Human Performance Laboratory, Ball State University, Muncie, IN 47306, USA.
J Appl Physiol (1985). 2011 Aug;111(2):508-15. doi: 10.1152/japplphysiol.01348.2010. Epub 2011 May 19.
Millions of older individuals consume acetaminophen or ibuprofen daily and these same individuals are encouraged to participate in resistance training. Several in vitro studies suggest that cyclooxygenase-inhibiting drugs can alter tendon metabolism and may influence adaptations to resistance training. Thirty-six individuals were randomly assigned to a placebo (67 ± 2 yr old), acetaminophen (64 ± 1 yr old; 4,000 mg/day), or ibuprofen (64 ± 1 yr old; 1,200 mg/day) group in a double-blind manner and completed 12 wk of knee extensor resistance training. Before and after training in vivo patellar tendon properties were assessed with MRI [cross-sectional area (CSA) and signal intensity] and ultrasonography of patellar tendon deformation coupled with force measurements to obtain stiffness, modulus, stress, and strain. Mean patellar tendon CSA was unchanged (P > 0.05) with training in the placebo group, and this response was not influenced with ibuprofen consumption. Mean tendon CSA increased with training in the acetaminophen group (3%, P < 0.05), primarily due to increases in the mid (7%, P < 0.05) and distal (8%, P < 0.05) tendon regions. Correspondingly, tendon signal intensity increased with training in the acetaminophen group at the mid (13%, P < 0.05) and distal (15%, P = 0.07) regions. When normalized to pretraining force levels, patellar tendon deformation and strain decreased 11% (P < 0.05) and stiffness, modulus, and stress were unchanged (P > 0.05) with training in the placebo group. These responses were generally uninfluenced by ibuprofen consumption. In the acetaminophen group, tendon deformation and strain increased 20% (P < 0.05) and stiffness (-17%, P < 0.05) and modulus (-20%, P < 0.05) decreased with training. These data suggest that 3 mo of knee extensor resistance training in older adults induces modest changes in the mechanical properties of the patellar tendon. Over-the-counter doses of acetaminophen, but not ibuprofen, have a strong influence on tendon mechanical and material property adaptations to resistance training. These findings add to a growing body of evidence that acetaminophen has profound effects on peripheral tissues in humans.
数以百万计的老年人每天都服用对乙酰氨基酚或布洛芬，同时也鼓励他们进行抗阻训练。一些体外研究表明，环氧化酶抑制剂可以改变跟腱代谢，并可能影响对抗阻训练的适应。36 名参与者以双盲方式随机分配到安慰剂（67±2 岁）、对乙酰氨基酚（64±1 岁；4000mg/天）或布洛芬（64±1 岁；1200mg/天）组，并完成了 12 周的膝关节伸肌抗阻训练。在训练前后，通过 MRI[横截面积（CSA）和信号强度]和髌腱变形与力测量相结合的超声检查评估髌腱特性，以获得刚度、模量、应力和应变。在安慰剂组中，训练前后髌腱 CSA 无变化（P>0.05），且布洛芬的摄入并未影响这一反应。在对乙酰氨基酚组中，腱 CSA 随训练而增加（3%，P<0.05），主要是由于中（7%，P<0.05）和远（8%，P<0.05）腱区域的增加。相应地，随着对乙酰氨基酚组的训练，腱信号强度在中（13%，P<0.05）和远（15%，P=0.07）区域增加。当与训练前的力水平归一化时，在安慰剂组中，髌腱变形和应变减少 11%（P<0.05），而刚度、模量和应力保持不变（P>0.05）。在对乙酰氨基酚组中，腱变形和应变增加 20%（P<0.05），而刚度（-17%，P<0.05）和模量（-20%，P<0.05）随着训练而降低。这些数据表明，在老年人中进行 3 个月的膝关节伸肌抗阻训练会导致髌腱机械性能的适度变化。非处方剂量的对乙酰氨基酚，而不是布洛芬，对跟腱机械和材料特性对抗阻训练的适应有很大影响。这些发现增加了越来越多的证据表明，对乙酰氨基酚对人体周围组织有深远的影响。
