Membrane Capacitance from a Bioimpedance Approach: Associations with Insulin Resistance in Relatively Healthy Adults

Objective: This study aimed to determine whether higher membrane capacitance (C_M), a bioelectrical measure of cell membrane function, is associated with insulin resistance (IR) and/or metabolic syndrome (MetS). Methods: Cross-sectional analyses were performed on 2,191 relatively healthy adults from the National Health and Nutrition Examination Survey. The C_M of those with low/no disease risk was compared with those with IR, MetS, or both IR and MetS using ANCOVA. The associations between C_M and related clinical measures were assessed with multiple linear regression. Results: Compared with those with low/no risk, women and men with IR (P < 0.001) and IR + MetS (P < 0.001) had higher C_M, whereas C_M was similar in women (P = 0.4526) and men (P = 0.1126) with MetS alone. Positive associations with C_M were seen with waist circumference (women and men standardized beta [STD-β] = 0.18, P < 0.0001) and fasting insulin (women STD-β = 0.15, P < 0.0001; men STD-β = 0.12, P < 0.0001). Conclusions: Higher C_M was associated with IR in relatively healthy adults. In the absence of IR, higher C_M was not associated with MetS as defined by its clinical diagnostic criteria. This study suggests that with further investigation, C_M may be a potential tool to detect IR-related cell membrane dysfunction.