TNF and airway hyperresponsiveness: To date, it is not known whether this association is mechanical, related to an asthma inflammatory mechanism due to fat accumulation in the abdomen limiting diaphragm movement [28,29] or inflammatory related to the action of leptin and other cytokines such as IL-6 and TNF-alpha produced by visceral fat [39], that are possibly capable of increasing airway hyperresponsiveness in obese asthmatics [42].