Cognitive Impairment and its Association with Glycemic Control among Patients with Type 2 Diabetes Mellitus

Abstract

Background: Cognitive impairment is increasingly recognized as an important complication of type 2 diabetes mellitus. Hyperglycaemia over time, recurrent hypoglycaemia, vascular comorbidities, and exposure to metabolic abnormalities, may play a role in causing memory, attention, and executive function deficits. But a lot of people who get diabetes treatment don't have cognitive function checked routinely.

Objective: To determine the frequency of cognitive impairment and evaluate its association with glycaemic control among patients with type 2 diabetes mellitus.

Methodology: A cross-sectional study was conducted in the Department of Neurology, PIMS Islamabad and Department of Neurology/Medicine Khyber Teaching Hospital, Peshawar, from January 2025 to June 2025 in hospital setting. Patients with type 2 diabetes mellitus were recruited using consecutive non-probability sampling to achieve a total of 85 patients. Demographic data, diabetes duration, treatment history, comorbidities and diabetic complications were noted. The glycated haemoglobin (HbA1c) was used to assess glycemic control, and HbA1c <7% was considered as good glycemic control, whereas HbA1c ≥7% was considered as poor glycemic control. Cognitive function was assessed with the Montreal Cognitive Assessment and a score of less than 26 was defined as cognitive impairment. Appropriate comparative tests, correlation analysis and binary logistic regression were used to assess associations.

Results: The mean age of the participants was 56.82 ± 9.74 years, and the mean duration of diabetes was 10.24 ± 6.08 years. The mean HbA1c level was 8.31 ± 1.47%, while 54 (63.5%) patients had poor glycaemic control. Cognitive impairment was identified in 38 (44.7%) patients, including 28 (32.9%) with mild and 10 (11.8%) with moderate impairment. Cognitive impairment was significantly more frequent among patients with HbA1c ≥7% than among those with HbA1c <7% (57.4% versus 22.6%, p = 0.002). HbA1c demonstrated a significant inverse correlation with the MoCA score (r = −0.48, p < 0.001). Poor glycaemic control, increasing age and longer duration of diabetes remained independent predictors of cognitive impairment.

Conclusion: Cognitive impairment was common among patients with type 2 diabetes mellitus and was significantly associated with poor glycaemic control. Routine cognitive screening, particularly among older patients and those with longstanding or poorly controlled diabetes, may support early detection and safer individualized management.