After adjusting for potential confounding factors (age, gender, smoking, diabetes, hypertension, creatinine, uric acid, hs-CRP), TC marginal high (OR: 1.68, 95% CI: 1.05–2.69, P = 0.031) or high (OR: 1.92, 95% CI: 1.25–2.95, P = 0.003) was positively correlated with CAD severity. The gene discussed is CRP; the disease is diabetes mellitus.