[Leptin and activity of tumor necrosis factor alpha relations with parameters of the trophologic status and digestion in patients with chronic obstructive pulmonary disease].

OBJECTIVE

To study effects of leptin regulation of energy and activity of TNF-alpha on the trophologic status and digestion of main nutrients in patients with stable chronic obstructive pulmonary disease (COPD).

METHODS

Somatometric methods were used to examine trophologic status in 93 patients with stable COPD. Of them, 22 had stage I, 36 - stage II, 35 patients - stage III. Serum leptin was measured with enzyme immunoassay (EIA) using DSL kit (USA), TNF-alpha and receptors sTNF-R55 and -R75 with EIA (kits BioSource, Belgium). The absorption was assessed biochemically and with radionuclide investigation. Body fat was estimated by bioelectric impedance (OmRon BF-302, Japan).

RESULTS

The level of circulating leptin decreased with progression of COPD and correlated with body fat depletion (r = 0.88 +/- 0.12). Activation of the TNF-alpha system was detected in the presence and progression of trophologic insufficiency (TI) in patients with COPD stage II and III. A correlation was found between an elevated level of circulating TNF-alpha and enhanced fat and 131-I-albumin excretion, subnormal excretion of D-xylose.

CONCLUSIONS

Low blood serum leptin concentration in patients with moderate and severe stable COPD correlates with fat tissue depletion reflecting reduced energetic potential of adipocytes. High TNF-alpha concentration in the serum was seen only in TI and its progression. This evidences for cytokine involvement in induction of metabolic disorders in COPD patients. Elevated concentration of circulating TNF-alpha closely correlated with excretion of higher quantities of fats, protein, low excretion of D-xylose and proves its involvement in TI development in COPD patients. Activation of TNF-alpha system in COPD does not influence leptin concentration in blood serum as it functions as an independent physiological system.