PDF(Pubmed)
Abstract：
Aging is associated with increased risk for cognitive decline and dementia due in part to increases in systolic blood pressure (SBP) and cerebrovascular dysfunction. High-resistance inspiratory muscle strength training (IMST) is a time-efficient, intensive respiratory training protocol (30 resisted inspirations/day) that lowers SBP and improves peripheral vascular function in midlife/older adults with above-normal SBP. However, whether, and by what mechanisms, IMST can improve cerebrovascular function is unknown. We hypothesized that IMST would increase cerebrovascular reactivity to hypercapnia (CVR to CO2), which would coincide with changes to the plasma milieu that improve brain endothelial cell function and enhance cognitive performance (NIH Toolbox). We conducted a 6-wk double-blind, randomized, controlled clinical trial investigating high-resistance IMST [75% maximal inspiratory pressure (PImax); 6×/wk; 4 females, 5 males] vs. low-resistance sham training (15% PImax; 6×/wk; 2 females, 5 males) in midlife/older adults (age 50-79 yr) with initial above-normal SBP. Human brain endothelial cells (HBECs) were exposed to participant plasma and assessed for acetylcholine-stimulated nitric oxide (NO) production. CVR to CO2 increased after high-resistance IMST (pre: 1.38 ± 0.66 cm/s/mmHg; post: 2.31 ± 1.02 cm/s/mmHg, P = 0.020). Acetylcholine-stimulated NO production increased in HBECs exposed to plasma from after vs. before the IMST intervention [pre: 1.49 ± 0.33; post: 1.73 ± 0.35 arbitrary units (AU); P < 0.001]. Episodic memory increased modestly after the IMST intervention (pre: 95 ± 13; post: 103 ± 17 AU; P = 0.045). Cerebrovascular and cognitive function were unchanged in the sham control group. High-resistance IMST may be a promising strategy to improve cerebrovascular and cognitive function in midlife/older adults with above-normal SBP, a population at risk for future cognitive decline and dementia.NEW & NOTEWORTHY Midlife/older adults with above-normal blood pressure are at increased risk of developing cognitive decline and dementia. Our findings suggest that high-resistance inspiratory muscle strength training (IMST), a novel, time-efficient (5-10 min/day) form of physical training, may increase cerebrovascular reactivity to CO2 and episodic memory in midlife/older adults with initial above-normal blood pressure.
摘要：
衰老与认知下降和痴呆的风险增加相关,部分原因是收缩压(SBP)和脑血管功能障碍的增加。高阻力吸气肌肉力量训练（IMST）是一种省时的，强化呼吸训练方案(30次抵抗灵感/天)可降低SBP并改善高于正常SBP的中年/老年人的外周血管功能。然而,如果,以及通过什么机制，IMST能否改善脑血管功能是未知的。我们假设IMST会增加脑血管对高碳酸血症的反应性（CVR对CO2），这将与改善脑内皮细胞功能和增强认知表现的血浆环境变化相一致(NIH工具箱)。我们进行了为期6周的活动，双盲,随机化，研究高阻性IMST的对照临床试验(75%最大吸气压力[PIMAX];6x/周;4F/5M)与在中年/老年人（年龄50-79岁）进行低阻力假训练（15％PIMAX；6x/周；2F/5M），初始SBP高于正常水平。将人脑内皮细胞（HBEC）暴露于参与者血浆中，并评估乙酰胆碱刺激的一氧化氮（NO）产生。高阻IMST后对CO2的CVR增加(pre:1.38±0.66cm/s/mmHg,岗位：2.31±1.02cm/s/mmHg，p=0.020)。乙酰胆碱刺激的NO产生在暴露于血浆后的HBECs中增加。在IMST干预之前(pre：1.49±0.33au，员额：1.73±0.35au；p<0.001)。在IMST干预后，情景记忆略有增加（pre：95±13au，员额：103±17au；p=0.045）。假手术对照组脑血管和认知功能无变化。高阻IMST可能是改善SBP高于正常的中年/老年人脑血管和认知功能的有希望的策略。有未来认知能力下降和痴呆风险的人群。
