Circulating leptin and body composition in chronic obstructive pulmonary disease

Abstract

Nutritional depletion and weight loss are two features of chronic obstructive pulmonary disease (COPD), and the association between low body mass index (BMI) and poor prognosis in patients with COPD is a common clinical observation. Mechanisms of weight loss are still unclear in COPD. Excessive energy expenditure partly due to increased work of breathing was shown, but other mechanisms have been searched for. Leptin is a hormone secreted by adipocytes that plays an important role in energy homeostasis and regulates body weight through control of appetite and energy expenditure. The aim of this study was to evaluate the association of circulating leptin levels and measures of body composition in COPD patients. Thirty male COPD outpatients (mean age 66.3 +/- 8.4) and 20 controls (mean age 65.9 +/- 10.8) were included in the study. After standard spirometry and body composition measurements, serum leptin concentration was measured by ELISA assay. COPD patients were grouped according to BMI. Mean BMI was 19.01 +/- 2.26 kg/m2 in group 1 (COPD patients with low BMI), 26.85 +/- 4.51 in group 2 COPD (COPD patients with normal/high BMI) and 27.64 +/- 2.75 kg/m2 in healthy controls (group 3). Mean serum leptin concentration was 1.41 +/- 1.86 ng/ml in group 1, 2.60 +/- 1.38 ng/ml in group 2 and 2.82 +/- 1.46 ng/ml in group 3 (p = 0.002). Leptin correlated to not only BMI but also body weight, waist circumference, triceps and biceps skinfold thickness and body fat percent (p < 0.05 for all). Results of this study suggest that the cause of weight loss is not increased circulating leptin in COPD. Instead, leptin remains regulated in COPD and further decreased in patients with low BMI, probably as a compensatory mechanism to preserve body fat content, which should be evaluated in further studies.

The Relation of Weight Loss with Hyperinflation, Serum Adiponectin, Ghrelin and Leptin Levels in Chronic Obstructive Pulmonary Disease

“…Comparison of body composition, endocrine and biochemical parameters according to the presence of hyperinflation associated with a decrease in body mass index and lean body mass. In addition, it supports the notion that weight loss in COPD patients does not lead to an increase in circulating leptin levels but contrarily leptin remains at certain levels as compensatory mechanism to preserve lean body mass in COPD patients (14).…”

“…In another study serum leptin levels were found to be low in COPD patients with a low BMI (14). Moreover, it was claimed that weight loss in COPD patients does not cause an increase in leptin levels, but contrarily leptin remain at certain levels as a compensatory mechanism to preserve lean body mass in COPD patients (14).…”

Circulating Leptin Concentrations in Patients with Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

“…Likewise, in our meta-analysis, circulating leptin levels were correlated with nutritional parameters in COPD patients. Four articles [17,30,35,44] reported that circulating leptin levels decreased in COPD patients with lower BMI compared to healthy controls, which was not consistent with the small study of Takabatake et al [31], who reported that no difference was found between stable COPD patients and healthy controls. In addition, there was no difference in either circulating leptin levels or BMI between noncachexic COPD patients and healthy controls.…”

Effects of Lung Volume Reduction Surgery for Emphysema on Glycolipidic Hormones*

“…24 The chronic elevation of inflammatory cytokine levels, which disrupts normal hormonal secretion and peripheral tissue substrate metabolism, is the main cause of such alterations. 25 Several reports 26 have described reduced leptin levels in stable patients compared to control subjects, in accordance with a low body mass index and FM. On the contrary, leptin levels appeared to be increased and directly correlated to inflammatory cytokine levels, causing nutritional decay, in unstable or exacerbated patients.…”