title: A pilot study to examine the correlation between cognition and blood biomarkers in a Singapore Chinese male cohort with type 2 diabetes mellitus.
abstract: BACKGROUND
  Diabetes is reported to be linked to poorer cognitive function. The purpose of this study is to examine (a) clinical correlation between cognitive function and the biochemical perturbations in T2DM, and (b) the impact of statin treatment on cognitive function in diabetic subjects.
  
  
  METHODS
  Forty Singaporean Chinese males with diabetes and twenty Singaporean Chinese males without diabetes were recruited for this study. Twenty-two of the diabetic subjects were on statin therapy and all subjects were non-demented. This was a 2-period non-interventional case-control study in which subjects were assessed for cognitive function in period 1 and blood samples taken over 2 periods, approximately 1 week apart. Blood was collected to determine the level of total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides, glucose and insulin. Cognitive performance was measured by a neuropsychological battery covering domains of attention, language, verbal and visual memory, visuomotor speed and executive function. Z-scores were derived for each cognitive domain using the mean and standard deviations (SDs), and they were used to compare between (a) diabetic and non-diabetic groups, and (b) diabetic subjects with and without statin treatment. ANCOVAs with age, education, BMI, and the duration of diabetes as covariates were employed to examine differences in mean score of cognitive domains and subtests between the two groups.
  
  
  RESULTS
  Overall cognitive function was similar among diabetics and age matched non-diabetic controls. Among diabetic statin users, HDL, LDL and total cholesterol were negatively correlated with executive function, whereas peripheral insulin levels and insulin resistance were negatively associated with attention.
  
  
  CONCLUSIONS
  Diabetic statin users were likely to have poorer performance in attention and executive function. Increasing levels of the peripheral biomarkers are likely to contribute to poorer cognitive performance.
authors.affiliation: Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors.forename: Deborah Amanda
authors.initials: DA
authors.lastname: Goh
authors.affiliation: Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore; Memory Ageing and Cognition Centre (MACC), National University Health System (NUHS), Singapore, Singapore; Centre for Healthy Brain Ageing and Dementia Collaborative Research Centre, School of Psychiatry, The University of New South Wales, Sydney, New South Wales, Australia.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Dong
authors.affiliation: Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore; Memory Ageing and Cognition Centre (MACC), National University Health System (NUHS), Singapore, Singapore.
authors.forename: Wah Yean
authors.initials: WY
authors.lastname: Lee
authors.affiliation: Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore; Memory Ageing and Cognition Centre (MACC), National University Health System (NUHS), Singapore, Singapore.
authors.forename: Way Inn
authors.initials: WI
authors.lastname: Koay
authors.affiliation: Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore; Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore; Memory Ageing and Cognition Centre (MACC), National University Health System (NUHS), Singapore, Singapore.
authors.forename: Stephen Ziyang
authors.initials: SZ
authors.lastname: Tay
authors.affiliation: Lilly-NUS Centre for Clinical Pharmacology, Singapore, Singapore.
authors.forename: Danny
authors.initials: D
authors.lastname: Soon
authors.affiliation: Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore; Memory Ageing and Cognition Centre (MACC), National University Health System (NUHS), Singapore, Singapore.
authors.forename: Christopher
authors.initials: C
authors.lastname: Chen
authors.affiliation: Lilly Erl Wood, Windlesham, Surrey, United Kingdom.
authors.forename: Claire Frances
authors.initials: CF
authors.lastname: Brittain
authors.affiliation: Lilly-NUS Centre for Clinical Pharmacology, Singapore, Singapore.
authors.forename: Stephen Loucian
authors.initials: SL
authors.lastname: Lowe
authors.affiliation: Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors.forename: Boon-Seng
authors.initials: BS
authors.lastname: Wong
mesh_terms: D015415:Biomarkers / Q000097:blood; D003071:Cognition / Q000187:drug effects; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy / Q000453:epidemiology / Q000503:physiopathology*; D056344:Executive Function / Q000187:drug effects; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D007328:Insulin / Q000097:blood; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012846:Singapore / Q000453:epidemiology
chemical_list: D015415:Biomarkers; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D007328:Insulin; D008055:Lipids