title: Are neurocognitive speed and inconsistency similarly affected in type 2 diabetes?
abstract: Type 2 diabetes (T2D) is a disease of aging with indirect but detectable and cumulative neurological implications. We systematically tested whether neurocognitive speed (mean rate) or inconsistency (intraindividual variability) was the more sensitive clinical marker of T2D. Three of four research questions used a cross-sectional wave of the Victoria Longitudinal Study (VLS) divided into T2D (age 55-81 years) and control (age = 53-91 years) groups. The fourth question addressed relative two-wave longitudinal changes. Each of four speeded tasks produced intraindividual mean rate (IM) and intraindividual standard deviation (ISD) scores. First, the T2D group performed more slowly than the controls. Second, this deficit extended to inconsistency, but less uniformly. Third, based on logistic regression analyses, IM was the more effective predictor of T2D status. Fourth, we observed similar longitudinal change patterns for IM and ISD. Results are linked to the theoretical location of T2D on an adjusted neural vulnerability continuum.
authors.affiliation: Department of Psychology, University of Alberta, Edmonton, AB, Canada.
authors.forename: Bonnie P
authors.initials: BP
authors.lastname: Whitehead
authors.forename: Roger A
authors.initials: RA
authors.lastname: Dixon
authors.forename: David F
authors.initials: DF
authors.lastname: Hultsch
authors.forename: Stuart W S
authors.initials: SW
authors.lastname: MacDonald
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002755:Choice Behavior; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology*; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D005260:Female; D006801:Humans; D007802:Language; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time; D012044:Regression Analysis; D013997:Time Factors