The Relationship between Functional Physical Fitness and Mild Cognitive Impairment in Older Adults

Han, Jinhee; Kang, Hyunsik

Abstract

In a cross-sectional design, this study examined the relationship between functional physical fitness and mild cognitive impairment (MCI) in older adults. A total of 306 older adults (91 men and 215 women) aged 65 years or older were recruited from our local community. A senior fitness test (SFT) was used to assess functional domains of physical fitness consisting of upper and lower body strength, endurance, upper and lower body flexibility, and agility/dynamic balance. Korean version of mini-mental state examine for dementia screening and short-form geriatric depression scale were used to assess global cognitive performance and depression, respectively. Age, sex, education, body mass index, percent body fat, blood lipids, glucose, insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) were assessed. A composite score of physical fitness was calculated as a sum of z scores for each domain of the SFT parameters. Based on the composited score of physical fitness, subjects were classified as low fit (lower 25 percentile), moderate fit (middle 50 percentile), and high fit (high 25 percentile). Linear contrast analysis using one-way analysis of variance showed significant linear trends for age (p<0.001), education (p<0.001), cognitive function (p<0.001), and depression scale (p=0.006) across incremental composite score of physical fitness. Functional physical fitness was positively associated with age, years of education and global cognitive performance and negatively with depression scale. Logistic regression analyses showed that compared to the low fit group, the moderate (p=0.004) and high fit (p=0.010) groups had significantly lower odds ratios for having MCI even after adjusted for age, sex, education, and body fatness parameters. However, the odds ratios of the moderate (p=0.101) and high fit (p=0.191) groups were not significant when additionally controlling for depression scale and HOMA-IR. The current findings suggest that physical fitness promotion along with treatments of depression and HOMA-IR should be key components of interventions to prevent and/or treat MCI with normal aging.