Attenuated forearm vascular conductance responses to rhythmic handgrip in young African-American compared with Caucasian-American men
Attenuated forearm vascular conductance responses to rhythmic handgrip in young African-American compared with Caucasian-American men
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DOI：
10.1152/ajpheart.00387.2018
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发表时间：
2018-11-01
影响因子：
4.8
通讯作者：
Fadel, Paul J.
中科院分区：
文献类型：
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作者：
Barbosa, Thales C.;Kaur, Jasdeep;Fadel, Paul J.
先前的研究表明，与高加索裔美国人（CA）相比，非裔美国人（AA）在静息条件下血管收缩反应增强，血管舒张反应减弱。然而，血管对运动反应的潜在差异仍不清楚。因此，我们检验了这样的假设，即与CA受试者相比，AA受试者在有节奏的握力训练中会出现前臂血管传导（PVC）的衰减性增加。在4、8、12、16、20和24 kg负荷下进行的6次有节奏握力试验中，我们测量了健康年轻CA （n = 10）和AA （n = 10）男性的前臂血流量（FBF）和平均动脉压（MAP）。静息时两组间PVC（以FBF/MAP计算）、FBF和MAP相似（PVC: 63 +/- 7 ml.min(-1)）。CA受试者100 mmHg(-1) vs. 62±7 ml.min（-1）。AA组100 minHg(-1), P = 0.862)。两组的FVC用餐运动均呈强度依赖性增加；然而，AA受试者在8、12、16、20和24 kg负荷（例如，24 kg: 324±20 ml.min(-1)）时表现出较低的FVC（交互作用P < 0.001）。CA受试者100 mmHg(-1) vs. 241 +/- 21 ml.min（-1）。AA受试者100 mmHg(-1), P < 0.001)。AA受试者对运动的FBF反应也较低（相互作用P < 0.001），而MAP反应在组间没有差异（例如，24公斤时CA受试者的δ MAP: +19 +/- 2 mmHg vs. AA受试者的+19 +/- 2 mmHg，相互作用P = 0.950）。这些发现表明，与CA男性相比，AA男性对有节奏的握力运动的充血反应较低。新的和值得注意的是，众所周知，与白人美国人相比，非裔美国人在静息条件下血管收缩加剧，血管舒张减弱。在这里，我们发现，在健康的年轻非裔美国男性中，中度和高强度有节奏的握力运动的充血反应较低。
Previous studies have demonstrated that African-American (AA) individuals have heightened vasoconstrictor and reduced vasodilator responses under resting conditions compared with Caucasian-American (CA) individuals. However, potential differences in vascular responses to exercise remain unclear. Therefore, we tested the hypothesis that, compared with CA subjects, AA subjects would present an attenuated increase in forearm vascular conductance (PVC) during rhythmic handgrip exercise. Forearm blood flow (FBF; duplex Doppler ultrasound) and mean arterial pressure (MAP; finger photoplethysmography) were measured in healthy young CA (n = 10) and AA (n = 10) men during six trials of rhythmic handgrip performed at workloads of 4, 8, 12, 16, 20, and 24 kg. PVC (calculated as FBF/MAP), FBF, and MAP were similar between groups at rest (PVC: 63 +/- 7 ml.min(-1).100 mmHg(-1) in CA subjects vs. 62 +/- 7 ml.min(-1).100 minHg(-1) in AA subjects, P = 0.862). There was an intensity-dependent increase in FVC dining exercise in both groups; however, AA subjects presented lower FVC (interaction P < 0.001) at 8-, 12-, 16-, 20-, and 24-kg workloads (e.g., 24 kg: 324 +/- 20 ml.min(-1).100 mmHg(-1) in CA subjects vs. 241 +/- 21 ml.min(-1).100 mmHg(-1) in AA subjects, P < 0.001). FBF responses to exercise were also lower in AA subjects (interaction P < 0.001), whereas MAP responses did not differ between groups (e.g., Delta MAP at 24 kg: +19 +/- 2 mmHg in CA subjects vs. +19 +/- 2 mmHg in AA subjects, interaction P = 0.950). These findings indicate lower hyperemic responses to rhythmic handgrip exercise in AA men compared with CA men.NEW & NOTEWORTHY It is known that African-American individuals have heightened vasoconstriction and reduced vasodilation under resting conditions compared with Caucasian-American individuals. Here, we identified that the hyperemic response to moderate and high-intensity rhythmic handgrip exercise was lower in healthy young African-American men.