title: Small and large fiber neuropathy in those with type 1 and type 2 diabetes: a 5-year follow-up study.
abstract: The purpose of this study was to evaluate progression of diabetic polyneuropathy and differences in the spectrum and evolution of large- and small-fiber involvement in patients with diabetes type 1 and 2 over 5 years. Fifty-nine patients (35 type 1 and 24 type 2) were included. Nerve conduction studies (NCS), quantitative sensory testing, skin biopsy for quantification of intraepidermal nerve fiber density (IENFD), symptom scoring and clinical evaluations were performed. Z-scores were calculated to adjust for the physiologic effects of age and height/gender. Neuropathic symptoms were not significantly more frequent in type 2 than in type 1 diabetic patients at follow-up (54% vs. 37%). The overall mean NCS Z-score remained within the normal range, but there was a small significant decline after 5 years in both groups: type 1 (p = 0.004) and type 2 (p = 0.02). Mean IENFD Z-scores changed from normal to abnormal in both groups, but only significantly in those with type 2 diabetes (reduction from 7.9 ± 4.8 to 4.3 ± 2.8 fibers/mm, p = 0.006). Cold perception threshold became more abnormal only in those with type 2 diabetes (p = 0.049). There was a minimal progression of large fiber neuropathy in both groups. Reduction of small fibers predominated and progressed more rapidly in those with type 2 diabetes.
authors.affiliation: Department of Neurology and Neurophysiology, University Hospital of North Norway, Tromsø, Norway.|Department of Clinical Medicine, The Arctic University of Norway, Tromsø, Norway.
authors.forename: Sissel
authors.initials: S
authors.lastname: Løseth
authors.affiliation: Institute of Neurosciences, Uppsala University, Uppsala, Sweden.|Department of Clinical Neurophysiology, Uppsala University Hospital, Uppsala, Sweden.
authors.forename: Erik V
authors.initials: EV
authors.lastname: Stålberg
authors.affiliation: Department of Clinical Pathology, University Hospital of North Norway, Tromsø, Norway.|Department of Medical Biology, The Arctic University of Norway, Tromsø, Norway.
authors.forename: Sigurd
authors.initials: S
authors.lastname: Lindal
authors.affiliation: Department of Clinical Medicine, The Arctic University of Norway, Tromsø, Norway.
authors.forename: Edel
authors.initials: E
authors.lastname: Olsen
authors.affiliation: Department of Clinical Medicine, The Arctic University of Norway, Tromsø, Norway.|Department of Internal Medicine, University Hospital of North Norway, Tromsø, Norway.
authors.forename: Rolf
authors.initials: R
authors.lastname: Jorde
authors.affiliation: Department of Neurology and Neurophysiology, University Hospital of North Norway, Tromsø, Norway.|Department of Clinical Medicine, The Arctic University of Norway, Tromsø, Norway.
authors.forename: Svein I
authors.initials: SI
authors.lastname: Mellgren
mesh_terms: D003922:Diabetes Mellitus, Type 1 / Q000150:complications*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D003929:Diabetic Neuropathies / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction; D012684:Sensory Thresholds
keywords: diabetes; follow-up study; nerve conduction studies; neuropathy; skin biopsy