Association between knee extension strength and cognitive function in older adults with type 2 diabetes: a
Takahiro Nonaka1,2, Kono Kenichi3, Go Owari1
1Department of Rehabilitation, International University of Health and Welfare Narita Hospital, Narita, Japan.
Background:
Cognitive impairment is a common complication among older adults with type 2 diabetes mellitus (T2DM). Reduced muscle strength has been associated with adverse health outcomes; however, the relationship between relative knee extension strength and cognitive function in older adults with T2DM remains unclear. This study aimed to examine the association between relative knee extension strength and cognitive function in older adults with T2DM.
Methods:
This cross-sectional study included 42 older adults with T2DM (mean age 72.8 ± 7.4 years; 35% male). Relative knee extension strength was calculated by normalizing knee extension strength to body weight. Cognitive function was assessed using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Hierarchical regression analyses were performed using sequentially adjusted models culminating in a fully adjusted model including age, relative knee extension strength, HbA1c, and visceral fat area.
Results:
In the crude model, relative knee extension strength showed a positive association with cognitive function (B = 8.18, 95% CI - 0.57 to 16.93, p = 0.066; adjusted R² = 0.059). After adjustment for age, relative knee extension strength remained positively associated with MoCA score (B = 8.30, 95% CI - 0.07 to 16.70, p = 0.052; adjusted R² = 0.18). In the model additionally adjusted for HbA1c, the association was similar (B = 8.40, 95% CI - 0.059 to 16.80, p = 0.052; adjusted R² = 0.14). In the fully adjusted model including age, HbA1c, and visceral fat area, the estimated association between relative knee extension strength and cognitive function remained positive (B = 6.12, 95% CI - 2.72 to 14.97, p = 0.168), although the confidence interval included the null value.
Conclusions:
Relative knee extension strength was positively associated with cognitive function in older adults with T2DM after adjustment for age and metabolic factors. These findings suggest that lower-limb muscle strength may represent a relevant physical correlate of cognitive function in this population. Longitudinal studies are needed to clarify causality.
Supplementary Information:
The online version contains supplementary material available at 10.1007/s40200-026-02031-1.
