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 twoway 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 agerelated decline in muscle mass. The close associations of MCI with shrinking and muscle mass loss have important implications for targeting interventions among MCI women.