title: Plasma Amyloid-β Peptides and Homocysteine in Depression in the Homebound Elderly.
abstract: Both plasma amyloid-β peptide 40 (Aβ40) and homocysteine (tHcy) are linked to vascular disease, which is related to depression in the elderly. We sought to study whether the relationship between tHcy and plasma Aβ40 differs in those with and without depression.
  
  
  
  In a cross-sectional study of 1058 homebound elders, vascular depression was defined as a score ≥ 16 on the Center for Epidemiological Studies Depression scale (CES-D) along with self-reported cardiovascular disease (CVD). Plasma Aβ40 and Aβ42, and serum tHcy and creatinine were measured.
  
  
  
  Elders with high tHcy had higher concentrations of plasma Aβ40 (median: 147.5 vs. 123.1 pg/ml, P < 0.0001) and Aβ42 (median: 20.2 vs. 16.6 pg/ml, P < 0.0001) than those with low tHcy. In elders with depression, the relationship between logarithm of plasma Aβ40 (LogAβ40), but not LogAβ42, and tHcy was significant (β = +0.010, SE = 0.004, P = 0.007); in contrast, this relationship was not observed in those without depression. Subjects with vascular depression had the highest concentration of tHcy (mean ± SD: 12.8 ± 4.6 vs. 11.7 ± 4.5 vs. 11.9 + 5.5, P = 0.008) compared to those without CVD and those without depression. Depressed subjects without CVD had the lowest concentration of plasma Aβ42 (median: 15.5 vs. 19.1 vs. 18.7, P = 0.01) compared to those with CVD and those without depression.
  
  
  
  Vascular depression, which is associated with tHcy and Aβ40 in blood, appears to be different from depression that is associated with low plasma Aβ42. This suggests that reducing tHcy and Aβ40 may be an adjunct treatment for vascular depression.
authors.affiliation: Department of Psychiatry, Tufts-New England Medical Center, Tufts University School of Medicine ; Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy at Tufts University ; Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA).
authors.forename: Wei Qiao
authors.initials: WQ
authors.lastname: Qiu
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Sun
authors.forename: D Mkaya
authors.initials: DM
authors.lastname: Mwamburi
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Haker
authors.forename: David
authors.initials: D
authors.lastname: Lisle
authors.forename: Abishek
authors.initials: A
authors.lastname: Rizal
authors.forename: Yu-Min
authors.initials: YM
authors.lastname: Lin
authors.forename: Liyan
authors.initials: L
authors.lastname: Qiao
authors.forename: Paul
authors.initials: P
authors.lastname: Summergrad
authors.forename: Marshal
authors.initials: M
authors.lastname: Folstein
authors.forename: Irwin
authors.initials: I
authors.lastname: Rosenberg
keywords: Aβ; Depression; Homocysteine