Serum seladin-1 levels in diabetes mellitus and Alzheimer's disease patients.

ABSTRACT

BACKGROUND: Diabetes mellitus (DM) has been shown to increase the risk of Alzheimer's disease (AD). Downregulation of selective Alzheimer's disease indicator-1 (seladin-1) occurs in the cerebral regions affected by AD. However, inconsistent results have been reported for the relationship between seladin-1 levels and AD. The effect of DM on serum seladin-1 levels in AD is unknown. The present study is aimed to investigate serum seladin-1 levels in diabetic and non-diabetic patients with AD. METHODS: Forty-six patients with AD and 25 healthy volunteers over 65 years of age were included in this study. The patients were divided into three groups-those with AD only, those with DM and AD, and control groups. Demographic characteristics and serum seladin-1 levels were compared among the groups. RESULTS: There was no statistically significant difference in seladin-1 levels in the AD only group compared to the control group (p = 0.376). However, seladin-1 levels were significantly lower in the DM and AD group compared to the AD only and control groups (p = 0.002, p = 0.001; respectively). Negative correlations were present between seladin-1 and fasting glucose, postprandial glucose, HbA1c, and insulin (p < 0.05; all). CONCLUSION: Decreased serum seladin-1 values in the presence of DM and inverse correlations with diabetic parameters in patients with AD, together with a non-significant difference from the control group, suggests that seladin-1 may be altered only in the presence of DM in patients with AD. Lower serum seladin-1 levels may also play a role in the pathogenesis of AD in patients with DM.