Abstract
BACKGROUND: Cardiovascular disease (CVD) is the leading cause of mortality and morbidity worldwide. While the effect of cigarette smoking on conventional markers that account for <50% of CVD s has been well studied, there are only a few studies on the effect of cigarette smoking on novel cardiovascular (CV) risk markers. OBJECTIVE: To evaluate the effect of cigarette smoking on the novel CV markers such as homocysteine (HCY), lipoprotein (a) (Lp(a)), and C-reactive protein (CRP). MATERIALS AND METHODS: One hundred and forty smokers, 12 ex-smokers, and 84 controls were recruited for the study. A structured questionnaire was used to obtain information on their clinical history, daily cigarette consumption, and duration of smoking. The smokers were further grouped according to the amount of cigarette consumption: light (<5 sticks/day), moderate (6-10 sticks/day), and heavy (>10 sticks/day) and duration of smoking: short (5-10 years), medium (11-20 years), and long (>20 years). HCY was determined by enzyme-linked immunosorbent assay method, and Lp(a) and CRP were determined spectrophotometrically. RESULTS: HCY, Lp(a), and CRP were significantly elevated in smokers when compared with control (P < 0.05) and they correlated with daily cigarette consumption and duration of smoking. Ex-smokers also exhibited a significant increase in HCY, Lp(a), and CRP level (P < 0.05) when compared with the control, but were significantly lower than the current smokers. CONCLUSION: There is a linear relationship between the intensity and duration of cigarette smoking and serum levels of all three novel risk CV markers. These findings suggest that these markers may be an important mechanism by which smoking promotes atherosclerosis.