In insomnia sufferers, risk factors obtained by the method of automatic selection (stepwise backward) that were associated significantly with an increased risk of moderate to severe OSA included male gender, snoring, lower maintenance insomnia complaint, ESS score > 10, metabolic syndrome, age ≥ 50 & <65 years, age ≥ 65 years, BMI ≥25 & <30 kg/m2, BMI >30 kg/m2, and CRP >7 mg/L. The gene discussed is CRP; the disease is obstructive sleep apnea syndrome.