Relationship between the level of troponin and some trace elements in sera of patients with heart disease.
Ischemic heart disease (IHD) is the leading cause of death in most population of the world which can be decreased by changing life style. (1) IHD and coronary heart disease (CHD) are the generic designation for the four forms of cardiac diseases, i.e., angina pectoris, sudden cardiac death, myocardial infarction and chronic ischemic heart disease. (2) In most cases the imbalance results from insufficient blood flow secondary to the development of atherosclerosis resulting in narrowing of the coronary arteries and hence the term 'Coronary Heart Disease'. (2,3) Myocardial cell death can be appeared of different proteins and enzymes into the circulation from the damaged myocytes includes: myoglobin, creatinine kinase (CK), lactate dehydrogenase (LDH), glutamate oxalo acetate transaminase (GOT) and TnT, TnI (4). Troponin is a complex of three proteins that bind to the thin filament of striated muscle (cardiac and skeletal) but are not present in smooth muscle. The complex consists of TnT, TnI and TnC. Together, their function are to regulate muscle contraction (7). cTnT and cTnl are now regarded as the most specific biochemical markers of myocardial injury. Studies have shown that cardiac troponin should replace CK-MB as the diagnostic "gold standard" for the diagnosis of myocardial injury. The reasons being (5):1-Troponins are highly cardio specific especially the cTnl, 2. The prolonged elevation (4-14 days) make it a good marker for patients admitted to the hospital after several days of MI, 3-cTns have greater sensitivity for minor degrees of myocardial injury due to the cardio specificity and their very low concentration in serum of normal individuals, 4. These are excellent prognostic indicator in patients with (UA) and is very useful parameter for stratifying risk in Acute Coronary Syndrome (ACS) patient and their predictive value is superior to that of CK-MB alone, 5- The early serial measurement of cTns is a more accurate predictor of early coronary artery reperfusion after thrombolytic therapy as compared to CK-MB and myoglobin and it is also identified a sub to group of patients with unstable coronary syndrome in whom prolonged antithrombotic treatment with low-molecular weight heparin can improve the prognosis, figure. (1)
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The aim of this work is to Estimate the levels of cTn (T,I) in patients with MI, UA and compared with control group and study some trace elements such as (Zn, Cu, Ca, Fe) in patients with MI, UA and compared with control group. Also studying the correlation between the above parameters.
Materials and methods
Patients, Controls and General Plan
Two groups of patients with MI, UA were included in this study : Consist of (39) patients with MI, and (21) patients with UA. The main age are 50 [+ or -] 10 and control (30) persons of the same mean age 50 [+ or -] 10. The samples collected from patients treated in Ibn Al--Bitar hospital for cardiac surgery from March 2008 to May 2008. Each serum samples were analyzed for TnI, TnT quantitative and trace elements Zn, Cu, Ca and Fe. 5 ml of venous blood samples were taken. Only 1 ml of this blood was anticoagulated with sodium heparin to diagnosis TnT and not frozen, while 4 ml separated by centrifugation for 10 min at 1500Xg. The sera were stored and frozen at -20 [degrees]C until analysis TnI and trace elements.
Determination of TnI and TnT
Biochek human cardiac specific troponin I enzyme immunoassay (cTnI ELISA) used for quantitative determination of cardiac specific TnI in human serum (8). The cardiac T quantitative rapid assay is intended for the quantitative determination of cardiac troponin T (cTnT) in anti coagulant venous whole blood with the CARDIAC reader instrument (9,10). Measurements of cTnT have been shown to aid in the diagnosis of MI injury. Catalog No. 1894307 ROCHE CARDIAC.
Trace elements (11)
Trace elements Fe, Cu, Ca and Zn were assessed in this study by using atomic absorption spectrophotometer (AAS). This is equipped with nitrous oxide acetylene burner-Hollow Cathode Lamps are used for these elements.
Statistical analyses were done using Microsoft office (SPSS version 11.4) which includes the following : Mean [+ or -] standard deviation, Student t-test, Correlation regression, P value of less than 0.05 was considered significant.
Table (1) list the (mean [+ or -]SD) ng/ml of TnT, TnI in the sera of control group and patients with MI, UA.
Table (2) shows the concentration (ppm) of Zn, Fe, Ca and Cu in sera of control and patients groups.
The relationship between troponin (T, I) and some trace elements like (Ca, Cu, Fe, Zn) , as clear in figures from (2) to (10):
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The preferred biomarker of myocardial necrosis is cardiac Tn (I or T) which has nearly absolute myocardial tissue specificity as well as high clinical sensitivity there by reflecting even microscopic zones of myocardial necrosis in clinical trails, as in clinical practice, measurement of cardiac Tn (I or T) is preferred over measurement of CK-MB or other biomarkers for the diagnosis of MI (12,13).
The results show a highly significant increase (P < 0.05) in the concentration of TnI and TnT in MI and UA comparing to control group. Cardiac reader instrument has low sensitivity to read level troponin for healthy persons because it reads only positive results. These results are in agreement with James P. et al (14) who studied relation between troponin T concentration and mortality in patients presenting with an acute stroke, Collonson P., et al (15) studied multicentre evaluation of the assessing patients with suspected acute coronary syndrome, Ham C.W., et al (16) studied prognostic value of serum troponin T in unstable angina, and Peter P., et al (17) studied troponin as a risk factor for mortality in critically ill patients without ACS.
This study shows that the level of TnT for MI higher than UA patients and this may be due to that TnT more sensitive indicator of myocardial cell injury and can diagnose even in micro cell damage (14).
Infarct size can be estimated by TnT than with TnI which suggests that cTnT level measured at acute coronary syndrome(ACS) (18,19). In cTnI results show that the concentration of TnI in MI higher than its concentration in UA., TnT more sensitive indicator for MI, some studies proved that (94%) of cTnI sensitive for MI. TnI elevation levels can be detected 3-4 hrs after the onset symptoms of MI (20). On the other hand, cTnI values in patients with UA were much lower than those in patients with MI and sensitively cTnI was also low. It is strongly suggested that the former is the case with MI and the latter occurs in case of UA because the elevation of cTnI values can last until (1 week -10 days) after onset (21). MI is more likely in patients with elevated cTnI than in those with normal value (22) and mortality of patients with elevated TnI is significantly increased (odds ratio = 3 : 1) compared to that of patients with a negative test (23). However, much of troponin is released as a complex with a higher molecular weight. Some studies argued that the transient troponin release in experimental model of vital exhaustion, experimental studies with longer ischemia time may be due to the release of troponin from "cytosolic pool" only (24). Other studies showed that the early troponin release during ACS is thought to steam from cytosolic pool and the subsequent gradual release is prolonged with degradation of the actin and myosin filament in the damaged myocardium because the cardiac forms of both proteins come from specific genes. The failure of continuing release has been attributed to the lack of release structurally bound troponin and thus "reversible injury" such right ventricle infarction and with the recovery of left ventricular function in patients with septic shock since one cannot distinguish one type of release from the other (25). Acute Coronary Syndrome (ACS) mainly a rises from the rupture of an atheromatous plaque troponin release predominantly occurs due to mechanisms of exposure of the plaque core results in platelet activation and aggregation (white thrombus). These aggregates are unstable and produce distal embolosation with micro infarction and troponin release progression to activation of the clotting cascade results in fibrin clot formation (red thrombus) with vessel occlusion and an area of necrosis in the territory supplied by the artery. The release of cTnI and cTnT in these circumstances occurs due to temporal events and follows. Troponin release occurring due to down stream embolosation from thrombus, atheromatous debris, side branch occlusion, then the troponin release seen in cerebrovascular events (26). Still the controversy whether there is a clinically significant difference between cTnT and cTnI in regard to predictive value and cardiac specifity remains unsettled (27). In the initial two hours, cTnT was significantly better than cTnT, but still low sensitivity later, cTnT was significantly more specific for acute MI than cTnT (28). On the other hand cTnT was more predictive for long term adverse outcome and possessed maximum prognostic value for the 30-days outcome (29). In spite of this, TnT and TnI are highly sensitive and specific markers for cardiac damage in patients with UA or MI (30).
The results of trace elements showed significant increase (P< 0.05) in Zn concentration in patients groups, also P value was significant in MI (P = 0.05) while UA showed non significant increase(P> 0.05), these results were compared with reports by Metwalli et al (31) studied the serum metals in patients with acute myocardial infraction. He showed that serum zinc levels of MI patients were not significant increased. It was reported that a drop in serum zinc level occurred within the first three post-infarction days. These changes rose back to near normal level by the tenth day, Our finding is in accordance with this result since our blood samples were withdrawn on the seventh day after onset of infraction.
These results are disagree with that reported by Nouraei et al (32) studied zinc level in dilated and ischemic cardiomyopathy, Zehra et al (33) studied trace of element status (Se, Zn, Cu) in heart failure. Lekakis J. et al (34) studied zinc concentration in related to MI. All these authors suggested that low Zn concentration is probably that Zn might not have a role in pathogenesis in CAD. However, low serum Zn level has been related to excess release of steroids due to release factor called "leukocyte endogenous mediator" by poly morphonuclear cells. Stimuli that cause release of this factor include infections as well as tissue injury such as myocardial infraction, when this factor is released, amino acid flow to the liver increases, the amount of Zn in the serum decreases.
The results of the present study show a decrease value of Fe in sera of patients with MI, UA when compared with control group, as well as P value (p = 0.05) was significant in MI, UA (p < 0.05). These results were compared with that reported by Helena, et al (35) who studied serum iron, infection and inflammation, effects on coronary risk (33). There are a number of ways in which Fe could be of relevance to IHD, a low circulating haemoglobin level consequent on anemia has been shown to be associated with a proliferation in the anastomostic network of the coronary vessels (36). In iron deficiency, strong iron declines until iron delivery to the bone marrow is insufficient for erythropoiesis. This can be monitored with clinical indicators, beginning with low plasma ferritin, followed by decreased plasma iron and transferring saturation and culminating in red blood cells with low--Hb content and effect on coronary arteries (36). Metwalli studied serum metals and lipids in patients with acute MI showed that decrease serum iron may be explained by infarction including a shift of serum iron into the reticule endothelial system which may initiate ferritin synthesis. In addition, stress accompanying infarction increase the steroid activity which causes impairment of ferrokinetics (31). Reduced dietary iron intake may participate in the decrease of serum iron level but in the presence of infarction serum iron level continues to fall even during increasing dietary intake iron (37). The results of this study disagreed with those reported by Kurian G.A, et al (38) who studied trace elements and electrolyte balance in sera of CABG because the author thought that the higher levels of Fe may be came from protein ferritin which increased in coronary arteries and too much iron will release many oxygen free radicals and that may damage the coronary arteries (39). Yarnell (40) thought that a high dietary intake can arise circulating haemoglobin level and lead to an increase in blood and plasma viscosity, which in turn are strong predictors of IHD events (40).
The results show a significant increase (P< 0.05) in Cu concentration in (MI, UA) patients as compared to control groups. The elevation in Cu concentration is described by other workers such as Leon et al (41) studied zinc, copper and magnesium and risk cause for all cancer and cardiovascular mortality and Metwalli (31) studied the serum metals and lipids profile in patients with acute myocardial infarction and Issa N.M. (42) who studied serum levels of Zn, Cu, Cr, Ni in iranian subjects with athero sclerosis. The elevation in Cu concentration may be due to a rise in the copper--binding capacity of ceruloplasmin and the increase in Cu may be also due to injury and subsequent necrosis of myocardial cells (40). Metwalli said that increased Cu levels in MI, UA are a part of a specific defense mechanism to provide more copper at the site of an infarction to reduce its size and the extent or damage. Also, the increase of ceruloplasmin which is a copper containing enzyme and acute phase reactant may account for the significant increase in serum copper levels (29) that is in agreement with this study.
The results of the present study show a decrease in the value of Ca in sera of patients with MI, UA when compared with normal control group, as well as (p > 0.05) was non significant in MI, UA. These results were compared with reports by Michelle, et al (43) who studied statistical interpretation of concentration of Zn, Ca, K, cholesterol and CK isoenzymes in men at different stages of IHD and Jeremias, et al (44) who studied the possible correlation between decrease of ionized magnesium and calcium in blood to patients outcome after acute myocardial infarction.
Hypocalcaemia is responsible for approximately 150 different degenerative diseases and conditions and other problems that can be harmful or dangerous to the body. All degenerative disease, such as diabetes, cancer, heart disease gallstones, kidney stone, osteoporosis, heart palpitation which can cause arrhythmia and many more have been scientifically linked to deficiencies in calcium (45).
Finally : the relationship study between TnI, TnT and trace elements indicated that there were correlation between TnI, TnT in patients with MI, UA and trace elements with cardiac troponin (I,T).
(1) Paffenbarger RS Jr, Hyde RT, Wing AL, Lee IM, Jung DL, Kampert JB. 1993. The association of changes in physical-activity level and other lifestyle characteristics with mortality among men. N Engl J Med;328:538-45.
(2) Buja LM. The heart. In: Robbin and Kumar (eds). 1988.Basic Pathology. 4th Ed. WB Saunders Company,: pp 312-50.
(3) Kannel WB, Castelli WP, Gordon T. 1979.Cholesterol in the prediction of atherosclerotic disease. New perspectives based on the Framingham study. Ann Intern Med.;90:85-91.
(4) Amman P., fisterer M., Feher T. and Rickli H.2004. "Raised cardiac troponin", troponin wikipedia, The free encyclopedia, 328, 1028-1029.
(5) Amkatz and Braunwald E.2002. "Atlas of heart diseases", Philadelphia, current medicine, cardiac function and disfunction, p. 2441.
(6) Nigam P.K.2007, "Biochemical markers of myocardial injury", Indian Journal of clinical biochemistry, 22 (1), 10-17.
(7) Bishop I, Michael II, Fody, Edward P III, Schoeff and Larry E. 2005," Clinical Chemistry", London, P. 200.
(8) Foster C., Biocheck Inc, 323 vintage park, CA 94404, Catalog No. : BC-1105.
(9) Katuas H.A., Muller-bardoff M. and Scheffdd T.1995, "Development and characterization of a rapid assay for bedside determinations of cardiac troponin T. circulation", 92, 2869-2875.
(10) Antman E.M., Grudzien C. and Sacks D.B. 1995, "Evaluation of a rapid bedside assay for detection of serum cardiac TnT", JAMA., 273, 1279-1282.
(11) Alanh, Gowenlock, Janet R., Mc Murray, Donald M. and Mc Lauchlan, 1988 "Varlyes practical clinical bio chemistry", 6th Ed., Heinemann professional publishing, p. 69-75.
(12) Prusz C., Zyke P., Bochowicz A., Torbiki A., Szulc M., Kurzyna M., Fijalkowska A. and Kuch-Wocial A. 2003, "Cardiac troponin T monitoring identifies high--risk group of normotensive patients with acute pulmonary embolism", 123, 1947-1952.
(13) Yeh E.T., Tong A.T., Lenihan D.J., Yusuf S.W., Swafford J. and Champion C. 2004, "Cardiovascular complications of cancer therapy; diagnosis, pathogensis and management", 109, 3122-3131.
(14) James P., Ellis C.J, Whitlock R.M, Mcneilar, Henley J. and Anderson N.E, 2000 "Relation between troponin T concentration and mortality in patients presenting with an acute stroke : observational study", BMJ, New Zealand, 320 (7248), 1502-1504.
(15) Collonson P, Stubbs P.J. and Kessler A.C. 2003, "Multicentre evaluation of the diagnostic value of cardiac troponin T, CK--MB mass, and myoglobin for assessing patients with suspected acute coronary syndromes in routine clinical practice", Cardiovasvular Medicine, germany, 89, 280-286.
(16) Ham C.W., Ravkilde J., Gerhard T.W., Jorgensen P, Peheim E., Ljungdahl L, Goldmann B. and Katus H.A. 1992, "The prognostic value of serum troponin T in unstable angina", The new England Journal of Medicine, USA, 327, 146-150.
(17) Peter A.P., Maggiorine M, Bertel O., Haenseler E., Helen I. and Jemeka J, 2004 "Troponin as a risk factor for mortality in critically ill patients without acute coronary syndromes", J. Am. Coll. Cardial, Zuirch, 3, 421-422.
(18) Licka M., Zimmermanrl R. and Zeheleni J, 2002 "Troponin T concentration 72 hours after myocardial infarction as serological estimate of infarct size", Heart J., London, 87, 520-524.
(19) Panteghini M., Cuccia C. and Bonetti G. 2002, "Single point cardiac troponin T at coronary care unit discharge after myocardic infarction correlates with infarct size and ejection fraction", Clin. Chem., 48, 1432-1436.
(20) Maij J., Morandell D., Genser N., Lechleitner P., Dienstt F. and Puschendrop B, 1995 "Equivalent early sensitive of myoglobin, creatine kinase MB mass, creatine kinase isoform ratios and cardiac troponin I, T for acute myocardial infarction", Clin. Chem., 41, 1266-1272.
(21) Sato Y., Yamada T, Taniguchi R, Nagaik, Makiyama T. and Okada H, 2001 "Persistently increased serum concentration of cardiac troponin I in patients with idiopathic dilated cardio myopathy are predictive of adverse ontcomes", Cir. J., 369-374.
(22) Ottani F., Galvanic M. and Ferrini D. 1991, "Direct comparison of early elevations of cardiac troponin t and I in patients with clinical unstable angina", Am Heart J., 137, 284-91.
(23) Hedienreich P.A, Alloggiamento T and Melso P.K. 2001, "The prognostic value of troponin in patients with non st elevation a cut coronary syndromes: ameta-analysis". J. Am Coll. Cardiol., 38, 478-85.
(24) Allans and Jaffe, 2005" Troponin: the biomarker of choice for the detection of cardiac injury" CMAJ. Canada, 173, 1-10.
(25) Astushi S. M.S. and Hisash U. M.D 2007.," Diversity of the elevation of serum cardiac troponin I levels in patients during their visit to the emergency room", Cir. J. Japan, 71, 1458-1462.
(26) Collinson P. and Stubb P.J. 2003, "Are troponin confusing" BMJ, London; 89: 1285-1287, "value of troponin in patients with non--ST elevation acute coronary syndromes: a meta-analysis", J. Am. Coll. Cardiac, 38, 478485,2001.
(27) Heechen C., Deu A, Langenbrink L, Gddmann B.U. and Hamm C.W, "Analytical and diagnostic performance of troponin assays in patients suspicious for acute coronary synodromes", Clin. Biochem., 33, 359-368, 2000.
(28) Tucker J.F., Collins R.A. and Andrson A.J, 1997 "Early diagnosis efficiency of cardiac troponin I and troponin T for acute myocardial infarction", Acad. Emerg. Med., 4, 13-21.
(29) May K. I., Cupta S. and Deshmurk U.U. 1994, Ph.D. Thesis, "Formation and function of free radicals in human body", Ann. Nat. Acad. Med. Science, 30, 45-59.
(30) Tomas L., Goran B. and Gumar F. 1989, "Apolipoprotein B in human aortic biopsies in relation to serum lipids and lipoproteins atherosclerosis", 77, 159-166.
(31) Metwalli O., Al-Okbis, Motawi T., El-Ahmady O., Abdoul-Hafeez S. and El-Said E. 1998, "Study of serum metals and lipid profile in patients with myocardial infarction", Journal of Islamic Academy of Sciences, Egypt, 11 (1), 5-12.
(32) Norae S., Ali G. and Ebrahim S. 2007, "Serum zinc level in dialated and ischemic cardiomyopathy", J. Tech. Univ. Heart, 157-160.
(33) Zehra K., Freidum K. and Cagatoy T. 2006, "Serum levels of Zn and cu in patients with heart failure", Anadolu Kardioyl Derg., Turkey, 6, 216-220.
(34) Lekakis J. and Kalofoutis A. 1980, "Zinc concentration in serum as related to myocardial infarction", Clin. Chem., 26-12, 1660-1661.
(35) Helena K., Leena T., Timo P., Merja R. and Vesa M. 2004, "Serum iron, infection and inflammation, effects on coronary risk", Scandinavian Cardiovascular Journal, Finland, 38, 345-348.
(36) Zoll P., Wessler S. and Schlesinger J. 1951, "Inter-arterial coronary anastamoses in the human heart with particular reference to anemia and relative cardiac anoxia" Circulation Journal, 4, 797-815.
(37) Handelman G.I. 2009, "Iron and anemia in human biology", A review of mechanism" Human Nutrition J., 13 (4), 393-404.
(38) Kurian G.A. and Paddikkala J. 2007, "Effect of intraoperative Mg in plasma antioxidant levels trace elements and electrolyte balance in serum of CABG", Clinical and basic Cardiology J., 10 (1-4), 11-15.
(39) Hershko C., Cook J.D. and Frinch C.A. 1977, "Stirange iron kinetics, the effects of inflammation on iron exchange in rat", Br. J. Lame., 28, 67.
(40) Yarneu J.W, Baker I.A., Jweetnam P.M., Bainton D. and Brien J.R., 1991 "Fibrinogen, viscosity and white blood cell count are major risk factors for ischemic heart disease", Circulation J., 83, 836-844.
(41) Leone, Nathalie, Courbon, Dominique, Ducimeterie and Pierre M. 2006, "Zinc, copper and magnesium and risks for all cause, cancer and cardiovascular mortality", Epidemiology J., France, 17, 308-314.
(42) http:// www.ama.ac.ir/AIM/0141/issa0141.html.
(43) Michelle S., Jean L. and Pierre A. 1989, "Statistical interpretation of concentrations of magnesium, zinc, calcium, potassium, cholesterol and creatine kinase in men at different stage of IHD", Clin. Chem., France, 35 (5), 833-835.
(44) Jeremias A., Bertschat F.L., Ising H. and Jeremias E. 2000, Journal of clinical and basic cardiology, Berlin, 3, 123-128.
(45) Budvari S., Cronqusit A. and Mc Grow N. 1996, "Calcium an important food element", 3, 431-434.
Israa Ghassan. Zainal (1), Ali A. AL-Mussawi (2) and Massara Najim. Abd-Alla (2)
(1) AL-Mustansiriyah University, College of Science, Chemistry Depertment.
(2) Ibn Al-Bitar Hospital, Baghdad, Iraq
(1) E-mail: firstname.lastname@example.org
Table 1: Concentration of TnT, TnI in the sera of normal groups and patients with MI & UA. Groups No. TnT ng/ml TnI ng/ml (mean (mean [+ or -] SD) [+ or -] SD) MI 39 0.914 [+ or -] 0.581 21.44 [+ or -] 23.01 UA 21 0.597 [+ or -] 0.514 17.69 [+ or -] 24.32 Control 30 - 0.578 [+ or -] 0.246 Table 2: The mean concentration of Zn in sera of control and MI, UA patients. Groups No. Zn ppm (mean Fe ppm (mean [+ or -] SD) [+ or -] SD) MI 39 2.011 [+ or -] 0.682 2.597 [+ or -] 0.707 UA 21 2.061 [+ or -] 0.883 2.401 [+ or -] 0.832 control 30 1.577 [+ or -] 0.277 3.067 [+ or -] 0.583 Groups Ca ppm mean Cu ppm (mean [+ or -] SD [+ or -] SD) MI 46.570[+ or -]9.013 1.294 [+ or -] 0.258 UA 49.720[+ or -]9.417 1.319 [+ or -] 0.284 control 50.280[+ or -]7.786 1.18 [+ or -] 0.246