Diabetes has long been recognised as a risk factor for dementia, but new research reveals its connection to accelerated brain ageing. A recent study, led by the Karolinska Institutet, Stockholm, Sweden, aimed to explore the link between glycaemic status – whether normoglycemic, prediabetic, or diabetic – and older brain age, while investigating whether modifiable lifestyle behaviours could mitigate this effect.
The study, conducted on 31,229 dementia-free adults aged 40 to 70 from the UK Biobank, assessed participants’ glycaemic status at baseline using medical history, medication use, and HbA1c levels. Additionally, information on cardiometabolic risk factors, such as obesity, hypertension, and abnormal cholesterol and triglyceride levels, was collected alongside lifestyle behaviours like smoking, drinking, and physical activity.
Participants underwent brain MRI scans, which were used to estimate brain age and calculate the brain age gap – the difference between a person’s brain age and chronological age. The study followed these participants for up to 11 years, tracking how glycaemic status affected brain ageing.
The findings showed that, at baseline, 43.3% of participants had prediabetes, and 3.7% had diabetes. Both conditions were linked to accelerated brain ageing, with diabetes showing a much more pronounced effect. Individuals with diabetes had an average brain age gap of 2 years older than their chronological age, while prediabetics had a smaller but still notable increase. The association was particularly strong among men and those with multiple cardiometabolic risk factors.
Importantly, the study also highlighted that lifestyle interventions can make a difference. Individuals who maintained a healthy lifestyle, for example by avoiding smoking, limiting alcohol intake, and staying physically active, showed a significant reduction in the impact of diabetes on brain ageing.
In conclusion, diabetes and prediabetes are associated with accelerated brain ageing, particularly in individuals with poor cardiometabolic health. However, adopting healthier lifestyle habits can help counteract these effects, highlighting the importance of lifestyle modification in managing long-term brain health.
Katie Wright, EMJ
Reference
Dove A, Wang J, Huang H, et al. Diabetes, prediabetes, and brain aging: the role of healthy lifestyle. Diabetes Care. 2024;DOI:10.2337/dc24-0860
