Cerebral microbleeds are associated with deficits in cognitive processing speed and executive functions in middle-aged adults with type 1 diabetes.

AIMS: Adults with type 1 diabetes (T1D) have an increased risk of cerebral small vessel disease (cSVD)-related brain changes already in midlife, yet their significance for cognitive functions remains poorly understood. We investigated associations between cerebral microbleeds (CMBs), white matter hyperintensities (WMHs), and cognition in individuals with T1D and without any neurological symptoms.

METHODS

Participants (n=167; age 46.4±7.7 years) underwent cross-sectional clinical and biochemical evaluations, brain magnetic resonance imaging, and neuropsychological assessment. CMB number and topography (lobar, deep/infratentorial, or mixed location) and WMHs, quantified volumetrically, were evaluated.

RESULTS

Compared to absence of CMBs, higher burden of CMBs (≥3) was associated independently of age with poorer processing speed (standardized β from 0.18 to 0.23, p<0.05) and executive functions (standardized β from 0.18 to -0.25, p<0.05), but not with episodic memory. Mild WMHs had no independent relationships with cognition. Compared to other topographies, mixed CMB location was more often negatively related to cognition (standardized β from 0.20 to 0.32, p<0.05).

CONCLUSIONS

CMBs were related to a subtle, yet systematic impairment in cognition, whereas mild WMHs were not. The results provide insight into the development of early cSVD-related cognitive changes already in midlife and suggest an increased risk of cognitive decline in T1D.