Association of Blood Pressure with Mild Cognitive Impairment in Patients with Type 2 Diabetes Mellitus: A Multicenter Cross-Sectional Study

Abstract

Background Type 2 diabetes mellitus (T2DM) and hypertension frequently coexist and independently elevate the risk of cognitive decline. Although blood pressure (BP) dysregulation is hypothesized to accelerate neurovascular damage, its independent association with mild cognitive impairment (MCI) among individuals with T2DM remains insufficiently characterized in real-world multicenter cohorts. Methods This multicenter cross-sectional study evaluated 489 adult patients with T2DM recruited from tertiary outpatient clinics. Cognitive performance was measured using the Montreal Cognitive Assessment (MoCA, including MoCA-Basic for low-literacy participants), with MCI defined as a score < 26. Resting blood pressure was measured using standardized protocols. Statistical analyses included Pearson and Spearman correlations, multiple linear and binary logistic regression, independent samples t-tests, ROC analyses, and age-stratified subgroup assessments. Results Overall, 79.8% (n = 390) of the participants met the criteria for MCI, with a sample MoCA score of 21.40 ± 5.35. In multivariable models, cognitive performance was independently predicted by: Education: Higher formal education was protective and associated with higher MoCA scores (B = 0.70, p < 0.001; aOR = 0.93, 95% CI: 0.86–1.00). Age: Advancing age independently increased the odds of impairment (B = -0.08, p < 0.001; OR = 1.03, 95% CI: 1.00–1.05). Sex: Female sex was associated with lower cognitive scores and elevated MCI risk (B = -1.71, p < 0.001; OR = 2.02, 95% CI: 1.21–3.37). In contrast, systolic BP, diastolic BP, pulse pressure, and hypertension status showed no significant independent associations with cognitive scores or MCI risk after multivariable adjustment (all p > 0.05). Blood pressure parameters demonstrated negligible discriminative accuracy for MCI (AUC range: 0.52–0.53), and MoCA scores did not significantly differ between normotensive and hypertensive patients (21.64 vs. 20.94, p = 0.175). Conclusion Mild cognitive impairment affects nearly four in five diabetic patients in this population. Poorer cognitive performance is primarily driven by demographic and socioeconomic determinants—specifically older age, female sex, and limited education—rather than clinic blood pressure indices. These findings highlight the critical need for routine cognitive screening protocols tailored to high-risk demographic profiles within diabetes management pathways.