When multivariate logistic regression analysis was performed after adjusting for age, sex, hypertension, diabetes, coronary heart disease, drinking history, smoking history, education years, preoperative MMSE score, preoperative MoCA score, preoperative PSQI score, Aβ40, Aβ42, T-tau, P-tau, Aβ40/Aβ42, T-tau/P-tau, Aβ40/T-tau, Aβ42/T-tau, and Aβ42/P-tau, age (OR = 1.035, 95% CI: 1.020 ~ 1.049, p < 0.001), higher preoperative PSQI score (OR = 1.047, 95% CI: 1.014 ~ 1.080, p = 0.005), and P-tau (OR = 1.015, 95% CI: 1.002 ~ 1.028, p = 0.021) were still risk factors for SCD. The gene discussed is MAPT; the disease is diabetes mellitus.