Serum and exhaled condensate leptin levels in asthmatic and obese children: a pilot study

Leptin acts as a lypostate: when the amount of fats stored in the adipocytes increases leptin is released into the bloodstream. This constitutes a negative feedback signal for the hypothalamus, which responds by releasing anorexigenic peptides. Studies on murine models and in humans as well demonstrated that a lack of leptin promotes obesity. However, plasma leptin concentrations are higher in obese than in normal weight subjects, suggesting that human obesity is a leptin resistance condition.Therefore, it has been hypothesized a potential role for leptin also in airway inflammation, contributing to explain the potential link between obesity and asthma. Recent studies have highlighted the possible involvement of leptin in inflammation. Leptin receptor is also expressed by alveolar macrophages, T lymphocytes and bronchial epithelial cells, thus suggesting a possible role of this protein in the cascade of the airway inflammation. At present, no data are available on the potential relationship between leptin concentration in the airways and asthma.