Obesity and asthma: possible mechanisms

Area of Science:

• Pulmonology
• Immunology
• Endocrinology

Background:

• Epidemiologic studies show obesity elevates asthma incidence and prevalence, while impairing asthma control.
• Obese mice display inherent airway hyperresponsiveness and heightened reactions to asthma triggers, supporting the obesity-asthma link.

Purpose of the Study:

• To explore the multifaceted mechanisms linking obesity to asthma.
• To identify how obesity-related physiological and inflammatory changes impact asthma development and severity.

Main Methods:

• Review of existing epidemiologic data and preclinical findings.
• Discussion of proposed pathophysiological pathways, including mechanical, inflammatory, hormonal, and comorbidity-related factors.

Main Results:

• Obesity reduces lung and tidal volumes, promoting airway narrowing.
• Low-grade systemic inflammation and altered adipose-derived hormones (leptin, adiponectin) in obesity may exacerbate lung inflammation.
• Obesity comorbidities like GERD, sleep apnea, and diabetes can worsen asthma control.
• Shared etiologies, including genetics and in utero exposures, may link obesity and asthma.

Conclusions:

• Multiple mechanisms, including mechanical changes, systemic inflammation, hormonal alterations, comorbidities, and shared etiologies, connect obesity and asthma.
• Further understanding of these mechanisms is crucial for developing targeted therapies for obese asthma patients.