Abstract
Background: The expression of the key iron regulatory hormone hepcidin is regulated by iron availability, inflammation, hormones, hypoxia, and anaemia. Increased serum concentrations of hepcidin have recently been linked to atherosclerosis. We studied demographic, haematologic, biochemical, and dietary correlates of serum hepcidin levels and its associations with incident cardiovascular disease and with carotid atherosclerosis.
Methods: Serum hepcidin concentrations were measured by tandem mass spectrometry in samples taken in 2000 from 675 infection-free participants of the prospective population-based Bruneck study (age, mean±standard deviation, 66.0±10.2; 48.1% male). Blood parameters were measured by standard methods. Dietary intakes of iron and alcohol were surveyed with a food frequency questionnaire. Carotid atherosclerosis (365 cases) was assessed by ultrasound and subjects were observed for incident stroke, myocardial infarction, or sudden cardiac death (91 events) until 2010.
Results: Median (interquartile range) hepcidin levels were 2.27 nM (0.86, 4.15). Most hepcidin correlates were in line with hepcidin as an indicator of iron stores. Independently of ferritin, hepcidin was related directly to physical activity (p=0.024) and fibrinogen (p<0.0001), and inversely to alcohol intake (p=0.006), haemoglobin (p=0.027), and γ-glutamyltransferase (p<0.0001). Hepcidin and hepcidin-to-ferritin ratio were not associated with prevalent carotid atherosclerosis (p=0.43 and p=0.79) or with incident cardiovascular disease (p=0.62 and p=0.33).
Conclusions: In this random sample of the general community, fibrinogen and γ-glutamyltransferase were the most significant hepcidin correlates independent of iron stores, and hepcidin was related to neither atherosclerosis nor cardiovascular disease.
Acknowledgments
We thank the anonymous referees for valuable comments and suggestions.
Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.
Research funding: Financial support by the Austrian Research Fund project TRP-188 (to G.W., S.K. and J.W.) is gratefully acknowledged. M.M. is a Senior Research Fellow of the British Heart Foundation. The study was supported by the NIHR Biomedical Research Centre based at Guy’s and St Thomas’ NHS Foundation Trust and King’s College London in partnership with King’s College Hospital.
Employment or leadership: None declared.
Honorarium: None declared.
Competing interests: The funding organisation(s) played no role in the study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the report for publication.
References
1. Ganz T. Systemic iron homeostasis. Physiol Rev 2013;93: 1721–41.10.1152/physrev.00008.2013Search in Google Scholar PubMed
2. Hentze MW, Muckenthaler MU, Galy B, Camaschella C. Two to tango: regulation of mammalian iron metabolism. Cell 2010;142:24–38.10.1016/j.cell.2010.06.028Search in Google Scholar PubMed
3. Sonnweber T, Nachbaur D, Schroll A, Nairz M, Seifert M, Demetz E, et al. Hypoxia induced downregulation of hepcidin is mediated by platelet derived growth factor BB. Gut 2014;63:1951–9.10.1136/gutjnl-2013-305317Search in Google Scholar PubMed
4. Hou Y, Zhang S, Wang L, Li J, Qu G, He J, et al. Estrogen regulates iron homeostasis through governing hepatic hepcidin expression via an estrogen response element. Gene 2012;511:398–403.10.1016/j.gene.2012.09.060Search in Google Scholar PubMed
5. Vecchi C, Montosi G, Zhang K, Lamberti I, Duncan SA, Kaufman RJ, et al. ER stress controls iron metabolism through induction of hepcidin. Science 2009;325:877–80.10.1126/science.1176639Search in Google Scholar PubMed PubMed Central
6. Goodnough JB, Ramos E, Nemeth E, Ganz T. Inhibition of hepcidin transcription by growth factors. Hepatology 2012;56:291–9.10.1002/hep.25615Search in Google Scholar PubMed PubMed Central
7. Latour C, Kautz L, Besson-Fournier C, Island M-L, Canonne-Hergaux F, Loréal O, et al. Testosterone perturbs systemic iron balance through activation of epidermal growth factor receptor signaling in the liver and repression of hepcidin. Hepatology 2014;59:683–94.10.1002/hep.26648Search in Google Scholar PubMed
8. Nemeth E, Tuttle MS, Powelson J, Vaughn MB, Donovan A, Ward DM, et al. Hepcidin regulates cellular iron efflux by binding to ferroportin and inducing its internalization. Science 2004;306:2090–3.10.1126/science.1104742Search in Google Scholar PubMed
9. Theurl I, Aigner E, Theurl M, Nairz M, Seifert M, Schroll A, et al. Regulation of iron homeostasis in anemia of chronic disease and iron deficiency anemia: diagnostic and therapeutic implications. Blood 2009;113:5277–86.10.1182/blood-2008-12-195651Search in Google Scholar PubMed
10. Sullivan JL. Iron in arterial plaque: a modifiable risk factor for atherosclerosis. Biochim Biophys Acta 2009;1790:718–23.10.1016/j.bbagen.2008.06.005Search in Google Scholar PubMed
11. Kiechl S, Aichner F, Gerstenbrand F, Egger G, Mair A, Rungger G, et al. Body iron stores and presence of carotid atherosclerosis. Results from the Bruneck Study. Arterioscler Thromb Vasc Biol 1994;14:1625–30.10.1161/01.ATV.14.10.1625Search in Google Scholar
12. Kiechl S, Willeit J, Egger G, Poewe W, Oberhollenzer F. Body iron stores and the risk of carotid atherosclerosis prospective results from the Bruneck study. Circulation 1997;96:3300–7.10.1161/01.CIR.96.10.3300Search in Google Scholar
13. Saeed O, Otsuka F, Polavarapu R, Karmali V, Weiss D, Davis T, et al. Pharmacological suppression of hepcidin increases macrophage cholesterol efflux and reduces foam cell formation and atherosclerosis. Arterioscler Thromb Vasc Biol 2012;32:299–307.10.1161/ATVBAHA.111.240101Search in Google Scholar PubMed PubMed Central
14. Kautz L, Gabayan V, Wang X, Wu J, Onwuzurike J, Jung G, et al. Testing the iron hypothesis in a mouse model of atherosclerosis. Cell Rep 2013;5:1436–42.10.1016/j.celrep.2013.11.009Search in Google Scholar PubMed PubMed Central
15. Li JJ, Meng X, Si HP, Zhang C, Lv HX, Zhao YX, et al. Hepcidin destabilizes atherosclerotic plaque via overactivating macrophages after erythrophagocytosis. Arterioscler Thromb Vasc Biol 2012;32:1158–66.10.1161/ATVBAHA.112.246108Search in Google Scholar PubMed
16. Sullivan JL. Macrophage iron, hepcidin, and atherosclerotic plaque stability. Exp Biol Med 2007;232:1014–20.10.3181/0703-MR-54Search in Google Scholar PubMed
17. Galesloot TE, Holewijn S, Kiemeney LA, de Graaf J, Vermeulen SH, Swinkels DW. Serum hepcidin is associated with presence of plaque in postmenopausal women of a general population. Arterioscler Thromb Vasc Biol 2014;34:446–56.10.1161/ATVBAHA.113.302381Search in Google Scholar PubMed
18. van der Weerd NC, Grooteman MP, Bots ML, van den Dorpel MA, den Hoedt CH, Mazairac AH, et al. Hepcidin-25 is related to cardiovascular events in chronic haemodialysis patients. Nephrol Dial Transplant 2013;28:3062–71.10.1093/ndt/gfs488Search in Google Scholar PubMed
19. Kuragano T, Itoh K, Shimonaka Y, Kida A, Furuta M, Kitamura R, et al. Hepcidin as well as TNF-α are significant predictors of arterial stiffness in patients on maintenance hemodialysis. Nephrol Dial Transplant 2011;26:2663–7.10.1093/ndt/gfq760Search in Google Scholar PubMed
20. Valenti L, Dongiovanni P, Motta BM, Swinkels DW, Bonara P, Rametta R, et al. Serum hepcidin and macrophage iron correlate with mcp-1 release and vascular damage in patients with metabolic syndrome alterations. Arterioscler Thromb Vasc Biol 2011;31:683–90.10.1161/ATVBAHA.110.214858Search in Google Scholar PubMed
21. Kiechl S, Lorenz E, Reindl M, Wiedermann CJ, Oberhollenzer F, Bonora E, et al. Toll-like receptor 4 polymorphisms and atherogenesis. N Engl J Med 2002;347:185–92.10.1056/NEJMoa012673Search in Google Scholar PubMed
22. Kiechl S, Wittmann J, Giaccari A, Knoflach M, Willeit P, Bozec A, et al. Blockade of receptor activator of nuclear factor-κB (RANKL) signaling improves hepatic insulin resistance and prevents development of diabetes mellitus. Nat Med 2013;19:358–63.10.1038/nm.3084Search in Google Scholar PubMed
23. Willeit K, Pechlaner R, Egger G, Weger S, Oberhollenzer M, Willeit J, et al. Carotid atherosclerosis and incident atrial fibrillation. Arterioscler Thromb Vasc Biol 2013;33:2660–5.10.1161/ATVBAHA.113.302272Search in Google Scholar PubMed
24. Kiechl S, Schett G, Schwaiger J, Seppi K, Eder P, Egger G, et al. Soluble receptor activator of nuclear factor-κb ligand and risk for cardiovascular disease. Circulation 2007;116:385–91.10.1161/CIRCULATIONAHA.106.686774Search in Google Scholar PubMed
25. Bansal SS, Abbate V, Bomford A, Halket JM, Macdougall IC, Thein SL, et al. Quantitation of hepcidin in serum using ultra-high-pressure liquid chromatography and a linear ion trap mass spectrometer. Rapid Commun Mass Spectrom 2010;24:1251–9.10.1002/rcm.4512Search in Google Scholar PubMed
26. Compendium of physical activities: an update of activity codes and MET intensities.Search in Google Scholar
27. Kiechl S, Willeit J. The natural course of atherosclerosis. Part I: incidence and progression. Arterioscler Thromb Vasc Biol 1999;19:1484–90.10.1161/01.ATV.19.6.1484Search in Google Scholar PubMed
28. Willeit J, Kiechl S, Oberhollenzer F, Rungger G, Egger G, Bonora E, et al. Distinct risk profiles of early and advanced atherosclerosis: prospective results from the Bruneck Study. Arterioscler Thromb Vasc Biol 2000;20:529–37.10.1161/01.ATV.20.2.529Search in Google Scholar PubMed
29. Nomenclature and criteria for diagnosis of ischemic heart disease. Report of the Joint International Society and Federation of Cardiology/World Health Organization task force on standardization of clinical nomenclature. Circulation 1979;59:607–9.10.1161/01.CIR.59.3.607Search in Google Scholar
30. Walker AE, Robins M, Weinfeld FD. The National Survey of Stroke. Clinical findings. Stroke J Cereb Circ 1981;12 (2 Pt 2 Suppl 1):I13–44.Search in Google Scholar
31. Koenker R, Hallock KF. Quantile regression. J Econ Perspect 2001;15:143–56.10.1257/jep.15.4.143Search in Google Scholar
32. Galesloot TE, Vermeulen SH, Geurts-Moespot AJ, Klaver SM, Kroot JJ, van Tienoven D, et al. Serum hepcidin: reference ranges and biochemical correlates in the general population. Blood 2011;117:e218–25.10.1182/blood-2011-02-337907Search in Google Scholar PubMed
33. den Elzen WP, de Craen AJ, Wiegerinck ET, Westendorp RG, Swinkels DW, Gussekloo J. Plasma hepcidin levels and anemia in old age. The Leiden 85-Plus Study. Haematologica 2013;98:448–54.10.3324/haematol.2012.068825Search in Google Scholar PubMed PubMed Central
34. Kroot JJ, Kemna EH, Bansal SS, Busbridge M, Campostrini N, Girelli D, et al. Results of the first international round robin for the quantification of urinary and plasma hepcidin assays: need for standardization. Haematologica 2009;94:1748–52.10.3324/haematol.2009.010322Search in Google Scholar PubMed PubMed Central
35. Traglia M, Girelli D, Biino G, Campostrini N, Corbella M, Sala C, et al. Association of HFE and TMPRSS6 genetic variants with iron and erythrocyte parameters is only in part dependent on serum hepcidin concentrations. J Med Genet 2011;48:629–34.10.1136/jmedgenet-2011-100061Search in Google Scholar PubMed
36. Schaap CC, Hendriks JC, Kortman GA, Klaver SM, Kroot JJ, Laarakkers CM, et al. Diurnal rhythm rather than dietary iron mediates daily hepcidin variations. Clin Chem 2013;59:527–35.10.1373/clinchem.2012.194977Search in Google Scholar PubMed
37. Kroot JJ, Hendriks JC, Laarakkers CM, Klaver SM, Kemna EH, Tjalsma H, et al. (Pre)analytical imprecision, between-subject variability, and daily variations in serum and urine hepcidin: implications for clinical studies. Anal Biochem 2009;389:124–9.10.1016/j.ab.2009.03.039Search in Google Scholar PubMed
38. Ganz T, Olbina G, Girelli D, Nemeth E, Westerman M. Immunoassay for human serum hepcidin. Blood 2008;112:4292–7.10.1182/blood-2008-02-139915Search in Google Scholar PubMed
39. Pantopoulos K, Porwal SK, Tartakoff A, Devireddy L. Mechanisms of mammalian iron homeostasis. Biochemistry (Mosc) 2012;51:5705–24.10.1021/bi300752rSearch in Google Scholar PubMed PubMed Central
40. Thomas C, Kobold U, Balan S, Roeddiger R, Thomas L. Serum hepcidin-25 may replace the ferritin index in the Thomas plot in assessing iron status in anemic patients. Int J Lab Hematol 2011;33:187–93.10.1111/j.1751-553X.2010.01265.xSearch in Google Scholar PubMed
41. Weiss G, Theurl I, Eder S, Koppelstaetter C, Kurz K, Sonnweber T, et al. Serum hepcidin concentration in chronic haemodialysis patients: associations and effects of dialysis, iron and erythropoietin therapy. Eur J Clin Invest 2009;39:883–90.10.1111/j.1365-2362.2009.02182.xSearch in Google Scholar PubMed
42. Weiss G, Goodnough LT. Anemia of chronic disease. N Engl J Med 2005;352:1011–23.10.1056/NEJMra041809Search in Google Scholar PubMed
43. Busti F, Campostrini N, Martinelli N, Girelli D. Iron deficiency in the elderly population, revisited in the hepcidin era. Drug Metab Transp 2014;5:83.10.3389/fphar.2014.00083Search in Google Scholar PubMed PubMed Central
44. Bode JG, Albrecht U, Häussinger D, Heinrich PC, Schaper F. Hepatic acute phase proteins – regulation by IL-6- and IL-1-type cytokines involving STAT3 and its crosstalk with NF-κB-dependent signaling. Eur J Cell Biol 2012;91: 496–505.10.1016/j.ejcb.2011.09.008Search in Google Scholar PubMed
45. Poli M, Girelli D, Campostrini N, Maccarinelli F, Finazzi D, Luscieti S, et al. Heparin: a potent inhibitor of hepcidin expression in vitro and in vivo. Blood 2011;117:997–1004.10.1182/blood-2010-06-289082Search in Google Scholar PubMed
46. Zmijewski E, Lu S, Harrison-Findik DD. TLR4 signaling and the inhibition of liver hepcidin expression by alcohol. World J Gastroenterol 2014;20:12161–70.10.3748/wjg.v20.i34.12161Search in Google Scholar PubMed PubMed Central
47. Fleming DJ, Tucker KL, Jacques PF, Dallal GE, Wilson PW, Wood RJ. Dietary factors associated with the risk of high iron stores in the elderly Framingham Heart Study cohort. Am J Clin Nutr 2002;76:1375–84.10.1093/ajcn/76.6.1375Search in Google Scholar PubMed
48. Theurl I, Schroll A, Nairz M, Seifert M, Theurl M, Sonnweber T, et al. Pathways for the regulation of hepcidin expression in anemia of chronic disease and iron deficiency anemia in vivo. Haematologica 2011;96:1761–9.10.3324/haematol.2011.048926Search in Google Scholar PubMed PubMed Central
49. Vecchi C, Montosi G, Garuti C, Corradini E, Sabelli M, Canali S, et al. Gluconeogenic signals regulate iron homeostasis via hepcidin in mice. Gastroenterology 2014;146:1060–9.e3.10.1053/j.gastro.2013.12.016Search in Google Scholar PubMed PubMed Central
Supplemental Material:
The online version of this article (DOI: 10.1515/cclm-2015-0068) offers supplementary material, available to authorized users.
©2016 by De Gruyter
