title: Heat-washout - an objective method for diagnosing neuropathy and atherosclerosis in diabetic patients.
abstract: BACKGROUND
  The heat-washout method is an objective method that measures cutaneous blood flow rate (BFR) in ml (100 g. min)(-1), previously found useful for measuring toe BFR in non-diabetic patients with claudication.
  
  
  OBJECTIVE
  The method is used for evaluating the presence of a veno-arteriolar reflex (VAR) in the forefoot and signs of atherosclerosis in the first toe in type 2 diabetics.
  
  
  METHODS
  Nine type 2 diabetics for +10 years, peripheral neuropathy, median age 62, and 9 healthy subjects without diabetes, median age 52 were examined for the presence of a VAR in the forefoot. A VAR was present when BFR decreased 25% or more with the foot 50 cm below heart level. Examinations for atherosclerosis were made in the pulp of the first toe. An increase in BFR of 50% or more with the foot 50 cm below heart level indicated the presence of atherosclerosis.
  
  
  RESULTS
  The VAR was significantly attenuated in type 2 diabetics with neuropathy compared to controls, (P<0·01). Only one patient with known neuropathy and diabetes showed a reflex compared to eight out of nine controls (P<0·01). The VAR was correlated to the vibration perception threshold measured with biothesiometry (r = -0·661, P = 0·0003). Two patients with type 2 diabetes and neuropathy without clinical sign of peripheral artery disease (PAD) had an abnormal response similar to that seen in subjects with intermittent claudication.
  
  
  CONCLUSIONS
  The heat-washout method seems useful as and objective method for evaluating as well the presence of a VAR as atherosclerosis in type 2 diabetics.
authors.affiliation: Department of Geriatrics, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark. info@mettemidttun.dk
authors.forename: M
authors.initials: M
authors.lastname: Midttun
authors.forename: O
authors.initials: O
authors.lastname: Snorgaard
mesh_terms: D000328:Adult; D000368:Aged; D050197:Atherosclerosis / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D001783:Blood Flow Velocity; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D003925:Diabetic Angiopathies / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D003928:Diabetic Nephropathies / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012039:Regional Blood Flow; D012684:Sensory Thresholds; D012867:Skin / Q000098:blood supply*; D012881:Skin Temperature; D013817:Thermography / Q000379:methods*; D013997:Time Factors