Background and Aims: Sensorimotor polyneuropathy (DPN) is the most common diabetic complication and a major contributor to increased morbidity and mortality in diabetic patients. With diagnostic methods still being limited, we aimed to correlate the phase angle (PhA) , a marker derived from bioelectrical impedance analysis, with determinants of DPN. In particular we used magnetic resonance neurography (MRN) together with state-of-the-art clinical and electrophysiological measurements of DPN.
Materials and Methods: In this cross-sectional observational study we included 1healthy subjects and 2patients with type 2 diabetes (T2D) , amongst which 63 had DPN. The PhA was calculated using a multi-frequency bioelectrical impedance analyzer. Nerve conduction studies, quantitative sensory testing (QST) and diffusion weighted 3 Tesla MRN to determine the fractional anisotropy (FA) were performed.
Results: In the group comparison lower PhA values were found in T2D patients with DPN in contrast to T2D patients without DPN (5.71+/-0.vs. 6.07+/-0.08, p=0.007) and healthy controls (5.71+/-0.vs. 6.18+/-0.08, p<0.001) . Confounder-adjusted analysis among T2D patients showed positive correlations of the PhA with the FA of MRN (r=0.41, p=0.006) , with conduction velocities and action potentials of the peroneal (r=0.27, p<0.001; r=0.29, p<0.001) and tibial nerve (r=0.22, p=0.005; r=0.30, p<0.001) and with Z-scores of QST (thermal detection r=0.31, p<0.001; thermal pain r=0.20, p=0.010; mechanical pain r=0.19, p=0.015; mechanical detection r=0.19, p=0.013) .
Conclusion: The close association of the PhA with the FA, a marker of structural nerve integrity of MRN, might reflect the similar physics of current or diffusion respectively being impaired by altered nerve composition. Due to correlations of the PhA with classical diagnostics of DPN it could become a novel, easily accessible and powerful marker for a quick assessment of DPN.
L.Schimpfle: None. C.Mooshage: None. D.Tsilingiris: None. Z.Kender: None. F.T.Kurz: None. J.M.E.Jende: None. J.M.Szendroedi: Consultant; Boehringer Ingelheim International GmbH. M.Bendszus: None. S.Kopf: Board Member; Novo Nordisk, Speaker's Bureau; AstraZeneca, Recordati S.p.A.
The German Research Council (DFG, SFB 1158)