Jeong Sanghoon, Kim Junghoon
Department of Marine Sports, Pukyong National University.
Department of Preventive Medicine, Gachon University College of Medicine.
Tohoku J Exp Med. 2018 Feb;244(2):83-91. doi: 10.1620/tjem.244.83.
Dementia is one of the priority public health problems in the older population, and the number of people with dementia is steadily increasing. The longitudinal association of muscle strength with risk of new-onset cognitive dysfunction in a general population including middle and older adults remains unknown. The purpose of this study was to investigate the effects of low muscle strength on risk for new-onset cognitive dysfunction over 6 years using a large nationwide sample of cognitively healthy adults. Study participants included 6,435 middle and older adults (33,554 person-years of follow-up), using data from the Korean Longitudinal Study of Ageing 2006-2012. Muscular strength was measured using the maximum handgrip strength of each participant as an index of muscle quality. Low muscle strength was defined as one standard deviation below the mean using the handgrip strength index based on the study population. Cognitive function was evaluated using the Mini-Mental Status Evaluation. The hazard ratio (HR) for cognitive dysfunction significantly and linearly increased according to muscle strength status independent of potential confounding factors (HR: 1.36, 95% confidence interval [CI]: 1.18-1.56 for low vs. normal-high group). Using stratified analyses, a significant association between muscle strength status and risk of cognitive impairment was observed in those with low physical activity, but not those with high physical activity. We show that handgrip strength is associated with increased risk of new-onset cognitive dysfunction over 6 years of follow-up in cognitively healthy middle aged and older adults at baseline.
痴呆是老年人群中重点关注的公共卫生问题之一，且痴呆患者数量在稳步增加。在包括中老年人在内的普通人群中，肌肉力量与新发认知功能障碍风险之间的纵向关联尚不清楚。本研究的目的是利用全国范围内大量认知健康成年人样本，调查低肌肉力量对6年内新发认知功能障碍风险的影响。研究参与者包括6435名中老年人（随访33554人年），使用的数据来自2006 - 2012年韩国老龄化纵向研究。肌肉力量通过测量每位参与者的最大握力作为肌肉质量指标。根据研究人群的握力指数，将低肌肉力量定义为低于平均值一个标准差。认知功能采用简易精神状态检查表进行评估。认知功能障碍的风险比（HR）根据肌肉力量状况显著且呈线性增加，不受潜在混杂因素影响（低肌肉力量组与正常 - 高肌肉力量组相比，HR：1.36，95%置信区间[CI]：1.18 - 1.56）。通过分层分析，在体力活动水平低的人群中观察到肌肉力量状况与认知障碍风险之间存在显著关联，而在体力活动水平高的人群中未观察到这种关联。我们发现，在基线时认知健康的中老年人中，握力与随访6年期间新发认知功能障碍风险增加有关。
