Table 1 Implications of obesity and the relationship with asthma. Obese asthmatics have multiple consequences related to excess adipose tissue, including mechanical or physiologic effects on lung function and the airways as well as changes in the immune response and metabolic effects. The combination of these alterations contributes to the phenotypic characteristics of the obese asthmatic
From: Asthma and obesity: mechanisms and clinical implications
Mechanical or physiologic effects | Lung function | • Restriction or reduced total lung capacity and decreased expiratory reserve volume |
• Ventilation and perfusion mismatch | ||
Airways Changes | • Bronchial hyperresponsiveness | |
• Loss of beep breath induced bronchodilation | ||
• Reduced exhaled NO (certain phenotypes) | ||
Immune and metabolic effects | Immune function | • Decreased airway eosinophils (lumen, sputum) |
• Increased airway neutrophils | ||
• Predominately Th-1 related inflammation versus Th-2 | ||
• Potential IL-17 related inflammation | ||
• Enhanced inflammatory/oxidative response to elevated leptin levels | ||
Metabolic function | • Higher plasma and airway leptin levels with reduced airway leptin receptors | |
• Leptin receptors in visceral fat and relationship with bronchial hyperresponsiveness | ||
• Leptin may increase oxidative stress levels | ||
• Effect of adiponectin remains unclear | ||
• Lower L-arginine/ADMA ratio and increase in oxidative stress resulting in an impaired bronchial dilatory response |