Glycilated Hemoglobin and Cognitive Impairment

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. KeywordsDiabetes mellitus, Hyperglycemia, HbA1c, Mild cognitive impairment, Dementia, Alzheimer, Subjective memory impairment, Cognitive blackouts, Memory clinic [7]. Even prediabetes and insulin resistance are associated with cognitive decline and brain atrophy [8].Diabetes may compromise cognitive function by various mechanisms, such as brain vascular lesions, insulin resistance, oxidative stress, the accumulation of advanced glycilation end products, inflammation or a competition of insulin and β-amyloid on the insulin-degrading enzyme [9].This may also apply to subjects with prediabetes as reflected by a moderately increased HbA1c level. Accordingly, it has been shown that the HbA1c value correlates with the rate of brain atrophy [10] and that it predicts conversion to dementia and mild cognitive impairment [11]. Glycosilated hemoglobin (HbA1c) is a measure of blood glucose concentration over the past two to three months and is used both for the diagnosis of diabetes and the assessment of diabetes management [12].We studied the effects of diabetes and hyperglycemia as determined by elevated HbA1c values on cognitive performance, subjective memory impairment and self-perceived cognitive blackouts in a group of patients of our memory clinic. Subjects and MethodsThe analyses were carried out in 113 patients consecutively presenting for the first time for memory assessment at our memory clinic. They were 70 women (61.9%) and 43 men (38.1%) at ages between 50 and 87 years (mean ± SD: 61.2 ± 9.1 years). Subjects with a history of neurological disorder, with an actual neurological or psychiatric disorder, or with a medication that may compromise cognitive performance were not

Investigation of the Effects of Biochemical Parameters on Alzheimer’s Disease

“…14 Jana et al show in participants with hyperglycemia the rate of self-perceived cognitive blackouts were elevated and it was positively associated with the HbA 1c levels higher than confirmed those correlations. 15 On a quantitative level, mainly HbA 1c levels higher than 5.6% confirmed those correlations. 15 A small rise has been observed between HbA 1c levels of groups.…”

“…15 On a quantitative level, mainly HbA 1c levels higher than 5.6% confirmed those correlations. 15 A small rise has been observed between HbA 1c levels of groups. Our results showed that 12 patients (body mass index [BMI] > 30.06) with elevated levels of HbA 1c are using combined therapy for the AD.…”

“…Especially women are prone to be affected by raised levels of TSH. 15 Considering folic acid levels, 13 individuals with lower than 4 ng/mL had increased severity of AD with MMSE mean values of 14.07. For the remaining 62 patients, the MMSE mean score was 17.14.…”

Selbstwahrnehmung als Hilfsmittel zur Früherkennung der Alzheimer-Demenz

“…In weiteren Auswertungen untersuchten wir die Zusammenhänge zwischen der Checkliste und bekannten Risikofaktoren für die Entwicklung einer AD und fanden insbesondere erhöhte CKB-Scores bei über-50-jährigen Personen mit erhöhten Langzeitblutzuckerwerten [25] und über-50-jährigen Personen mit schlechter körperlicher Fitness [26]. In einer laufenden Untersuchung wird bei kognitiv uneingeschränkten Personen der Zusammenhang zwischen kognitiven Blackouts und Zeichen der Alzheimer-Pathologie im Liquor untersucht.…”

Medizinische Maßnahmen zur Demenzprävention

“…Dabei sind vermutlich verschiedene Mechanismen wirksam, unter anderem die Konkurrenz von Insulin mit β-Amyloid um das insulin-degrading enzyme (IDE), wodurch der Abbau von Amyloid gehemmt wird [9]. Bei einer Erhebung bei über 50-jährigen Teilnehmern eines Gedächtnispräventionsprogramms fanden wir gehäuft kognitive Beeinträchtigungen und kognitive Blackouts bei erhöhtem HbA1c [10].…”