Our analysis revealed that participants with both periodontitis and diabetes mellitus had 2.73 times higher odds of being classified in the high-risk hs-CRP category (>3.0 mg/L) (adjusted OR 2.73; 95% CI: 1.64–4.54), suggesting that the coexistence of these conditions substantially increases systemic inflammation and may critically elevate cardiovascular risk. This evidence concerns the gene MAP3K14 and diabetes mellitus.