The effects of acute hypoglycaemia on memory acquisition and recall and prospective memory in type 1 diabetes

Warren, R. E.; Zammitt, Nicola N.; Deary, Ian J.; Frier, Brian M.

doi:10.1007/s00125-006-0535-6

Cited by 30 publications

(20 citation statements)

References 40 publications

(44 reference statements)

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“…Subjects were blind to clamp order, which was randomized and counterbalanced. Six studies were postponed (two NHA and four IHA) because of symptomatic hypoglycemia or blood glucose Ͻ4.0 mmol/l during the preceding 48 h. Using a modified hyperinsulinemic glucose clamp technique (18), blood glucose was stabilized at 4.5 mmol/l (81 mg/dl) (euglycemia) and maintained for 30 min while subjects practiced the cognitive tests. In the euglycemic condition, glucose was maintained at this level.…”

Section: Methodsmentioning

confidence: 99%

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

et al. 2008

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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 ϭ 0.03, 2 ϭ 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 ϭ 0.04, 2 ϭ 0.125) with a significant glycemia-awareness interaction for CRT after one hour of hypoglycemia (P ϭ 0.045, 2 ϭ 0.124). Performance on the trail-making B task was impaired for up to 10 min after euglycemia was restored (P ϭ 0.024, 2 ϭ 0.158). T he recovery of cognitive function following hypoglycemia has not received rigorous evaluation. Previous studies examined nondiabetic volunteers (1-3) in small numbers (3), did not include a euglycemia control arm (1,4), measured neurophysiological parameters rather than cognitive function (1,2,5,6), or restricted cognitive testing to one or two time points (3-5). The interval between restoration of euglycemia and cognitive testing was usually ill defined (2,4 -6). Controversy exists as to whether impaired awareness of hypoglycemia is associated with relative preservation (7-13) or exacerbation of the cognitive impairment induced by hypoglycemia (14 -16). The present study examined the time taken for recovery of cognitive function in adults with type 1 diabetes and assessed the effect of their state of awareness on the response to, and recovery from, hypoglycemia. CONCLUSIONS-Following RESEARCH DESIGN AND METHODSThe local medical research ethics committee approved the protocol, and subjects gave informed consent for participation.Inclusion criteria were a diagnosis of type 1 diabetes and age 18 -45 years. Exclusion criteria included pregnancy or any significant concurrent medical condition, history of head injury, epilepsy, or history of hypoglycemia-induced seizure.A total of 36 subjects with type 1 diabetes were recruited, 20 with normal hypoglycemia awareness (NHA) and 16 with impaired hypoglycemia awareness (IHA) confirmed by documenting their hypoglycemia history and using a validated hypoglycemia awareness scale (17). Microvascular complications were defined as any clinical diag...

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Section: Methodsmentioning

confidence: 99%

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

et al. 2008

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“…Some researchers discovered specific cognitive deficits, including impaired information processing speed and memory (e.g., Gold et al, 2007;McAulay, Deary, Sommerfield, & Frier, 2006;Warren, Zammitt, Deary, & Frier, 2007), while others reported reduced performance particularly in tasks that require higher mental efficiency (e.g., Brands, Bissels, et al, 2007;Watari et al, 2006; for a review, see also Heller & Macdonald, 1996). The presence and severity of cognitive impairments appear to be associated with the duration of illness and glycemic control.…”

mentioning

confidence: 96%

The Relationship Between Adult Neuropsychological Profiles and Diabetic Patients' Glycemic Control

Zihl¹,

Schaaf²,

Zillmer³

2010

Applied Neuropsychology

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The purpose of this study was to assess, in relation to metabolic control, the cognitive, depressive, and anxiety symptoms among 40 adult patients (age: 18-60 years) with either type 1 (n = 28) or type 2 (n = 12) diabetes mellitus (DM1, DM2). Nineteen healthy subjects matched for age, gender, and education served as the control group. For most cognitive domains, no significant performance differences were found between subjects from the diabetic groups and control subjects. However, diabetes patients demonstrated reduced information processing accuracy along with impaired visual and verbal working memory performance. In addition, psychopathology scores were significantly elevated but did not reach the clinical criteria for depression or anxiety. Overall, there were no significant differences between diabetic subgroups, and no significant correlation was found between cognitive performance, psychopathology scores, and HbA1c values for either subgroup. Thus, patients with DM1 or DM2 may show mild-to-moderate cognitive impairment as well as subtle psychopathological symptoms. While cognitive impairments may be understood in terms of diabetes-associated cognitive dysfunction, psychopathological symptoms may also result from unsuccessful coping with high task demands in everyday life activities. The outcome of the current study underscores the importance of early clinical neuropsychological standardized assessment as well as the diagnosis of cognitive and psychopathological symptoms in adult patients with diabetes.

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“…Post hoc calculations showed that the study had good power to detect a 'large' effect, according to Cohen's conventions [26]. We previously published a study of hypoglycaemia during learning and recall of verbal and visual material (this was carried out after the present study and could not inform its sample size) [15]. The greatest effect of hypoglycaemia was seen for delayed verbal memory, with a 'medium' effect equivalent to approximately 0.6 standard deviations.…”

Section: Discussionmentioning

confidence: 92%

“…We have recently demonstrated that moderate hypoglycaemia impairs both learning and recall [15]. If hypoglycaemia also impairs consolidation, then depending on the duration of the consolidation process, it could impair recall of information learned prior to the onset of hypoglycaemia.…”

Section: Introductionmentioning

confidence: 99%

Moderate hypoglycaemia after learning does not affect memory consolidation and brain activation during recognition in non‐diabetic adults

Warren

Sommerfield

Greve

et al. 2007

Diabetes Metabolism Res

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One hour of hypoglycaemia at 2.5 mmol/L induced 20-40 min after learning did not disrupt memory consolidation. fMRI did not show evidence of altered brain activation after hypoglycaemia. Consolidation may be relatively resistant to hypoglycaemia, or may have been complete before hypoglycaemia was induced. The study was powered to detect a large effect, and provides some reassurance that moderate hypoglycaemia does not cause major disruption of previously learned memories in people with insulin-treated diabetes.

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The effects of acute hypoglycaemia on memory acquisition and recall and prospective memory in type 1 diabetes

Cited by 30 publications

References 40 publications

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

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

The Relationship Between Adult Neuropsychological Profiles and Diabetic Patients' Glycemic Control

Moderate hypoglycaemia after learning does not affect memory consolidation and brain activation during recognition in non‐diabetic adults

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