Prediabetes, diabetes, metabolic syndrome, and small fiber neuropathy

• Published in: Muscle & nerve Vol. 61; no. 4; pp. 475 - 479
• Main Authors: Thaisetthawatkul, Pariwat, Lyden, Elizabeth, Americo Fernandes, J., Herrmann, David N.
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.04.2020; Wiley Subscription Services, Inc
• Subjects: Adult; Aged; Autonomic nervous system; autonomic neuropathy; Axons - pathology; Biopsy; Diabetes; Diabetes mellitus; Diabetes Mellitus - pathology; Diabetes Mellitus - physiopathology; Diabetic neuropathy; Electrophysiology; Female; Fibers; Humans; Male; Metabolic disorders; Metabolic syndrome; Metabolic Syndrome - pathology; Metabolic Syndrome - physiopathology; Middle Aged; Neural Conduction - physiology; peripheral neuropathy; prediabetes; Prediabetic State - pathology; Prediabetic State - physiopathology; Sensory testing; Skin; Skin - innervation; small fiber neuropathy; Small Fiber Neuropathy - pathology; Small Fiber Neuropathy - physiopathology; Structure-function relationships; metabolic syndrome; small fiber neuropathy; diabetes mellitus; autonomic neuropathy; peripheral neuropathy; prediabetes
• ISSN: 0148-639X; 1097-4598
• DOI: 10.1002/mus.26825

Introduction This study was conducted to evaluate the association between prediabetes (PD), elements of the metabolic syndrome (MetS), and small fiber neuropathy (SFN). Methods A total of 268 patients with SFN symptoms and normal electrophysiology underwent tests to assess small fibers. SFN was diagnosed based on abnormality of at least two among intraepidermal nerve fiber density (IEFND), quantitative sensory testing, and quantitative sudomotor axon reflex testing. Results There was no difference in IENFD or abnormal skin biopsy frequency between PD and normoglycemia (NG). However, IENFD was lower in people with diabetes mellitus (DM) than in those with NG. An association between HbA1C and IENFD was observed only if DM patients were included. Attributes of the MetS were more common in those with an abnormal skin biopsy but not among those with autonomic dysfunction or meeting SFN criteria. Discussion DM, but not PD alone, is associated with SFN. Other MetS elements appear to preferentially impact small fiber structure over function.