Sixteen patients with newly diagnosed stages I-III NSCLC having <10%weight loss and ten healthy controls were studied. Body composition, systemic inflammation and exercise capacity were assessed in all subjects and NF-魏B and UPS activity in vastus lateralis muscle biopsies in a subset.
Patients showed increased plasma levels of C-reactive protein (CRP) (P < 0.001), soluble Tumor Necrosis Factor receptor 1 (sTNF-R1) (P < 0.05), fibrinogen (P < 0.001) and decreased levels of albumin (P < 0.001). No changes in fat free body mass or skeletal muscle NF-魏B and UPS activity were observed, while peak oxygen consumption () was significantly decreased in patients compared with healthy controls.
In conclusion, this exploratory study demonstrates significantly reduced exercise capacity in NSCLC pre-cachexia despite maintenance of muscle mass and unaltered indices of UPS activation. The absence of muscular NF-魏B-dependent inflammatory signaling supports the notion that transition of systemic to local inflammation is required to initiate UPS-dependent muscle wasting characteristic for (experimental) cachexia.