To estimate the pooled prevalence of cognitive impairment among adults with T2DM in India and to evaluate the association between T2DM and cognitive decline, considering age and glycemic parameters. 

Type 2 Diabetes Mellitus (T2DM) is increasingly recognized as a risk factor for cognitive impairment and dementia. Insulin resistance, chronic hyperglycaemia, and microvascular dysfunction have been implicated in neurodegeneration and cognitive decline. However, findings from individual studies are heterogeneous, particularly within the Indian population, where the diabetes burden is rapidly increasing.

We searched PUBMED, Embase, SCOPUS and Web of Science from 2005 to December 2025 for clinical studies comparing cognitive outcomes in adults with T2DM. Two reviewers independently screened and extracted data. Effect estimates (OR/HR/mean differences) were pooled using random-effects meta-analysis. Heterogeneity was assessed with I²; subgroup analyses examined age, glycemic parameters and cognitive assessment tools. 

A total of 30 studies (n = 7367 participants) were included. The pooled prevalence of MCI among individuals with T2DM was 46% (95% CI: 36%–57%), indicating substantial variability across studies. Results were robust in sensitivity analyses excluding high-risk-of-bias studies. The Montreal Cognitive Assessment (MoCA) was the most frequently employed screening tool across studies, followed by the Mini-Mental State Examination (MMSE), indicating a preference for instruments sensitive to early cognitive deficits.

Nearly half of adults with Type 2 Diabetes Mellitus exhibit Mild Cognitive Impairment. Routine cognitive screening using sensitive tools should be integrated into diabetes management to enable early detection and intervention aimed at preventing further cognitive decline.