Reduction of Cognitive Decline in Patients with or at High Risk for Diabetes

Common pathways in dementia and diabetic retinopathy: understanding the mechanisms of diabetes-related cognitive decline

Type 2 diabetes (T2D) is associated with multiple comorbidities, including diabetic retinopathy (DR) and cognitive decline, and T2D patients have a significantly higher risk of developing Alzheimer's disease (AD). Both DR and AD are characterized by a number of pathological mechanisms that coalesce around the neurovascular unit, including neuroinflammation and degeneration, vascular degeneration, and glial activation. Chronic hyperglycemia and insulin resistance also play a significant role, leading to activation of pathological mechanisms such as increased oxidative stress and the accumulation of advanced glycation end-products (AGEs). Understanding these common pathways and the degree to which they occur simultaneously in the brain and retina during diabetes will provide avenues to identify T2D patients at risk of cognitive decline.

Non-pharmacological interventions for cognition in patients with Type 2 diabetes mellitus: a systematic review

Midlife Type II diabetes mellitus (T2DM) is an important yet often unrecognized risk factor for the later development of dementia. We conducted a systematic review to assess the efficacy of non-pharmacological interventions (namely diet, exercise and cognitive training) for T2DM on cognition. A search strategy was constructed and applied to four databases: EMBASE, Medline, CINAHL and Web of Science. Peer-reviewed journal articles in English were considered assessing the effect of exercise, dietary or cognitive training/stimulation-based interventions (or any combination of these) in patients with T2DM on cognition. Results were dual-screened and extracted by two independent reviewers. Of 4820 results, 3782 remained after de-duplication. Forty full-texts were screened and two studies were included in the final review. The first assessed the impact of a 10-year intensive lifestyle intervention on T2DM-related complications (Look-AHEAD study) and the second was a post hoc analysis of T2DM patients from a trial of a physical activity intervention in older non-demented adult with functional limitations (LIFE study). Whilst the Look-AHEAD study found no impact on diagnosis of mild cognitive impairment or dementia, the LIFE study demonstrated beneficial effects on global cognitive function and delayed memory specifically in older adults with T2DM. There is insufficient evidence to fully assess the effect of non-pharmacological interventions on cognition in T2DM. Well-constructed trials must be designed to specifically assess the effect of non-pharmacological and multi-domain interventions for cognition in patients with T2DM in midlife. All trials examining interventions in T2DM should consider cognition as at least a secondary outcome.

Understanding prediabetes: definition, prevalence, burden and treatment options for an emerging disease

Prediabetes is defined as a state of abnormal glucose homeostasis where blood glucose levels are elevated above those considered normal, but not as high as those required for a diagnosis of diabetes. As a condition intermediate between normal glucose homeostasis and the pathological condition of diabetes, the characterization of prediabetes as a distinct pathogenic condition is controversial. Emerging evidence suggests that the condition of prediabetes is associated with pathophysiological changes in several tissues and organs, which would support its recognition as a distinct pathological entity; the recent inclusion of prediabetes and associated billable conditions in the most recent ICD-10 codes provides additional credence to this position. This minireview summarizes our understanding of prediabetes and provides evidence that it should be considered a distinct and important clinical entity.