title: The Expanded Bead Size of Corneal C-Nerve Fibers Visualized by Corneal Confocal Microscopy Is Associated with Slow Conduction Velocity of the Peripheral Nerves in Patients with Type 2 Diabetes Mellitus.
abstract: This study aims to establish the corneal nerve fiber (CNF) morphological alterations in a large cohort of type 2 diabetic patients and to investigate the association between the bead size, a novel parameter representing composite of accumulated mitochondria, glycogen particles, and vesicles in CNF, and the neurophysiological dysfunctions of the peripheral nerves. 162 type 2 diabetic patients and 45 healthy control subjects were studied in detail with a battery of clinical and neurological examinations and corneal confocal microscopy. Compared with controls, patients had abnormal CNF parameters. In particular the patients had reduced density and length of CNF and beading frequency and increased bead size. Alterations in CNF parameters were significant even in patients without neuropathy. The HbA1c levels were tightly associated with the bead size, which was inversely related to the motor and sensory nerve conduction velocity (NCV) and to the distal latency period of the median nerve positively. The CNF density and length positively correlated with the NCV and amplitude. The hyperglycemia-induced expansion of beads in CNF might be a predictor of slow NCV in peripheral nerves in type 2 diabetic patients.
authors: Ishibashi Clinic, 1-9-41-2 Kushido, Hatsukaichi, Hiroshima 738-0033, Japan.
authors: Fukashi
authors: 0000-0002-8880-2168
authors: F
authors: Ishibashi
authors: Ishibashi Clinic, 1-9-41-2 Kushido, Hatsukaichi, Hiroshima 738-0033, Japan.
authors: Rie
authors: 0000-0002-8369-8322
authors: R
authors: Kojima
authors: Ishibashi Clinic, 1-9-41-2 Kushido, Hatsukaichi, Hiroshima 738-0033, Japan.
authors: Miki
authors: 0000-0001-6346-9808
authors: M
authors: Taniguchi
authors: Ishibashi Clinic, 1-9-41-2 Kushido, Hatsukaichi, Hiroshima 738-0033, Japan.
authors: Aiko
authors: 0000-0001-6313-1583
authors: A
authors: Kosaka
authors: Ishibashi Clinic, 1-9-41-2 Kushido, Hatsukaichi, Hiroshima 738-0033, Japan.
authors: Harumi
authors: 0000-0003-3636-6242
authors: H
authors: Uetake
authors: Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK; University of Exeter Medical School, St Luke's Campus, South Cloisters, Exeter EX1 2LU, UK.
authors: Mitra
authors: 0000-0003-2319-1543
authors: M
authors: Tavakoli
mesh_terms: D016022:Case-Control Studies; D003315:Cornea / Q000473:pathology*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D003929:Diabetic Neuropathies / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006003:Glycogen; D006801:Humans; D000069416:Intravital Microscopy; D008297:Male; D008475:Median Nerve / Q000503:physiopathology; D018613:Microscopy, Confocal; D008875:Middle Aged; D008928:Mitochondria; D036421:Nerve Fibers, Unmyelinated / Q000473:pathology*; D009431:Neural Conduction; D010525:Peripheral Nerves / Q000503:physiopathology*; D012684:Sensory Thresholds; D013572:Synaptic Vesicles
chemical_list: D006442:Glycated Hemoglobin; D006003:Glycogen; C517652:hemoglobin A1c protein, human