title: Impaired glycemia and diabetic polyneuropathy: the OC IG Survey.
abstract: OBJECTIVE
  To test whether diabetic polyneuropathies (DPNs), retinopathy, or nephropathy is more prevalent in subjects with impaired glycemia (IG) (abnormality of impaired fasting glucose [IFG], impaired glucose tolerance [IGT], or impaired HbA(1c) [IA1C]) than in healthy subjects (non-IG).
  
  
  METHODS
  Matched IG and non-IG volunteers were randomly identified from population-based diagnostic and laboratory registries, restudied, and reclassified as non-IG (n = 150), IG (n = 174), or new diabetes (n = 218).
  
  
  RESULTS
  Frequency (%) of DPN in non-IG, IG, and new diabetes was 3 (2.0%), 3 (1.7%), and 17 (7.8%) narrowly defined (no other cause for polyneuropathy) and 19 (12.7%), 22 (12.6%), and 38 (17.4%) broadly defined. Mean and frequency distribution of composite scores of nerve conduction and quantitative sensation tests were not significantly different between IG and non-IG but were worse in new diabetes. Frequency of retinopathy and nephropathy was significantly increased only in new diabetes. In secondary analysis, small but significant increases in retinopathy and nephropathy were found in IGT, IFG, and IGT combined groups.
  
  
  CONCLUSIONS
  In population studies of Olmsted County, Minnesota, inhabitants, prevalence of typical DPN, retinopathy, and nephropathy was significantly increased only in subjects with new diabetes-not in subjects with IG as defined by American Diabetes Association (ADA) criteria of abnormality of IFG, IGT, or IA1C. For atypical DPN, such an increase was not observed even in subjects with new diabetes. In medical practice, explanations other than IG should be sought for patients with atypical DPN (chronic idiopathic axonal polyneuropathy) who have IG.
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA. dyck.peter@mayo.edu
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Dyck
authors.forename: Vicki M
authors.initials: VM
authors.lastname: Clark
authors.forename: Carol J
authors.initials: CJ
authors.lastname: Overland
authors.forename: Jenny L
authors.initials: JL
authors.lastname: Davies
authors.forename: John M
authors.initials: JM
authors.lastname: Pach
authors.forename: P James B
authors.initials: PJ
authors.lastname: Dyck
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Klein
authors.forename: Robert A
authors.initials: RA
authors.lastname: Rizza
authors.forename: L Joseph
authors.initials: LJ
authors.lastname: Melton
authors.forename: Rickey E
authors.initials: RE
authors.lastname: Carter
authors.forename: Ronald
authors.initials: R
authors.lastname: Klein
authors.forename: William J
authors.initials: WJ
authors.lastname: Litchy
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism*; D003929:Diabetic Neuropathies / Q000097:blood* / Q000453:epidemiology; D005260:Female; D018149:Glucose Intolerance / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011236:Prediabetic State; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D001786:Blood Glucose