Mediation Effect of the Duration of Diabetes Mellitus on the Decrease in Bioimpedance Phase Angles in ethnically Korean People - a Multicenter Clinical Study.

AIMS We performed a multicenter clinical study to investigate whether the decrease in segmental phase angles (PhA values) observed using bioelectrical impedance is useful in screening for diabetes mellitus and monitoring disease progression. MATERIALS AND METHODS The segmental PhA values of the four limbs were acquired using multifrequency bioimpedance at 5, 50 and 250 kHz in three clinics. Differences in PhA values between the diabetes and control groups were analyzed using the two-sample t-test and analysis of variance (ANOVA). Changes in PhA values with increasing durations of diabetes were analyzed using a moderated mediation model and multivariate linear regression analysis. We recruited 217 subjects aged ≥40 years (diabetes: 158, controls: 59, males: 106, females: 111, A-clinic: 71, B-clinic: 70, and C-clinic: 76). RESULTS PhA values at 50 kHz were significantly decreased in people with diabetes (PhA of the right arm in males: t-value -4.0 (p < 0.001); PhA of the right leg in females: t-value -4.6 (p < 0.001)), and the difference was partially attributable to the duration of diabetes as well as aging. Specifically, the mediation effect of the duration of diabetes on the decrease in PhA values was 29.8% in the left arm of males, 53.3% in the right arm of females, and 36.3% in the left arm of both sexes. CONCLUSIONS PhA values at 50 kHz decreased in people with diabetes, and the changes were exacerbated as the disease duration increased. Thus, bioimpedance PhA values represent a noninvasive tool for monitoring the progression of diabetes mellitus.