HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Online-Only Appendix All Versions of this Article: db07-0695v1 57/3/732    most recent Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Zammitt, N. N. Articles by Frier, B. M. Search for Related Content PubMed PubMed Citation Articles by Zammitt, N. N. Articles by Frier, B. M. Social Bookmarking                What's this?

Delayed Recovery of Cognitive Function Following Hypoglycemia in Adults With Type 1 Diabetes

Effect of Impaired Awareness of Hypoglycemia

¹ Department of Diabetes, Royal Infirmary of Edinburgh, Edinburgh, Scotland, U.K
² Department of Psychology, University of Edinburgh, Edinburgh, Scotland, U.K

Address correspondence and reprint requests to Professor Brian M. Frier, Department of Diabetes, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh EH16 4SA., Scotland, U.K. E-mail: brian.frier{at}luht.scot.nhs.uk

Key Words: CRT, choice reaction time • DSST, digit symbol substitution test • IHA, impaired hypoglycemia awareness • NHA, normal hypoglycemia awareness • RVIP, rapid visual information processing • TMB, trail making B

OBJECTIVE—Recovery times of cognitive functions were examined after exposure to hypoglycemia in people with diabetes with and without impaired hypoglycemia awareness.

RESEARCH DESIGN AND METHODS—A total of 36 subjects with type 1 diabetes were studied (20 with normal hypoglycemia awareness [NHA] and 16 with impaired hypoglycemia awareness [IHA]). A hyperinsulinemic glucose clamp was used to lower blood glucose to 2.5 mmol/l (45 mg/dl) (hypoglycemia) for 1 h or to maintain blood glucose at 4.5 mmol/l (81 mg/dl) (euglycemia) on separate occasions. Cognitive tests were applied during each experimental condition and were repeated at 10- to 15-min intervals for 90 min after euglycemia had been restored.

RESULTS—In the NHA group, performance was impaired on all cognitive tasks during hypoglycemia and remained impaired for up to 75 min on the choice reaction time (CRT) task (P = 0.03, ² = 0.237). In the IHA group, performance did not deteriorate significantly during hypoglycemia. When all subjects were analyzed within the same general linear model, performance was impaired during hypoglycemia on all tasks. Significant impairment during recovery persisted for up to 40 min on the CRT task (P = 0.04, ² = 0.125) with a significant glycemia-awareness interaction for CRT after one hour of hypoglycemia (P = 0.045, ² = 0.124). Performance on the trail-making B task was impaired for up to 10 min after euglycemia was restored (P = 0.024, ² = 0.158).

CONCLUSIONS—Following hypoglycemia, the recovery time for different cognitive tasks varied considerably. In the IHA group, performance was not significantly impaired during hypoglycemia. The state of awareness of hypoglycemia may influence cognitive function during and after hypoglycemia.

CiteULike    Del.icio.us    Digg    Reddit    Technorati    What's this?