Patient Care brings primary care clinicians a lot of medical news every day—it’s easy to miss an important study. The Daily Dose provides a concise summary of one of the website's leading stories you may not have seen.
On August 29, 2024, we reported on a study published in the journal Diabetes Care that examined the association between prediabetes, type 2 diabetes (T2D), and brain aging and whether this can be attenuated by modifiable lifestyle behaviors.
The study
Investigators assessed data from 31 229 dementia-free adults aged 40 to 70 years from the UK Biobank.
Glycemic status (ie, normoglycemia, prediabetes, or diabetes) was based on medical history, medication use, and HbA1c levels measured at baseline. Researchers also collected information on cardiometabolic risk factors (eg, obesity, hypertension, low HDL, and high triglycerides) and lifestyle behaviors (eg, smoking, drinking, exercise) at baseline. Over the 11-year follow-up period, all participants had 1 or 2 brain MRI scans. Investigators estimated participants’ brain age using a machine learning model based on 1079 brain MRI phenotypes, which was then used to calculate brain age gap (BAG; ie, brain age minus chronological age). At baseline, 43.3% of the cohort (n=13 518) had prediabetes and 3.7% (n=1149) were diagnosed with T2D.
The findings
Compared with normoglycemia, prediabetes (β = 0.22, 95% CI 0.10-0.34) and T2D (β = 2.01, 95% CI 1.70-2.32) were associated with significantly higher BAG. Specifically, on average, brain age was 0.50 years older than the chronological age of participants with prediabetes and 2.29 years older than the age of those with T2D.
Among study participants with poor glycemic control (HbA1c of 8% or higher), BAG rose up to 4.18 years. Researchers reported that when used as a continuous variable, HbA1c was associated with significantly higher BAG (β = 0.77, 95% CI 0.65-0.90). In addition, T2D was associated with significant increase in BAG over time (β = 0.27, 95% CI 0.01-0.53).
In joint exposure analysis, investigators found that an optimal healthy lifestyle significantly attenuated the association between T2D and BAG. On average, the brain age was 0.78 years older than the chronological age of participants with T2D and an optimal lifestyle compared with 2.46 years older than those with a nonoptimal lifestyle.
Authors' comment
"The results highlight the potential of modifiable lifestyle behaviors to compensate against the detrimental influence of (pre)diabetes on brain health."
