Physiological age-related alterations in the interstitial flow in the brain, which plays an important role in waste product removal, remain unclear. Using [O]HO positron emission tomography (PET), water dynamics were evaluated in 63 healthy adult participants aged between 20 and 80 years. Interstitial flow was assessed by influx ratio (IR) and drain rate (DR), using time-activity concentration data. Participants were divided into four age groups with 15-year ranges, to evaluate age-related functional alterations. At least one of the indices declined significantly with age across all groups. A significant linear negative correlation between age and both indicators was found in the scatter plots (IR: R = 0.54, DR: R = 0.44); both indicators were predominantly lower after age 50 years. These results suggest interstitial flow decreases with age, especially after 50 years. These important findings can contribute to devising therapeutic interventions for neurological diseases characterized by abnormal accumulation of waste products, and suggest the need for taking measures to maintain interstitial flow starting around the age of 50 years.

中文翻译：

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间质液流量随着年龄的增长而减少，尤其是 50 岁以后


大脑间质流在废物清除中发挥着重要作用，但与年龄相关的生理变化仍不清楚。使用 [O]H2O 正电子发射断层扫描 (PET)，对 63 名年龄在 20 至 80 岁之间的健康成人参与者进行了水动力学评估。使用时间-活动浓度数据，通过流入率（IR）和排出率（DR）来评估间质流量。参与者被分为四个年龄组（每组 15 岁），以评估与年龄相关的功能变化。所有群体中至少有一项指数随着年龄的增长而显着下降。散点图中发现年龄与两个指标之间存在显着的线性负相关（IR：R = 0.54，DR：R = 0.44）； 50 岁以后这两项指标均显着降低。这些结果表明间质流量随着年龄的增长而减少，尤其是 50 岁以后。这些重要的发现有助于设计针对以废物异常积累为特征的神经系统疾病的治疗干预措施，并表明需要从 50 岁左右开始采取措施维持间质流动。