title: Effects of axonal ion channel dysfunction on quality of life in type 2 diabetes.
abstract: OBJECTIVE
  Pharmacological agents for diabetic peripheral neuropathy (DN) target a number of mechanisms, including sodium channel function and γ-aminobutyric acid-minergic processes. At present, prescription is undertaken on a trial-and-error basis, leading to prolonged medication trials and greater healthcare costs. Nerve-excitability techniques are a novel method of assessing axonal ion channel function in the clinical setting. The aim of this study was to determine the effects of axonal ion channel dysfunction on neuropathy-specific quality-of-life (QoL) measures in DN.
  
  
  METHODS
  Fifty-four patients with type 2 diabetes mellitus underwent comprehensive neurologic assessment, nerve-conduction studies, and nerve-excitability assessment. Neuropathy severity was assessed using the Total Neuropathy Score. Neuropathy-specific QoL was assessed using a DN-specific QoL questionnaire (Neuropathy-Specific Quality of Life Questionnaire [NeuroQoL]). Glycosylated hemoglobin and BMI were recorded in all patients.
  
  
  RESULTS
  NeuroQoL scores indicated significant QoL impairment (mean 9.08 ± 5.93). Strength-duration time constant (SDTC), an excitability parameter reflecting sodium channel function, was strongly correlated with QoL scores (r = 0.545; P < 0.005). SDTC was prolonged in 48.6% of patients who experienced neuropathic symptoms. A significant correlation was also noted between SDTC and neuropathy severity (r = 0.29; P < 0.05). This relationship was strengthened when looking specifically at patients with clinically graded neuropathy (r = 0.366; P < 0.05).
  
  
  CONCLUSIONS
  The current study has demonstrated an association between markers of sodium channel function and QoL in DN. The study demonstrates that excitability techniques may identify patients in whom altered sodium channel function may be the dominant abnormality. The findings suggest that excitability techniques may have a role in clinical decision making regarding neuropathic treatment prescription.
authors: School of Medical Sciences, University of New South Wales, Kensington, Australia.
authors: Natalie C G
authors: NC
authors: Kwai
authors: Ria
authors: R
authors: Arnold
authors: Chathupa
authors: C
authors: Wickremaarachchi
authors: Cindy S-Y
authors: CS
authors: Lin
authors: Ann M
authors: AM
authors: Poynten
authors: Matthew C
authors: MC
authors: Kiernan
authors: Arun V
authors: AV
authors: Krishnan
mesh_terms: D001369:Axons / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism* / Q000503:physiopathology*; D003929:Diabetic Neuropathies / Q000378:metabolism / Q000503:physiopathology; D005260:Female; D006801:Humans; D007473:Ion Channels / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011788:Quality of Life
chemical_list: D007473:Ion Channels
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