A Three-Year Longitudinal Follow-Up Study: Does Mild Cognitive Impairment Accelerate Age-Related Changes in Physical Function and Body Composition?

Age-related declines in physical function, body composition, and cognitive function are interrelated. This prospective study aimed to examine the impact of mild cognitive impairment (MCI) on age-related changes in physical function and body composition among community-dwelling older adults. We analyzed data from 180 older adults (aged ≥70 years) who completed a longitudinal assessment of physical function and body composition in the community. Physical function included grip strength and time taken to walk 10 m at normal and maximum pace. Body composition assessments calculated the body mass index (BMI) and appendicular skeletal muscle index (ASMI) using bioelectrical impedance analysis at baseline and three-year follow-up assessments. MCI was defined as values below the age- and education-adjusted reference threshold in several tests, including memory, attention, executive function, and processing speed. Participants were divided into the MCI and non-MCI groups based on their MCI status at baseline. A two-way repeated-measures analysis of covariance (ANCOVA), adjusting for age and gender, was used to analyze the group (MCI and non-MCI) by time (baseline and three-year follow-up) interaction. Thirty participants (16.7%) had MCI at baseline. The repeated-measures ANCOVA indicated that no variables had significant group by time interactions. Stratified analyses by gender (repeated-measures ANCOVA, adjusted for age) confirmed a significant group by time interaction on BMI (F=5.63, p=0.02) and ASMI (F=6.33, p=0.01) among women. Older women with MCI may experience a greater impact of the acceleration of shrinking and age-related decline in muscle mass. The close associations of MCI with shrinking and muscle mass loss have important implications for targeting interventions among MCI women.