Abstract

Objective Hyperglycemia and type 2 diabetes mellitus have been shown to have a negative impact on cognitive performance in older adults. In order to assess the relevance of this effect in memory clinic patients, we examined the relationship between hyperglycemia and cognition in an unselected out-patient sample. Design In a cross-sectional study in memory clinic patients, glycosylated hemoglobin (HbA1c) was determined and related to cognitive performance, subjective memory impairment, and self-perceived cognitive blackouts. Results The frequency of mild cognitive impairment or mild dementia of the Alzheimer type was increased 1.7-fold in subjects with hyperglycemia. The HbA1c value was negatively correlated with global cognitive performance as well as with orientation, short-term memory and visuospatial capabilities. The frequency of cognitive blackouts was positively correlated with HbA1c levels and it was increased in hyperglycemic subjects. Conclusions Hyperglycemia could be confirmed as a major risk factor for cognitive impairment. This could be shown even in a non-representative cross-sectional memory clinic sample. Thus, the HbA1c determination may be recommended for a routine diagnostic memory clinic work-up.

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