Serum soluble urokinase plasminogen activator receptor in adolescents: interaction of chronic pain and obesity.

Abstract

Obesity in adolescents is increasing in frequency and is associated with short-term and long-term negative consequences that include the exacerbation of co-occurring chronic pain. To determine whether the interaction between chronic pain and obesity would be reflected in changes in serum soluble urokinase plasminogen activator receptor (suPAR) concentrations, a novel marker of systemic inflammation associated with obesity, insulin resistance, and cardiovascular disease. We measured serum suPAR levels in 146 adolescent males and females with no pain or obesity (healthy controls; n = 40), chronic pain with healthy weight (n = 37), obesity alone (n = 41), and the combination of chronic pain and obesity (n = 28). Serum suPAR (median [interquartile range]) was not increased by chronic pain alone (2.2 [1.8-2.4] ng/mL) or obesity alone (2.2 [2.0-2.4] ng/mL) but was increased significantly with the combination of chronic pain and obesity (2.4 [2.1-2.7] ng/mL; P < 0.019). This finding confirms the proposition that pain and obesity are inflammatory states that display a classic augmenting interaction. We propose that measurement of serum suPAR can be added to the armamentarium of serum biomarkers useful in the evaluation of mechanisms of inflammation in adolescent obesity and chronic pain.