Department of Epidemiology and Biostatistics, School of Public Health, Indiana University, Bloomington, IN, United States of America.
Department of Epidemiology and Biostatistics, School of Public Health, Indiana University, Bloomington, IN, United States of America.
Exp Gerontol. 2022 Nov;169:111947. doi: 10.1016/j.exger.2022.111947. Epub 2022 Sep 7.
Cognitive impairment imposes substantial psychological, emotional, and economic burdens on affected individuals, families and society. A better understanding of potentially modifiable risk factors that may be used in the prevention of cognitive impairment is therefore a high priority in aging research.
This study included 9268 community-dwelling women aged 65 years or older from the Study of Osteoporotic Fractures launched between 1986 and 1988 in the US. Participants were followed for 20 years. Modified Mini-Mental State Examination (m-MMSE) was administered up to 6 times. Six updated measurements of gait speed and handgrip strength at the same visit time when m-MMSE was administered were used. The m-MMSE score was used to define cognitive impairment states (normal, mild, and severe impairment). A multi-state model (MSM) was used to estimate the transitions between different states of cognitive function.
Faster gait speed (one unit increase of meter/s) was associated with lower risk of transition from cognitively normal status to mild cognitive impairment (HR = 0.50, 95 % CI: 0.37-0.67), and from mild impairment to severe impairment (HR = 0.52, 95 % CI: 0.37-0.72). Higher gait speed was associated with increased risk of cognitive transition from severe impairment to mild impairment (HR = 2.56 95 % CI: 0.97-6.77), although the result did not reach statistical significance. Similarly, we observed greater handgrip strength (per kg increase) was associated with lower risk of transition of cognitive status from normal to mild impairment (HR = 0.96 95 % CI: 0.95-0.97), and from mild to severe impairment (HR = 0.98, 95 % CI: 0.96-0.99). Greater handgrip strength was associated with increased risk of cognitive transition from severe to mild cognitive impairment (HR = 1.05, 95 % CI: 1.01-1.09). In addition, we also observed that both faster gait speed and greater handgrip strength were associated with lower risk of transitions from normal or mild cognitive impairment status to death.
Our results confirmed that screening for slow gait speed or weak handgrip strength may be useful for identifying older adults at risk for cognitive decline when they are still cognitively normal or only mildly impaired. Exercise programs to improve gait speed and muscle strength may delay or prevent transitions into cognitive impairment in older adults.
认知障碍给受影响的个人、家庭和社会带来了巨大的心理、情感和经济负担。因此，更好地了解可能改变的风险因素，这些因素可能用于预防认知障碍，是老龄化研究的当务之急。
本研究纳入了 1986 年至 1988 年期间在美国开展的骨质疏松性骨折研究中年龄在 65 岁及以上的 9268 名社区居住女性。参与者随访 20 年。共进行了 6 次改良简易精神状态检查（m-MMSE）。在进行 m-MMSE 检查的同一就诊时间，使用了 6 次更新的步态速度和手握力测量值。使用 m-MMSE 评分来定义认知障碍状态（正常、轻度和重度障碍）。使用多状态模型（MSM）来估计认知功能不同状态之间的转变。
更快的步速（米/秒增加 1 个单位）与从认知正常状态向轻度认知障碍（HR=0.50，95%CI：0.37-0.67）以及从轻度障碍向严重障碍（HR=0.52，95%CI：0.37-0.72）的转变风险降低相关。更高的步速与从严重障碍向轻度障碍的认知转变风险增加相关（HR=2.56，95%CI：0.97-6.77），尽管结果未达到统计学意义。同样，我们观察到更大的握力（每公斤增加）与从认知正常状态向轻度障碍（HR=0.96，95%CI：0.95-0.97）以及从轻度障碍向严重障碍（HR=0.98，95%CI：0.96-0.99）的认知状态转变风险降低相关。更大的握力与从严重认知障碍向轻度认知障碍（HR=1.05，95%CI：1.01-1.09）的认知转变风险增加相关。此外，我们还观察到，更快的步速和更大的握力均与从认知正常或轻度认知障碍状态向死亡的转变风险降低相关。
我们的研究结果证实，当老年人认知功能正常或仅轻度受损时，筛查较慢的步态速度或较弱的握力可能有助于识别认知能力下降的高风险人群。改善步态速度和肌肉力量的运动计划可能会延迟或预防老年人认知障碍的发生。
