Compared with the participants without periodontitis and CRP levels of ≤ 0.5 mg/dL, the participants with periodontitis and those with CRP levels of > 0.5 mg/dL had higher HRs (1.38, 95% CI, 1.08–1.75 for periodontitis only; 1.23, 95% CI, 0.97–1.55 for CRP > 0.5 mg/dL only), and the participants with both periodontitis and CRP levels of > 0.5 mg/dL had the highest HR (2.01, 95% CI, 1.42–2.84). The gene discussed is CRP; the disease is periodontitis.