In vitro mononuclear cell production of tumour necrosis factor-alpha and weight loss

Abstract

<h4>Objective</h4>Elevated tumour necrosis factor-alpha (TNF-alpha) production in adipose tissue has been associated with obesity. We investigated whether mononuclear cell production of TNF-alpha decreased with weight loss in an obese population.<h4>Research methods and procedures</h4>Seventeen obese patients with type 2 diabetes (BMI 32.5+/-0.9 kg/m(2)) and 33 obese, non-diabetic controls (BMI 31.2+/-0.5 kg/m(2)) underwent 12 weeks of 30% total energy restriction (6622+/-84 KJ per day). Every 4 weeks, weight and blood pressure were measured and fasting venous blood was analysed for lipid, glucose and insulin concentrations. At the beginning and end of energy restriction, mononuclear cells were isolated from whole blood and TNF-alpha production measured by ELSIA.<h4>Results</h4>TNF-alpha production was not associated with the degree of adiposity but was higher in diabetic subjects (P<0.04). There was a reduction after energy restriction (281+/-43 to 182+/-30 pg/ml, P<0.05) however the presence of type 2 diabetes did not influence the magnitude of this change. Plasma glucose and insulin levels decreased after weight loss in all subjects and weak correlations were found with TNF-alpha concentrations (r=0.3, P<0.05).<h4>Conclusions</h4>We conclude that maximal production of TNF-alpha from mononuclear cells decreases with energy restriction and is weakly associated with plasma glucose and insulin concentrations in obese patients.