title: The effects of hyperventilation on axonal excitability parameters in patients with diabetes mellitus and polyneuropathy.
abstract: OBJECTIVE
  We aimed to explore axonal excitability parameters in patients with diabetes mellitus (DM) and polyneuropathy (PNP) as well as those without PNP.
  
  
  METHODS
  We used the short TROND protocol by QTRAC to measure axonal excitability parameters (strength-duration time constant (SDTC), rheobase, etc.) in 12 healthy subjects and 14 DM patients with PNP and 10 DM patients without PNP. The short TROND protocol was performed before and after 20min of deep hyperventilation in healthy subjects and patients with DM. Also, venous blood pH and partial pressure of O2 and CO2 were recorded before hyperventilation (HPV) and after 20min of HPV. A "hyperventilation score" was evaluated before and after HPV.
  
  
  RESULTS
  When the values of DM with PNP group and control group before HPV were compared, SDTC and latency were statistically significant. Comparing the values of the excitability parameters after HPV showed statistically significant changes in the SDTC, rheobase, and refractoriness at 2.5ms in controls and DM patients without PNP. HPV resulted in no changes in SDTC in DM patients with PNP.
  
  
  CONCLUSIONS
  The results of this study suggest that patients with DM and healthy subjects have different responses to HPV, and pH changes have different effects on diabetic PNP compared with healthy controls and DM patients without PNP.
authors.affiliation: Akdeniz University Faculty of Medicine, Department of Neurology, Antalya, Turkey.
authors.forename: Gökçen
authors.initials: G
authors.lastname: Akça
authors.affiliation: Başkent University Faculty of Medicine, Department of Neurology, Adana, Turkey.
authors.forename: Deniz
authors.initials: D
authors.lastname: Yerdelen
authors.affiliation: Akdeniz University Faculty of Medicine, Department of Internal Medicine and Endocrinology, Antalya, Turkey.
authors.forename: Mustafa Kemal
authors.initials: MK
authors.lastname: Balcı
authors.affiliation: Akdeniz University Faculty of Medicine, Department of Neurology, Antalya, Turkey.
authors.forename: Hilmi
authors.initials: H
authors.lastname: Uysal
mesh_terms: D000200:Action Potentials; D001369:Axons / Q000502:physiology; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000503:physiopathology*; D003929:Diabetic Neuropathies / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006985:Hyperventilation; D008297:Male; D008475:Median Nerve / Q000503:physiopathology; D008875:Middle Aged
keywords: Axonal excitability; Diabetes mellitus; Hyperventilation; Polyneuropathy