Relationship between increase of serum homocysteine caused by smoking and oxidative damage in elderly patients with cardiovascular disease

摘要

Background: To investigate the mechanism of smoking on cardiovascular diseases. Material and methods: 576 elderly patients with cardiovascular diseases in stable condition were consecutive recruited, asked about the living habits and smoking history in a way of face to face. Results: Of all the enrolled patients, current smoking rate was 34.8% for males and 3.4% for females. Average smoking quantity was 17 cigarettes per day and incidence of hyperhomocysteinemia was 38.0%. The homocysteine level in current smokers was significantly higher than that in never smokers (P = 0.004); while the serum folic acid and serum superoxide dismutase (SOD) level were significantly lower those in never smokers (P = 0.012; P = 0.004). The daily smoking consumption and the pack-years of smoking were significantly positively correlated with total homocysteine (tHcy) level (P = 0.020; P = 0.003). The reduced serum SOD level might be associated with increased risk of hypertension (P = 0.023), coronary heart disease (P = 0.018), and stroke (P = 0.035). However, the elevated serum tHcy level was not correlated with increased risk of hypertension and coronary heart disease, while may increase the risk of ischemic stroke (P = 0.075). Conclusions: Smoking status is still prevalent among Chinese elderly patients with cardiovascular diseases, which causes the increase of serum tHcy and the decrease of serum folate as well as SOD; smoking consumption per day and pack-years of smoking have indirect effects on tHcy. And decrease of serum SOD is a risk factor for cardiovascular diseases, increase of serum tHcy may be associated with changes of metabolism caused by oxidative damage.