Understanding the Association Between Type 2 Diabetes Mellitus and Cognitive Impairment: A Single-centre Experience

Abstract

The global prevalence of diabetes mellitus has been increasing, leading to a rise in morbidity associated with the disease. While diabetic nephropathy, retinopathy and neuropathy are routinely screened in diabetic patients, the cognitive decline associated with diabetes is often overlooked. The purpose of this study is to investigate the prevalence of cognitive impairment and its associated risk factors among patients with type 2 diabetes mellitus (T2DM). An observational cross-sectional study was conducted for two months. The Montreal Cognitive Assessment (MoCA) test, which consists of 30 questions, was used to assess cognitive function. In-depth clinical history along with glycaemic parameters were collected. The chi-square test was used to find out the association between categorical variables and cognitive impairment. Pearson’s correlation test was performed to determine the correlation between glycaemic parameters and cognitive impairment. A total of 96 patients participated in the study. The mean HbA1c (%) was 9.08 ± 1.73, and the mean MoCA score was 25.14 ± 1.63. Mild cognitive impairment (MCI) was noted in 56% patients. Attention was the most common cognitive domain defect found in all MCI patients—100%. Delayed recall and memory were the second most common cognitive domain defect found—92.5%. Higher HbA1c, high FBS and higher PPBS were found to be statistically associated with MCI. A negative correlation was found between glycaemic parameters (HbA1c, FBS and PPBS levels) and MoCA scores. More than half of our study participants reported mild cognitive impairment. It highlights the need for the implementation of routine cognitive testing for diabetes patients. There is a strong negative correlation between MoCA scores and parameters of glycaemic control; higher levels of HbA1c, FBS, and PPBS are seen in people with a lower MoCA score, indicating mild cognitive impairment. Further studies are needed to evaluate whether improving glucose levels helps in improving cognition or not.