Abstract
Both elevated plasma total homocysteine and cigarette smoking are associated with an increased risk of occlusive cardiovascular disease. We examined whether smoking cessation for a mean time of 10-11 weeks lowered plasma total homocysteine concentrations in men and women with (n = 59) and without (n = 55) established cardiovascular disease. Blood tests were available for 58 quitters and 29 subjects who did not stop smoking. Compared with subjects who continued to smoke, quitters had statistically significant higher HDL cholesterol concentrations, but plasma total homocysteine concentrations did not differ between the two groups. Likewise, no differences were found between quitters and non-quitters whose baseline homocysteine concentrations were above the 75th percentile.