Dual-task performance and its associations with glycemic status, serum BDNF, cognitive function, and reaction time in older adults with type 2 diabetes

Introduction Type 2 diabetes mellitus (DM) imposes a multidimensional burden on older adults by impairing glycemic control and altering brain structure and function, ultimately affecting cognitive performance, reaction time, and motor abilities. In daily life, dual-task situations provide a sensitive framework for assessing executive functions, attention, and processing speed. The aim of this study was to examine the relationship between dual-task performance and glycemic status, serum brain-derived neurotrophic factor (BDNF), cognitive function, and reaction time in older adults with Type 2 DM. Methods A total of 46 participants were included in the study (25 females, 21 males; mean age 66.8±2.4 years; mean Hemoglobin A1c (HbA1c) level 6.92±1.18; mean disease duration 10.3±6.7 years). Dual-task performance was assessed using the Dual-Task Timed Up and Go (Dual-TUG) test. During the dual-task condition, participants were instructed to subtract by threes from 100 while walking. Blood samples were collected to measure HbA1c and serum BDNF levels. Cognitive status was evaluated using the Montreal Cognitive Assessment (MoCA). Reaction time was assessed using the FitLight Trainer visual reaction system, and both initial and mean reaction time values were recorded. Results The mean single-task TUG duration was 6.56±0.92 s, while the mean Dual-TUG duration was 11.09±4.29 s. Correlation analyses showed that Dual-TUG duration was significantly negatively correlated with MoCA total score (r=–0.295; p = 0.046) and MoCA attention subscore (r=–0.368; p=0.012). A significant positive correlation was observed between Dual-TUG duration and mean reaction time (r=0.380; p=0.009). However, no statistically significant correlations were found between dual-task performance and HbA1c levels or serum BDNF concentrations (p>0.05). Conclusions Our results indicate that poorer dual-task performance in older adults with type 2 DM is associated with lower global cognitive function, reduced attention, and slower reaction time, whereas no significant associations were observed with HbA1c levels or serum BDNF concentrations. These results suggest that dual-task difficulties in individuals with diabetes may be more closely linked to neurocognitive and psychomotor factors than to short-term glycemic control or peripheral neurotrophin levels. Emphasizing cognitive preservation and enhancement—alongside optimal glucose regulation—may contribute to improved dual-task performance and functional mobility in daily living among older adults with diabetes.