Applied Physiology, Nutrition, and Metabolism, Ahead of Print.
When controlling for baseline diameter, males have greater brachial flow-mediated dilation (BA-FMD) responses than females. It is unclear whether sex differences in baseline diameter also influences popliteal FMD (POP-FMD), which may be impacted by cardiorespiratory fitness and physical activity levels. We hypothesized that males would exhibit greater BA-FMD and POP-FMD when allometrically scaled to baseline diameter. FMD (ultrasonography), cardiorespiratory fitness (indirect calorimetry), and objectively measured physical activity were assessed in males (n = 13; age, 23 ± 3 years; peak oxygen consumption, 48.0 ± 7.1 mL·kg−1·min−1) and females (n = 13; age, 24 ± 2 years; peak oxygen consumption, 36.8 ± 6.0 mL·kg−1·min−1). Both groups had similarly high levels of moderate-to-vigorous intensity physical activity (503 ± 174 vs. 430 ± 142 min·week−1, p = 0.25). However, males were more aerobically fit (p < 0.001) and females accumulated more light-intensity physical activity (182 ± 67 vs. 127 ± 53 min·week−1, p = 0.03). Relative and allometrically scaled BA-FMD were similar (both, p ≥ 0.09) between sexes. In contrast, relative (6.2% ± 1.0% vs. 4.6% ± 1.4%, p = 0.001) and scaled (6.8% ± 1.7% vs. 4.7% ± 1.7%, p = 0.03) POP-FMD were greater in females. Relative POP-FMD was related to light-intensity physical activity in the pooled sample (r = 0.43; p = 0.04). However, the enhanced relative POP-FMD in females remained after adjusting for higher light-intensity physical activity levels (p = 0.01). Young females have enhanced popliteal, but not brachial, endothelial health than males with similar moderate-to-vigorous intensity physical activity levels and higher cardiorespiratory fitness. Novelty In physically active adults, females had greater POP-FMD but not BA-FMD than males. The enhanced POP-FMD in females was not related to greater vascular smooth muscle sensitivity to nitric oxide or their smaller baseline diameters. POP-FMD was associated with light physical activity levels in the pooled sample.

中文翻译：

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性生活和轻微的体力活动会影响身体活跃的年轻人的腘动脉，但不会影响肱动脉，血流介导的扩张。

应用生理学、营养学和代谢，提前出版。
在控制基线直径时，男性比女性有更大的肱动脉血流介导扩张 (BA-FMD) 反应。目前尚不清楚基线直径的性别差异是否也会影响腘窝口蹄疫（POP-FMD），这可能受心肺健康和身体活动水平的影响。我们假设，当异速缩放至基线直径时，雄性会表现出更大的 BA-FMD 和 POP-FMD。在男性（n = 13；年龄，23 ± 3 岁；峰值耗氧量，48.0 ± 7.1 mL·kg−1·min−1）中评估了 FMD（超声检查）、心肺适能（间接量热法）和客观测量的体力活动和女性（n = 13；年龄，24 ± 2 岁；峰值耗氧量，36.8 ± 6.0 mL·kg−1·min−1）。两组的中等至剧烈强度的体力活动水平相似（503 ± 174 vs. 430 ± 142 min·week−1，p = 0.25）。然而，男性更适合有氧运动（p < 0.001），而女性积累了更多的光强度体力活动（182 ± 67 vs. 127 ± 53 min·week−1，p = 0.03）。性别之间的相对和异速缩放 BA-FMD 相似（两者，p ≥ 0.09）。相比之下，女性的相对 (6.2% ± 1.0% vs. 4.6% ± 1.4%, p = 0.001) 和缩放 (6.8% ± 1.7% vs. 4.7% ± 1.7%, p = 0.03) POP-FMD 更大。相对 POP-FMD 与合并样本中的光强度身体活动有关（r = 0.43；p = 0.04）。然而，在调整较高的光强度身体活动水平后，女性的相对 POP-FMD 仍然增强（p = 0.01）。与具有相似中等至剧烈强度体育活动水平和更高心肺适能的男性相比，年轻女性的腘窝内皮健康状况有所改善，但并未增强肱动脉内皮健康。新奇 在身体活跃的成年人中，女性比男性有更多的 POP-FMD，但 BA-FMD 没有。女性中增强的 POP-FMD 与血管平滑肌对一氧化氮的敏感性更高或其基线直径更小无关。POP-FMD 与合并样本中的轻度体力活动水平相关。