Blood viscosity is associated with smoking status rather than the presence of chronic obstructive pulmonary disease: findings from the Korea COPD Subgroup Study (KOCOSS).

Abstract

Background: The relationship between smoking and blood viscosity is well established. However, the role of blood viscosity in the development of chronic obstructive pulmonary disease (COPD) and its impact on lung function decline remains unclear. Therefore, we aimed to investigate the association of blood viscosity with COPD and lung function decline, independent of smoking status.

Methods: Data from 292 participants in the Korea COPD Subgroup Study (KOCOSS), a multicenter prospective cohort, were analyzed. Subjects were classified into four groups based on smoking history and COPD status. Multiple linear regression analysis was performed to determine the association between baseline viscosity and lung function decline after adjusting for age, sex, smoking status, and COPD status.

Results: Of the 292 participants, 93 (31.8%) patients had COPD. Ever smokers with or without COPD were older than never smokers and predominantly male. Never smokers with COPD reported the highest scores for the Modified Medical Research Council Dyspnea Scale. Blood viscosity was significantly higher in ever smokers (with COPD: 9.0 ± 1.4; without COPD 9.2 ± 1.5) than in never smokers (with COPD: 8.7 ± 1.8; without COPD: 8.4 ± 1.5). Viscosity did not differ significantly with the presence of COPD within the same smoking category. Adjusted multiple linear regression revealed that baseline blood viscosity was not associated with 2-year declines in forced expiratory volume in 1 s (p = 0.557), forced vital capacity (p = 0.686), or diffusing capacity of the lung for carbon monoxide (p = 0.947).

Conclusion: Blood viscosity appeared to be more closely associated with smoking-related hemorheological changes than with COPD. Its potential as a predictive biomarker for lung function decline appears to be limited, necessitating further long-term investigation.