Abstract
BACKGROUND: Weight loss is a frequently occurring problem in patients with lung cancer due to an increased resting energy expenditure (REE) and a decreased energy intake. The aim of the present study was to compare the metabolic and inflammatory characteristics of patients with small cell lung carcinoma (SCLC) and non-small cell lung carcinoma (NSCLC). The metabolic parameters of the lung cancer population were compared with those of a healthy control group. METHODS: REE was measured in 66 patients with lung cancer, subdivided according to their histology, and in 33 healthy controls matched for sex, age, and fat free mass (FFM). Inflammatory mediators were measured in the plasma of the patients with lung cancer. RESULTS: An increased REE adjusted for FFM was found in the patients with lung cancer. Those with small cell lung carcinoma (SCLC) had an increased REE adjusted for FFM (mean 1925 kcal/day) compared with those with non-small cell lung carcinoma (NSCLC) (mean 1789 kcal/day, 95% CI for difference 36 to 236). FFM accounted for 69% and 48% of the inter-individual variation in REE in controls and those with NSCLC, respectively, while FFM accounted for only 25% of the variation in REE in patients with SCLC in whom the fat mass (FM) also contributed significantly (28%) to the variation in REE. Increased concentrations of soluble TNF-receptor 75 (sTNF-R75) and cortisol were found in patients with SCLC compared with those with NSCLC. Lipopolyasccharide binding protein (LBP) and sTNF-R55 were related to plasma levels of cortisol. CONCLUSION: An enhanced REE adjusted for FFM occurred in patients with SCLC compared with those with NSCLC.