Assessment of cognitive impairment and depressive signs in patients with type 2 diabetes treated with metformin from Southeast Mexico: A cross-sectional study

Abstract

Multiple factors associate diabetes with cognitive impairment and depression. Antidiabetic drugs have reported antidepressant and pro-cognitive effects in diabetic and non-diabetic subjects. Antidepressant and pro-cognitive effects of metformin are reported in various studies; however, these effects are not consistent among researches. We designed a cross-sectional study. We recruited patients with T2D diagnosis from the Diabetes Clinic of the Regional Hospital of High Specialty “Dr. Gustavo A. Rovirosa Pérez” from January 2019 to May 2022. We included 431 subjects with T2D, 374 patients with metformin treatment and 57 subjects without metformin. These patients were on intensive therapies and had not a previous diagnosis of cognitive impairment or depression. We applied Mini-Mental State Examination (MMSE) to evaluate cognitive impairment, and Hamilton Depression Rating Scale (HAM-D) to assess depressive signs. Our sample had a mean age of 53.77 ± 13.43 years. Metformin users were 374 individuals, and 57 subjects didn't use metformin. MMSE found cognitive impairment in 8.3% (n = 31) of metformin users, and 14.8% (n = 8) of patients without metformin. HAM-D scale showed that 39.5% (n = 147) of patients with metformin had depression signs, subjects without metformin and depressive signs were 44.6% (n = 25). We found no differences between groups for cognitive impairment and depression grades. We did not find associations between metformin treatment, cognitive impairment measures and depression sign measures. However, chronic metformin treatment, insulin use, glycemic control and age could influence our results.