Glycaemic Burden and Cognitive Screen-Positive Status in Younger Indian Adults with Long-Standing Type 2 Diabetes: A Cross-Sectional Study with a MoCA Cutoff Sensitivity Analysis in a Lower-Education Population

BackgroundStructured cognitive screening in diabetes is recommended only from age 65, leaving younger adults with prolonged type 2 diabetes mellitus (T2DM) exposure unmonitored. We quantified the association of HbA1c and diabetes duration with Montreal Cognitive Assessment (MoCA) screen-positive status in adults aged [&le;] 60 years with T2DM of [&ge;] 5 years, and examined against matched controls how the MoCA cutoff (< 26, < 24, < 23) affects the group contrast in a lower-education population. MethodsCross-sectional study at a tertiary-care centre in North India: 110 adults with T2DM and 50 controls frequency-matched for age, sex, and education. Within diabetics, HbA1c and duration were modelled continuously by modified Poisson regression at each pre-specified cutoff and by Spearman correlation with MoCA total score. Prevalence ratios (PR) for diabetics versus controls at each cutoff were adjusted for age, sex, education, BMI, and hypertension. ResultsWithin diabetics, MoCA total score correlated with HbA1c ({rho} = -0.456) and duration ({rho} = -0.318; both p < 0.001). Screen-positive prevalence rose 5% per 1% HbA1c at < 26 (PR 1.05, 95% CI 1.02-1.09), 12% at < 24 (PR 1.12, 1.06-1.18), and 17% at < 23 (PR 1.17, 1.09-1.26), and 11% per year of duration at < 23 (PR 1.11, 1.06-1.17). Median education was 10 and 9 years; 76.0% of controls screened positive at < 26, and the diabetes association was cutoff-dependent: adjusted PR 1.08 (0.89-1.29) at < 26, 1.70 (1.10-2.63) at < 24, and 6.72 (2.23-20.23) at < 23, where 44.5% of diabetics versus 6.0% of controls screened positive (absolute difference 38.5 percentage points, 95% CI 25.0 to 48.7). ConclusionsIn working-age adults with long-standing T2DM, screen-positive prevalence rose continuously with HbA1c at every cutoff, a glycaemic signal independent of threshold choice. The standard < 26 cutoff flagged over three-quarters of both groups and could not triage; < 23 separated diabetics from controls. Screen-positive status is not a diagnosis; MoCA triage at a population-appropriate cutoff in this group warrants prospective validation against a neuropsychological reference standard.