Old people with diabetes are more likely to develop cognitive impairment, Alzheimer's disease and vascular dementia. However, the determinants of the association between diabetes and cognitive impairments are only partially known.

To evaluate cognitive disorders in elderly diabetic patients and to identify risk factors of cognitive impairment in this population.

It was a cross-sectional study. It involved outpatients aged 65 and older, who were followed for diabetes in the endocrinology department at the Hedi Chaker University Hospital in Sfax (Tunisia), from October 1 to December 31, 2015. For each patient, we collected sociodemographic, clinical and therapeutic data. We used the Montreal Cognitive Assessment (MoCA) to identify mild cognitive decline (score < 26/30).

We identified 70 patients, all with type 2 diabetes. The average age was 66.8 years. The sex ratio (M: F) was 0.7. The mean duration of diabetes was 14.76 years. The average MoCA score was 20.68 ± 6. Forty patients (57%) had cognitive decline. The cognitive impairment was statistically correlated with female sex (P = 0.02), low level of education (P = 0.00), high levels of glycated hemoglobin (Hb A1c ≥ 7%) (P = 0.00), presence of hypoglycemic episodes (P = 0.05) and presence of dyslipidemia (P = 0.00).

Our study confirmed the high rate of cognitive decline in older type 2 diabetes patients. The profile of subjects at risk was consistent with the literature: poorly controlled diabetes, severe recurrent hypoglycaemia and associated dyslipidemia. Acting on these risk factors would prevent cognitive decline and therefore progression to dementia.

The authors have not supplied their declaration of competing interest.