Oral glucose loading modulates plasma ß-amyloid level in alzheimer's disease patients: potential diagnostic method for Alzheimer's disease.

BACKGROUND: Although plasma ß-amyloid (Aß) 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 Aß. METHODS: As our previous animal studies demonstrated a relation of glucose with plasma Aß, we examined the effect of glucose loading on plasma Aß 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 Aß levels were measured. RESULTS: The plasma levels of baseline blood glucose, plasma insulin, and plasma Aß were not different between the two groups. However, immediately after glucose loading, a significant increase in plasma Aß40 and Aß42 levels was observed in AD patients, whereas a mild decrease in plasma Aß40 and Aß42 levels was detected in non-AD dementia patients. CONCLUSION: The present study clearly demonstrated a different response in plasma Aß40 and Aß42 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 Aß level after glucose loading, although further studies are necessary.

Effect of angiotensin II receptor blocker, olmesartan, on turnover of bone metabolism in bedridden elderly hypertensive women with disuse syndrome.

AIMS: Although recent studies suggest that several antihypertensive drugs could reduce the risk of bone fracture, it is still unclear how these drugs act on bone remodeling, especially in elderly women with severe osteoporosis with disuse syndrome. In the present study, we investigated the effects of a calcium channel blocker (CCB) and an angiotensin II receptor blocker (ARB) on bone metabolism in elderly bedridden women with hypertension and disuse syndrome. METHODS: Elderly bedridden women (aged >75 years) receiving antihypertensive therapy treated with CCB were recruited in the present study. The participants were divided into two groups--CCB group and ARB group--and followed up to 12 months. RESULTS: Markers of bone resorption were markedly increased, suggesting accelerated bone resorption in the participants of the present study. In the follow-up period, the patients treated with a CCB showed a significant decrease in bone mineral density in a time-dependent manner, accompanied by a significant increase in bone resorption markers, whereas treatment with olmesartan inhibited bone loss, associated with attenuation of increased bone resorption markers. Bone mineral density of femoral neck in the CCB group was significantly lower than that in the ARB group at 6 months. CONCLUSION: The present study showed inhibitory effects of an ARB on bone resorption in hypertensive patients with accelerated bone resorption, such as elderly bedridden women, and indicated an important role of the renin-angiotensin system in bone metabolism. In elderly hypertensive patients, ARB might be expected to have additional beneficial potential to maintain bone health in bedridden patients.