title: Established diabetic neuropathy seems irreversible despite improvements in metabolic and vascular risk markers--a retrospective case-control study in a hospital patient cohort.
abstract: OBJECTIVE
  To gain insight into the natural history of diabetic peripheral neuropathy (DPN) and its risk factors by means of sequential quantitative testing in a hospital patient cohort.
  
  
  METHODS
  A retrospective case-control study involving 300 diabetic patients (100 subjects with neuropathy and 200 control subjects) attending Poole Hospital diabetes clinic between 1995 and 2002. All subjects had a detailed annual clinic assessment including vibration perception threshold (VPT) and physical and metabolic assessments and were categorized according to neuropathy status. Established neuropathy was defined as a VPT > 25 V. Cross-sectional data were analysed by means of a t-test and longitudinal data by means of ANOVA.
  
  
  RESULTS
  VPTs increased over time in neuropathy patients, with no change in control patients (P < 0.001). Glycaemic control was better over that period in control patients but the rate of improvement in HbA1c over time was similar in both groups. Triglyceride and high-density lipoprotein cholesterol levels improved in both groups, with significantly greater change in the control group.
  
  
  CONCLUSIONS
  Data on reversibility of neuropathy are scarce and our 8-year series shows a continual deterioration in VPT in patients with a threshold > 25 V despite modest improvements in glycaemic control and lipid parameters. This work also supports a vascular association with neuropathy and identifies neuropathic patients as a high-risk cardiovascular group in whom, despite little influence on neuropathy itself, the above metabolic factors should be actively addressed.
authors.affiliation: Department of Diabetes, Dorset Research, Poole Hospital NHS Trust, Poole, UK. david.coppini@poole.nhs.uk
authors.forename: D V
authors.initials: DV
authors.lastname: Coppini
authors.forename: M C
authors.initials: MC
authors.lastname: Spruce
authors.forename: P
authors.initials: P
authors.lastname: Thomas
authors.forename: M G
authors.initials: MG
authors.lastname: Masding
mesh_terms: D000328:Adult; D000368:Aged; D015982:Bias; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure; D003925:Diabetic Angiopathies / Q000097:blood; D003929:Diabetic Neuropathies / Q000097:blood* / Q000150:complications / Q000523:psychology; D018450:Disease Progression; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology; D011379:Prognosis; D012684:Sensory Thresholds; D014732:Vibration
chemical_list: D015415:Biomarkers; D006442:Glycated Hemoglobin; D008055:Lipids