In fully adjusted models controlling for age, sex, and ATP III metabolic syndrome components (triglycerides ≥ 150 mg/dL, HDL cholesterol < 40 mg/dL in men or < 50 mg/dL in women, blood pressure ≥ 130/85 mmHg or treatment, glucose ≥ 100 mg/dL) plus BMI, leptin remained independently associated with MASLD (RRR 1.58, 95% CI 1.20–2.09, p = 0.001) and MetALD (RRR 1.74, 95% CI 1.02–2.98, p = 0.043). Here, LEP is linked to metabolic syndrome.