Increased levels of adipokines in bipolar disorder

Bipolar disorder (BD) is associated with considerable higher chronic medical comorbidities, overweight and obesity. Adipokines are adipocyte-derived secretory factors which have functions in immune response and seem to be associated with both BD and overweight. The aim of this study was to evaluate the plasma levels of adipokines (adiponectin, resistin and leptin) and TNF-α and its receptors (sTNFR1 and sTNFR2) in BD overweight patients in comparison with overweight controls. Thirty euthymic BD type-I patients and thirty controls matched by age, gender and body-mass index (BMI) were assessed by Mini-International Neuropsychiatric Interview, Young Mania and Hamilton Depression rating scales (YMRS and HDRS, respectively). Plasma levels of adiponectin, resistin, leptin, TNF-α and its soluble receptors were measured by ELISA. BD patients presented increased plasma levels of adiponectin (p < 0.001), leptin (p < 0.001) and sTNFR1 (p = 0.01). Plasma levels of adipokines were not correlated neither with clinical parameters nor TNF-α, sTNFR1 and sTNFR2 plasma levels. This study provides further support to the hypothesis of the immune/inflammatory imbalance in BD.