Activation of TNF-α System by Hypoxia in COPD Patients and Its Correlation with Malnutrition

ObjectivesTo investigate the correlation between hypoxia activating the tumor necrosis factor α(TNF α) system in patients with chronic obstructive pulmonary disease (COPD) and their malnutrition as well as to explore the pathogenesis.MethodsTwenty seven COPD patients in stable stage and 29 healthy controls were studied. COPD patients were divided into two groups :①Group I, 12 malnourished cases and ②Group II, 15 cases without malnutrition. Serum levels of soluble TNF receptor 55(sTNF R55), body mass index (BMI), percentage of normal body weight (NW%), percentage of body fat (fat%),mid upper arm circumference (MAC),serum albumin levels(ALB) and total lymphocyte counts(LYM) were measured. Arterial blood gas analysis was carried out in COPD patients. Serum sTNF R55 levels were detected by enzyme linked immunosorbent assay (ELISA). The correlations between serum sTNF R55 levels and arterial blood partial pressure of oxygen (PO 2) /nutritional parameters were analyzed.Results①BMI, NW%, fat%, MAC, ALB and LYM in stable COPD patients were significantly lower than those in healthy controls (P0.01) , whereas their serum sTNF R55 levels were significantly higher than those in healthy controls(P0.05) ; ②The age and serum sTNF R55 levels in Group I were distinctly higher than those in healthy controls(P 0.05 ), while their BMI, NW%, fat% ,MAC, ALB and LYM were obviously lower than those in healthy controls and Group Ⅱ(P0.01 ). ③A significant negative correlation existed between serum sTNF R55 levels in Group I and results of their PO 2 , BMI, NW%, fat% and ALB (P0.05); ④Serum sTNF R55 levels in COPD patients were positively correlated with their age, but this was not found in healthy controls.ConclusionHypoxia may activate the TNF α system in COPD patients and takes part in the development of malnutrition.