With regard to the associations of lung function and inflammatory factors with LRTIs, increased FEV1 (OR per SD = 0.80 [95% CI: 0.73, 0.88]) and FVC (OR per SD = 0.87 [95% CI: 0.79, 0.95]) lowered the risk of acute bronchitis, while elevated CRP augmented the risk. The gene discussed is CRP; the disease is Acute bronchitis.