Lower cognitive performance among long-term type 1 diabetes survivors: A case-control study

Area of Science:

• Neuroscience
• Endocrinology
• Clinical Medicine

Background:

• Type 1 diabetes (T1D) is associated with an elevated risk of cognitive dysfunction.
• Cognitive decline in T1D is often attributed to vascular complications and disease duration.
• Some T1D patients experience cognitive symptoms despite the absence of these complications.

Purpose of the Study:

• To investigate the association between long-standing T1D without micro- or macrovascular complications and cognitive performance.
• To determine if cognitive deficits exist in T1D patients who have managed to avoid typical diabetes-related complications.

Main Methods:

• A cohort of 43 patients with T1D for over 30 years, free of vascular complications, was compared to 86 non-diabetic controls.
• Cognitive function was assessed using six tests measuring episodic memory, semantic memory, episodic short-term memory, visual attention, and psychomotor speed.
• Participants were matched for age, gender, and education; data were analyzed using a linear mixed-effects model.

Main Results:

• Patients with long-standing T1D demonstrated significantly lower performance in episodic short-term memory (p<0.001).
• A decline was also observed in tests of visual attention and psychomotor speed (p=0.019) in the T1D group compared to controls.
• Key demographic and clinical factors like BMI, blood pressure, and smoking status did not significantly differ between groups, except for lower diastolic blood pressure in T1D patients.

Conclusions:

• Long-standing type 1 diabetes is independently associated with reduced cognitive performance.
• Cognitive impairment in T1D may occur even in the absence of macro- and microvascular complications.
• These findings highlight potential neurological impacts of T1D beyond its known vascular sequelae.