Risk factors of mild cognitive impairment in middle aged patients with type 2 diabetes: a cross-section study

The aim of this study was to evaluate the risk factors of mild cognitive impairment (MCI) in middle-aged patients with type 2 diabetes (T2DM).

Montreal Cognitive Assessment (MoCA) was applied as cognition assessment implement. One hundred and fifty-seven middle-aged type 2 diabetic patients were enrolled in this cross-section study (age 40~69, mean age 55 ± 7). There were 93 patients with MCI (MoCA score<26) in MCI group and 64 with normal cognitive function (MoCA score ≥ 26) in control group. Information of history of disease, family history, data of BMI, WHR, HbA1c, FINS, C-Peptide (C-P), SBP, DBP, blood lipid (TG, TC, LDL-C, HDL-C and carotid ultrasound (carotid IMT, carotid resistance index [RI]) was collected.

There were significant differences in the rate of patients with hypertension ([40.63 vs. 58.06%], P=0.026), duration of diabetes mellitus ([3.09 ± 4.04 y vs. 4.80 ± 4.94 y], P=0.024), C-P ([2.79 ± 1.09 ng/ml vs. 2.26 ± 1.00 ng/ml], P=0.008), Max C-IMT ([0.81 ± 0.15 mm vs. 0.91 ± 0.15 mm], P<0.001), Min C-RI (0.71 ± 0.06 vs. 0.68 ± 0.06, P<0.05), and no significant differences in the duration of hypertension and hyperlipidemia, BMI, WHR, HbA1c, SBP, DBP and blood lipid between control group and MCI group. MoCA scores were positively correlated with C-P (r=0.252, P=0.005), and negatively correlated with the history of hypertension (r=-0.244, P=0.002), duration of DM (r=-0.161, P=0.044), Max C-IMT (r=-0.253, P=0.005) and Min C-RI (r=-0.183, P=0.023). Multiple regression analysis showed that history of hypertension (Beta=-0.267, P=0.002), C-P (Beta=0.281, P=0.001) and Min C-RI (Beta=-0.221, P=0.011) were significantly independent determinants for the MoCA scores.

The longer duration of diabetes, history of hypertension, lower serum C-P levels, thickened C-IMT and higher C-RI could be risk factors of MCI in type 2 diabetic patients. This finding could have an important impact on the management of cognitive decline in diabetic patients.