Association between pre-diabetes or diabetes and cognitive impairment in a -community dwelling older population: Bushehr Elderly Health (BEH) program

Abstract Background Uncontrolled hyperglycemia is one of the risk factors for cognitive disorders. By this finding, both type 1 and type 2 diabetes may predispose to cognitive impairment in poorly controlled cases. The current large-scale study is aimed at cognitive impairments in diabetic and non-diabetic older adults separately. Methods This is a cross-sectional study from phase 2 of the Bushehr elderly health program (BEHP). Mini-cog and categorical verbal fluency tests (CFTs) were used to assess cognitive function. Patients were classified as non-diabetics, pre-diabetics, or diabetics based on the diagnostic criteria for diabetes mellitus (DM). To compare the means of the two groups, we used the t-test or the Mann-Whitney test. Multivariable logistic regression models were also used to determine the association between pre-diabetes or DM and cognitive impairment. Results Six hundred and ninety-three (45.2%) out of 1533 participants were ascertained to be cognitively impaired. The average hemoglobin A1C was higher in diabetic patients with cognitive impairment compared to those without cognitive impairment. (5.8 ± 1.6% vs. 5.5 ± 1.4%, P = 0.004). Besides, the mean blood glucose levels were found to be more elevated in cognitively impaired cases (108.0 ± 47.4 mg/dL vs. 102.1 ± 0.35 mg/dL, P = 0.002). After adjusting for age, gender, body mass index(BMI), waist circumference, amount of physical activity, and smoking, the multivariable logistic regression model, declared an association between diabetes and cognitive impairment (OR = 1.48, P = 0.003). Older patients, females, widows, and patients with elevated LDL-Cs and blood pressure are also more vulnerable to cognitive impairment. Conclusion In the BEHP, there is a positive association between cognitive impairment and DM, notably in long-term, poorly controlled cases, whereas no association was found among pre-diabetics in our elderly study populations.