Chronic Kidney Disease Diminishing Mini-Mental State Examination Score in Older Patients with Type 2 Diabetes and Low Normal Ankle-Brachial Index

Abstract

Objective Dementia is an aging-related process and highly prevalent in patients with type 2 diabetes. Mini-mental state examination (MMSE) is a useful tool to screen dementia. The present study assesses whether a low MMSE score is associated with micro- and macro-vascular diseases in older patients with type 2 diabetes. Methods Among patients aged ≥ 65 years with type 2 diabetes, subjects were enrolled if they had undergone assessments of MMSE score and ankle-brachial index (ABI) during the annual evaluation of pay-for-performance program. Peripheral artery disease (PAD) was defined as ABI ≤ 0.90, low normal ABI was defined as a value>0.90 and<1.10, and normal ABI was defined as a value between 1.10 and 1.40. Chronic kidney disease (CKD) was defined as estimated glomerular filtration rate (eGFR)<60 mL/min/1.73 m2. Results MMSE score was significantly lower in patients with PAD than in those without PAD (23.4 ± 5.2 vs. 25.9 ± 3.7; P<0.001). In addition to PAD, both CKD and the low normal ABI value were associated with a low MMSE score (24.9 ± 4.2 in CKD vs. 26.4 ± 3.3 in non-CKD, P<0.001; 25.5 ± 3.9 in low normal ABI vs. 26.2 ± 3.5 in normal ABI, P=0.021; respectively). On multivariate regression analysis, the lowest MMSE score was observed in patients with PAD (95% confidence interval: -3.401 to -1.182, P<0.001) among all patients, and the MMSE score was also significantly lower in those with CKD and low normal ABI than those with normal ABI and without CKD (95% confidence interval: -1.778 to -0.051, P=0.038). Conclusion PAD is an independent factor for low MMSE scores in older patients with type 2 diabetes. In those without PAD, CKD and low normal ABI exert synergistic effects on the low MMSE score.