Adiponectin is an adipokine that has recently been under investigation for potential neuroprotective effects in various brain disorders including Alzheimer's disease, stroke, and depression.
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.
Conversely, serum adiponectin showed a negative correlation with and body weight gain, TG, AI as well as CRI, but showed a positive correlation with locomotor activity, exploration, declined memory, and depression- and anxiety-like behavior.
In T2D, IL-18 and IL-1RA were positively associated with depression for two scores (IL-18: PHQ-9, WHO-5; IL-1RA: CES-D, WHO-5), hsCRP was associated with one depression score (PHQ-9), and adiponectin showed an inverse association with one depression score (PHQ-9) after adjustment (P = 0.006-0.048).
Despite these controversies, adiponectin is gaining attention as a potential therapeutic target for diverse CNS disorders, such as stroke, Alzheimer's disease, anxiety, and depression.
Small clinical studies suggest depression is associated with alterations in adiponectin and leptin, adipocyte-derived secretory proteins involved in metabolic regulation; however, longitudinal data on these association are lacking.
Indeed, clinical studies found altered concentration of adiponectin both in plasma and cerebrospinal fluid in several pathologies including depression, multiple sclerosis, Alzheimer's disease and stroke.
The relationship between serum serotonin concentration and depression is well known, but there are no enough data regarding the serum change of leptin and adiponectin.
More interestingly, increases in adiponectin levels following Qigong exercise were associated with decreases in depression scores for the Qigong group (r = -0.38, p = 0.04).
The female T allele carriers of adiponectinrs1501299 had lower prevalence of depression (p=0.008) and BDI scores (p=0.024) than the female GG homozygotes at 18 months, but not at 6 or 12 months after the earthquake, which were significantly reduced (p=0.022 for the prevalence and p<0.001 for the scores) in the female T allele carriers at 18 months after the earthquake when compared with those at 12 months.