The correlation between mild cognitive impairment in the elderly and impaired fasting glucose tolerance and low fasting blood glucose / 中华老年医学杂志

ABSTRACT

Objective:To investigate the correlation between mild cognitive impairment(MCI)and abnormal glucose metabolism and thus to provide a basis for MCI prevention.Methods:A total of 1 074 elderly outpatients with normal cognitive function and without confirmed diabetes mellitus, hyperlipoidemia or gout were enrolled.During a five-year follow-up period, 121 subjects were diagnosed with MCI based on the mini mental state examination(MMSE)and the Montreal cognitive assessment(MoCA). Furthermore, annual blood glucose and glycated hemoglobin monitoring was carried out to examine the long-term effects of abnormal glucose metabolism on MCI risk.Results:According to cognitive function, 1 074 subjects were divided into the MCI group and the non-MCI group.Compared with the non-MCI group, the mean values of fasting blood glucose(FBG), glycosylated hemoglobin(HbA1c), triglycerides(TG)and total cholesterol(TC)in the MCI group were elevated( P<0.05). The receiver operating characteristic(ROC)curve showed that the cut-off value of FBG was 6.2 mmol/L for the hyperglycemia group(sensitivity 84.1%, specificity 90.9%, area under curve 0.875, P<0.001)and 4.5mmol/L for the hypoglycemic group(sensitivity 77.4%, specificity 87.3%, area under curve 0.823, P<0.001); the cut-off value of HbA1c was 5.5%(sensitivity 76.0%, specificity 87.0%, area under curve 0.815, P<0.001). Multiple Logistic regression analysis showed that increased risk of MCI was associated with the mean values of fasting blood glucose <4.5 mmol/L( RR 1.69, 95% CI 1.11-2.59)or ≥6.2 mmol/L( RR 1.81, 95% CI 1.15-2.86)and of glycosylated hemoglobin ≥ 5.5%( RR 2.13, 95% CI 1.51-2.99). Conclusions:Impaired fasting glucose tolerance and low fasting blood glucose are independent risk factors for MCI in the elderly.