Oral glucose loading modulates plasma β-amyloid level in alzheimer's disease patients: potential diagnostic method for Alzheimer's disease.
BACKGROUND
Although plasma β-amyloid (Aβ) has been suggested to be a noninvasive diagnostic biomarker for Alzheimer's disease (AD), its significance and validity have been inconclusive. Thus, it is quite important to establish a novel diagnostic method related to plasma Aβ.


METHODS
As our previous animal studies demonstrated a relation of glucose with plasma Aβ, we examined the effect of glucose loading on plasma Aβ levels in AD patients. After fasting, an oral glucose load was administered to AD patients and non-AD dementia patients, and subsequently, blood glucose, plasma insulin, and plasma Aβ levels were measured.


RESULTS
The plasma levels of baseline blood glucose, plasma insulin, and plasma Aβ were not different between the two groups. However, immediately after glucose loading, a significant increase in plasma Aβ40 and Aβ42 levels was observed in AD patients, whereas a mild decrease in plasma Aβ40 and Aβ42 levels was detected in non-AD dementia patients.


CONCLUSIONS
The present study clearly demonstrated a different response in plasma Aβ40 and Aβ42 levels after glucose loading between AD and non-AD dementia patients, which is consistent with our previous animal studies. These findings suggest a novel diagnostic tool for AD using the elevation of plasma Aβ level after glucose loading, although further studies are necessary.
Department of Clinical Gene Therapy, Graduate School of Medicine, Osaka University, Suita, Japan.
Shuko
S
Takeda
Naoyuki
N
Sato
Kozue
K
Uchio-Yamada
Hisahiro
H
Yu
Atsushi
A
Moriguchi
Hiromi
H
Rakugi
Ryuichi
R
Morishita
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood* / Q000175:diagnosis*; D016229:Amyloid beta-Peptides / Q000097:blood*; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D015140:Dementia, Vascular / Q000097:blood / Q000175:diagnosis; D003937:Diagnosis, Differential; D005260:Female; D057180:Frontotemporal Dementia / Q000097:blood / Q000175:diagnosis; D005947:Glucose; D006801:Humans; D006850:Hydrocephalus, Normal Pressure / Q000097:blood / Q000139:chemically induced; D007328:Insulin / Q000097:blood; D008297:Male
D016229:Amyloid beta-Peptides; D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D005947:Glucose