Hypoglycaemia: a history of coma was not associated with neurophysiological damage

Clinical bottom line (level 3b)

  1. In diabetic patients on intensive therapy, with a history of hypoglycaemic coma, neurophysiological tests were not significantly different than in patients without history of coma
Kramer et al: Diabetes 1998; 47: 1909-1914
Expires August 2003

The study

Case-control study with objective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: outpatients at a University hospital in Austria

55 patients (aged mean 38y, 66% female) IDDM and a history of >1 hypoglycaemic coma

Excluded if
  • IDDM onset <16y
  • comatose hypoglycaemia <4wk prior to study examination
  • intensive insulin treatment for <6mo
  • use of sedatives, alcohol or opiates
  • cerebrovascular or mental disorder




    • Spearman and Pearson correlation coefficients with partial correlation


    Outcomes studied:
    • 53 patients with no history of hypoglycaemic coma were compared with the 55 cases.

    The evidence


    • The mean Mini-Mental State Exam Score was 29.5 (sd 0.90) in the control group and 29.6 (sd 0.70) in the case group- mean difference 0.10 (95% CI: -0.41 to 0.21).
    • The mean P300 latency (Cz ms) in the control group was 342 (sd 21) and 346 (sd 23)- mean difference -4.0 (95% CI: -12.4 to 4.40).

    Comments

    1. Patients selected from a group attending a tertiary centre who agreed to undergo detailed testing; ?how relevant to a community population
    2. Psychometric tests chosen are standard clinical measures, P300 latency is said to be an objective measure of cognitive brain function
    3. Uncertain how the measures used reflect important clinical differences

    Citation

    1. Kramer L, Fasching P, Madl C, et al: Previous episodes of hypoglycemic coma are not associated with permanent cognitive brain dysfunction in IDDM patients on intensive insulin treatment. Diabetes 1998; 47: 1909-1914
    Contributor: Bob Philips and Clare Wotton, August 1999
    Reviewer:

    Clinical Question.
    Patient adults with IDDM
    Intervention or Exposure who experience episodes of severe hypoglycaemia
    Outcome suffer cognitive dysfunction