Cognitive Impairment in Diabetes: Rationale and Design Protocol of the Cog-ID Study

Abstract

BackgroundCognitive impairment frequently co-occurs with type 2 diabetes but is often undiagnosed. Cognitive impairment affects self-management leading to treatment-related complications.ObjectiveThe aim of this study is to develop a stepped diagnostic procedure, consisting of a screening test complemented by an evaluation by a general practitioner (GP), to detect undiagnosed cognitive impairment in older people with type 2 diabetes.MethodsThe accuracy of two self-administered cognitive tests, the “Test Your Memory” (TYM) and “Self-Administered Gerocognitive Examination” (SAGE) alone, and in combination with an evaluation by a GP will be assessed. A diagnosis of mild cognitive impairment (MCI) or dementia at a memory clinic will serve as reference standard. This cognitive impairment in diabetes (Cog-ID) study will include 513 people from primary care facilities aged ≥70 with type 2 diabetes. The participants will first fill out the TYM and SAGE tests, followed by a standardized GP evaluation for cognitive impairment, including a mini mental state examination (MMSE). Subsequently, participants suspected of cognitive impairment (on either test or the GP assessment) and a random sample of 15% (65/435) of participants without suspected cognitive impairment will be referred to the memory clinic. At the memory clinic, a medical examination, neuropsychological examination, and magnetic resonance imaging (MRI) of the brain will be performed. Participants will also fill out questionnaires assessing health status and depressive symptoms at baseline and after 6 and 24 months.ResultsThis research obtained funding and ethical approval. Enrolment started in August, 2012, and all study-related activities will be completed in September, 2016.ConclusionsWith the results from this study, physicians will be able to detect cognitive impairment affecting type 2 diabetes patients through case-finding, and can use tailored care to reduce associated complications. Additionally, the results may stimulate discussions about cognitive impairment and whether early recognition is desirable.

Positive correlation between cognitive impairment and renal microangiopathy in patients with type 2 diabetic nephropathy: a multicenter retrospective study

“…T2DN is closely associated with diabetic cognitive impairment, which can be explained by a variety of mechanisms. 13–16 One possibility is that brain and kidney damage are characterized by similar microvascular lesions. 17,18 The microvascular structure shows many similarities between kidney tissue affected by microangiopathy and brain tissue affected by cognitive impairment, such as thickening of the capillary basement membrane, narrowing of the lumen, and increased vascular permeability.…”

Undiagnosed cognitive impairment, health status and depressive symptoms in patients with type 2 diabetes

“…In the last step, medical and neuropsychological examinations and an MRI were performed at the memory clinic to establish or rule out a diagnosis of MCI or dementia (Koekkoek et al, 2015b).…”

“…The Cognitive Impairment in Diabetes (Cog-ID) study aims to establish a diagnostic procedure to detect undiagnosed cognitive impairment in patients with type 2 diabetes ≥ 70 year (Koekkoek et al, 2015b). During the first examinations -before any suspicion of cognitive impairment was raised -health status and depressive symptoms were assessed.…”

Depressive symptoms and quality of life after screening for cognitive impairment in patients with type 2 diabetes: observations from the Cog-ID cohort study

“…The design of the Cog-ID study has been described previously 9. In brief, people ≥70 years with type 2 diabetes were invited by their general practitioner (GP) between August 2012 and September 2014.…”

“…The Cognitive Impairment in Diabetes (Cog-ID) study aimed to establish a primary care-based screening strategy to detect cognitive impairment in people with type 2 diabetes 9. The study showed that self-administered cognitive screening tests can be used for this purpose and that the Self-Administered Gerocognitive Examination (SAGE) had the best diagnostic accuracy (negative predictive value of 85%; positive predictive value of 40%) with a memory clinic established diagnosis as a reference standard 10…”