Effect of cigarette smoking cessation on risk factors for coronary atherosclerosis. A control clinical trial

The effect of cigarette smoking on other cardiovascular risk factors, serum lipids, body weight, blood pressure and blood sugar was assessed in a randomized control trial of reduction or cessation of cigarette smoking. In the intervention group (n = 107), reported cigarette use fell from 28.5 +/- 1.2 (+/- SEM) to 10.6 +/- 1.2 cigarettes/day and serum thiocyanate, a biochemical indicator of the extent of tobacco exposure, decreased -42.8 +/- 5.5 mumol/l (P less than 0.001). Compared to the control group, the intervention group showed significant (P less than 0.05) decreases in reported cigarette consumption and serum thiocyanate and significant (P less than 0.05) increases in body weight and skinfold thickness. Change in thiocyanate correlated significantly (P less than 0.05) and inversely with change in HDL-C, body weight and skinfold thickness, but not with change in LDL-C, triglycerides or blood pressure. These relationships remained significant even after adjusting in multivariate analysis, for initial measurements of these variables or regression to the mean. For those who quit smoking (n = 35) HDL-C increased 5.9 +/- 1.7 mg/dl (P less than 0.01). The usual inverse relationship between body weight and HDL-C does not exist with cessation of cigarette smoking. Thus, benefits of stopping cigarette smoking extend to favourable alterations in HDL-C and there are no adverse effects on blood pressure, fasting blood sugar, triglycerides or LDL-C.