Association of Cognitive Impairment and Type 2 Diabetes Mellitus: A Case-Control Study

Abstract

Introduction: Patients with type 2 diabetes mellitus (T2DM) have cognitive deficits that can be attributed to their disease. Mild cognitive impairment (MCI) is a transitional phase between the cognitive decline that is expected due to the normal aging process and the more disconcerting decline of dementia. This case-control study aimed to explore the association between type 2 diabetes mellitus and mild cognitive impairment and compare the prevalence of mild cognitive impairment between non-diabetics and type 2 diabetics. Material and Methods: 50 patients with T2DM and 50 age and sex matched non-diabetic controls were selected for the study. Demographic data and medical history was collected by face to face interview following which the Mini-Mental state examination (MMSE) and the Montreal Cognitive Assesment (MoCA) were conducted. If either of the screening instruments suggested MCI, the patient was then subjected to an extensive medical examination conducted by qualified medical clinicians blinded to the MMSE and MoCA scores for a more detailed diagnosis of MCI. Chi square test was performed to determine if T2DM was significantly correlated with MCI. Linear regression was performed to determine the strength of years of illness as a predictor of MMSE and MoCA score. Results: Chi square test revealed a statistically significant correlation between T2DM and MCI. Years of illness was found to predict 5% of the variance in MMSE score and 14% of the variance in MoCA score. Conclusion: The study established that mild cognitive impairment had a significant statistical association with T2DM.