Mediating effect of physical activity on the association between body fat distribution, dysmobility syndrome, and cognitive impairment in older women in the community

Purpose

To examine the association between body fat distribution, dysmobility syndrome, and cognitive impairment in 181 community-dwelling older women and assess physical activity’s mediating role.

Methods

Body composition was assessed using dual-energy X-ray absorptiometry, and the android-to-gynoid (A/G) fat ratio was calculated as the android fat proportion divided by the gynoid fat proportion. Participants were categorized into high and low 50 % groups based on the A/G fat ratio. Dysmobility syndrome was defined as the presence of at least three of the following: increased body fat percentage, decreased muscle mass, osteoporosis, slow gait speed, reduced grip strength, or a history of falls. Cognitive impairment was defined as a Mini-Mental State Examination for Dementia Screening score ≤ 23. Physical activity was measured using the International Physical Activity Questionnaire, with ≥600 metabolic equivalent of task-minutes per week classified as active and < 600 as inactive. Binary logistic regression was used to compute odds ratios (OR) and 95 % confidence intervals (CI) for the A/G fat ratio and physical activity. The mediating effects of physical activity were analyzed using Process Macro Model 4.

Results

Participants in the low 50 % A/G fat ratio group had higher odds of dysmobility syndrome (crude OR = 3.500, p < 0.001; adjusted OR = 3.678, p = 0.002) and cognitive impairment (crude OR = 2.714, p = 0.005; adjusted OR = 3.293, p = 0.005) than did those in the high 50 % group, even after covariate adjustments. The inactive group had higher odds of dysmobility syndrome (crude OR = 4.185, p < 0.001; adjusted OR = 3.199, p = 0.005) and cognitive impairment (crude OR = 3.190, p = 0.001; adjusted OR = 2.551, p = 0.022) than did the active group. Mediation analysis indicated that physical activity partially mediated the association between the A/G fat ratio and dysmobility syndrome (indirect effect = −0.5099, 95 % CI = −0.9045 to −0.1786) and cognitive impairment (indirect effect = 0.1446, 95 % CI = 0.0554 to 0.2582).

Conclusion

A lower A/G fat ratio increases the risks of dysmobility syndrome and cognitive impairment in older women; physical activity may mitigate these effects.