Segmental Bioimpedance Variables in Association With Mild Cognitive Impairment

Area of Science:

• Gerontology
• Neuroscience
• Biomedical Engineering

Background:

• Mild cognitive impairment (MCI) affects a significant portion of the elderly population.
• Early detection of MCI is crucial for timely intervention and management.
• Understanding the physiological changes associated with MCI can aid in developing new diagnostic tools.

Purpose of the Study:

• To investigate alterations in body composition, water distribution, and bioimpedance parameters in individuals with MCI compared to cognitively normal (CN) individuals.
• To explore the association between bioelectrical impedance analysis (BIA) variables and MCI prevalence.
• To determine if these associations differ based on sex.

Main Methods:

• Segmental multi-frequency bioelectrical impedance analysis (BIA) was performed on 939 elderly participants (266 MCI, 673 CN).
• Whole-body and segmental body composition, water compartment, and impedance variables were analyzed.
• Correlations with neuropsychological tests and logistic regression analyses were conducted, controlling for age, sex, and comorbidities.

Main Results:

• Participants with MCI exhibited poorer cognitive function, increased depressive symptoms, and were slightly older than CN individuals.
• After adjusting for confounders, lower extremity segmental lean mass and water volume were positively associated with MCI.
• Lower extremity resistance and reactance showed a negative association with MCI, suggesting a shift of water from intracellular to extracellular space, particularly in women.

Conclusions:

• Changes in body composition, including increased segmental water and lean mass, and decreased body cell strength (indicated by reduced resistance and reactance), are associated with MCI.
• These BIA-derived changes are more pronounced in the lower extremities and in women.
• These characteristic BIA alterations may serve as early indicators of cognitive impairment in the elderly.