Objective: This study was designed to evaluate insulin sensitivity, proinflammatory markers and adiponectin concentration in young males with different subtypes of depressive disorder.
Methods: Nonobese young males with depressive disorder (ages between 18 years and 30 years; body mass index, BMI < or = 25 kg/m(2)) were recruited and divided into reactive depression (RD, N = 14), major depression (MD, N = 21) and bipolar depression (BD, N = 15) based on clinical course and symptom changes in Hamilton rating scale for depression (HAM-D). Fourteen age- and BMI-matched healthy males were enrolled as controls. All of the participants received a 75-g oral glucose tolerance test (OGTT). Insulin sensitivity and beta-cell function were calculated by minimal model method from the frequently sampled intravenous glucose tolerance test. Plasma C-reactive protein (CRP), adiponectin, tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were determined.
Results: Compared to the controls, insulin sensitivity (S(I)) were significantly lower in MD and BD (0.78 +/- 0.09 min(-1)/pmol and 0.75 +/- 0.09 min(-1)/pmol vs. 1.09 +/- 0.08 x 10(-5) min(-1)/pmol, P < 0.05, respectively). Acute insulin response (AIR) to intravenous glucose was elevated in BD as compared to control and RD groups (6079.9 +/- 841.8 pmol vs. 3339.8 +/- 356.4 pmol and 3494.8 +/- 337.7 pmol, P < 0.05, respectively). Plasma adiponectin level was diminished in BD group as compared to the control and RD groups (7.41 +/- 0.45 microg/ml vs. 9.07 +/- 0.54 microg/ml and 9.38 +/- 0.46 microg/ml; P < 0.05 and P < 0.01, respectively). By regression analysis, a significantly negative correlation between HAM-D score and S(I) was found in MD (r = -0.60, P = 0.005) and BD groups (r = -0.57, P = 0.04).
Conclusions: The results suggest that there is an inverse relationship between both major and bipolar depression and insulin resistance in nonobese young males.