CAT and plasma cell myeloma: Multivariable logistic regression (adjusted for age, sex, and comorbidities) revealed that high MDA (OR: 6.336, 95% CI: 1.886–21.289, p = 0.003), high NO (OR: 1.217, 95% CI: 1.084–1.366, p = 0.001), low GSH-Px (OR: 0.931, 95% CI: 0.892–0.972, p = 0.001), low CAT (OR: 0.910, 95% CI: 0.865–0.957, p < 0.001), and low SOD (OR: 0.895, 95% CI: 0.833–0.962, p = 0.003) were independently associated with multiple myeloma (Table 3).