Decline in lung function is associated with elevated lipoprotein (a) in individuals without clinically apparent disease: A cross-sectional study

Background and objective: Reduced lung function and high lipoprotein (a) (Lp(a)) levels are both recognized risk factors for cardiovascular disease. Few studies have investigated the association between serum Lp(a) and lung function in the general population. We evaluated the association between reduced lung function and high Lp(a) levels in healthy individuals without known medical disease diagnoses. Methods: We performed a cross-sectional study on 64 082 Korean health screening examinees (33 049 males, 38 ± 7 years) who underwent a health examination in 2015. Results: The median Lp(a) level was 12 (6–25)mg/dL. The prevalence of high Lp(a) (defined as >30 mg/dL) was 19.5%. Subjects with a high Lp(a) had both lower values of measured forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC; L) than those with a low Lp(a) (P < 0.001). However, FEV₁/FVC ratio was not significantly different between groups (P = 0.112). Comparison of the second, third and fourth measured FVC (L) quartiles with that of the lowest quartile (1Q) group (reference) on regression analysis revealed adjusted odd ratios (OR) for a high Lp(a) of 0.928 (95% CI: 0.876–0.982), 0.860 (0.808–0.916) and 0.895 (0.839–0.954), respectively (P for trend < 0.001). In addition, adjusted OR for high Lp(a) compared with reference was 0.894 (0.844–0.947), 0.857 (0.806–0.912) and 0.882 (0.8727–0.940) across the measured FEV₁ (L) quartiles in increasing order (P for trend < 0.001). Conclusion: High Lp(a) levels were associated with reduced lung function in this cross-sectional population study. Longitudinal follow-up studies will be required to validate our findings.