Imbalance of Endogenous Hydrogen Sulfide and Homocysteine in Chronic Obstructive Pulmonary Disease Combined with Cardiovascular Disease

Yanjing He, Shaoyu Liu, Zhe Zhang, Chengcheng Liao, Fan Lin, Wanzhen Yao, Yahong Chen

Background: Considerable studies showed associations between chronic obstructive pulmonary disease (COPD) and cardiovascular disease (CVD), we evaluated the role of endogenous hydrogen sulfide (H2S)/homocysteine (Hcy) in patients with COPD combined with CVD. Methods: Fifty one stable patients with COPD were enrolled (25 COPD, 26 COPD + CVD). Lung function, sputum, peripheral blood samples, serum H2S, Hcy, high-sensitivity C-reactive protein (hs-CRP) and tumor necrosis factor-α (TNF-α) levels were measured. Dyspnea, symptoms and quality of life were quantified by modified Medical Research Council dyspnea scale (mMRC), COPD assessment test (CAT) and St. George's Respiratory Questionnaire (SGRQ). Results: Compared with COPD group, waist circumference and body mass index (BMI) were higher in COPD + CVD group, mMRC, CAT and activity scores were also higher, high density lipoprotein cholesterol (HDL-C) was lower, total cells, neutrophils (%) in sputum and serum hs-CRP level were higher, whereas macrophages (% ) in sputum was lower. H2S and Hcy levels from COPD + CVD group were higher than those from COPD group, but H2S/Hcy ratio was lower. With increasing COPD severity, H2S level was decreased, however, Hcy level was increased. H2S level was positively correlated with FEV1/FVC, FEV1% predicted, lymphocytes (%) and macrophages (%) in sputum, but negatively correlated with smoking pack-years and neutrophils (%) in sputum. Hcy level was positively correlated with BMI and total cells in sputum. The ratio of H2S/Hcy was also positively correlated with FEV1/FVC, but negatively correlated with total cells in sputum. Conclusion: The imbalance of H2S/Hcy may be involved in the pathogenesis of COPD combined with CVD and provide novel targets for therapy.