THE EFFECT OF SMOKING CESSATION ON PLASMA MICRONUTRIENTS

流行病学研究表明，高膳食摄入量和血液中微量营养素维生素C、13-胡萝卜素、叶酸和维生素B与降低心血管疾病和/或癌症风险有关。确定影响这些微量营养素血浆浓度的可改变的危险因素可以提供降低疾病风险的手段。许多横断面研究表明，吸烟与这些微量营养素的低血浆浓度和饮食摄入有关，可能使吸烟者患病风险增加。然而，很少有研究检查戒烟对这些微量营养素摄入量或血浆浓度的影响。在拟议的研究中，将利用最近资助的戒烟和宫颈发育不良进展研究的受试者，以经济有效的方式研究戒烟对这些血浆微量营养素的影响。戒烟以降低宫颈癌风险（WISH）研究的受试者将被随机分配到常规治疗组或基于理论的强化戒烟干预组，并随访18个月，以评估戒烟对现有宫颈发育不良进展的影响。在拟议的研究中，所有220名随机WISH受试者的维生素C、β -胡萝卜素、叶酸和α -生育酚的浓度将在基线、干预前和戒烟干预强化部分完成后的第一个6个月随访时进行测量。饮食评估也将在同样的两次访问中进行，使用食物频率问卷。在控制饮食摄入和其他因素的情况下，将使用多元线性回归来确定戒烟对这些微量营养素血浆浓度的影响。回归分析还将用于确定戒烟对这些微量营养素膳食摄入量的影响。如果戒烟如假设的那样与血浆微量营养素增加有关，这将为鼓励吸烟者戒烟提供进一步的理由。

High dietary intakes and blood concentrations of the micronutrients vitamin C, 13-carotene, folate, and vitamin B have been associated with a decreased risk of cardiovascular disease and/or cancer in epidemiologic studies. Identifying modifiable risk factors which influence plasma concentrations of these micronutrients could provide a means of decreasing disease risk. Cigarette smoking has been shown in numerous cross-sectional studies to be associated with lower plasma concentrations and dietary intake of these micronutrients, potentially placing smokers at increased risk for disease. However, very few studies have examined the effect of smoking cessation on intake or plasma concentrations of these micronutrients. In the proposed study, subjects in a recently-funded study of smoking cessation and cervical dysplasia progression will be utilized to study the effects of smoking cessation on these plasma micronutrients in a cost-effective manner. Subjects in the Smoking Cessation to Reduce Cervical Cancer Risk (WISH) study will be randomized to either usual care or an intensive theory-based smoking cessation intervention and followed for 18 months to assess the effect of smoking cessation on the progression of existing cervical dysplasia. In the proposed study, concentrations of vitamin C, beta-carotene, folate, and alpha-tocopherols will be measured in all 220 randomized WISH subjects at baseline, prior to the intervention, and at the first 6-month follow-up visit, following completion of the intensive portion of the smoking cessation intervention. Dietary assessment will also be conducted at the same two visits, using a food frequency questionnaire. Multiple linear regressions will be used to determine the effect of smoking cessation on plasma concentrations of these micronutrients, controlling for dietary intake and other factors. Regression analysis will also be used to determine the effect of smoking cessation on the dietary intake of these micronutrients. If smoking cessation is associated with increased plasma micronutrients as hypothesized, this would provide further justification for encouraging smokers to quit.