Abstract Background Substantive previous work has shown that both gait speed and global cognition decline as people age. Rates of their decline, as opposed to cross-sectional measurements, could be more informative of future functional status and other clinical outcomes because they more accurately represent deteriorating systems. Additionally, understanding the sex and racial disparity in the speed of deterioration, if any, is also important as ethnic minorities are at an increased risk of mobility disability and dementia. Method Data from 2 large longitudinal intervention studies were integrated. Rates of decline were derived from individual-level measures of gait speed of 400-m walk and scores on the Modified Mini Mental State Examination (3MSE). We also assessed age-associated declines and accelerations in changes across the ages represented in the studies (age range 53–90). Results The mean rate of decline in 400-m gait speed across individuals was 0.03 m/s per year, and multivariable analysis showed a significant acceleration in decline of −0.0013 m/s/y2 (p < .001). Both race and sex moderated the rate of decline. For global cognition, the mean rate of decline was 0.05 of a point per year on the 3MSE scale, and acceleration in the rate of decline was significant (−0.017 point/y2, p < .001), but neither sex nor race moderated the decline. Conclusion Rate of decline in physical but not cognitive function appears moderated by sex and race. This finding, as well as rates and accelerations of decline estimated herein, could inform future intervention studies. Clinical Trials Registration Number NCT00017953 (Look AHEAD); NCT01410097 (Look AHEAD ancillary); NCT00116194 (LIFE).

中文翻译：

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老年人身体和认知功能下降的梯度和加速度：差异分析

摘要 背景先前的大量研究表明，随着人们年龄的增长，步态速度和整体认知能力都会下降。与横截面测量相比，它们的下降率可以为未来的功能状态和其他临床结果提供更多信息，因为它们更准确地代表恶化的系统。此外，了解恶化速度的性别和种族差异（如果有的话）也很重要，因为少数族裔患行动障碍和痴呆症的风险增加。 方法整合了两项大型纵向干预研究的数据。下降率来自 400 米步行步态速度的个人测量和改良简易精神状态检查 (3MSE) 分数。我们还评估了研究中各个年龄段（年龄范围 53-90 岁）与年龄相关的变化的下降和加速。 结果个体 400 米步态速度的平均下降率为每年 0.03 m/s，多变量分析显示下降速度显着加速 -0.0013 m/s/y2 (p < .001)。种族和性别都减缓了下降速度。对于全球认知，在 3MSE 量表上，平均下降率为每年 0.05 个点，并且下降速度的加速非常显着（-0.017 点/y2，p < .001），但性别和种族都没有减弱下降。 结论身体功能而非认知功能的下降速度似乎受到性别和种族的影响。这一发现以及本文估计的下降速度和加速度可以为未来的干预研究提供信息。 临床试验注册号NCT00017953（向前看）； NCT01410097（向前看辅助）； NCT00116194（生活）。