Effects of chronic use of thickened liquids in a rat model of aging

摘要 吞咽障碍在老年人中非常普遍，包括那些患有年龄相关疾病的人。 增稠的液体经常用于治疗吞咽障碍，并已被证明 立即减少呼吸道侵犯的机会。然而，增稠的液体与 对健康有害的影响，如脱水、尿路感染和生活质量下降。尽管他们 临床常用，增稠液体的长期疗效，以及它们对吞咽运动学的影响， 全身性水合作用和潜在的生物学作用还没有被很好地理解。鉴于中国人口的快速增长 据估计，到2051年，65岁以上的人口将达到21亿，了解吞咽困难的疗效至关重要 干预措施。这项建议的首要目标是贡献生物学的基础知识。 功能吞咽变化的潜在机制是对一种经常使用但未被研究的 老年人口吞咽困难管理的干预措施。拟议的研究将使用衰老的大鼠 使用增稠液体如何影响吞咽运动学、全身水合作用和 随着时间的推移，潜在的生物学。我们有三个具体的目标，每个目标都有一个独特的假设。目标1将测试 假设长期使用增稠的液体纹理会降低推注速度，减少协调 吞咽肌肉，并扰乱正常的呼吸-吞咽事件序列。目标2将检验这一假设 这种增稠的液体会导致液体摄入量减少和全身脱水，这将是 因粘度和年龄而加剧。目标3将检验假设，在没有稀释液的情况下，增稠的液体 液体，会减慢吞咽运动，动态改变肌肉的收缩特性，包括减少 随着年龄的增长，舌力和收缩次数增加。一致认为，FAST- 舌中收缩IIb型肌球蛋白重链(MyHC)亚型会减少，导致 收缩较慢的异构体比例，如IIa型和I型。 这将是在衰老动物模型中第一次检测增稠液体对全身水合作用的影响。 以及潜在的肌肉生物学、运动学和生理学，以及与临床相关的关系 吞咽功能的结果指标。从这项工作中获得的知识将导致在 对临床决策至关重要的临床研究，这些临床决策必须平衡患者的抽吸风险和后续风险 医疗并发症，防止增稠液体对患者整体的潜在有害影响 医疗状况和生活质量。

Abstract Swallowing disorders are highly prevalent in elderly people, including those with age-related diseases. Thickened liquids are frequently used in the treatment of swallowing disorders and have been shown to immediately reduce the chance of airway invasion. However, thickened liquids have been associated with deleterious health effects such as dehydration, urinary tract infection, and reduced quality of life. Despite their common clinical use, the long-term efficacy of thickened liquids, and their effect on swallowing kinematics, systemic hydration, and underlying biology, is not well understood. Given the rapidly increasing population of persons over 65, estimated to reach 2.1 billion by 2051, it is critical to understand the efficacy of dysphagia interventions. The overarching goal of this proposal is to contribute foundational knowledge of biological mechanisms underlying functional swallowing changes in response to a frequently used, but understudied, intervention for dysphagia management in the aging population. The proposed study will use an aging rat model to interrogate how use of thickened liquids affects swallowing kinematics, systemic hydration, and underlying biology over time. We have 3 specific aims, each with a unique hypothesis. Aim 1 will test the hypothesis that chronic use of thickened liquid textures reduces bolus speed, reduces coordination of swallowing muscles, and disrupts normal respiratory-swallow event sequencing. Aim 2 will test the hypothesis that thickened liquids result in reduced volume of fluid intake and systemic dehydration, which will be exacerbated by viscosity and age. Aim 3 will test the hypothesis that thickened liquids, in the absence of thin liquid, will slow swallowing movements, dynamically altering muscle contractile properties to include reduced tongue forces and increased contraction times in an age-dependent manner. In concert, the proportion of fast- contracting type IIb myosin heavy chain (MyHC) isoforms in the tongue will be reduced, causing an increased proportion of slower-contracting isoforms, such as type IIa and type I. This research is highly significant in that it will be the first in an aging animal model to examine the effects of thickened liquids on systemic hydration along with underlying muscle biology, kinematics, and physiology, and the relationship to clinically relevant outcome measures of swallow function. Knowledge gained from this work will lead to hypotheses for testing in clinical studies that are crucial for clinical decisions that must balance patient risk of aspiration and subsequent medical complications, against the impact of potential deleterious effects of thickened liquids on patient overall medical status and quality of life.