Rosebud O. Roberts, MB, ChB, of the Mayo Clinic in Rochester, MN, and colleagues reviewed medical records and conducted neuropsychological testing and magnetic resonance imaging for 1,437 participants (median age, 80 years) in a population-based cohort without dementia. The researchers investigated the associations of diabetes and hypertension with cognition and imaging biomarkers of brain pathology.
The researchers found that participants with midlife diabetes were more likely to have subcortical infarctions (odds ratio [OR], 1.85; 95% confidence interval [CI], 1.09–3.15; P=0.02), reduced hippocampal volume (−4%; 95% CI, −7–−1.0%; P=0.01), reduced whole brain volume (−2.9%; 95% CI, −4.1–−1.6%), and prevalent mild cognitive impairment (OR, 2.08; P=0.01). Midlife hypertension was linked with infarctions and white matter hyperintensity volume and was marginally linked with decreased performance in executive function. Participants with late-life onset of diabetes and hypertension appeared to have few effects.
“Midlife onset of diabetes may affect late-life cognition through loss of brain volume. Midlife hypertension may affect executive function through ischemic pathology,” the authors write. “Late-life onset of these conditions had fewer effects on brain pathology and cognition.”
Several study authors disclosed financial ties to pharmaceutical and biomedical companies.