title: The impact of obesity on cardiac troponin levels after prolonged exercise in humans.
abstract: Elevated cardiac troponin I (cTnI), a marker for cardiac damage, has been reported after high-intensity exercise in healthy subjects. Currently, little is known about the impact of prolonged moderate-intensity exercise on cTnI release, but also the impact of obesity on this response. 97 volunteers (55 men and 42 women), stratified for BMI, performed a single bout of walking exercise (30-50 km). We examined cTnI-levels before and immediately after the exercise bout in lean (BMI < 25 kg/m(2), n = 30, 57 ± 19 years), overweight (25 ≤ BMI < 30 kg/m(2), n = 29, 56 ± 11 years), and obese subjects (BMI ≥ 30 kg/m(2), n = 28, 53 ± 9 years). Walking was performed at a self-selected pace. cTnI was assessed using a high-sensitive cTnI-assay (Centaur; clinical cut-off value ≥ 0.04 μg/L). We recorded subject characteristics (body weight, blood pressure, presence of cardiovascular risk) and examined exercise intensity by recording heart rate. Mean cTnI-levels increased significantly from 0.010 ± 0.006 to 0.024 ± 0.046 μg/L (P < 0.001). The exercise-induced increase in cTnI was not different between lean, overweight and obese subjects (two-way ANOVA interaction; P = 0.27). In 11 participants, cTnI was elevated above the clinical cut-off value for myocardial infarction. Logistic regression analysis identified exercise intensity (P < 0.001), but not BMI, body fat percentage or waist circumference to significantly relate to positive troponin tests. In conclusion, prolonged, moderate-intensity exercise results in a comparable increase in cTnI-levels in lean, overweight and obese subjects. Therefore, measures of obesity unlikely relate to the magnitude of the post-exercise elevation in cTnI.
authors: Department of Physiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands, t.eijsvogels@fysiol.umcn.nl.
authors: Thijs M H
authors: TM
authors: Eijsvogels
authors: Matthijs T W
authors: MT
authors: Veltmeijer
authors: Keith
authors: K
authors: George
authors: Maria T E
authors: MT
authors: Hopman
authors: Dick H J
authors: DH
authors: Thijssen
mesh_terms: D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D001831:Body Temperature; D002318:Cardiovascular Diseases / Q000097:blood*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006339:Heart Rate; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000503:physiopathology*; D012307:Risk Factors; D011795:Surveys and Questionnaires; D019210:Troponin I / Q000097:blood*; D016138:Walking / Q000502:physiology
chemical_list: D015415:Biomarkers; D019210:Troponin I