Relationship between physiological tremor and cognitive function in physically active older women.

Purpose: This study aimed to compare the physiological tremor, grip strength, and cognitive function of sedentary and physically active older adults.

Methods: Twenty-four older adults aged ≥65 years participated in this study and were divided into the sedentary (76.5±4.4 years, n=12) and physically active (73.5±3.3 years, n=12) groups. Each group completed the Mini-Mental State Examination (MMSE) for cognitive function assessment. Physiological tremor was measured using an accelerometer for both hands at rest and the left/right hand with a 1,000 g dumbbell on the palm in neutral positions and the elbow flexed at 90°. Physical fitness was measured by grip strength and completion of the Short Physical Performance Battery (SPPB) and the 6-min walk test.

Results: The physically active group showed a significantly lower level of physiological tremor in both hands at rest and the left/right hand with a 1,000 g dumbbell on the palm (P<0.05) than that in the sedentary group. For cognitive function, the physically active group showed significantly higher scores than those in the sedentary group (P<0.001). No significant correlation was found between cognitive function and left/right grip strength (left: r = 0.117, P = 0.585; right: r = 0.230, P = 0.279), physiological tremor in both hands at rest (left: r = -0.524, P < 0.001; right: r = -0.508, P < 0.05), and the left/right hand with a 1,000 g dumbbell on the palm (left: r = -0.505, P < 0.05; right: r = -0.458, P < 0.05).

Conclusion: Physiological tremor of the hands has the potential to be a useful predictor of cognitive function in older adults.