CST3 and pulmonary emphysema: Clinically, stroke patients exhibited significantly elevated cystatin C levels (1.09 ± 0.55 mg/L vs. 0.81 ± 0.35 mg/L; p < 0.001) and a higher burden of comorbidities, including BMI (29.32 ± 6.07 vs. 28.33 ± 6.19 kg/m2), hypertension (71.55% vs. 30.38%), diabetes (23.20% vs. 9.10%), CHD (18.51% vs. 3.95%), CHF (15.75% vs. 2.52%), emphysema (6.63% vs. 1.73%), and CKD (9.67% vs. 2.41%) (all p < 0.001).