Mediation effect of the duration of diabetes mellitus on the decrease in bioimpedance phase angles in ethnically Korean people: A multicenter clinical study

AIMS/INTRODUCTION: We carried out 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 participants aged ≥40 years (diabetes 158, controls 59, men 106, women 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 men: t‐value −4.0, P < 0.001; PhA of the right leg in women: 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 men, 53.3% in the right arm of women, and 36.3% in the left arm of both sexes. CONCLUSIONS: Phase angle 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 non‐invasive tool for monitoring the progression of diabetes mellitus.