Depression and Plasma Amyloid beta Peptides in the Elderly With and Without the Apolipoprotein E4 Allele

作者：Sun Xiaoyan; Chiu Chi Chia; Liebson Elizabeth; Crivello Natalia A; Wang Lixia; Claunch Joshua; Folstein Marshal; Rosenberg Irwin; Mwamburi D Mkaya; Peter Inga; Qiu Wei Qiao^*

来源：Alzheimer Disease and Associated Disorders, 2009, 23(3): 238-244.

DOI：10.1097/wad.0b013e31819cb3ac

• depression
• ApoE4
• amyloid-beta peptide
• plasma
• cognition

Depression associated with low plasma amyloid-beta peptide 42 (A beta 42) leading to a high ratio of A beta 40/A beta 42 a biomarker of Alzheimer disease (AD), may represent a unique depression subtype. The relationship between low plasma A beta 42 in depression and the major risk factor of AD, apolipoprotein E4 (ApoE4), is unknown. With the goal of clarifying this relationship, we analyzed 1060 homebound elders with ApoE characterization and depression status in a cross-sectional study. Plasma A beta 40 and A beta 42 were measured, and cognition were evaluated. In the absence of the ApoE4 allele, depressed subjects had lower plasma A beta 42 [median (Q1, Q3): 17.1 (11.6 27,8) vs. 20.2 (12.9, 32.9) pg/mL, P = 0.006], a higher A beta 40/A beta 42 ratio [median (Q1, Q3): 7.1 (4.6, 11.3) vs. 6.9 (3.4, 9.7) P = 0.03], and lower cognitive mean +/- SD of Mini-Mental State Examination: 24.5 +/- 3.1 vs. 25.5 +/- 3.3. P < 0.0001) than those without depression. In contrast, these relationships were not observed in the presence of ApoE4. Instead, regardless the depression status ApoE4 carriers had lower plasma A beta 42 and a higher A beta 40/A beta 42 ratio than non-ApoE4 carriers. Using multivariate logistic regression, it was found that depression was not associated with ApoE4 allele, but with the interaction between plasma A beta 42 and ApoE4 (odds ratio = 3.94, 95% confidence interval = 1.50, 10.33, P = 0.005), denoting low plasma A beta 42 in the absence of ApoE4. Both ApoE4 carriers and non-ApoE4 carriers with depression had lower A beta 42 and a higher A beta 40/A beta 42 ratio in plasma compared with non-ApoE4 carriers Without depression in the homebound elderly. As a combination of low plasma A beta 42 and high plasma A beta 40 has been shown to increase the risk of AD in 2 large cohort studies, amyloid-associated depression shown in this study may suggest a risk factor of AD in the absence of ApoE4.

• 出版日期2009-9