探讨久坐诱导的微血管功能障碍的性别差异：来自急性维生素 C 补充的新视角。
Examining sex differences in sitting-induced microvascular dysfunction: Insight from acute vitamin C supplementation.
机构信息
Department of Kinesiology and Health Sciences, Virginia Commonwealth University, Richmond, VA, USA.
Department of Kinesiology, University of Virginia, Charlottesville, VA, USA.
出版信息
Microvasc Res. 2021 May;135:104147. doi: 10.1016/j.mvr.2021.104147. Epub 2021 Feb 19.
PURPOSE
Lower limb microvascular dysfunction resulting from prolonged sitting (PS) bouts has been revealed to occur independent of sex. Although acute antioxidant supplementation has been reported to blunt conduit artery dysfunction following PS in young males, it is unknown if this protective effect extends to the microvasculature or is relevant in young females, who possess intrinsic vascular protective mechanisms specific to antioxidant defense. Therefore, this study employed an acute antioxidant supplementation to further examine sex differences during PS with a specific focus on microvascular function.
METHODS
On two separate visits, 14 females (23 ± 3 years) and 12 males (25 ± 4 years) had leg microvascular function (LMVF) assessed (via the passive leg movement technique) before and after 1.5 h of sitting. Prior to each visit, one gram of vitamin C (VC) or placebo (PL) was consumed.
RESULTS
PS significantly reduced LMVF [PL: (M: -34 ± 20; F: -23 ± 18%; p < 0.01) independent of sex (p = 0.7)], but the VC condition only blunted this reduction in males (VC: -3 ± 20%; p < 0.01), but not females (VC: -18 ± 25%; p = 0.5).
CONCLUSION
Young males and females reported similar reductions LMVF following PS, but only the young males reported a preservation of LMVF following the VC supplementation. This finding in young females was highlighted by substantial variability in LMVF measures in response to the VC condition that was unrelated to changes in the potential contributors to sitting-induced reductions in LMVF (e.g. lower limb venous pooling, reduced arterial shear rate).
NEW AND NOTEWORTHY
In this study, we employed an acute Vitamin C (VC) supplementation to examine sex differences in leg microvascular function (LMVF) following a bout of prolonged sitting. This study revealed that prolonged sitting reduced LMVF independent of sex, but only young males reported an attenuation to this lowered LMVF following VC supplementation. The young females revealed substantial variability in sitting-induced changes to LMVF that could not be explained by the potential contributors to sitting-induced reductions in LMVF (e.g. lower limb venous pooling, reduced arterial shear rate).
目的
久坐（PS）会导致下肢微血管功能障碍，这种障碍与性别无关。尽管有报道称，急性抗氧化剂补充可以减轻年轻男性 PS 后导动脉功能障碍，但目前尚不清楚这种保护作用是否延伸至微血管，或者在具有特定抗氧化防御内在血管保护机制的年轻女性中是否相关。因此，本研究采用急性抗氧化剂补充来进一步研究 PS 过程中的性别差异，重点关注微血管功能。
方法
在两次单独的访问中，14 名女性（23±3 岁）和 12 名男性（25±4 岁）在静坐 1.5 小时前后通过被动腿部运动技术评估腿部微血管功能（LMVF）。在每次访问之前，都服用一克维生素 C（VC）或安慰剂（PL）。
结果
PS 显著降低了 LMVF[PL：（男性：-34±20%；女性：-23±18%；p<0.01）与性别无关（p=0.7）]，但 VC 条件仅减轻了男性的这种降低（VC：-3±20%；p<0.01），但对女性没有（VC：-18±25%；p=0.5）。
结论
年轻男性和女性在 PS 后报告的 LMVF 降低相似，但只有年轻男性在 VC 补充后报告 LMVF 得到保护。这一发现突显了年轻女性对 VC 条件的 LMVF 测量存在很大的变异性，这与坐姿引起的 LMVF 降低的潜在因素无关（例如下肢静脉充血、动脉剪切率降低）。
新的和值得注意的是
在这项研究中，我们采用急性维生素 C（VC）补充来研究久坐后腿部微血管功能（LMVF）的性别差异。这项研究表明，久坐会降低 LMVF，与性别无关，但只有年轻男性在 VC 补充后报告 LMVF 降低得到缓解。年轻女性对坐姿引起的 LMVF 变化存在很大的变异性，这不能用坐姿引起的 LMVF 降低的潜在因素来解释（例如下肢静脉充血、动脉剪切率降低）。
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