Cognitive Processing Speed Is Vulnerable to Glucose Fluctuations in Patients With T1D

Patients with type 1 diabetes (T1D) face numerous challenges, including managing insulin levels and navigating the intricacies of blood glucose fluctuations. Investigators of a recent study in NPJ Digital Medicine noted that, historically, “technological limitations prevented researchers from understanding how naturally occurring glucose fluctuations impact cognitive fluctuations.” However, “new advances in cognitive ecological momentary assessment (EMA) and continuous glucose monitoring enable high-frequency, high-quality data collection within individuals over time.”

The researchers employed hierarchical Bayesian modeling to analyze data on a cohort of 200 patients with T1D to estimate dynamic, within-person associations between glucose and cognition. Cognitive ability was measured during EMA via digit symbol matching (DSM), a gradual onset continuous performance test (GCPT), and multiple object tracking.

Additionally, data-driven lasso regression techniques were employed to identify clinical characteristics that could predict individual differences in cognitive vulnerability to glucose fluctuations.

Consistent with previously conducted laboratory studies, “large glucose fluctuations were associated with slower and less accurate DSM performance,” the researchers wrote. The pattern remained significant across all EMA completion cutoffs for DSM reaction time.

However, the study found that group estimates of cognitive vulnerability to glucose fluctuations were not significant for GCPT. These results “suggest that processing speed (DSM) may be more vulnerable to glucose fluctuations than sustained attention (GCPT).”

Moreover, the research identified 7 clinical characteristics that predicted individual differences in cognitive vulnerability to glucose fluctuation: age, time spent in hypoglycemia, lifetime severe hypoglycemic events, presence of microvascular complications, glucose variability, fatigue, and neck circumference.

According to the researchers, these results have significant clinical implications on behavioral interventions and risk screening in patients with T1D.

Regarding behavioral interventions, the study brings attention to a select few modifiable risk factors that could be addressed to enhance cognitive performance and minimize cognitive susceptibility to glucose fluctuations. The researchers also argued their “results suggest that individual estimates of cognitive vulnerability to glucose fluctuations can be feasibly, remotely ascertained using scalable digital technologies and show preliminary validity as digital biomarkers of neurocognitive dysfunction in T1D.”