PP-299 : Leukocyte mitochondrial DNA content is associated with depression in community dwelling older women.

Moo Young Kim, Ji Won Lee, Choon Ok Kim, Kwang Shik Park, Seung Beom Lee, Won Yong Kim, Duk Chul Lee, Republic Of Korea
Depression and suicide in older adults are serious social problems. In an animal model of depression, which is induced by chronic stress, brain mitochondrial function is decreased. The purpose of this study is to investigate whether the mitochondrial DNA content in peripheral blood is related to depression in community dwelling older women.

This study was conducted with Yonsei Cognitive ageing Study data. We analysed the data of 142 older women who were able to independently carry out daily life activities. Mitochondrial DNA (mtDNA) copy numbers were measured using real-time PCR methods. Depression was assessed by the 15-item geriatric depression scale (GDS), and cognitive function was examined by the Mini-Mental State Examination. Depressive cases defined as the subjects whose GDS score was = 6 or who were taking anti-depressant medication. We also measured physical performances (gait speed, chair-stand times, tandem standing times), metabolic and endocrine factors.

The depression group had a significantly lower mtDNA copy number than the control group (81.1(43.6~130.0) vs 113.8(46.5~215.6), P=0.034). And MMSE score and physical performance score were significantly lower in the depression group than the control group (respectively, 23.8 ± 3.89 vs 25.2 ± 3.71, P=0.027; 7.0 ± 2.16 vs 8.1 ± 2.56, P=0.006). After adjustment for confounding factors using logistic regression analysis, mtDNA copy number was significantly related to depression (odds ratio 0.49, P=0.034).

We demonstrated that low leukocyte DNA content is related to depression in older women. It is suggested that mitochondrial dysfunction may be a mechanism of geriatric depression.