Niger. J. Physiol. Sci. 32(December 2017) 213-217 www.njps.com.ng Serum Troponin I levels among Hypertensive Military Service Personnel at a Military Health Facility in Abuja, Nigeria Nwagbara G.O. N 1 and Emokpae M. A* 2 1 Defence Reference Laboratory, Abuja Nigeria. 2 Department of Medical Laboratory Science, School of Basic Medical Sciences, College of Medical Sciences, University of Benin, Benin, Nigeria Summary: Hypertension constitutes one of the major metabolic disease in Nigeria especially among military personnel and their families. Myocardial infarction and other cardiovascular diseases may occur in this group of patient due to uncontrolled or poorly controlled hypertension. The objective of this study was to determine serum cardiac Troponin I (cTnI), levels in hypertensive Nigerian Military service personnel attending clinic in a military Health facility. We measured the serum levels of cTnI in 126 hypertensive subjects [76 males (19-73 years) and 50 females (26-77years)] and 82 normotensive controls [41 males (19-60years) and 41 females (18-53years)] using Latex Enhanced Immunoturbidimetry technique. The data were compared between test and control group using Students’t -test. Serum cTnI was detected in the sample of 95(75.4%) subjects and was not detected in 31 (24.6%) subjects. Nine subjects (2.38%) had cTnI levels within the normal range(0.00- 0.01ng/mL), 85 (67.5%) subjects had significantly higher (p<0.001) cTnI levels (0.100 ± 0.091 ng/ml; CL: 0.02 – 0.47ng/mL), while one (0.8%) subject had a cTnI value of 1.09 ng/mL. Nine (10.98%) control subjects had detectable cTnI levels (0.01ng/mL) while 73(89.02%) controls had a 0.00 ng/mL cTnI level. There was no significance difference in cTnI levels when subjects on chemotherapy were compared with newly diagnosed subjects (P = 0.0694). This study revealed that cTnI was detectable in the serum of majority of the study participants which may suggest sub-clinical cardiac necrosis. There may be risk of developing adverse cardiovascular disorders and the need for appropriate intensive management is emphasized. Keywords: Cardiac Troponin I, Hypertension, Military service personnel. ©Physiological Society of Nigeria *Address for correspondence: mathias.emokpae@uniben.edu Manuscript Accepted: November, 2017 INTRODUCTION Hypertension (High blood pressure) is a major health risk factor for heart attack and stroke with attendant biochemical consequences (Boyles and Salynn, 2011). It is a common condition, but little is known about its prevalence among military service personnel and their families. Rigorous-stress activities such as combat deployment of military service personnel might pose a potential risk factor for hypertension. There are paucity of published reports on the levels of cardiac biomarkers in the serum of hypertensive Nigerian military personnel and their families. Uncontrolled hypertension leads to heart attacks, stroke and cardiovascular diseases (CVDs) and kills more than infectious diseases (Kearney et al., 2005; Ogah et al., 2012). Early prediction of cardiovascular disease risk among subjects with hypertension provides an opportunity for appropriate intensive management, reduces morbidity and mortality. Assay of serum cardiac troponins are considered as standard biochemical markers in the diagnosis of myocardial infarction (MI) (Karar et al., 2015) but these markers are rarely assayed for in this health facility. Troponin which is a trimeric regulatory protein complex consisting of troponin C, troponin I, and troponin T, is very necessary for muscle contraction in skeletal and cardiac muscles, but not smooth muscle (Takeda et al., 2003). They are released into circulation about 3-4 hours after myocardial infarction and are still detectable for 10 days afterwards. The long half-life allows for late diagnosis of MI, but makes it difficult to detect re- infarction. These three Troponin subunits form a complex that checks the interaction of actin and myosin, and thus regulate heart contraction. Troponin is localized primarily in the myofibrils (94-97%) with smaller cytoplasmic fraction (3-6%) (Heresi et al.,2012). Cardiac troponin (cTn) subunits I and T have different amino acid residue on the amino sequences encoded by different genes, and are different from skeletal muscle. Troponin I in humans is presented in three isoforms, two isoforms are expressed in skeletal muscle tissue and one isoform is expressed in cardiac muscle tissue (Scheitz et al., 2015). Cardiac troponin has absolute myocardial tissue specificity and reflect even microscopic zones of myocardial necrosis but