Male gender, snoring, ESS score > 10, BDI score ≤ 8, BDI score > 8 & <16, ISI score < 15, ISI score ≥ 15 & <21, metabolic syndrome, alcohol consumption, lower maintenance insomnia complaint, age ≥ 50 & <65 years, age ≥ 65 years, BMI ≥25 & <30 kg/m2, BMI >30 kg/m2, and CRP >7 mg/L were associated with an increased risk of moderate to severe OSA in insomnia sufferers. The gene discussed is CRP; the disease is obstructive sleep apnea syndrome.