Abstract：
Near-infrared spectroscopy combined with vascular occlusion test (NIRS-VOT) is a reactive hyperemia technique for in vivo evaluation of skeletal muscle microvascular reactivity. Previous studies using NIRS-VOT have been shown to be able to detect impairments in microvascular function in high-risk cardiovascular disease populations, such as older individuals. It has been demonstrated that older individuals have slower reactive hyperemia compared with young individuals. Importantly, older individuals also show less desaturation during ischemia compared with young individuals. Based on these findings, it has been suggested that the slower reactive hyperemia observed in older individuals is explained by the lower desaturation during blood flow occlusion (reduced ischemic stimulus). This retrospective analysis compared reactive hyperemia in 36 young and 47 older tissue desaturation-matched individuals that underwent 5-min blood flow occlusion. Overall, we showed that older individuals have impaired reactive hyperemia compared with young when matching for the degree of desaturation and blood flow occlusion time. These findings provide evidence that lower tissue desaturation during ischemia is not a major determinant of impaired reactive hyperemia in older individuals.NEW & NOTEWORTHY Previous findings have suggested that aging-related impairment in skeletal muscle reactive hyperemia is majorly influenced by a lower degree of tissue desaturation during ischemia in older individuals compared with young individuals. In a retrospective analysis including 83 tissue desaturation-matched individuals, we show that the degree of tissue desaturation is not a major determinant of aging-related impairments in reactive hyperemia.
摘要：
近红外光谱（NIRS）结合血管闭塞试验（NIRS-VOT）是一种用于体内评估骨骼肌微血管反应性的反应性充血技术。先前使用NIRS-VOT的研究已被证明能够检测高风险心血管疾病（CVD）人群（如老年人）的微血管功能受损。已经证明，与年轻人相比，老年人的反应性充血较慢。重要的是,与年轻人相比，老年人在缺血期间的去饱和程度也较低。基于这些发现,有人提出,在老年个体中观察到的反应性充血较慢,原因是血流阻塞期间的去饱和较低(缺血刺激减少).这项回顾性分析比较了36名年轻和47名年龄较大的组织去饱和匹配个体的反应性充血，这些个体经历了5分钟的血流闭塞。总的来说,我们发现,在去饱和程度和血流闭塞时间匹配时,与年轻人相比,老年人的反应性充血受损.这些发现提供了证据，表明缺血期间较低的组织去饱和并不是老年人反应性充血受损的主要决定因素。
