Effects of insulinic therapy on cognitive impairment in patients with Alzheimer disease and Diabetes Mellitus type-2

Background: Type-2 Diabetes Mellitus (DM-2) is an important risk factor for Alzheimer disease (AD) and vascular dementia (VD). The role of insulinic therapy on cognitive decline is controversial. Objective: To evaluate cognitive impairment in patients with AD and DM-2 treated with either oral antidiabetic drugs or combination of insulin with other diabetes medications. Methods: 104 patients with mild-to-moderate AD and DM-2 were divided into two groups, according to antidiabetic pharmacotherapy: group A, patients treated with oral antidiabetic drugs and group B, patients treated with insulin combined with other oral antidiabetic medications. Cognitive functions were assessed by the Mini Mental State Examination (MMSE) and the Clinician's Global Impression (CGI), with a follow-up of 12 months. Results: At the end of the study, the MMSE scores showed a significant worsening in 56.5% patients of group A and in 23.2% patients of group B, compared to baseline MMSE scores (P=.001). Also CGI-C scores showed a significant worsening for all domains after 12 months in group A vs group B (P=.001). The two groups were matched for body mass index, serum lipids, triglycerides, Apo epsilon 4 allele and smoke habit. Conversely, ischemic heart disease and hypertension were significantly higher in group B (P=.002). After adjustment for this risk variables, our results remained significant (P=.001). Conclusions: Our study suggests that insulinic therapy could be effective in slowing cognitive decline in patients with AD. (C) 2009 Elsevier B.V. All rights reserved.