title: Biopsychobehavioral model of severe hypoglycemia. II. Understanding the risk of severe hypoglycemia.
abstract: OBJECTIVE
  To evaluate the clinical/research utility of the biopsycho-behavioral model of severe hypoglycemia in differentiating patients with and without a history of severe hypoglycemia and in predicting occurrence of future severe hypoglycemia.
  
  
  METHODS
  A total of 93 adults with type 1 diabetes (mean age 35.8 years, duration of diabetes 16 +/- 10 years, HbA1 8.6 +/- 1.8%), 42 of whom had a recent history of recurrent severe hypoglycemia (SH) and 51 who did not (NoSH), used a handheld computer for 70 trials during 1 month recording cognitive-motor functioning, symptoms, blood glucose (BG) estimates, judgments concerning self-treatment of BG, actual BG readings, and actual treatment of low BG. For the next 6 months, patients recorded occurrence of severe hypoglycemia.
  
  
  RESULTS
  SH patients demonstrated significantly more frequent and extreme low BG readings (low BG index), greater cognitive-motor impairments during hypoglycemia, fewer perceived symptoms of hypoglycemia, and poorer detection of hypoglycemia. SH patients were also less likely to treat their hypoglycemia with glucose and more likely to treat with general foods. Low BG index, magnitude of hypoglycemia-impaired ability to do mental subtraction, and awareness of neuroglycopenia, neurogenic symptoms, and hypoglycemia correlated separately with number of SH episodes in the subsequent 6 months. However, only low BG index, hypoglycemia-impaired ability to do mental subtraction, and awareness of hypoglycemia entered into a regression model predicting future severe hypoglycemia (R2 = 0.25, P < 0.001).
  
  
  CONCLUSIONS
  Patients with a history of severe hypoglycemia differed on five of the seven steps of the biopsychobehavioral model of severe hypoglycemia. Helping patients with a recent history of severe hypoglycemia to reduce the frequency of their low-BG events, become more sensitive to early signs of neuroglycopenia and neurogenic symptoms, better recognize occurrence of low BG, and use fast-acting glucose more frequently in the treatment of low BG, may reduce occurrence of future severe hypoglycemia.
authors.affiliation: University of Virginia Health Sciences Center, Behavioral Medicine Center, Charlottesville 22908, USA. djc4f@virginia.edu
authors.forename: D J
authors.initials: DJ
authors.lastname: Cox
authors.forename: L A
authors.initials: LA
authors.lastname: Gonder-Frederick
authors.forename: B P
authors.initials: BP
authors.lastname: Kovatchev
authors.forename: D L
authors.initials: DL
authors.lastname: Young-Hyman
authors.forename: T W
authors.initials: TW
authors.lastname: Donner
authors.forename: D M
authors.initials: DM
authors.lastname: Julian
authors.forename: W L
authors.initials: WL
authors.lastname: Clarke
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D003922:Diabetes Mellitus, Type 1 / Q000150:complications*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007003:Hypoglycemia / Q000209:etiology / Q000523:psychology*; D008297:Male; D008954:Models, Biological; D012189:Retrospective Studies; D012307:Risk Factors
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin