Brain Microbleeds May Signal Cognitive Changes in T1D

TOPLINE:

In middle-aged adults with type 1 diabetes (T1D), having three or more cerebral microbleeds (CMBs) was associated with subtle systematic deficits in cognitive processing speed and executive functions compared with having no CMBs.

METHODOLOGY:

Researchers in Finland conducted a cross-sectional analysis of 167 patients with T1D (mean age, 46.37 years; 53.3% women) who had no history of overt neurologic disease to examine whether CMBs and white matter hyperintensities were associated with cognitive performance.
Participants underwent brain MRI to determine the number and distribution of CMBs (lobar, deep/infratentorial, or mixed) and to quantify white matter hyperintensities volumetrically.
Comprehensive neuropsychological testing focused on processing speed, executive functions (cognitive flexibility, inhibitory control, and working memory), and verbal episodic memory; blood glucose concentrations were required to be above 3.0 mmol/L at the start of the assessment.

TAKEAWAY:

Compared with having no CMBs, having three or more CMBs was associated with weaker performance in processing speed (standardised beta-coefficient [β], 0.18-0.23; P < .05) and executive function subdomains (standardised β, 0.18 to -0.25; P < .05 for all), but not in verbal episodic memory, after adjustment for age.
White matter hyperintensity volume showed no independent relationships with cognitive performance.
CMBs in the mixed location were linked to worse cognitive performance across processing speed, executive functions, and immediate verbal memory than those in strictly lobar or deep/infratentorial locations (P < .05 for all).

IN PRACTICE:

“Our findings suggest that the presence of multiple CMBs is associated with subtle, incipient cognitive deficits in middle-aged individuals with T1D. Interventional and follow-up studies are warranted to clarify whether these early microvascular and cognitive symptoms develop further and how they could be prevented,” the authors wrote.

SOURCE:

This study was led by Iiris Kyläheiko, University of Helsinki, Helsinki, Finland. It was published online on January 02, 2026, in Diabetes Research and Clinical Practice.

LIMITATIONS:

As a cross-sectional analysis, it could not determine causal links between markers of cerebral small vessel disease and cognition. Subgroup sizes were limited, especially for CMB location analyses. Moreover, this study lacked an external control group.

DISCLOSURES:

The FinnDiane Study was supported by the Folkhälsan Research Foundation, Wilhelm and Else Stockmann Foundation, Medical Society of Finland, and State Funding for University-level Health Research from Helsinki University Hospital. One author reported being a shareholder and co-founder of RokoteNyt Oy, and few authors reported receiving investigator-initiated research grants, serving on advisory boards, and receiving lecture fees from various companies and organisations, including Medscape.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.