The correlation between adiposity and adiponectin, tumor necrosis factor α, interleukin-6 and high sensitivity C-reactive protein levels. Is adipocyte size associated with inflammation in adults?

Abstract

Hypertrophic obesity correlates with metabolic complications of obesity. We evaluated adipocyte volume and its relationship with tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), adiponectin and high sensitivity C-reactive protein (hs-CRP) levels. Patients were divided into 4 groups; lean healthy controls [body mass index (BMI): 24.2+/-1.4 kg/m2], non-diabetic obese patients (30.2+/-2.9), obese (30.1+/-3.2) and non-obese (22.2+/-1.5) Type 2 diabetic patients. TNF-alpha, hs-CRP, adiponectin and IL-6 levels were measured preoperatively and sc fat specimens were obtained during operation. Semi-thin sections were stained with toluidine-blue and evaluated by light microscopy. Fat volumes were calculated by Goldrick's formulation. Mean adipocyte volumes were higher in obese diabetic patients than in other groups (p<0.0001). Mean TNF-alpha, hs-CRP and IL-6 levels were higher in obese diabetic patients than in control subjects, obese non-diabetic and non-obese diabetic patients (p<0.0001, p<0.02 and p<0.01, respectively). Mean TNF-alpha levels of non-diabetic obese patients were higher than the control group (p<0.05). Mean IL-6 levels of diabetic and non-diabetic obese patients were higher than control subjects (p<0.02 and p<0.0001, respectively). Mean adiponectin levels of control subjects were higher than non-diabetic obese, non-obese diabetic and obese-diabetic subjects (p<0.0001). Mean adiponectin levels of obese diabetic patients were lower than non-diabetic obese subjects (p<0.008). Mean hs-CRP levels were higher in diabetic patients whether they were obese or not. There was a positive correlation between adipocyte size and TNF-alpha (p<0.01), IL-6 (p<0.03) and hs-CRP levels (p<0.004), and negative correlation between adipocyte size, adiponectin levels (p<0.0001). TNF-alpha, IL-6 and hs-CRP levels were positively, adiponectin negatively correlated with adipocyte size. Therefore, adiposity may be an inflammatory condition.