Diabetes and Dementia

What are Diabetes and Dementia?  

Diabetes is a group of chronic metabolic disorders characterised by elevated levels of blood glucose. It is a highly complex condition, involving a variety of mechanisms and risk factors. Dementia is a term used to describe a group of symptoms affecting memory, thinking and social abilities and is caused by damage to or loss of nerve cells and their connections in the brain (1). Alzheimer’s disease accounts for 50-75% of all cases of dementia (2). Other types include vascular dementia, dementia with Lewy bodies (abnormal deposits of protein inside nerve cells) and a group of diseases that contribute to frontotemporal dementia (degeneration of the frontal lobe of the brain) (2). 

Over 55 million people worldwide live with dementia, a number projected to reach 153 million by 2025 (1). Despite its prevalence, approximately three out of four people living with dementia remain undiagnosed (1). 

The link between Age, Diabetes and Dementia  

Age is an important factor in both conditions. About 2 in every 100 people aged 65-69 live with dementia, and prevalence doubles approximately every five years (3). In Europe, about 60% of people living with diabetes are between 60–79 years old, compared to just 35% in the 40–59 age group (4). Despite aging being a risk factor, the 2019 World Alzheimer’s report found that 62% of health care professionals mistakenly believe dementia is a normal part of the ageing process.   

Diabetes and dementia hold a bidirectional relationship. Diabetes increases the risk of developing dementia (1.5x for Alzheimer’s and 2.5x for vascular dementia) (5). Conversely, dementia can impair a person’s ability to manage diabetes effectively. Both conditions are chronic, progressive and complex, requiring ongoing support.    

How Diabetes Contributes to Dementia  

For people living with T1D: Severe or repeated episodes of hypoglycaemia and hyperglycaemia increase dementia risk. Recurrent hypoglycaemia damages the hippocampus (the brain’s memory centre), while chronic hyperglycaemia contributes to vascular damage and inflammation. People with T1D have a 50% higher risk of dementia compared to those without T1D (6).  

For people living with T2D: The key mechanism is insulin resistance. When the brain becomes insulin resistant:  

• Amyloid plaques (a hallmark of Alzheimer’s) are less effectively cleared because insulin-degrading enzymes are preoccupied with excess insulin (7).  
• Chronic inflammation and impaired blood flow further damage brain cells (7).  

 Together, these processes significantly increase dementia risk (3, 7).  

Opportunities for Prevention   

Dementia risk develops across the life course. Midlife diabetes is more strongly associated with dementia than later-onset diabetes, highlighting the importance of early prevention and long-term risk reduction (3, 8). 

Medical management:  

• Some diabetes medications reduce dementia risk (SGLT2 inhibitors, GLP-1 receptor agonists, DPP-4 inhibitors), while others (sulfonylureas) may increase it (3).  
• GLP-1 receptor agonists show potential in reducing Alzheimer’s symptoms due to anti-inflammatory and vascular effects (3). 
• Maintaining vascular health by managing blood pressure, blood glucose, cholesterol and inflammation is key to protecting brain health (3).  

Lifestyle interventions:

Regular physical activity, cognitive engagement, social connection and avoiding smoking or excessive alcohol lower dementia risk. Addressing vision and hearing loss also supports brain health (8, 9).  

Social determinants:

Poverty, lack of education, unsafe environments and poor access to healthcare increase the risk of both diabetes and dementia. Structural and policy interventions are needed to reduce these inequities (3).  

Screening and Early Detection:  

Early detection for dementia is critical. Several validated tools are available to assess cognitive function. The European Medical Agency places emphasis on the two most widely used are the Montreal Cognitive Assessment (MoCA), a 30-question test that evaluates short term memory, executive function, abstract reasoning and language (9). The Mini-Mental State Examination (MMSE) is a brief questionnaire that assess orientation to time and place, attention, recall, and language (9). 

Other commonly used tools include the Mini-Cog, Clock drawing test, Memory Impairment Screen, and Verbal Fluency Test. In addition to cognitive testing, more in-depth neuropsychological assessments may be used to evaluate memory, executive function, language, praxis and visuospatial abilities (5, 9). 

Emerging diagnostic approaches include blood-based biomarker tests for amyloid and tau proteins, which can aid in early detection of Alzheimer’s disease (3, 9). Clinicians should also monitor for microvascular complications of diabetes, such as retinopathy and nephropathy, as these may indicate increased cerebrovascular vulnerability. Maintaining vascular health is therefore cornerstone of dementia and Alzheimer’s disease prevention.  

To improve detection, clinicians are also encouraged to incorporate standardised cognitive screening protocols into annual diabetes checkups, discuss changes in lifestyle and functional status and foster collaboration between endocrinology and neurology teams to ensure comprehensive care. This highlights why integrated, person-centred care is essential for addressing the complex needs of people living with diabetes.  

Management of Diabetes with Dementia  

Living with diabetes requires continuous and comprehensive self-management to maintain a healthy lifestyle and prevent potentially life-threatening complications. Diabetes self-management includes blood glucose management and monitoring, physical activity, nutrition, managing psychological well-being and more. Every daily decision and action can affect diabetes management, requiring a high level of cognitive function to monitor, plan and adjust management strategies effectively. Dementia makes these tasks significantly harder, leading to risks such as hypoglycameia, dehydration or diabetes ketoacidosis.

Challenges for people with diabetes while living with dementia

1. Challenges  following a consistent medication schedule
2. Limited recall, such as remembering when they have eaten or taken medication, potentially leading to hypo- or hyperglycaemia from having too little or too much medication or food
3. Difficulty interpreting blood glucose readings, and understanding how to adequately respond, for example adjusting insulin doses or addressing hypoglycaemia
4. Skipping meals and not staying hydrated, risking experiencing low blood glucose levels and dehydration

Currently, there is no systematic method for managing diabetes and dementia. In the early stages of dementia, the main approach focuses on continuing to support self-management strategies and providing continuous self-management education. While this approach may be suitable during the early stages of dementia, as the condition progresses, the individual’s ability to self-manage diminishes, requiring more involvement from family and/or caregivers (10).  

Disruptions to diabetes self-management can lead to both acute and long-term risk to health such as hypoglycaemia, diabetes ketoacidosis and other diabetes related complications. For this reason, it is of the utmost importance to plan for, and provide, clear and easy-to-follow recommendations, to facilitate diabetes management.  

For people living with diabetes and dementia, frequent communication and collaboration between HCPs  and between HCPs and PwD/families/caregivers is key to anticipate transitions and help people with diabetes and dementia as well as their families cope with new care requirements.  

Some studies have also shown that tools such as decision aids are recommended for a patient-centred approach, enabling patient engagement and involvement in the (co) decision-making processes. HCPs should tailor their advice and support to the individual while also maintaining planned regular contact. 

Conclusion  

Diabetes and dementia are deeply interconnected through shared biological mechanisms and social determinants. With dementia cases projected to triple by 2050, addressing this dual burden requires   

• Better diabetes management across the lifespa
• Integrating dementia prevention into diabetes care
• Reducing social inequities in healthcare access
• Supporting families and caregivers in managing both conditions  

Sources:

1. World Health Organization. Dementia [Internet]. Geneva: World Health Organization; 2025 [cited 2025 Sep 16]. Available from: https://www.who.int/news-room/fact-sheets/detail/dementia
2. Alzheimer’s Society. Risk factors for dementia. Factsheet 450LP. London: Alzheimer’s Society; 2021. 
3. Livingston G, Huntley J, Liu KY, Costafreda SG, et al. Dementia prevention, intervention, and care. Lancet. 2024;404:572–628. 
4. International Diabetes Federation. IDF diabetes atlas. 11th ed. Brussels: International Diabetes Federation; 2025. 
5. Wium-Andersen IK, Rungby J, Jørgensen MB, Sandbæk A, Osler M, Wium-Andersen MK. Risk of dementia and cognitive dysfunction in individuals with diabetes or elevated blood glucose. Epidemiol Psychiatr Sci. 2019;29:e43. 
6. Li L, Wang D, Fisher CA, Conn JJ, Wraight PR, Davies A, et al. Increased risk of dementia in type 1 diabetes: a systematic review with meta-analysis. Diabetes Res Clin Pract. 2025;112043:9. 
7. PRIME Study Group. Prevention and remediation of insulin multimorbidity in Europe (PRIME study) [Internet]. European Union; 2025 [cited 2025 Sep 16]. Available from: https://prime-study.eu 
8. Alzheimer’s Society. Diabetes and the risk of dementia [Internet]. London: Alzheimer’s Society; 2025 [cited 2025 Sep 16]. Available from: https://www.alzheimers.org.uk/about-dementia/managing-the-risk-of-dementia/reduce-your-risk-of-dementia/diabetes 
9. Diabetes in Control. Alzheimer’s disease prevention for existing diabetes patients [Internet]. Diabetes in Control; 2025 [cited 2025 Sep 16]. Available from: https://www.diabetesincontrol.com/alzheimers-disease-prevention-for-existing-diabetes-patients/#:~:text=Although%20screening%20for%20Alzheimer’s%20in,Journal%20of%20the%20Alzheimer’s%20Association 
10. Bunn F, Goodman C, Malone JR, Jones PR, Burton C, Rait G, et al. Managing diabetes in people with dementia: protocol for a realist review. Syst Rev. 2016;5(1):5.