Prevalence and pattern of cognitive dysfunction in young adults and middle-aged patients with type-2 diabetes

With the world's aging population, twin epidemics of type-2 diabetes (T2D) and dementia take a great toll on the healthcare burden. T2D carries a 2-3 times greater risk of developing cognitive impairment than controls. Early identification of cognitive impairment is important as it impairs diabetes self-management, making patients prone to complications. However, data about the assessment of cognitive impairment in T2D using a comprehensive cognitive battery is sparse in India. This study was undertaken to estimate the prevalence and pattern of cognitive impairment among young and middle-aged patients with T2D.

A cross-sectional observational study was conducted in a tertiary care teaching hospital in Kolkata (2022-2024) among 125 Bengali-speaking T2D patients with formal education > class IV, aged between 20 and 60 years. The cognitive evaluation was done using the clinical dementia rating scale, mini-mental status examination (MMSE), Montreal cognitive assessment (MoCA), and Addenbrooke's cognitive examination (ACE)-III. Statistical analyses were done by Jeffrey's Amazing Statistics Program version 0.19 with appropriate tests (Chi-squared test, Mann-Whitney U test, Spearman correlation statistics, and logistic regression). P value < 0.05 was considered significant.

T2D patients reported a more subjective sensation of forgetfulness compared to the control group (P = 0.001). MMSE was an insufficient screening tool to distinguish between these two groups. On MoCA and ACE-III, there was a significant difference in total scores between case and control groups (MoCA, P = 0.012 and ACE-III, P < 0.001). Based on ACE-III, 59.20% of T2D patients had cognitive impairment (P < 0.001). The odds of having cognitive impairment in T2D were 3.72 times higher than in the control group (P < 0.001). There was significant impairment of memory (P < 0.001), fluency (P = 0.020), and visuospatial ability (P = 0.032). Females (P = 0.010), less education (P < 0.001), lower socioeconomic status (P < 0.001), BMI < 23 kg/m² (P = 0.049), peripheral neuropathy (P = 0.001), hypothyroidism (P = 0.007), anxiety (P < 0.001), and depression (P < 0.001) were significantly associated with cognitive impairment in diabetes.

This is the first study from Eastern India to use a comprehensive cognitive scale validated in the local vernacular. Cognitive impairment is prevalent among a significant portion of middle-aged, educated individuals with T2D. Cognitive evaluation should be incorporated into diabetes management from the onset, with a focus on addressing modifiable factors.