Association of Type 2 Diabetes, According to the Number of Risk Factors Within Target Range, With Structural Brain Abnormalities, Cognitive Performance, and Risk of Dementia
Research Design and Methods Prospective data from UK Biobank of 87,856 individuals (n=10,663 diabetes/n=77,193 controls; baseline 2006-2010; dementia follow-up until February, 2018). Individuals with diabetes were categorized according to the number of seven selected risk factors within guideline-recommended target range (nonsmoking; guideline-recommended levels of HbA1c, blood pressure, BMI, albuminuria, physical activity, diet). Outcomes were incident dementia, domain-specific cognitive performance, white matter hyperintensities and total brain volume.
Results After a mean follow-up of 9.0 years, 147(1.4%) individuals with diabetes and 412(0.5%) controls had incident dementia. Among individuals with diabetes, excess dementia risk decreased stepwise for a higher number of risk factors on target. Compared to controls (incidence rate per 1,000 person-years 0.62(95%CI:0.56;0.68)), individuals with diabetes who had 5-7 risk factors on target had no significant excess dementia risk (absolute rate difference per 1,000 person-years 0.20(-0.11;0.52); HR:1.32(0.89;1.95)). Similarly, differences in processing speed, executive function, and brain volumes were progressively smaller for a higher number of risk factors on target; these results were replicated in the Maastricht Study.
Conclusions Among individuals with diabetes, excess dementia risk, lower cognitive performance and brain abnormalities decreased stepwise for a higher number of risk factors on target.