Circulating leptin and the trophological status of patients with chronic obstructive pulmonary disease

AIM: To study the specific features of the nutritional status of patients with persistent chronic obstructive pulmonary disease (COPD) in relation to the hormone-regulating function of energy exchange in terms of leptin and to concurrently evaluate the functional status of fat and protein digestion and absorption and to measure body fat percentage. To assess the influence of these factors on the regulation of the serum concentration of leptin and its potential role in the development of trophological insufficiency in patients. SUBJECTS AND METHODS: In 93 patients with COPD (Stages I, II, and III in 22, 36, and 35 patients, respectively, the nutritional status was evaluated by somatometric methods. The concentration of leptin was measured by enzyme immunoassay using a test system (DSL, USA). Absorption was estimated by biochemical studies and by using radionuclides. Body fat content was determined, by measuring bioelectric impedance with an OmRon BF-302 apparatus (Japan). RESULTS: Protein and fat absorption was decreased in patients with moderate and mainly severe COPD as compared with that in the control group and correlated with body weight deficit and lower body fat percentage. Decreased leptin levels were detected in Stages II-III COPD and correlated with the degree of the disease and reduced protein (r = 0.68 +/- 0.02) and fat (r = 0.64 +/- 0.18) absorption. CONCLUSION: Protein and fat absorption impairments correlating with body weight deficit in patients with COPD underline the significant role of this mechanism in the development of trophological insufficiency. In COPD patients with trophological insufficiency, the lower circulating leptin levels that correlate with impaired absorption of fatty acids and protein characterize the pathogenetic role of secondary malabsorption syndrome in leptin-mediated impairments of energy exchange mechanisms. Functional insufficiency of the hormone-regulating mechanism responsible for energy exchange in terms of leptin in patients with Stages II-III COPD gives warning of the insufficient stock of adipose tissue and its reduced energy reserve.