Statin Use and Cognitive Impairment in Patients With Type 1 Diabetes: An Observational Study.

OBJECTIVE: We aimed to assess a wide range of cognitive functions in patients with type 1 diabetes (DM1) compared with healthy control subjects and to evaluate the effects of statins on cognitive functions in DM1 patients.

MATERIALS AND METHODS: The sample studied consisted of 55 DM1 patients (80.0% with hyperlipidemia, 20% with statin treatment) and 36 age-matched control subjects (77.8% with hyperlipidemia) without diabetes or statin use. Their cognitive functions (attention, memory, and executive functions) were evaluated with the trail making test, controlled oral word association test (COWAT), Rey-Osterrieth complex figure test, brain damage test (diagnosticum für cerebralschädigung, DCS), Wisconsin card sorting test (WCST), and digit span and block design tests from the revised Wechsler adult intelligence scale.

RESULTS: Cognitive performance was impaired in DM1 patients when compared with the control group with regard to semantic verbal fluency (COWAT_animals), visual learning (DCS), conceptual-level responses, executive functions (WCST random errors), and WCST trials to complete the first category. Subgroups of DM1 patients distinguished on the basis of statin therapy did not differ with regard to verbal fluency (COWAT_animals), visual learning (DCS), conceptual-level responses, executive functions (WCST random errors), and WCST trials to complete the first category. Multivariate analysis also does not show the impact of statin therapy on cognitive functioning regardless of the duration of education, microangiopathic evidence, the presence of hyperlipidemia, or antihypertensive therapy.

CONCLUSIONS: We find impairment of cognitive functions in DM1 patients when compared with control subjects without diabetes. However, we show neither the effect of statins nor the significant influence of metabolic control, microangiopathic complications, or the presence of hyperlipidemia on cognitive functions in DM1 patients.