Objective: The aim of this cross-sectional case-control study was to determine the relationship between serum cystatin C (sCysC) levels and lung function in elderly male patients with chronic obstructive pulmonary disease (COPD).
Methods: This study included 251 Chinese men (age ≥ 65 years) who were divided into COPD (n = 129) and non-COPD (n = 122) groups. Participants underwent lung function and laboratory testing, including measurement of sCysC levels. Relationships between sCysC concentration and indices of lung function were assessed by multiple regression analysis.
Results: Participants in the COPD group displayed higher sCysC concentrations (P = 0.041) and lower lung function (P < 0.001) compared to participants in the non-COPD group. Multiple linear regression analyses revealed that the reciprocal of the sCysC concentration (1/sCysC) was positively associated with the predicted forced expiratory volume in 1 s in all subjects (β = 0.156, P = 0.009). The findings indicate that high sCysC levels were directly associated with decreased lung function in elderly Chinese men with COPD.
Conclusions: High sCysC concentration may be a potential indicator of impaired lung function, and its application may improve the diagnosis and assessment of COPD severity in elderly male patients.