The study of common pathways in dementia and diabetic retinopathy could be the key to shedding light on diabetes-related cognitive impairment mechanisms. This is the main pathway explored in an article recently published in the journal Trends in Endocrinology and Metabolism, signed by authors from research centres in six countries (Spain, The Netherlands, Belgium, Italy, United Kingdom and Switzerland), with the participation of the Vall d’Hebron Research Diabetes and Metabolism group, led by Dr Rafael Simó, and the Diabetes and Associated Diseases Network Biomedical Networking Researching Centre (CIBERDEM).

Type 2 diabetes (T2D) is associated with numerous co-morbidities, including diabetic retinopathy and cognitive impairment, and these patients have a significantly higher risk of developing Alzheimer’s disease. According to the authors of this review, “understanding aspects that appear in these pathologies and the degree to which they occur simultaneously in the brain and retina during diabetes will provide new keys to identifying patients with T2D at risk of cognitive impairment”. They note that “the eye as a window onto the brain is an attractive concept in this field and measurable retinal changes in patients with T2D could reflect a brain condition”.

Recent advances have identified a number of mechanisms common to both T2D and Alzheimer’s disease, which centre on the neurovascular unit. “Both diabetic retinopathy and Alzheimer’s disease are characterised by a number of pathological mechanisms that come together around the neurovascular unit, which include neuroinflammation and degeneration, vascular degeneration and glial activation”, the researchers explain. “Chronic hyperglycaemia and insulin resistance also play a significant role, leading to the activation of pathological mechanisms, such as increased oxidative stress and the accumulation of advanced glycation end-products”.

They conclude that “identifying the common pathologies and molecular mechanisms involved in retinal and brain neurodegeneration could open up new therapeutic opportunities to prevent T2D-related cognitive impairment at an early stage”.