HealthDay News — Both prediabetes and known type 2 diabetes are associated with a heightened risk for vascular dementia, cognitive decline, and Alzheimer disease (AD), according to a study published online Feb. 14 in Diabetes, Obesity and Metabolism.
Victoria Garfield, Ph.D., from University College London, and colleagues used data from the U.K. Biobank cohort (including 500,000 individuals aged 40 to 69 years) to assess the effect of increasingly higher hemoglobin A1c (HbA1c) values on brain health outcomes compared to normoglycemic individuals (HbA1c value of 35 to <42 mmol/mol).
The researchers found that prediabetes and known diabetes increased the risk for incident vascular dementia (hazard ratios, 1.54 and 2.97, respectively). Known diabetes was associated with an increased risk for all-cause dementia and AD (hazard ratios, 1.91 and 1.84, respectively). An elevated risk of cognitive decline was associated with prediabetes and known diabetes (odds ratios, 1.42 and 1.39 respectively). Higher white matter hyperintensity (WMH) volumes were associated with prediabetes, undiagnosed diabetes, and known diabetes (3, 22, and 7 percent, respectively). Prediabetes, undiagnosed diabetes, and known diabetes were associated with lower hippocampal volume, while low-normal HbA1c was associated with lower WMH volume and greater hippocampal volume.
“In this relatively young age group, the risks of cognitive decline and of dementia are very low; the excess risks we observe in relation to elevated blood sugar only modestly increase the absolute rates of ill health,” a coauthor said in a statement. “Seeing whether these effects persist as people get older, and where absolute rates of disease get higher, will be important.”
One author disclosed financial ties to the pharmaceutical industry.