Decrease in Serum Levels of Adiponectin and Increase in 8-OHdG: a Culprit for Cognitive Impairment in the Elderly Patients with Type 2 Diabetes.

Background: Adiponectin and 8-Hydroxy-2'-deoxyguanosine (8-OHdG) are identified as important biomarkers in the pathogenesis process of type 2 diabetes mellitus (T2DM). Whether adiponectin and 8-OHdG have a relation to cognitive decline in the elderly T2DM patients has been poorly understood. The aim of this study was to evaluate the effects of adiponectin and 8-OHdG in the elderly patients with T2DM and to determine the role of adiponectin and 8-OHdG in the cognitive impairment of the elderly patients with T2DM.

Methods: 57 individuals were recruited and analyzed , with 26 cases of T2DM without cognitive impairment and 31 cases of T2DM with cognitive impairment. All of them underwent an examination of diabetes scales and blood glucose at different times. A primary diagnosis of diabetes was in line with the diagnosis criteria set by the American Diabetes Association (ADA). Statistical significance was defined as a P-value of less than 0.05.

Results: The variables of sex, age, body mass index (BMI), hypertension, diabetes, metabolic syndrome, lacunar cerebral infarction, smoking and drinking in T2DM patients without cognitive impairment and with cognitive impairment showed no difference according to the univariate analysis exploring each variable separately (p>0.05). A significant difference was observed in the serum levels of adiponectin and 8-OHdG and the scales of MMSE and MoCA (p<0.05). Therefore, it was inferred that there is no correlation between glucose metabolic value and cognitive outcome of T2DM patients. Serum levels of adiponectin and 8-OHdG could act as biomarkers of cognitive impairment degree in the elderly T2DM patients.

Conclusion: Serum levels of adiponectin and 8-OHdG could act as specific and sensitive biomarkers for the early diagnosis and treatment of cognitive impairment in elderly T2DM patients. Serum levels of adiponectin and 8-OHdG have a close relation to the neurological cognitive outcome of the elderly T2DM patients.