Differential effects of white matter hyperintensity on geriatric depressive symptoms according to APOE-ε4 status.

Background: We aimed to examine differential effects of WMH on progression of depressive symptoms according to APOE ε4 status in the elderly.
Methods: We obtained data from elderly Korean subjects (n=707) aged 60 years or older at baseline from the CREDOS study from November 2005 to July 2014. A linear mixed model stratified according to APOE genotype (APOE ε4 carrier vs. non-carrier) was constructed using GDS score as a primary outcome and degree of overall, deep, periventricular WMH evaluated by a visual rating scale as a risk factor of interest. We also tested interaction between APOE ε4, WMH and time as predictors of clinical progression on GDS scores to examine the moderating effect of APOE ε4 allele on the relationship between degree of WMH and progression of geriatric depressive symptoms.
Results: The mean (SD) follow-up duration of the participants was 2.0 (0.8) years. Among APOE ε4 carriers, a severe degree of overall and deep WMH, but not periventricular WMH, predicted progression of geriatric depressive symptoms (overall WMH: coefficient=0.96, p=0.010; deep WMH: 0.87, p=0.016). There were significant interaction between APOE ε4, degree of WMH and time in predicting GDS increase (5df, F=2.28, p=0.046).
Limitations: Only subjects seeking medical attention and with follow-up measurements were enrolled in this study. Specific location of WMH and use of antidepressant were uncontrolled.
Conclusions: Considering biological markers such as degree of WMH and APOE ε4 status may be clinically relevant to predicting progression of geriatric depressive symptoms.
(Copyright © 2015 Elsevier B.V. All rights reserved.)