Copyright 2005 American Medical Association. All Rights Reserved. Applicable FARS/DFARS Restrictions Apply to Government Use.
We read with interest the article by Dr Arvanitakis and colleagues whose prospective study reports an association between diabetes mellitus and an increased risk for Alzheimer Disease (AD),1 as well as more rapid decline in perceptual speed. Excellent cognitive testing also identified that persons with diabetes mellitus in their sample started with lower baseline scores in multiple areas of cognition and memory.
We were curious if patients with depression were excluded in the current study, particularly since prevalence rates of depression in patients with diabetes mellitus (15%-20%) run much higher than for aged matched controls. We noted Dr Wilson has written about depression, cognitive decline, and the risk of developing AD.2 Others support that finding and now there are data indicating that persons with depression are at an increased risk to develop diabetes mellitus.3 - 4
Since depression reduces the speed of cognitive processing, as well as the ability to remember, it would be important to know if there were patients included who were depressed prior to their onset of diabetes. This would partially explain why they started at lower cognitive levels or if there were some who became depressed after diabetes mellitus was diagnosed, potentially reducing perceptual speed.
In the discussion, the authors “raise the possibility that cerebral infarctions mediate the association between diabetes mellitus with AD.” We agree that “many people with cerebral infarcts do not experience clinical strokes,” and also that cerebral infarctions are preferentially associated with reduced perceptual speed.5 Individuals who do not develop depression until late in life are also quite likely to have increased evidence of vascular pathology on brain imagery with no reports of experiencing a clinical stroke.6 Patients without diabetes mellitus who have depression are more likely to have hyperglycemia, higher hemoglobin AIC levels, and hyperinsulinemia.7
Some have proposed “stress-related cortisol secretion,” clearly identified with depression, as a connecting link to endocrine, metabolic, and hemodynamic abnormalities, as well as obesity.8 - 9
Your discussion also brought out the possibility that hippocampal synaptic plasticity might be associated with greater risk of patients having diabetes mellitus to develop AD. Reduced hippocampal volume is described with both untreated depression10 and incident dementia in patients with geriatric depression.11
We have no doubt that having diabetes mellitus puts one at greater risk for AD, but that mood might play an even stronger role in both.
Correspondence: Dr Franco, Cleveland Clinic Foundation, 9500 Euclid Ave, P57, Cleveland, OH 44195 (francok@ccf.org).
Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature
Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal
Instructions
Comments are moderated and will appear on the site at the discretion of the Archives of Neurology editors. Comments should not exceed 500 words of text and 10 references.
Do not submit personal medical questions or information that could identify a specific patient, questions about a particular case, or general inquiries to an author. Only content that has not been published, posted, or submitted elsewhere should be submitted. By submitting this Comment, you and any coauthors transfer copyright to the journal if your Comment is posted.
* = Required Field
Disclosure of Any Conflicts of Interest* Indicate all relevant conflicts of interest of each author below, including all relevant financial interests, activities, and relationships within the past 3 years including, but not limited to, employment, affiliation, grants or funding, consultancies, honoraria or payment, speakers’ bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued. If all authors have none, check "No potential conflicts or relevant financial interests" in the box below. Please also indicate any funding received in support of this work. The information will be posted with your response.
Register and get free email Table of Contents alerts, saved searches, PowerPoint downloads, CME quizzes, and more
Subscribe for full-text access to content from 1998 forward and a host of useful features
Activate your current subscription (AMA members and current subscribers)
Some tools below are only available to our subscribers or users with an online account.
Download citation file:
Customize your page view by dragging & repositioning the boxes below.
and access these and other features:
Register Now
Enter your username and email address. We'll send you a reminder to the email address on record.
Athens and Shibboleth are access management services that provide single sign-on to protected resources. They replace the multiple user names and passwords necessary to access subscription-based content with a single user name and password that can be entered once per session. It operates independently of a user's location or IP address. If your institution uses Athens or Shibboleth authentication, please contact your site administrator to receive your user name and password.