title: Association between Visit-to-Visit Glucose Variability and Cognitive Function in Aged Type 2 Diabetic Patients: A Cross-Sectional Study.
abstract: OBJECTIVE
  Diabetes is associated with cognitive decline as well as the development of dementia. Although mean blood glucose levels are typically used to assess the status of diabetic patients, glucose variability is also involved in the manifestation of macro- and microvascular complications in this population. Thus, the present study sought to determine whether visit-to-visit glucose variability contributes to cognitive decline in patients with type 2 diabetes.
  
  
  METHODS
  The present study assessed 68 patients with type 2 diabetes using several validated neuropsychological measures. All patients had no cerebrovascular disease, history of hypoglycemia, psychiatric conditions, or other medical illnesses. Standard deviations (SDs) and coefficients of variance (CVs) of the patients' blood glucose (after fasting and 2 hours postprandial; FBS and PP2), and glycated hemoglobin (HbA1c) values were used as indices of glucose variability. The cognitive outcome parameters were transformed with z-scores and entered into a multiple linear regression model that included educational status, age, sex, vascular risk factors, and mean glucose parameters as covariates.
  
  
  RESULTS
  The mean age of the total patient population was 70.9 years; 46 (67.6%) of the patients were men, and the median follow-up duration at our endocrinology outpatient clinic was 4.8 years. The mean FBS and PP2 glucose levels of the patients were 132 mg/dL and 199 mg/dL, respectively, and the mean HbA1c level was 8.0%. A univariable analysis revealed that only the PP2 value was associated with the Mini-Mental State Examination (MMSE) score, and multivariable analysis revealed that a high SD and/or CV for PP2 glucose were associated with low scores on the Rey Complex Figure Copy test and/or the Verbal Learning Test. Additionally, a high SD and a higher CV for HbA1c level were significantly associated with low MMSE and Digit Span test scores even after adjusting for mean HbA1c values.
  
  
  CONCLUSIONS
  The present data indicate that a greater degree of visit-to-visit glucose variability influenced specific types of cognitive function in type 2 diabetic patients independently of mean blood glucose levels. Future studies should focus on whether reductions in glycemic variability will improve the cognitive decline observed in type 2 diabetic patients.
authors.affiliation: Department of Neurology, Hallym University Sacred Heart Hospital, Chuncheon-si, Republic of Korea.
authors.forename: Chulho
authors.initials: C
authors.lastname: Kim
authors.affiliation: Department of Neurology, Hallym University Sacred Heart Hospital, Chuncheon-si, Republic of Korea.
authors.forename: Jong-Hee
authors.initials: JH
authors.lastname: Sohn
authors.affiliation: Department of Neurology, Hallym University Sacred Heart Hospital, Chuncheon-si, Republic of Korea.
authors.forename: Min Uk
authors.initials: MU
authors.lastname: Jang
authors.affiliation: Department of Neurology, College of Medicine, Kangwon National University, Chuncheon, Republic of Korea.
authors.forename: Sung-Hun
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Division of Endocrinology and Metabolism, Hallym University Sacred Heart Hospital, Chuncheon-si, Republic of Korea.
authors.forename: Moon-Gi
authors.initials: MG
authors.lastname: Choi
authors.affiliation: Division of Endocrinology and Metabolism, Hallym University Sacred Heart Hospital, Chuncheon-si, Republic of Korea.
authors.forename: Ohk-Hyun
authors.initials: OH
authors.lastname: Ryu
authors.affiliation: Division of Endocrinology and Metabolism, Hallym University Sacred Heart Hospital, Chuncheon-si, Republic of Korea.
authors.forename: Sungwha
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Neurology, Hallym University Sacred Heart Hospital, Chuncheon-si, Republic of Korea.
authors.forename: Hui-Chul
authors.initials: HC
authors.lastname: Choi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose / Q000032:analysis*; D003072:Cognition Disorders / Q000097:blood* / Q000453:epidemiology; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000453:epidemiology / Q000523:psychology; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000453:epidemiology / Q000523:psychology; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012494:Sampling Studies; D016037:Single-Blind Method; D012907:Smoking / Q000097:blood / Q000453:epidemiology / Q000523:psychology
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin