A newly observed negative association between cell membrane capacitance and depression using data measured by a HYDRA ECF/ICF Bio-Impedance Spectrum Analyzer and Cole model.
Authors: Liu Xinrui , Zhang Shaoyi 
Published: October 2022

Abstract
Cell’s bilayer phospholipid membranes work as insulators that separate the extracellular matrix and cytoplasm, creating a charge gradient across the cell membrane. Cell membrane capacitance, together with membrane resistance, impacts how fast the cell responds to the flow of ions currents. And for neurons, it affects how the neurons integrate electric signals and their synaptic efficacy. In this study, we performed logistic regression and used statistical analysis, and found a significant correlation with a relatively large R-squared value between depression and cell membrane capacitance.

Objective
This study aims to study if the lower cell membrane capacitance correlates with an increased rate of depression in participants aged 8-49 years old.

Data collection
Data used in this study were collected in the 1999-2000 and 2001-2002 CDC National Health and Nutrition Examination Survey (NHANES) database. 11,260 participants aged 8 – 49 years old in the 1999-2000 and 2001-2002 NHANES database were examined for bioelectrical impedance analysis (BIA), which indicates the impedance analyzing components in this study including the ECF volume, percent body fat, and cell membrane capacitance. 1,707 participants aging between 20-39 years old in the 1999-2000 and 2001-2002 NHANES database signed up for a depression mental health examination, which indicates the diagnosis of depression in this study. Logistic regression and statistical modeling were performed to study the association between cell membrane capacitance and odds of depression.

Results
For unadjusted correlation between cell membrane capacitance and depression odds, with one standard deviation decrease in cell membrane capacitance, the depression odds will increase by 3.742 [95%CI 3.598 - 3.885] times.
For demographics data adjusted correlation between cell membrane capacitance and depression odds, with one standard deviation decrease in cell membrane capacitance, the depression odds will increase by 2.675 [95%CI 2.310 - 3.042] times.
For demographics data and bioelectrical impedance analysis data adjusted correlation between cell membrane capacitance and depression odds, with one standard deviation decrease in cell membrane capacitance, the depression odds will increase by 2.193 [95%CI 1.407 - 2.979] times.
For demographics data and bioelectrical impedance analysis data adjusted correlation between cell membrane capacitance and depression odds, with one standard deviation decrease in cell membrane capacitance, the depression odds will increase by 2.654 [95%CI 1.695 - 3.612] times.

Conclusion
This study shows the correlation between cell membrane capacitance and depression scores using data collected from the 1999-2000 and 2001-2002 CDC National Health and Nutrition Examination Survey (NHANES) database. Among participants aging from 8 to 49 years old, after adjusting for demographics data and bioelectrical impedance analysis data as covariance, with one standard deviation decrease in cell membrane capacitance analysis, an increase in odds of depression by 2.654 [95%CI 1.695 - 3.612] times was observed in this statistical analysis. The p-value of cell membrane capacitance in logistic regression after being adjusted was significant (<0.05) and was in the 95% confidence interval, so we may conclude that there’s a significant correlation between cell membrane capacitance and depression scores and the coefficient obtained from the logistic regression was significant and valid.