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Diabetes, markers of brain pathology and cognitive function
Author(s) -
Qiu Chengxuan,
Sigurdsson Sigurdur,
Zhang Qian,
Jonsdottir Maria K.,
Kjartansson Olafur,
Eiriksdottir Gudny,
Garcia Melissa E.,
Harris Tamara B.,
Buchem Mark A.,
Gudnason Vilmundur,
Launer Lenore J.
Publication year - 2014
Publication title -
annals of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.764
H-Index - 296
eISSN - 1531-8249
pISSN - 0364-5134
DOI - 10.1002/ana.24063
Subject(s) - cognition , medicine , diabetes mellitus , white matter , hyperintensity , cognitive test , effects of sleep deprivation on cognitive performance , stroop effect , brain size , trail making test , mediation , episodic memory , confounding , executive functions , psychology , magnetic resonance imaging , psychiatry , neuropsychology , endocrinology , radiology , political science , law
Objective We investigated whether, and the extent to which, vascular and degenerative lesions in the brain mediate the association of diabetes with poor cognitive performance. Methods This cross‐sectional study included 4,206 participants (age > 65 years; 57.8% women) of the Age, Gene/Environment Susceptibility–Reykjavik Study. Data were collected through interview, clinical examination, psychological testing, and laboratory tests. The composite scores on memory, information‐processing speed, and executive function were derived from a cognitive test battery. Markers of cerebral macrovascular (cortical infarcts), microvascular (subcortical infarcts, cerebral microbleeds, and higher white matter lesion volume), and neurodegenerative (lower gray matter, normal white matter, and total brain tissue volumes) processes were assessed on magnetic resonance images. Mediation models were employed to test the mediating effect of brain lesions on the association of diabetes with cognitive performance controlling for potential confounders. Results There were 462 (11.0%) persons with diabetes. Diabetes was significantly associated with lower scores on processing speed and executive function, but not with memory function. Diabetes was significantly associated with all markers of brain pathology. All of these markers were significantly associated with lower scores on memory, processing speed, and executive function. Formal mediation tests suggested that markers of cerebrovascular and degenerative pathology significantly mediated the associations of diabetes with processing speed and executive function. Interpretation Diabetes is associated with poor performance on cognitive tests of information‐processing speed and executive function. The association is largely mediated by markers of both neurodegeneration and cerebrovascular disease. Older people with diabetes should be monitored for cognitive problems and brain lesions. Ann Neurol 2014;75:138–146