p<0.001) and reduction in hs-CRP (p = 0.034) were noted. No changes were seen in either flow-mediated endothelium-dependent or vasodilation. In cross-sectional analysis (second protocol), similar findings were seen in the baseline attributes of non-atazanavir-based and long-term atazanavir users. Increasing serum bilirubin levels with atazanavir in subjects with HIV reduces hs-CRP, temporarily reduces oxidative stress, but increases von Willebrand Factor. Atazanavir does not improve endothelial function of conduit arteries. Trial registration: ClinicalTrials.gov NCT03019783.
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9
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Abstract
Bilirubin is the final product of heme catabolism in the systemic circulation. For decades, increased serum/plasma bilirubin levels were considered an ominous sign of an underlying liver disease. However, data from recent years convincingly suggest that mildly elevated bilirubin concentrations are associated with protection against various oxidative stress-mediated diseases, atherosclerotic conditions being the most clinically relevant. Although scarce data on beneficial effects of bilirubin had been published also in the past, it took until 1994 when the first clinical study demonstrated an increased risk of coronary heart disease in subjects with low serum bilirubin levels, and bilirubin was found to be a risk factor for atherosclerotic diseases independent of standard risk factors. Consistent with these results, we proved in our own studies, that subjects with mild elevation of serum levels of unconjugated bilirubin (benign hyperbilirubinemia, Gilbert syndrome) have much lower prevalence/incidence of coronary heart as well as peripheral vascular disease. We have also demonstrated that this association is even more general, with serum bilirubin being a biomarker of numerous other diseases, often associated with increased risk of atherosclerosis. In addition, very recent data have demonstrated biological pathways modulated by bilirubin, which are responsible for observed strong clinical associations.
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Affiliation(s)
- L Vítek
- Fourth Department of Internal Medicine and Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University, Prague, Czech Republic.
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10
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Barber TJ, Moyle G, Hill A, Jagjit Singh G, Scourfield A, Yapa HM, Waters L, Asboe D, Boffito M, Nelson M. A cross-sectional study to evaluate the association of hyperbilirubinaemia on markers of cardiovascular disease, neurocognitive function, bone mineral density and renal markers in HIV-1 infected subjects on protease inhibitors. HIV CLINICAL TRIALS 2017; 17:123-30. [PMID: 27125367 DOI: 10.1080/15284336.2016.1176305] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
BACKGROUND Ongoing inflammation in controlled HIV infection contributes to non-AIDS comorbidities. High bilirubin appears to exhibit an anti-inflammatory effect in vivo. We therefore examined whether increased bilirubin in persons with HIV was associated with differences in markers of inflammation and cardiovascular, bone, renal disease, and neurocognitive (NC) impairment. METHODS This cross-sectional study examined inflammatory markers in individuals with stable HIV infection treated with two nucleoside reverse transcriptase inhibitors and a boosted protease inhibitor. Individuals recruited were those with a normal bilirubin (NBR; 0-17 μmol/L) or high bilirubin (>2.5 × upper limit of normal). Demographic and anthropological data were recorded. Blood and urine samples were taken for analyses. Pulse wave velocity (PWV) measurement, carotid intimal thickness (CIT), and calcaneal stiffness (CSI) were measured. Males were asked to answer a questionnaire about sexual function; NC testing was performed using CogState. RESULTS 101 patients were screened, 78 enrolled (43 NBR and 35 HBR). Atazanavir use was significantly higher in HBR. Whilst a trend for lower CIT was seen in those with HBR, no significant differences were seen in PWV, bone markers, calculated cardiovascular risk (Framingham), or erectile dysfunction score. VCAM-1 levels were significantly lower in the HBR group. HBR was associated with lower LDL and triglyceride levels. NBR was associated with a calculated FRAX significantly lower than HBR although no associations were found after adjusting for tenofovir use. No difference in renal markers was observed. Component tests of NC testing revealed differences favouring HBR but overall composite scores were similar. DISCUSSION High bilirubin in the context of boosted PI therapy was found not to be associated with differences in with the markers examined in this study. Some trends were noted and, on the basis of these, a larger, clinical end point study is warranted.
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Affiliation(s)
- T J Barber
- a St Stephen's Centre, Chelsea and Westminster NHS Foundation Trust , London , UK
| | - G Moyle
- a St Stephen's Centre, Chelsea and Westminster NHS Foundation Trust , London , UK
| | - A Hill
- a St Stephen's Centre, Chelsea and Westminster NHS Foundation Trust , London , UK
| | - G Jagjit Singh
- a St Stephen's Centre, Chelsea and Westminster NHS Foundation Trust , London , UK
| | - A Scourfield
- b University College London Hospitals NHS Foundation Trust , London , UK
| | - H M Yapa
- a St Stephen's Centre, Chelsea and Westminster NHS Foundation Trust , London , UK
| | - L Waters
- c Mortimer Market Centre , Central and North West London NHS Foundation Trust, London , UK
| | - D Asboe
- a St Stephen's Centre, Chelsea and Westminster NHS Foundation Trust , London , UK
| | - M Boffito
- a St Stephen's Centre, Chelsea and Westminster NHS Foundation Trust , London , UK.,d Imperial College School of Medicine , London , UK
| | - M Nelson
- a St Stephen's Centre, Chelsea and Westminster NHS Foundation Trust , London , UK.,d Imperial College School of Medicine , London , UK
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11
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Cho HS, Lee SW, Kim ES, Shin J, Moon SD, Han JH, Cha BY. Serum bilirubin levels are inversely associated with PAI-1 and fibrinogen in Korean subjects. Atherosclerosis 2015; 244:204-10. [PMID: 26684255 DOI: 10.1016/j.atherosclerosis.2015.11.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 10/22/2015] [Accepted: 11/06/2015] [Indexed: 12/20/2022]
Abstract
OBJECTIVES Oxidative stress may contribute to atherosclerosis and increased activation of the coagulation pathway. Bilirubin may reduce activation of the hemostatic system to inhibit oxidative stress, which would explain its cardioprotective properties shown in many epidemiological studies. This study investigated the association of serum bilirubin with fibrinogen and plasminogen activator inhibitor-1 (PAI-1), respectively. METHODS A cross-sectional analysis was performed on 968 subjects (mean age, 56.0 ± 11.2 years; 61.1% men) undergoing a general health checkup. Serum biochemistry was analyzed including bilirubin subtypes, insulin resistance (using homeostasis model of assessment [HOMA]), C-reactive protein (CRP), fibrinogen, and PAI-1. RESULTS Compared with subjects with a total bilirubin (TB) concentration of <10.0 μmol/L, those with a TB concentration of >17.1 μmol/L had a smaller waist circumference, a lower triglyceride level, a lower prevalence of metabolic syndrome, and decreased HOMA-IR and CRP levels. Correlation analysis revealed linear relationships of fibrinogen with TB and direct bilirubin (DB), whereas PAI-1 was correlated with DB. After adjustment for confounding factors, bilirubin levels were inversely associated with fibrinogen and PAI-1 levels, respectively. Multivariate regression models showed a negative linear relationship between all types of bilirubin and fibrinogen, whereas there was a significant linear relationship between PAI-1 and DB. CONCLUSIONS High bilirubin concentrations were independently associated with low levels of fibrinogen and PAI-1, respectively. The association between TB and PAI-1 was confined to the highest TB concentration category whereas DB showed a linear association with PAI-1. Bilirubin may protect against the development of atherothrombosis by reducing the hemostatic response.
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Affiliation(s)
- Hyun Sun Cho
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea; Health Promotion Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Sung Won Lee
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea; Division of Hepatology, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Eun Sook Kim
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea; Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
| | - Juyoung Shin
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea; Health Promotion Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Sung Dae Moon
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea; Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Je Ho Han
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea; Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Bong Yun Cha
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, South Korea
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12
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Looking to the horizon: the role of bilirubin in the development and prevention of age-related chronic diseases. Clin Sci (Lond) 2015; 129:1-25. [DOI: 10.1042/cs20140566] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Bilirubin, the principal tetrapyrrole, bile pigment and catabolite of haem, is an emerging biomarker of disease resistance, which may be related to several recently documented biological functions. Initially believed to be toxic in infants, the perception of bilirubin has undergone a transformation: it is now considered to be a molecule that may promote health in adults. Data from the last decade demonstrate that mildly elevated serum bilirubin levels are strongly associated with reduced prevalence of chronic diseases, particularly cardiovascular diseases (CVDs), as well as CVD-related mortality and risk factors. Recent data also link bilirubin to other chronic diseases, including cancer and Type 2 diabetes mellitus, and to all-cause mortality. Therefore, there is evidence to suggest that bilirubin is a biomarker for reduced chronic disease prevalence and a predictor of all-cause mortality, which is of important clinical significance. In the present review, detailed information on the association between bilirubin and all-cause mortality, as well as the pathological conditions of CVD, cancer, diabetes and neurodegenerative diseases, is provided. The mechanistic background concerning how bilirubin and its metabolism may influence disease prevention and its clinical relevance is also discussed. Given that the search for novel biomarkers of these diseases, as well as for novel therapeutic modalities, is a key research objective for the near future, bilirubin represents a promising candidate, meeting the criteria of a biomarker, and should be considered more carefully in clinical practice as a molecule that might provide insights into disease resistance. Clearly, however, greater molecular insight is warranted to support and strengthen the conclusion that bilirubin can prevent disease, with future research directions also proposed.
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13
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Bilirubin, platelet activation and heart disease: a missing link to cardiovascular protection in Gilbert's syndrome? Atherosclerosis 2014; 239:73-84. [PMID: 25576848 DOI: 10.1016/j.atherosclerosis.2014.12.042] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 12/18/2014] [Accepted: 12/19/2014] [Indexed: 02/07/2023]
Abstract
Gilbert's syndrome (GS) is a relatively common condition, inducing a benign, non-hemolytic, unconjugated hyperbilirubinemia. Gilbert's Syndrome is associated with mutation in the Uridine Glucuronosyl Transferase 1A1 (UGT1A1) gene promoter, reducing UGT1A1 activity, which normally conjugates bilirubin allowing its elimination from the blood. Individuals with GS demonstrate mildly elevated plasma antioxidant capacity caused by elevated levels of unconjugated bilirubin (UCB), reduced thiols and glutathione. Interestingly, the development of, and risk of mortality from, cardiovascular disease is remarkably reduced in GS individuals. An explanation for this protection may be explained by bilirubin's ability to inhibit multiple processes that induce platelet hyper-reactivity and thrombosis, thus far under-appreciated in the literature. Reactive oxygen species are produced continuously via metabolic processes and have the potential to oxidatively modify proteins and lipids within cell membranes, which may encourage the development of thrombosis and CVDs. Oxidative stress induced platelet hyper-reactivity significantly increases the risk of thrombosis, which can potentially lead to tissue infarction. Here, we discuss the possible mechanisms by which increased antioxidant status might influence platelet function and link this to cardiovascular protection in GS. In summary, this is the first article to discuss the possible role of bilirubin as an anti-thrombotic agent, which inhibits platelet activation and potentially, organ infarction, which could contribute to the reduced mortality rate in mildly hyperbilirbinemic individuals.
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Abstract
This review highlights the protective roles of bilirubin against the atherosclerotic process. Bilirubin belongs to the superfamily of tetrapyrrolic compounds formed during heme catabolism. Although for decades bilirubin was considered to be a harmful waste product, recent epidemiologic studies have shown that serum bilirubin levels have consistently been inversely associated with cardiovascular disease (CVD), as well as cardiovascular risk factors such as metabolic syndrome and diabetes. These clinical studies are supported by in vitro and in vivo experimental data and have demonstrated that bilirubin not only has an ability to scavenge overproduced reactive oxygen species and inhibit vascular smooth muscle cell proliferation but, additionally, has anti-inflammatory effects. In this review, we will discuss the inverse association of serum bilirubin and CVD and cardiovascular risk factors established in various clinical studies. We also review detailed experimental studies about the effect of bilirubin on atherosclerotic processes. In vitro, animal and human studies have proved that bilirubin inhibits oxidation of cholesterol which is an important step of atherosclerosis. Bilirubin attenuates chemotactic activity of monocytes and strongly inhibits adhesion of leukocytes to venule and production of pro-inflammatory cytokines. Bilirubin has inhibited serum-driven smooth muscle cell cycle progression at the G1 phase. Lastly, we will discuss briefly the influence of bilirubin on lipoprotein composition and endothelial dysfunction.
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Affiliation(s)
- Seung Joo Kang
- Department of Internal Medicine, Healthcare Research Institute, Seoul National University, Hospital Healthcare System Gangnam Center , Seoul , Korea
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Abstract
BACKGROUND The oxidative stress is thought to play an important role in Crohn's disease (CD). As serum bilirubin represents the major endogenous antioxidant, this article aimed to evaluate in a clinical study, whether serum bilirubin levels and genes affecting its systemic concentrations are associated with CD. METHODS This exploratory case-control study was based on pediatric (n = 119) and adult (n = 504) patients with CD and 370 appropriate healthy control subjects. The (GT)n and (TA)n dinucleotide variations in heme oxygenase 1 (HMOX1) and bilirubin UDP-glucuronosyl transferase (UGT1A1) gene promoters were determined by fragment analysis. Serum bilirubin levels were compared in a subset of 90 cases and 229 controls, for whom biochemical data were available. RESULTS Substantially lower serum bilirubin levels were detected in patients with CD compared with controls (7.4 versus 12.1 μmol/L, P < 10). Serum bilirubin levels were significantly lower in patients with CD within all UGT1A1*28 genotypes (P < 0.05). UGT1A1*28 homozygotes with wild-type NOD2 gene variant exhibited significant delay in CD manifestation (P = 0.004), while the protective effect of UGT1A1*28 homozygosity was lost in those patients with mutated NOD2 gene. No associations between CD risk and individual HMOX1 gene variants were observed. CONCLUSIONS CD is associated with significantly low serum bilirubin levels, most likely as a result of increased oxidative stress accompanying this inflammatory disease. UGT1A1*28 allele homozygosity, responsible for higher bilirubin levels, seems to be an important modifier of CD manifestation.
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Protection from age-related increase in lipid biomarkers and inflammation contributes to cardiovascular protection in Gilbert's syndrome. Clin Sci (Lond) 2013; 125:257-64. [PMID: 23566065 DOI: 10.1042/cs20120661] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Recent epidemiological and clinical data show protection from CVD (cardiovascular disease), all-cause mortality and cancer in subjects with GS (Gilbert's syndrome), which is characterized by a mildly elevated blood bilirubin concentration. The established antioxidant effect of bilirubin, however, contributes only in part to this protection. Therefore we investigated whether mildly elevated circulating UCB (unconjugated bilirubin) is associated with altered lipid metabolism. The study was performed on GS and age- and gender-matched healthy subjects (n=59 per group). Full lipoprotein profile, TAG (triacylglycerols), Apo (apolipoprotein)-A1, Apo-B, lipoprotein(a), the subfractions of LDL (low-density lipoprotein) and selected pro-inflammatory mediators were analysed. A hyperbilirubinaemic rodent model (Gunn rats, n=40) was investigated to further support the presented human data. GS subjects had significantly (P<0.05) improved lipid profile with reduced total cholesterol, LDL-C (LDL-cholesterol), TAG, low- and pro-atherogenic LDL subfractions (LDL-1+LDL-2), Apo-B, Apo-B/Apo-A1 ratio and lower IL-6 (interleukin 6) and SAA (serum amyloid A) concentrations (P=0.094). When the control and GS groups were subdivided into younger and older cohorts, older GS subjects demonstrated reduced lipid variables (total cholesterol and LDL-C, TAG and LDL-C subfractions, Apo-B/Apo-A1 ratio; P<0.05; Apo-B: P<0.1) compared with controls. These data were supported by lipid analyses in the rodent model showing that Gunn rat serum had lower total cholesterol (2.29±0.38 compared with 1.27±0.72 mM; P<0.001) and TAG (1.66±0.67 compared with 0.99±0.52 mM; P<0.001) concentrations compared with controls. These findings indicate that the altered lipid profile and the reduced pro-inflammatory status in hyperbilirubinaemic subjects, particularly in the older individuals, probably contribute additionally to the commonly accepted beneficial antioxidant effects of bilirubin in humans.
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Bulmer AC, Verkade HJ, Wagner KH. Bilirubin and beyond: a review of lipid status in Gilbert's syndrome and its relevance to cardiovascular disease protection. Prog Lipid Res 2012. [PMID: 23201182 DOI: 10.1016/j.plipres.2012.11.001] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Gilbert's syndrome (GS) is characterized by a benign, mildly elevated bilirubin concentration in the blood. Recent reports show clear protection from cardiovascular disease in this population. Protection of lipids, proteins and other macromolecules from oxidation by bilirubin represents the most commonly accepted mechanism contributing to protection in this group. However, a recent meta-analysis estimated that bilirubin only accounts for ~34% of the cardioprotective effects within analysed studies. To reveal the additional contributing variables we have explored circulating cholesterol and triacylglycerol concentrations, which appear to be decreased in hyperbilirubinemic individuals/animals, and are accompanied by lower body mass index in highly powered studies. These results suggest that bilirubin could be responsible for the development of a lean and hypolipidemic state in GS. Here we also discuss the possible contributing mechanisms that might reduce circulating cholesterol and triacylglycerol concentrations in individuals with syndromes affecting bilirubin metabolism/excretion, which we hope will stimulate future research in the area. In summary, this article is the first review of lipid status in animal and human studies of hyperbilirubinemia and explores possible mechanisms that could contribute to lowering circulating lipid parameters and further explain cardiovascular protection in Gilbert's syndrome.
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Affiliation(s)
- A C Bulmer
- Heart Foundation Research Centre, Griffith Health Institute, Griffith University, Gold Coast, Australia
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Boon AC, Hawkins CL, Bisht K, Coombes JS, Bakrania B, Wagner KH, Bulmer AC. Reduced circulating oxidized LDL is associated with hypocholesterolemia and enhanced thiol status in Gilbert syndrome. Free Radic Biol Med 2012; 52:2120-7. [PMID: 22521902 PMCID: PMC3377994 DOI: 10.1016/j.freeradbiomed.2012.03.002] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Revised: 03/09/2012] [Accepted: 03/10/2012] [Indexed: 12/22/2022]
Abstract
A protective association between bilirubin and atherosclerosis/ischemic heart disease clearly exists in vivo. However, the relationship between bilirubin and in vivo oxidative stress parameters in a clinical population remains poorly described. The aim of this study was to assess whether persons expressing Gilbert syndrome (GS; i.e., unconjugated hyperbilirubinemia) are protected from thiol oxidation and to determine if this, in addition to their improved lipoprotein profile, could explain reduced oxidized low-density lipoprotein (oxLDL) status in them. Forty-four matched GS and control subjects were recruited and blood was prepared for the analysis of lipid profile and multiple plasma antioxidants and measures of oxidative stress. GS subjects possessed elevated plasma reduced thiol (8.03±1.09 versus 6.75±1.39 nmol/mg protein; P<0.01) and glutathione concentrations (12.7±2.39 versus 9.44±2.45 μM; P<0.001). Oxidative stress status (reduced:oxidized glutathione; GSH:GSSG) was significantly improved in GS (0.49±0.16 versus 0.32±0.12; P<0.001). Protein carbonyl concentrations were negatively associated with bilirubin concentrations and were significantly lower in persons with >40 μM bilirubin versus controls (<17.1 μmol/L; P<0.05). Furthermore, absolute oxLDL concentrations were significantly lower in GS subjects (P<0.05). Forward stepwise regression analysis revealed that bilirubin was associated with increased GSH:GSSG ratio and reduced thiol concentrations, which, in addition to reduced circulating LDL, probably decreased oxLDL concentrations within the cohort. In addition, a marked reduction in total cholesterol concentrations in hyperbilirubinemic Gunn rats is presented (Gunn 0.57±0.09 versus control 1.69±0.40 mmol/L; P<0.001), arguing for a novel role for bilirubin in modulating lipid status in vivo. These findings implicate the physiological importance of bilirubin in protecting from atherosclerosis by reducing thiol and subsequent lipoprotein oxidation, in addition to reducing circulating LDL concentrations.
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Key Words
- bmi, body mass index
- cvd, cardiovascular disease
- dtnb, 5,5-dithiobis(2-nitrobenzoic acid)
- frap, ferric reducing ability of plasma
- gs, gilbert syndrome
- gsh, reduced glutathione
- gssg, oxidized glutathione
- hdl, high-density lipoprotein
- ho-1, heme oxygenase-1
- hplc, high-performance liquid chromatography
- ldl, low-density lipoprotein
- oxldl, oxidized low-density lipoprotein
- tca, trichloroacetic acid
- teac, trolox equivalent antioxidant capacity
- ugt, uridine diphosphate glucuronosyltransferase
- cardiovascular disease
- bile pigment
- thiol
- glutathione
- bilirubin
- free radicals
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Affiliation(s)
- Ai-Ching Boon
- Heart Foundation Research Center, Griffith Health Institute, Griffith University, Gold Coast, Qld 4222, Australia
| | | | - Kavita Bisht
- Heart Foundation Research Center, Griffith Health Institute, Griffith University, Gold Coast, Qld 4222, Australia
| | - Jeff S. Coombes
- School of Human Movement Studies, University of Queensland, St. Lucia, Qld 4067, Australia
| | - Bhavisha Bakrania
- Heart Foundation Research Center, Griffith Health Institute, Griffith University, Gold Coast, Qld 4222, Australia
| | - Karl-Heinz Wagner
- Department of Nutritional Science, University of Vienna, Vienna 1090, Austria
| | - Andrew C. Bulmer
- Heart Foundation Research Center, Griffith Health Institute, Griffith University, Gold Coast, Qld 4222, Australia
- Corresponding author. Fax: +61 755528908.
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Xia F, Wang XL, Li ZW. Gilbert syndrome: An analysis of 9 cases. Shijie Huaren Xiaohua Zazhi 2012; 20:1054-1056. [DOI: 10.11569/wcjd.v20.i12.1054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To analyze the clinical and pathological characteristics of Gilbert syndrome.
METHODS: The clinical and pathological data for 9 patients who were diagnosed with Gilbert syndrome by the fasting test, phenobarbital test and liver tissue pathology were retrospectively analyzed.
RESULTS: The onset of Gilbert syndrome is more common in adolescence (77.8%). More males were affected than females. Most patients showed no clinical symptoms or signs, and had serum bilirubin levels lower than 50 μmol/L. Pathological changes in the liver were mild.
CONCLUSION: Gilbert syndrome is usually asymptomatic, results in mild pathological changes in the liver, and does not need treatment.
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Tapan S, Karadurmus N, Dogru T, Ercin CN, Tasci I, Bilgi C, Kurt I, Erbil MK. Decreased small dense LDL levels in Gilbert's syndrome. Clin Biochem 2010; 44:300-3. [PMID: 21167147 DOI: 10.1016/j.clinbiochem.2010.12.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 11/11/2010] [Accepted: 12/06/2010] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To investigate the role of small dense low density lipoprotein cholesterol (sd-LDL-C) in the mechanism of decreased incidence of cardiovascular disease in Gilbert's syndrome (GS). DESIGN AND METHODS sd-LDL-C, ox-LDL, and high sensitive C reactive protein (hs-CRP) levels were investigated in subjects with GS (n=42) and compared to healthy controls (n=52). RESULTS Age, gender and body mass index (BMI) distributions were similar between the two groups. sd-LDL-C, ox-LDL and hs-CRP levels were lower in GS than the healthy controls (p<0.001, p<0.001 and p=0.001, respectively). Unconjugated bilirubin was negatively correlated with sd-LDL-C, ox-LDL and hs-CRP (r=-0.594, p<0.001; r=-0.249, p=0.016 and r=-0.373, p<0.001 respectively). In addition, sd-LDL-C was positively correlated with ox-LDL (r=0.307, p=0.003). CONCLUSIONS The findings of this preliminary study suggest that reduced sd-LDL-C, ox-LDL and hs-CRP levels may have a role in preventing atherosclerosis in subjects with GS.
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Affiliation(s)
- Serkan Tapan
- Department of Medical Biochemistry, Gulhane School of Medicine, Ankara, Turkey.
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Oda E, Kawai R. Bilirubin is negatively associated with hemoglobin a(1c) independently of other cardiovascular risk factors in apparently healthy Japanese men and women. Circ J 2010; 75:190-5. [PMID: 21139250 DOI: 10.1253/circj.cj-10-0645] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Serum total bilirubin (TB) is a potent antioxidant and may be a negative risk factor of cardiovascular disease. In non-diabetic adults, hemoglobin A(1c) (HbA(1c)), but not fasting plasma glucose, is an independent risk factor of cardiovascular disease. METHODS AND RESULTS Linear regression using TB as a dependent variable and cardiovascular risk factors, including HbA(1c), as independent variables, linear regression using HbA(1c) as a dependent variable and other cardiovascular risk factors, including TB, as independent variables, and logistic regression using the highest decile (≥ 5.4%) of HbA(1c) as a dependent variable and TB and other cardiovascular risk factors as independent variables were performed for 893 apparently healthy male smokers, 1,607 male nonsmokers, and 1,680 women. The standardized regression coefficient of HbA(1c) for TB and that of TB for HbA(1c) was -0.12 (P = 0.007) and -0.06 (P = 0.02), respectively, in the smokers, -0.20 (P < 0.0001) and -0.07 (P < 0.0001), respectively, in the nonsmokers, and -0.21 (P < 0.0001) and -0.14 (P < 0.0001), respectively, in the women. The odds ratio of 1 SD increment in TB for HbA(1c) ≥ 5.4% was not significant in the smokers, 0.67 (P = 0.002) in the nonsmokers, and 0.55 (P<0.0001) in the women. CONCLUSIONS Bilirubin was negatively associated with HbA(1c) independently of other cardiovascular risk factors in apparently healthy Japanese men and women. The association was weak in male smokers.
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Affiliation(s)
- Eiji Oda
- Medical Check-up Center, Tachikawa Medical Center, Nagaoka, Japan.
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Vítek L, Muchová L, Jančová E, Pešičková S, Tegzová D, Peterová V, Pavelka K, Tesař V, Schwertner HA. Association of systemic lupus erythematosus with low serum bilirubin levels. Scand J Rheumatol 2010; 39:480-4. [DOI: 10.3109/03009741003742748] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Schwertner HA, Vítek L. Gilbert syndrome, UGT1A1*28 allele, and cardiovascular disease risk: possible protective effects and therapeutic applications of bilirubin. Atherosclerosis 2008; 198:1-11. [PMID: 18343383 DOI: 10.1016/j.atherosclerosis.2008.01.001] [Citation(s) in RCA: 169] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2007] [Revised: 11/08/2007] [Accepted: 01/11/2008] [Indexed: 02/06/2023]
Abstract
Serum bilirubin has been shown to be inversely related to cardiovascular disease (CVD) in both retrospective and prospective studies. Meta-analysis of existing studies has also confirmed that serum bilirubin concentrations are inversely related to CVD. Less information is known about the protective effects of slightly elevated serum bilirubin concentrations. In this review, we will focus primarily on the association of serum bilirubin and CVD and the possible protective roles of bilirubin, heme oxygenase (HO), and bilirubin UDP-glucuronosyltransferase (UGT1A1). HO and biliverdin reductase control the formation of bilirubin, whereas UGT1A1 controls bilirubin conjugation and clearance. Because of the health and therapeutic implications of slightly elevated serum bilirubin concentrations, we will discuss the recent prospective studies on cardiovascular risk in individuals with Gilbert syndrome (GS) as well as those with the UGT1A1*28 allele. Such individuals have decreased hepatic bilirubin UDP-glucuronosyltransferase activity, decreased bilirubin clearance, and increased serum bilirubin concentrations. Lastly, we will discuss some of the therapeutic approaches that could be used to increase serum bilirubin concentrations to prevent CVD and other oxidative and inflammatory diseases.
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Merdink JL, Robison LM, Stevens DK, Hu M, Parker JC, Bull RJ. Kinetics of chloral hydrate and its metabolites in male human volunteers. Toxicology 2007; 245:130-40. [PMID: 18243465 DOI: 10.1016/j.tox.2007.12.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2007] [Revised: 12/15/2007] [Accepted: 12/18/2007] [Indexed: 01/12/2023]
Abstract
Chloral hydrate (CH) is a short-lived intermediate in the metabolism of trichloroethylene (TRI). TRI, CH, and two common metabolites, trichloroacetic acid (TCA) and dichloroacetic acid (DCA) have been shown to be hepatocarcinogenic in mice. To better understand the pharmacokinetics of these metabolites of TRI in humans, eight male volunteers, aged 24-39, were administered single doses of 500 or 1,500 mg or a series of three doses of 500 mg given at 48 h intervals, in three separate experiments. Blood and urine were collected over a 7-day period and CH, DCA, TCA, free trichloroethanol (f-TCE), and total trichloroethanol (T-TCE=trichloroethanol and trichloroethanol-glucuronide [TCE-G]) were measured. DCA was detected in blood and urine only in trace quantities (<2 microM). TCA, on the other hand, had the highest plasma concentration and the largest AUC of any metabolite. The TCA elimination curve displayed an unusual concentration-time profile that contained three distinct compartments within the 7-day follow-up period. Previous work in rats has shown that the complex elimination curve for TCA results largely from the enterohepatic circulation of TCE-G and its subsequent conversion to TCA. As a result TCA had a very long residence time and this, in turn, led to a substantial enhancement of peak concentrations following the third dose in the multiple dose experiment. Approximately 59% of the AUC of plasma TCA following CH administration is produced via the enterohepatic circulation of TCE-G. The AUC for f-TCE was found to be positively correlated with serum bilirubin concentrations. This effect was greatest in one subject that was found to have serum bilirubin concentrations at the upper limit of the normal range in all three experiments. The AUC of f-TCE in the plasma of this individual was consistently about twice that of the other seven subjects. The kinetics of the other metabolites of CH was not significantly modified in this individual. These data indicate that individuals with a more impaired capacity for glucuronidation may be very sensitive to the central nervous system depressant effects of high doses of CH, which are commonly attributed to plasma levels of f-TCE.
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Affiliation(s)
- J L Merdink
- Pharmacology/Toxicology, Washington State University, Pullman, WA, United States
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Bulmer AC, Blanchfield JT, Toth I, Fassett RG, Coombes JS. Improved resistance to serum oxidation in Gilbert's syndrome: a mechanism for cardiovascular protection. Atherosclerosis 2007; 199:390-6. [PMID: 18155709 DOI: 10.1016/j.atherosclerosis.2007.11.022] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Revised: 11/01/2007] [Accepted: 11/15/2007] [Indexed: 10/22/2022]
Abstract
Bilirubin is a potent antioxidant, however, uncertainty surrounds its physiological importance. Individuals with Gilbert's syndrome (GS) have increased circulating bilirubin and a reduced prevalence of cardiovascular disease (CVD). The aim of this study was to investigate mechanisms that may link bilirubin to protection from CVD seen in GS by examining markers of antioxidant and oxidative stress status and the susceptibility of serum to oxidation. Nine individuals with GS and twelve controls, matched for age, height and weight, were assessed for plasma antioxidant status, red blood cell antioxidant enzyme activities, plasma malondialdehyde, the susceptibility of serum to copper (Cu(2+)) induced oxidation and blood lipid profile. Individuals with GS had significantly elevated unconjugated bilirubin (GS: 26.0+/-6.4; control: 9.7+/-3.0 micromol/L; P<0.001), increased trolox equivalent antioxidant capacity (GS: 1.59+/-0.07; control: 1.52+/-0.07 mmol/L trolox Equ; P=0.035) and ferric reducing ability of plasma (GS: 1.09+/-0.16; control: 0.92+/-0.14 mmol/L Fe(2+) Equ; P=0.024). The lag phase of serum oxidation was significantly longer in the GS group (GS: 121.4+/-10.5; control: 106.8+/-14.6 min; P=0.020) and was positively correlated with the bilirubin concentration (r=0.451, P=0.040). A trend toward elevated HDL:LDL ratio was observed in GS (GS 0.96+/-0.31; control: 0.73+/-0.21; P=0.072). In summary, individuals with GS have an increased circulating antioxidant status and an improved resistance to serum oxidation which may partially explain their reduced prevalence of CVD.
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Affiliation(s)
- Andrew C Bulmer
- School of Human Movement Studies, University of Queensland, St Lucia, Queensland 4067, Australia.
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