title: Infrared thermographic assessment of changes in skin temperature during hypoglycaemia in patients with type 1 diabetes.
abstract: OBJECTIVE
  Hypoglycaemia is associated with reduced skin temperature (Ts). We studied whether infrared thermography can detect Ts changes during hypoglycaemia in patients with type 1 diabetes and how the Ts response differs between patients with normal hypoglycaemia awareness and hypoglycaemia unawareness.
  
  
  METHODS
  Twenty-four patients with type 1 diabetes (ten aware, 14 unaware) were studied during normoglycaemia (5.0-6.0 mmol/l), hypoglycaemia (2.0-2.5 mmol/l) and during recovery from hypoglycaemia (5.0-6.0 mmol/l) using hyperinsulinaemic glucose clamping. During each 1 h phase, Ts was measured twice by infrared thermography imaging in pre-defined areas (nose, glabella and the five left fingertips), symptoms of hypoglycaemia were scored and blood was sampled.
  
  
  RESULTS
  Ts decreased during hypoglycaemia on the nose and glabella. The highest decrements were recorded on the nose (aware: -2.6 °C, unaware: -1.1 °C). In aware patients, the differences in temperature were statistically significant on both nose and glabella, whereas there was only a trend in the unaware group. There was a significant difference in hypoglycaemia-induced temperature changes between the groups. Patients in the aware group had higher hypoglycaemia symptom scores and higher adrenaline (epinephrine) levels during hypoglycaemia.
  
  
  CONCLUSIONS
  The hypoglycaemia-associated decrement in Ts can be assessed by infrared thermography and is larger in patients with normal hypoglycaemia awareness compared with unaware patients.
authors.affiliation: Department of Cardiology, Nephrology and Endocrinology, Nordsjællands Hospital, Dyrehavevej 29, 3400, Hillerød, Denmark, sejl@regionh.dk.
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Sejling
authors.forename: Kai H W
authors.initials: KH
authors.lastname: Lange
authors.forename: Christian S
authors.initials: CS
authors.lastname: Frandsen
authors.forename: Sarah S
authors.initials: SS
authors.lastname: Diemar
authors.forename: Lise
authors.initials: L
authors.lastname: Tarnow
authors.forename: Jens
authors.initials: J
authors.lastname: Faber
authors.forename: Jens J
authors.initials: JJ
authors.lastname: Holst
authors.forename: Bolette
authors.initials: B
authors.lastname: Hartmann
authors.forename: Linda
authors.initials: L
authors.lastname: Hilsted
authors.forename: Troels W
authors.initials: TW
authors.lastname: Kjaer
authors.forename: Claus B
authors.initials: CB
authors.lastname: Juhl
authors.forename: Birger
authors.initials: B
authors.lastname: Thorsteinsson
authors.forename: Ulrik
authors.initials: U
authors.lastname: Pedersen-Bjergaard
mesh_terms: D000328:Adult; D000368:Aged; D001364:Awareness / Q000502:physiology*; D001786:Blood Glucose / Q000032:analysis; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000503:physiopathology*; D007328:Insulin / Q000097:blood; D008297:Male; D008875:Middle Aged; D012881:Skin Temperature / Q000502:physiology*
chemical_list: D001786:Blood Glucose; D007328:Insulin