Department of Psychology, University of Pittsburgh, PA, USA.
Neurology. 2010 Oct 19;75(16):1415-22. doi: 10.1212/WNL.0b013e3181f88359. Epub 2010 Oct 13.
Physical activity (PA) has been hypothesized to spare gray matter volume in late adulthood, but longitudinal data testing an association has been lacking. Here we tested whether PA would be associated with greater gray matter volume after a 9-year follow-up, a threshold could be identified for the amount of walking necessary to spare gray matter volume, and greater gray matter volume associated with PA would be associated with a reduced risk for cognitive impairment 13 years after the PA evaluation.
In 299 adults (mean age 78 years) from the Cardiovascular Health Cognition Study, we examined the association between gray matter volume, PA, and cognitive impairment. Physical activity was quantified as the number of blocks walked over 1 week. High-resolution brain scans were acquired 9 years after the PA assessment on cognitively normal adults. White matter hyperintensities, ventricular grade, and other health variables at baseline were used as covariates. Clinical adjudication for cognitive impairment occurred 13 years after baseline.
Walking amounts ranged from 0 to 300 blocks (mean 56.3; SD 69.7). Greater PA predicted greater volumes of frontal, occipital, entorhinal, and hippocampal regions 9 years later. Walking 72 blocks was necessary to detect increased gray matter volume but walking more than 72 blocks did not spare additional volume. Greater gray matter volume with PA reduced the risk for cognitive impairment 2-fold.
Greater amounts of walking are associated with greater gray matter volume, which is in turn associated with a reduced risk of cognitive impairment.
体力活动（PA）被假设可以延缓成年后期的灰质体积减少，但缺乏纵向数据来检验这种关联。在这里，我们测试了 PA 是否与 9 年随访后的更大灰质体积相关，是否可以确定一个步行量的阈值来保护灰质体积，以及与 PA 相关的更大灰质体积是否与 PA 评估 13 年后认知障碍的风险降低相关。
在心血管健康认知研究中的 299 名成年人（平均年龄 78 岁）中，我们研究了灰质体积、PA 和认知障碍之间的关联。PA 量化为每周走过的街区数。在 PA 评估 9 年后，对认知正常的成年人进行高分辨率脑部扫描。在基线时的白质高信号、脑室分级和其他健康变量被用作协变量。在基线后 13 年进行认知障碍的临床判断。
行走量的范围从 0 到 300 个街区（平均 56.3；标准差 69.7）。较大的 PA 预测了额叶、枕叶、内嗅皮质和海马区域 9 年后更大的体积。需要走 72 个街区才能检测到灰质体积的增加，但走得超过 72 个街区并不能额外保护灰质体积。PA 导致的更大灰质体积使认知障碍的风险降低了两倍。
更多的行走量与更大的灰质体积相关，而更大的灰质体积又与认知障碍风险降低相关。
