Department of Physical Medicine & Rehabilitation Medicine.
Department of Family Medicine, Kyung Hee University Medical Center, Seoul, Republic of Korea.
Medicine (Baltimore). 2021 Mar 5;100(9):e25027. doi: 10.1097/MD.0000000000025027.
The prevalence of obesity as well as cognitive impairment increases with age. Previous studies showed that obesity is associated with an increased risk of cognitive impairment and dementia. Body composition changes occur as part of the aging process; therefore, the assessment of obesity in elderly populations should include body composition as well as body weight. This study investigated the relationship between body mass index (BMI), body composition, and cognitive function in a community-dwelling elderly Korean population.This cohort-based cross-sectional analysis included 2386 elderly participants aged between 70 and 84 years from the Korean Frailty and Aging Cohort Study for 2016 to 2017. To investigate the relationship between body composition and cognitive function in community-dwelling individuals, BMI and body composition, including total and trunk fat mass and fat-free mass, were measured by dual-energy X-ray absorptiometry. Fat mass index (FMI), trunk fat mass index (TFMI), and fat-free mass index (FFMI) were used to represent the body composition. A short form of the Korean version of the Consortium to Establish a Registry for Alzheimer disease was used to assess cognitive function. To evaluate the relationship between variables, simple and fully adjusted multivariable analyses were performed using generalized linear regression models.The mean ages were 76.8 years for males and 76.1 years for females. The BMI of male participants was significantly lower than that of females (23.9 ± 2.89 vs 24.7 ± 3.02 kg/m2, P < .001). Among body composition parameters, the differences in FMI (6.44 ± 1.97 vs 9.29 ± 2.3 kg/m2), TFMI (3.68 ± 1.33 vs 5.03 ± 1.43 kg/m2), and FFMI (17.4 ± 1.64 vs 15.3 ± 1.39 kg/m2) were statistically significant. In linear regression analyses, BMI, FMI, and TFMI showed significant positive correlations with mini-mental state examination in the Korean version of the CERAD assessment packet; wordlist memory, recall, and recognition; and frontal assessment battery only in males. The significant positive correlations persisted even after fully adjusting for age, education periods, location of residence, depression, marriage, annual income, presence of diabetes mellitus, dyslipidemia, and hypertension. However, no significant correlations in either sex were observed between FFMI and cognitive functions in the fully adjusted models.In this study, BMI, and fat mass-related indexes including FMI and TFMI showed a positive linear correlation with cognitive functions but not FFMI. Moreover, the findings were significant only in men. Besides the difference between sexes, the results of this study showed a more apparent correlation in fat mass than in fat-free mass that comprises body weight.
肥胖症以及认知障碍的患病率会随着年龄的增长而增加。先前的研究表明,肥胖与认知障碍和痴呆的风险增加有关。随着衰老过程的进行,身体成分会发生变化;因此,对老年人群体的肥胖评估应包括身体成分和体重。本研究旨在调查在一个社区居住的韩国老年人群体中,体重指数(BMI)、身体成分和认知功能之间的关系。
这项基于队列的横断面分析包括 2016 年至 2017 年来自韩国虚弱与衰老队列研究的 2386 名年龄在 70 至 84 岁之间的社区居住的老年人。为了研究社区居住个体的身体成分与认知功能之间的关系,通过双能 X 射线吸收法测量了 BMI 和身体成分,包括总体和躯干脂肪量和无脂肪量。脂肪质量指数(FMI)、躯干脂肪质量指数(TFMI)和无脂肪质量指数(FFMI)用于代表身体成分。使用阿尔茨海默病协会注册研究的韩国简短形式来评估认知功能。为了评估变量之间的关系,使用广义线性回归模型进行了简单和完全调整的多变量分析。
男性的平均年龄为 76.8 岁,女性为 76.1 岁。男性参与者的 BMI 明显低于女性(23.9±2.89 与 24.7±3.02kg/m2,P<.001)。在身体成分参数中,FMI(6.44±1.97 与 9.29±2.3kg/m2)、TFMI(3.68±1.33 与 5.03±1.43kg/m2)和 FFMI(17.4±1.64 与 15.3±1.39kg/m2)的差异具有统计学意义。在线性回归分析中,BMI、FMI 和 TFMI 与 CERAD 评估包中的简易精神状态检查、单词记忆、回忆和识别以及额叶评估电池呈显著正相关;仅在男性中。即使在完全调整年龄、教育年限、居住地、抑郁、婚姻、年收入、糖尿病、血脂异常和高血压后,这种显著的正相关性仍然存在。然而,在完全调整模型中,男女之间的 FFMI 与认知功能之间均未观察到显著相关性。
在这项研究中,BMI 和包括 FMI 和 TFMI 在内的脂肪量相关指标与认知功能呈正线性相关,但与 FFMI 无关。此外,这些发现仅在男性中具有统计学意义。除了性别差异之外,研究结果表明,与包含体重的无脂肪量相比,脂肪量与认知功能的相关性更为明显。