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 phasebetween the cognitive decline that is expected due to thenormal aging process and the more disconcerting declineof dementia. This case-control study aimed to explorethe association between type 2 diabetes mellitus and mildcognitive impairment and compare the prevalence of mildcognitive impairment between non-diabetics and type 2diabetics.Material and Methods: 50 patients with T2DM and 50 ageand sex matched non-diabetic controls were selected for thestudy. Demographic data and medical history was collectedby face to face interview following which the Mini-Mentalstate examination (MMSE) and the Montreal CognitiveAssesment (MoCA) were conducted. If either of the screeninginstruments suggested MCI, the patient was then subjectedto an extensive medical examination conducted by qualifiedmedical clinicians blinded to the MMSE and MoCA scoresfor a more detailed diagnosis of MCI. Chi square test wasperformed to determine if T2DM was significantly correlatedwith MCI. Linear regression was performed to determine thestrength of years of illness as a predictor of MMSE and MoCAscore.Results: Chi square test revealed a statistically significantcorrelation between T2DM and MCI. Years of illness wasfound to predict 5% of the variance in MMSE score and 14%of the variance in MoCA score.Conclusion: The study established that mild cognitiveimpairment had a significant statistical association withT2DM