School of Life Sciences, The University of Nottingham Medical School, Queen's Medical Centre, Nottingham, UK.
Institute of Mental Health, The University of Nottingham Medical School, Nottingham, UK.
J Am Nutr Assoc. 2024 Aug;43(6):539-552. doi: 10.1080/27697061.2024.2333310. Epub 2024 Apr 2.
Sarcopenic-obesity (SO) is characterized by the concomitant presence of low muscle mass and high adiposity. This study explores the association of body composition and SO phenotypes with cognitive function in older adults.
Cross-sectional data in older adults (≥60 years) from NHANES 1999-2002 and 2011-2014 were used. In the 1999-2002 cohort, phenotypes were derived from body mass index (BMI) and dual-X-ray-absorptiometry, and cognition was assessed the by Digit-Symbol-Substitution-Test (DSST). In the 2011-2014 cohort, phenotypes were derived from BMI, waist-circumference (WC), and hand-grip-strength (HGS). Cognition was assessed using four tests: DSST, Animal Fluency, the Consortium-to-Establish-a-Registry-for-Alzheimer's-Disease-Delayed-Recall, and Word Learning. Mediation analysis was conducted to evaluate the contribution of inflammation (C-reactive-protein, CRP) and insulin resistance (Homeostatic-Model-Assessment-for-Insulin-Resistance, HOMA-IR) to the association between body composition and cognitive outcomes.
The SO phenotype had the lowest DSST mean scores ( < 0.05) and was associated with a significant risk of cognitive impairment [Odds Ratio (OR) = 1.9; 95%CI 1.0-3.7, = 0.027] in the 1999-2002 cohort. A higher ratio of fat mass and fat free mass (FM/FFM) also showed a greater risk of cognitive impairment (OR = 2.0; 95%CI 1.3-3.1, = 0.004). In the 2011-2014 cohort, the high WC-Low HGS group showed significantly lower scores on all four cognitive tests ( < 0.05) and a higher risk of cognitive impairment. CRP and HOMA-IR were significant partial mediators of the association between FM/FFM and DSST in the 1999-2002 cohort.
The SO phenotype was associated with a higher risk of cognitive impairment in older adults. Insulin resistance and inflammation may represent key mechanisms linking SO to the development of cognitive impairment.
肌少症合并肥胖症（SO）的特征是低肌肉量和高肥胖率同时存在。本研究旨在探讨老年人身体成分和 SO 表型与认知功能的关系。
本研究使用了 1999-2002 年和 2011-2014 年 NHANES 中的横断面数据。在 1999-2002 年的队列中，表型由身体质量指数（BMI）和双能 X 射线吸收法（DXA）得出，认知功能由数字符号替代测试（DSST）评估。在 2011-2014 年的队列中，表型由 BMI、腰围（WC）和握力（HGS）得出。认知功能使用四项测试进行评估：DSST、动物流畅性测试、建立阿尔茨海默病登记册联盟延迟回忆测试和单词学习测试。采用中介分析评估炎症（C 反应蛋白，CRP）和胰岛素抵抗（稳态模型评估的胰岛素抵抗，HOMA-IR）对身体成分和认知结果之间关联的贡献。
SO 表型的 DSST 平均得分最低（<0.05），与 1999-2002 年队列中认知障碍的显著风险相关（OR=1.9；95%CI 1.0-3.7，p=0.027）。较高的脂肪量与去脂体重（FM/FFM）比值也显示出更高的认知障碍风险（OR=2.0；95%CI 1.3-3.1，p=0.004）。在 2011-2014 年的队列中，高 WC-低 HGS 组在四项认知测试中的得分均显著较低（<0.05），且认知障碍的风险更高。CRP 和 HOMA-IR 是 1999-2002 年队列中 FM/FFM 与 DSST 之间关联的显著部分中介。
SO 表型与老年人认知障碍的风险增加相关。胰岛素抵抗和炎症可能是 SO 与认知障碍发展相关的关键机制。
