title: The effects of sitagliptin, a DPP-4 inhibitor, on cognitive functions in elderly diabetic patients with or without Alzheimer's disease.
abstract: OBJECTIVE
  The present study aimed to evaluate effect of sitagliptin, a dipeptidyl peptidase-4 inhibitor (DPP-4I), on cognitive functions in elderly diabetic patients with and without cognitive impairment.
  
  
  METHODS
  253 elderly patients with type 2DM, were enrolled in this prospective and observational study. After comprehensive geriatric assessment, the patients were divided into either sitagliptin or non-sitagliptin group.
  
  
  RESULTS
  A total of 205 patients who completed the study (52 with Alzheimer's Disease (AD)) were re-evaluated 6months later. Sixth-month evaluation revealed no difference between sitagliptin and non-sitagliptin groups in terms of weight, body mass index, and HbA1c (p>0.05). However, the number of patients that required reduced insulin dose was significantly higher in the sitagliptin group (p=0.01). Sitagliptin therapy was associated with an increase in the Mini-Mental State Examination (MMSE) scores (p=0.034); patients without AD receiving only sitagliptin or insulin showed higher MMSE scores as compared to the patients receiving metformin alone (p=0.024). Likewise, the change in MMSE scores in AD patients receiving sitagliptin was significant and indicated improvement as compared to the patients receiving metformin (p=0.047).
  
  
  CONCLUSIONS
  Besides its effects similar to those of insulin and metformin in glycemic control and in reducing need for insulin, 6-month sitagliptin therapy may also associated with improvement of cognitive function in elderly diabetic patients with and without AD. Further randomized controlled trials are needed to support these results.
authors.affiliation: Center for Aging Brain and Dementia, Department of Geriatric Medicine, Dokuz Eylul University, Faculty of Medicine, Izmir, Turkey. Electronic address: atisik@yahoo.com.
authors.forename: Ahmet Turan
authors.initials: AT
authors.lastname: Isik
authors.affiliation: Center for Aging Brain and Dementia, Department of Geriatric Medicine, Dokuz Eylul University, Faculty of Medicine, Izmir, Turkey.
authors.forename: Pinar
authors.initials: P
authors.lastname: Soysal
authors.affiliation: Department of Internal Medicine, Izmir Military Hospital, Izmir, Turkey.
authors.forename: Adnan
authors.initials: A
authors.lastname: Yay
authors.affiliation: Center for Aging Brain and Dementia, Department of Geriatric Medicine, Dokuz Eylul University, Faculty of Medicine, Izmir, Turkey.
authors.forename: Cansu
authors.initials: C
authors.lastname: Usarel
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000188:drug therapy*; D003071:Cognition; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D008297:Male; D011446:Prospective Studies; D000068900:Sitagliptin Phosphate / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D007004:Hypoglycemic Agents; D000068900:Sitagliptin Phosphate
keywords: Alzheimer disease; Cognitive function; Dementia; Elderly; Sitagliptin