Background Serum uric acid (SUA) is an end product from the action of xanthine oxidase on purine or purine-containing compounds. Recently, much attention has been paid to the role of uric acid in disease modification. A recent study supports the view that hyperuricemia may be an independent risk factor for impaired pulmonary function in the general population. On the other hand, in view of its antioxidant properties, uric acid potentially has important beneficial effects within the respiratory system. The double-edged characteristics of SUA and mixed results from previous studies have complicated determination of whether SUA plays a pulmonary-protective or pulmonary-destructive role.
Objectives The aim of this study was to determine whether level of SUA, a potent antioxidant, is linked to pulmonary function in health screening examinees without overt clinical disease.
Methods We performed a cross-sectional study on 69,928 Koreans without overt medical conditions who underwent a health examination in 2010.
Results A total of 30,572 male (43.7%) and 39,356 female eligible subjects were enrolled in our study. The overall prevalence of hyperuricemia among Korean health screening examinees was 25.5% in males and 8.5% in females. The median age of subjects was 40 (range 35–46) years. Increasing age was positively associated with SUA level. In sex-stratified analyses of SUA level, mean SUA level was positively associated with a quartile increase in FVC% and FEV1% in both genders (P <0.001). There were also a significant positive correlation between SUA level and spirometric measures (FEV1% or FVC%) in both genders (FVC%, r =0.361; FEV1% r =0.314 in men and FVC%, r =0.413; FEV1%, r =0.382 in women). Multiple regression analysis was performed to assess whether FEV1% and FVC% were independently associated with the prevalence of hyperuricemia. The adjusted ORs for hyperuricemia comparing quartiles 2, 3, and 4 to quartile 1 (the reference group, highest quartile) of FVC% in men were 0.876 (95% CI, 0.809–0.949), 0.631 (0.574–0.695), and 0.311 (0.278–0.349), respectively. The adjusted ORs for hyperuricemia comparing quartiles 2, 3, and 4 to quartile 1 of FEV1% in men were 0.791 (95% CI, 0.729–0.859), 0.565 (0.513–0.623), and 0.302 (0.270–0.337), respectively (p for trend <0.001). Similarly, the adjusted ORs of hyperuricemia in women decreased significantly across quartiles 2 to 4 of FEV1% and FVC % compared with the highest quartile as the reference group (P for trend <0.001).
Conclusions SUA was positively associated with FVC% and FEV1% in a healthy Korean population. This finding has important implications for the hypothesis that hyperuricemia might have a favorable effect on lung function. Longitudinal follow-up studies and prospective interventional studies are required to confirm this positive association between SUA and lung function.
Disclosure of Interest None declared