Department of Physiology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands,
Eur J Appl Physiol. 2012 May;112(5):1725-32. doi: 10.1007/s00421-011-2145-3. Epub 2011 Sep 4.
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.
肌钙蛋白 I 升高（cTnI）是心肌损伤的标志物，在健康受试者进行高强度运动后已有报道。目前，人们对长时间中等强度运动对 cTnI 释放的影响知之甚少，但也不知道肥胖对此反应的影响。97 名志愿者（55 名男性和 42 名女性）按 BMI 分层，进行了一次 30-50 公里的散步运动。我们在瘦体（BMI<25kg/m2，n=30，57±19 岁）、超重（25≤BMI<30kg/m2，n=29，56±11 岁）和肥胖者（BMI≥30kg/m2，n=28，53±9 岁）中，在运动前和运动后即刻测量 cTnI 水平。散步是在自我选择的速度下进行的。使用高敏感 cTnI 检测（Centaur；临床临界值≥0.04μg/L）评估 cTnI。我们记录了受试者的特征（体重、血压、心血管风险的存在），并通过记录心率来检查运动强度。cTnI 水平从 0.010±0.006μg/L 显著升高至 0.024±0.046μg/L（P<0.001）。瘦体、超重和肥胖受试者的 cTnI 升高程度没有差异（双因素方差分析交互作用；P=0.27）。在 11 名参与者中，cTnI 升高超过心肌梗死的临床临界值。Logistic 回归分析确定运动强度（P<0.001），而不是 BMI、体脂肪百分比或腰围，与阳性肌钙蛋白检测显著相关。总之，长时间的中等强度运动导致瘦体、超重和肥胖受试者的 cTnI 水平升高。因此，肥胖的测量值不太可能与运动后 cTnI 升高的幅度有关。
