Association between Oxidative Stress and Depressive Symptom Score

Abstract

Objectives Previous epidemiological studies about oxidative stress and depression are limited by hospital-based case-control design, single time measurement of oxidative stress biomarkers, and small number of study participants. Therefore in this study, we analyzed the association between biomarker of oxidative stress and scores of depressive symptom using repeatedly measured panel data from community dwelling elderly population. Methods From 2008 to 2010, a total of 478 elderly subjects residing in Seoul, Korea, were evaluated 3 times. Subjects underwent the Korean Version of the Short Form Generic Depression Scale test (SGDS-K) for screening depression and urinary malondialdehyde (MDA) level was measured as oxidative stress biomarker. We used generalized estimating equation with compound symmetry covariance structure to estimate effects of oxidative stress on depressive symptom scores. Results A two fold increase in urinary MDA concentration were significantly associated with 33.08% (95% confidence interval (CI): 21.59%, 47.42%) increase of total SGDS-K score. In subgroup analyses by sex, a two fold increase in urinary MDA concentration were significantly associated with increased SGDS-K score in both men and women. (Men: 30.88%, 95%CI: 10.24%, 55.37%

Women: 34.77%, 95%CI: 20.09%, 51.25%) In bivariate analysis after the SGDS-K score ≥ 8 was defined as depression, the third and the fourth urinary MDA quartile showed significantly increased odds ratio of depression compared to the lowest urinary MDA quartile. (Third quartile, OR: 6.51, 95%CI: 1.77-24.00

Fourth quartile, OR: 7.11, 95%CI: 1.99-25.42) Conclusion In conclusion, our study suggests significant association between oxidative stress and depressive symptoms in elderly population.