Clinical Differences between Early- and Late-Onset Asthma: A Population-Based Cross-Sectional Study.

Area of Science:

• Pulmonology
• Allergy and Immunology
• Clinical Medicine

Background:

• Limited research exists on late-onset asthma (LOA) without medication compared to early-onset asthma (EOA).
• Understanding the differences in clinical and pathophysiological features between EOA and LOA is crucial.

Purpose of the Study:

• To investigate and compare the clinical and pathophysiological characteristics of EOA and LOA.
• To identify distinct features of LOA in relation to EOA and chronic obstructive pulmonary disease (COPD).

Main Methods:

• A population-based cross-sectional study was conducted involving adults diagnosed with cough, sputum, or chest tightness.
• Patients were categorized into EOA (diagnosis before age 40) and LOA (diagnosis after age 40).
• Clinical variables, including allergic features and blood cell counts, were analyzed and compared between groups.

Main Results:

• LOA exhibited significantly lower spirometry values (FEV1/FVC, FEV1% predicted, FVC% predicted) compared to EOA.
• Mite sensitization was more common in EOA, while mold sensitization was more prevalent in LOA.
• Blood eosinophils were elevated in both EOA and LOA compared to COPD, and blood basophils were increased in both asthma groups compared to controls.

Conclusions:

• Late-onset asthma (LOA) is a distinct clinical entity separate from early-onset asthma (EOA).
• LOA is characterized by less frequent atopy and lower spirometry values compared to EOA.
• Significant correlations between blood basophils and eosinophils were observed in EOA, indicating different pathophysiological mechanisms.