The relationship between plasma amyloid-β peptides and the medial temporal lobe in the homebound elderly

✍ Scribed by Xiaoyan Sun; Rafeeque Bhadelia; Elizabeth Liebson; Peter Bergethon; Marshal Folstein; Jay-Jiguang Zhu; D. Mkaya Mwamburi; Samuel Patz; Wei Qiao Qiu

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 282 KB
• Volume: 26
• Category: Article
• ISSN: 0885-6230
• DOI: 10.1002/gps.2568

✦ Synopsis

Background:

The ratio of high amyloid-b peptide40 (Ab40) and low Ab42 in plasma predicts the risk of Alzheimer's disease (AD) and is associated with episodic recall in depression. We thus examined the relationship between plasma Ab levels and brain volumes. Methods: Homebound elders (N ¼ 352) who had undergone brain MRI were used. Plasma Ab1-40 and Ab1-42 were measured by ELISA. Volumes of medial temporal regions, including the amygdala and hippocampus, were manually measured. Results: Amygdala volume was associated with log 10 of plasma Ab1-42 (b ¼ þ0.19, SE ¼ 0.07, p ¼ 0.005) after adjusting for AD, infarcts, white matter hyperintensities and demographics. In the absence of dementia, decreasing quartiles of plasma Ab1-42 (Mean þ SD ml: Q4 ¼ 4.1 AE 0.8; Q3 ¼ 3.9 AE 0.7; Q2 ¼ 3.6 AE 0.8 and Q1 ¼ 3.7 AE 0.8, p ¼ 0.01) and increasing quartiles of plasma Ab1-40/1-42 ratio were associated with smaller amygdala volume. Those depressed subjects with a high plasma Ab1-40/1-42 ratio had smaller amygdala (Mean þ SD ml: 3.3 AE 0.8 vs. 3.6 AE 0.8, p ¼ 0.04) and total brain volume (Mean þ SD liter: 0.95 AE 0.07 vs. 1.04 AE 0.12, p ¼ 0.005), and had a higher rate of MCI (67 vs. 36%, p ¼ 0.02) than those with a low plasma Ab1-40/1-42 ratio. Conclusions: The combination of low plasma Ab1-42 concentration and atrophy of the medial temporal lobe structures, which regulates mood and cognition, may represent a biomarker for a prodromal stage of AD.