Association between knee extension strength and cognitive function in older adults with type 2 diabetes: a cross-sectional study.
Relative knee extension strength may be linked to cognitive function in older adults with T2DM, but more research is needed to confirm causality.
Where it sits
this study against the rest of the adamax corpusSummary and findings
This cross-sectional study examined the association between relative knee extension strength and cognitive function in 42 older adults with type 2 diabetes. Relative knee extension strength was positively associated with cognitive function, but the confidence intervals often included the null value. The study suggests a potential link between muscle strength and cognitive health in this population.
Abstract
<h4>Background</h4>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.<h4>Methods</h4>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.<h4>Results</h4>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, <i>p</i> = 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, <i>p</i> = 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, <i>p</i> = 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, <i>p</i> = 0.168), although the confidence interval included the null value.<h4>Conclusions</h4>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.<h4>Supplementary information</h4>The online version contains supplementary material available at 10.1007/s40200-026-02031-1.
Background
Cognitive impairment is a prevalent complication in older adults with type 2 diabetes mellitus (T2DM). Previous research has linked reduced muscle strength to adverse health outcomes, but the specific relationship between knee extension strength and cognitive function in this demographic remains unclear. This study aims to explore this potential association, which could inform interventions targeting physical health to support cognitive function.
Methods
The study employed a cross-sectional design involving 42 older adults with T2DM, with a mean age of 72.8±7.4 years and 35% male participants. Relative knee extension strength was calculated by normalizing knee extension strength to body weight, and cognitive function was assessed using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Hierarchical regression analyses were conducted, adjusting for age, HbA1c, and visceral fat area in sequential models.
Results
In the crude model, relative knee extension strength was positively associated with cognitive function (B=8.18, 95% CI -0.57 to 16.93, p=0.066). After adjusting for age, the association remained positive (B=8.30, 95% CI -0.07 to 16.70, p=0.052). The association was similar after further adjustment for HbA1c (B=8.40, 95% CI -0.059 to 16.80, p=0.052). In the fully adjusted model, the association persisted but was not statistically significant (B=6.12, 95% CI -2.72 to 14.97, p=0.168).
Interpretation
The study suggests a potential positive association between lower-limb muscle strength and cognitive function in older adults with T2DM, although the confidence intervals often included the null value, indicating uncertainty. The effect sizes were not statistically significant in fully adjusted models, limiting clinical relevance. The findings align with previous research linking physical strength to cognitive health but require further investigation through longitudinal studies to establish causality.
Key findings
- n=42 older adults with T2DM, mean age 72.8±7.4 years.
- B=8.18, 95% CI -0.57 to 16.93, p=0.066 in crude model.
- B=8.30, 95% CI -0.07 to 16.70, p=0.052 after adjusting for age.
- B=8.40, 95% CI -0.059 to 16.80, p=0.052 after adjusting for age and HbA1c.
- B=6.12, 95% CI -2.72 to 14.97, p=0.168 in fully adjusted model.
Limitations
- small n=42
- cross-sectional design
- confidence intervals include null value
- no causal inference possible