Association of up-regulated plasma adiponectin with risk of incident depression in a community-dwelling elderly population

Objective: Despite robust interest in the association between inflammation and depression, anti-inflammatory markers have been scarcely investigated as predictors of the future risk of depression. The aim of this study is to determine whether up-regulation of plasma adiponectin, an anti-inflammatory adipokine, precedes and predicts the development of depression in the elderly. Methods: This prospective cohort study was launched in 2005. Among 1,000 participants who were randomly sampled from community-dwelling individuals 65 years or older, 633 euthymic individuals without prior history of depressive disorders were enrolled for a baseline evaluation and follow-up after 5 years. Incident clinically significant depression, including major and minor depressive disorders (by DSM-IV criteria), subsyndromal depression (by operational criteria), and euthymia after antidepressant treatment, was assessed by clinical interviews. Results: Baseline plasma adiponectin values were divided into tertiles (low tertile: ≤ 5.685 μg/mL, middle tertile: 5.686-10.367 μg/mL, high tertile: ≥ 10.368 μg/mL). Among the 261 euthymic individuals who responded to the 5-year follow-up evaluation, 17 developed incident depression (7 from the high tertile, 8 from the middle tertile, and 2 from the low tertile). The risk of incident depression was much higher in the high tertile group than in the low tertile group after adjusting for age, sex, body mass index, burden of chronic medical illnesses, and Mini-Mental State Examination score (odds ratio = 10.64; 95% CI, 1.21-93.84; P = .033). Conclusions: Up-regulation of plasma adiponectin may precede the onset of clinically significant depression in the elderly, and thus plasma adiponectin level is a potential candidate marker for the risk of depression.