Authors: Sanjay Kalra,1 Anu Gupta,2 Mangesh Tiwaskar,3 Banshi Saboo4
1. Department of Endocrinology, Bharti Hospital, Karnal, India; 2. Department of Neurology, AIIMS, New Delhi, India; 3. Department of Medicine, Shilpa Medical Centre, Mumbai, India; 4. Department of Diabetology, DiaCare Clinic, Ahmedabad, India
Diabetes and dementia are two closely connected conditions, both with growing incidence. Though there is no proven pharmacological intervention for dementia, many evidence-based interventions can influence the impact of dementia on health. This Insight lists the five levels of prevention of diabetes dementia: primary, secondary, tertiary, quaternary and quinary, and discusses actionable items which will help plan both non-pharmacological and pharmacological management of diabetes and its associated comorbidities.
Though challenging to analyse, there is a clear-cut correlation between diabetes and dementia.1,2 Associated complications such as hypoglycaemia, and conditions like obesity, are also linked to dementia.3,4 In recent years, more attention has been paid to the prevention of dementia, this includes a focus on the association between diabetes and dementia.5,6
Cross sectional studies report a strong link between diabetes and dementia. A large analysis recently reviewed 14 studies, 2,310,330 individuals, and 102,174 cases of dementia. Diabetes was found to be associated with a 60% increased risk of any dementia in both women (relative risk [RR] 1.62; 95% confidence interval [CI] 1.45–1.80) and men (RR 1.58; 95% CI 1.38–1.81). The risk of dementia due to vascular causes is more than double in women, and 73% more in men: the RR for vascular dementia was 2.34 (95% CI 1.86–2.94) in women with diabetes, and 1.73 (95% CI 1.61–1.85) in men with diabetes. When the analysis was limited to non-vascular dementia, the risk was 50% more in persons with diabetes: RR 1.53 (95% CI 1.35–1.73) in women and 1.49 (95% CI 1.31–1.69) in men.7 The confidence interval limits suggest a robust and statistically significant correlation which cannot be ignored.
One of the largest and longest longitudinal studies supports this hypothesis as well. During 13.8 ± 5.8 years follow-up in the Freemantle Diabetes Study, incident dementia occurred in 13.9% and 12.4% people with and without diabetes, respectively (p=0.15). The incidence of dementia was higher in people with type 2 diabetes (incidence rate ratio [IRR] 1.28; 95% CI 1.08–1.51). The competing risk of mortality was also greater with type 2 diabetes (IRR 1.50; 95% CI 1.38–1.64). The age of onset of dementia and death were both earlier with people with diabetes: dementia occurred 1.7 years earlier (95% CI 0.6–2.9) and death occurred 2.32 years earlier (95% CI 1.1–3.6) in people with diabetes when compared to those without.8
Keeping the above discussion in mind, we suggest the following strategies for prevention of dementia in diabetes.
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- American Diabetes Association. 12. Older Adults: Standards of Medical Care in Diabetes—2020. Diabetes Care. 2020;43(Suppl 1):S152–62.
- Meneilly GS, Tessier DM. Diabetes, dementia and hypoglycemia. Can J Diabetes. 2016;40:73–6.
- Shalev D, Arbuckle MR. Metabolism and memory: obesity, diabetes, and dementia. Biol Psychiatry. 2017;82:e81–3.
- Kumar CS, George S, Kallivayalil RA. Towards a dementia-friendly India. Indian J Psychol Med. 2019;41:476–81.
- Biessels GJ, Whitmer RA. Cognitive dysfunction in diabetes: how to implement emerging guidelines. Diabetologia. 2020:63;3–9.
- Chatterjee S, Peters SA, Woodward M, et al. Type 2 diabetes as a risk factor for dementia in women compared with men: a pooled analysis of 2.3 million people comprising more than 100,000 cases of dementia. Diabetes care. 2016;39:300–7.
- Davis WA, Zilkens RR, Starkstein SE, et al. Dementia onset, incidence and risk in type 2 diabetes: a matched cohort study with the Fremantle Diabetes Study Phase I. Diabetologia. 2017;60:89–97.
Support: No funding was received in the publication of this insight article.
Published: 12 March 2020
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