<b>Objective </b>Type 2 diabetes
is associated with increased risks of cognitive dysfunction and brain
abnormalities. The extent to which risk factor modification can mitigate these
risks is unclear. We investigated the associations between incident dementia,
cognitive performance and brain abnormalities among individuals with type 2
diabetes, according to the number of risk factors on target, compared to
controls without diabetes.
<div><p><b>Research Design and Methods</b>
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.</p>
<p><b>Results </b>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.</p>
<p><b>Conclusions </b>Among
individuals with diabetes, excess dementia risk, lower cognitive performance
and brain abnormalities decreased stepwise for a higher number of risk factors on
target.</p></div>