Methods used to quit smoking in the United States. Do cessation programs help?

Using data from the 1986 Adult Use of Tobacco Survey, we analyzed smoking-cessation methods used by adult smokers in the United States who tried to quit. About 90% of successful quitters and 80% of unsuccessful quitters used individual methods of smoking cessation rather than organized programs. Most of these smokers who quit on their own used a "cold turkey" approach. Multivariate analysis showed that women, middle-aged persons, more educated persons, persons who had made more quit-smoking attempts, and, particularly, heavier smokers were most likely to use a cessation program. Daily cigarette consumption, however, did not predict whether persons would succeed or fail during their attempts to quit smoking. Rather, the cessation method used was the strongest predictor of success. Among smokers who had attempted cessation within the previous 10 years, 47.5% of persons who tried to quit on their own were successful whereas only 23.6% of persons who used cessation programs succeeded. We conclude that cessation programs serve a small, but important, population of smokers that includes heavier smokers, those most at risk for tobacco-related morbidity and mortality.     

Cigarette smoking as a risk factor for stroke. The Framingham Study

The impact of cigarette smoking on stroke incidence was assessed in the Framingham Heart Study cohort of 4255 men and women who were aged 36 to 68 years and free of stroke and transient ischemic attacks. During 26 years of follow-up, 459 strokes occurred. Regardless of smoking status and in each sex, hypertensive subjects had twice the incidence of stroke. Using the Cox proportional hazard regression method, smoking was significantly related to stroke after age and hypertension were taken into account. Even after pertinent cardiovascular disease risk factors were added to the Cox model, cigarette smoking continued to make a significant independent contribution to the risk of stroke generally and brain infarction specifically. The risk of stroke increased as the number of cigarettes smoked increased. The relative risk of stroke in heavy smokers (greater than 40 cigarettes per day) was twice that of light smokers (fewer than ten cigarettes per day). Lapsed smokers developed stroke at the same level as nonsmokers soon after stopping. Stroke risk decreased significantly by two years and was at the level of nonsmokers by five years after cessation of cigarette smoking.     

Studies in the distribution of body fat. III. Effects of cigarette smoking

Cross-sectional associations between smoking habits, body mass index, and waist-hip ratio (WHR) were examined in 1122 men aged 19 to 102 years. Weight and body mass index were significantly lower in cigarette smokers than in nonsmokers when age was taken into account. The WHR in smokers was significantly higher than in nonsmokers. A graded dose-response relationship was found between the number of cigarettes smoked and the WHR. Longitudinal associations between changes in smoking habits and changes in the WHR were examined during follow-up visits. In the period between these pairs of visits, weight increased when subjects quit smoking and decreased when they started smoking, as expected. The increase in WHR among those who quit smoking was, however, significantly less than the expected increase if smoking had continued. The WHR in those who started smoking actually increased despite their loss of weight. These paradoxical changes in WHR indicate that there are harmful effects of cigarette smoking on the pattern of distribution of body fat. These facts introduce still another reason to suggest that the decision to initiate or to continue smoking to control body weight is unwise.     

Smoke exposure in pipe and cigar smokers. Serum thiocyanate measures

Pipe or cigar smoking traditionally has been considered a less risky alternative to cigarette smoking. Some surveys and experimental studies have suggested, however, that former cigarette smokers who switch to cigars and/or pipe (CP) are more likely to inhale then CP users who never smoked cigarettes; but this relationship has not been consistently noted. To clarify smoke-exposure levels from CP smoking, smoking histories and serum thiocyanate (SCN) levels were studied in 9,106 adults aged 25 to 74 years in population-based surveys of seven upper Midwestern communities. Analyses of the 306 male CP smokers indicated a significantly higher SCN level in the ex-cigarette-smoking CP users vs the CP users who never smoked cigarettes. Serum thiocyanate levels of both CP groups were significantly higher than those of nonsmokers and lower than cigarette-only smokers. However, the number of pipe bowls or cigars smoked per day was also significantly related to SCN levels, and this could account for much of the association between SCN and previous cigarette smoking status. Individuals currently smoking four or more pipe bowls or four or more cigars per day had an elevated smoke exposure equivalent to about ten cigarettes per day, whether or not they previously smoked cigarettes. Because of these findings and because former cigarette smokers were more likely to report heavy CP usage, cigarette smokers should be advised to quit rather than to switch to a pipe or cigar.     

Predictors of physician's smoking cessation advice

OBJECTIVES--To determine the percentage of smokers reporting that a physician had ever advised them to smoke less or to stop smoking, and the effect of time, demographics, medical history, and cigarette dependence on the likelihood that respondents would state that a physician had ever advised them to stop smoking. DESIGN AND SETTING--Data were collected from the Stanford Five-City Project, a communitywide health education intervention program. The two treatment and three control cities were located in northern and central California. As there was no significant difference between treatment and control cities regarding cessation advice, data were pooled for these analyses. PARTICIPANTS--There were five cross-sectional, population-based Five-City Project surveys (conducted in 1979-1980, 1981-1982, 1983-1984, 1985-1986, and 1989-1990); these surveys randomly sampled households and included all residents aged 12 to 74 years. MAIN OUTCOME MEASURES--Improved smoking advice rates over time in all towns was an a priori hypothesis. RESULTS--Of the 2710 current smokers, 48.8% stated that their physicians had ever advised them to smoke less or stop smoking. Respondents were more likely to have been so advised if they smoked more cigarettes per day, were surveyed later in the decade, had more office visits in the last year, or were older. In 1979-1980, 44.1% of smokers stated that they had ever been advised to smoke less or to quit by a physician, vs 49.8% of smokers in 1989-1990 (P less than .07). Only 3.6% of 1672 ex-smokers stated that their physicians had helped them to quit. CONCLUSION--These findings suggest that physicians still need to increase smoking cessation counseling to all patients, particularly adolescents and other young smokers, minorities, and those without cigarette-related disease.     

Detection of reversible platelet aggregates in the blood of smokers and ex-smokers with peripheral vascular disease.

OBJECTIVE: To demonstrate that smoking increases platelet aggregation in vivo, that smoking cessation reverses platelet aggregation and that this explains, in part, why smoking perpetuates the development of peripheral vascular disease. DESIGN: Prospective case-control study involving three groups of patients: smokers with peripheral vascular disease, ex-smokers with peripheral vascular disease and smokers with peripheral vascular disease who quit smoking during the study. SETTING/PARTICIPANTS: Fourteen smokers and seven ex-smokers, new patients with confirmed peripheral vascular disease, attending the vascular clinic at Fremantle Hospital between February and November, 1988. INTERVENTIONS: Blood samples taken weekly from all subjects for five weeks. Week 1 was taken as the baseline before smoking cessation in the six smokers who were assigned to stop smoking during the study. MAIN OUTCOME CRITERIA: Platelet aggregate ratio, an indicator of in-vivo platelet aggregability where an increase in platelet aggregate ratio suggests a decrease in platelet function. RESULTS: Only three of six smokers stopped smoking for the duration of the study. Median platelet aggregate ratios were: smokers = 0.85 (range, 0.79-0.92) v. non-smokers = 0.93 (range, 0.91-1.00). The difference was statistically significant P less than 0.0002. The difference in platelet aggregate ratios between smokers and quitters was not statistically significant. CONCLUSIONS: This study demonstrated an increase in platelet aggregability in smokers compared to ex-smokers but there was no clear evidence that platelet function was fully reversed after only four weeks cessation of smoking. The data suggested that platelet function of the ex-smokers had fully reversed to normal over a longer period. This could explain the decreased incidence of complications of peripheral vascular disease in ex-smokers. The small number of patients able to quit smoking impeded this study.     

Cigarette smoking cessation and extracranial carotid atherosclerosis

Using B-mode ultrasonography, cigarette smoking was found to be a strong, independent risk factor for extracranial carotid atherosclerosis in 1692 black and white men and women admitted for diagnostic evaluation of the carotid arteries. We found that the difference in mean plaque thickness was smaller between past smokers and nonsmokers than between current smokers and nonsmokers, suggesting that the rate of progression of carotid atherosclerosis may be slower in people who quit smoking compared with people who continue to smoke.     

Smoking and myocardial infarction: secondary prevention

This prospective study examines the question ''Is it too late to stop smoking cigarettes once you have had a myocardial infarction?'' One hundred and nineteen cigarette smokers (90 men, 29 women) who survived their first myocardial infarction for one month were followed for five years or until their death if earlier. The age corrected mortality rate of men who continued to smoke cigarettes was 2.2 times the age corrected mortality rate of those who stopped smoking after their infarct. The women who continued to smoke had 2.4 times the age corrected mortality of those who stopped smoking. The age and sex corrected mortality rates for the combined group of men and women show that those who stopped smoking after their infarction have 55% of the mortality of those who continued to smoke (P less than 0.05). These results suggest that smoking is not merely a ''risk factor'' for myocardial infarction but is also a causal factor whose effects can be avoided by both men and women after an initial myocardial infarction.     

吸烟对血浆尿酸水平的影响

目的 测定吸烟对血浆尿酸的影响及其与烟草代谢物的关系.方法 选取健康体检者300例,其中吸烟者162例（男性145例,女性17例）,不吸烟者138例（男性62例,女性76例）,测定血浆尿酸、肌酐以及尿可替宁水平.结果 吸烟者血浆尿酸水平较不吸烟者明显降低,差异有统计学意义.血浆尿酸水平与吸烟量、吸烟时间呈负相关.结论 在排除影响血浆尿酸的因素以后,吸烟者尿酸水平较不吸烟者明显降低,且这种降低与尿酸内源性生成减少有关,是吸烟促发人体应激反应作用的结果.由于血浆尿酸测定方法简单,而且能反映人体的抗氧化物水平,因此它有可能作为了解吸烟应激状态的常规测定指标.     

The smoking cessation process

The purpose of this study was to identify and describe the smoking cessation process as perceived by smokers and ex-smokers. In-depth, open-ended interviews were conducted with 25 ex-smokers who had quit smoking for at least 1 year, but not more than 7 years, and 22 smokers who had quit smoking for at least 2 weeks and returned to smoking. A systematic analysis of content was used to generate categories of responses regarding the smoking cessation process. The results of this study support and enhance what is known about behavioral change. Although further testing for verification is needed, the smoking cessation process as described by the study participants is: thinking about quitting, making a case, quitting, making adjustments, meeting the challenge, resumption, or maintenance.     

Effects of cigarette smoking and smoking cessation on plasma constituents and enzyme activities related to oxidative stress

In order to study effects of cigarette smoking and smoking cessation on plasma constituents and enzyme activities related to oxidative stress, 1255 smokers and 524 healthy non-smokers were investigated in terms of plasma levels of lipoperoxides (LPO), nitric oxide (NO), vitamin C (VC), vitamin E (VE) and beta-carotene (beta-CAR). Additionally, erythrocytes were examined to determine the level of LPO, the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px). The results showed that, when compared with the average values of the non-smoker group, the average plasma values of LPO, NO and the average erythrocyte value of LPO in the smoker group were significantly increased (P < 0. 001), while the average plasma values of VC, VE, beta-CAR, and the average erythrocyte activities of SOD, CAT, GSH-Px were significantly decreased (P < 0.001). A linear regression and correlation analysis for 65 male smokers who were all 40 years old showed that with longer smoking duration and greater daily smoking quantity, the plasma values of LPO, NO and the erythrocyte value of LPO were elevated, while the plasma values of VC, VE, beta-CAR and erythrocyte values of SOD, CAT, GSH-Px were decreased. In a group of 73 smokers who stopped smoking completely for six months, the average plasma values of LPO, NO and the average erythrocyte value of LPO decreased, although they were still significantly higher than those in the matched non-smoker group (P < 0.05). Additionally, the average plasma values of VC, VE, beta-CAR and the average erythrocyte values of SOD, CAT, GSH-Px increased, although they were still significantly lower than those in the matched non-smoker group (P < 0.05). However, after smoking cessation for one year the above average values were not significantly different from those in the matched non-smoker group (P > 0.05). This finding indicates that the markedly increased oxidative stress in smokers might gradually return to normal but only after a long period of smoking cessation. In conclusion, in the bodies of smokers a series of free radical chain reactions were gravely aggravated, the dynamic balance between oxidation and antioxidation was seriously disrupted, and oxidative stress was clearly exacerbated, which is closely related to many disorders or diseases in smokers. The present study underscored the need, urgency and importance of complete smoking cessation.     

Modifying risk of developing lung cancer by changing habits of cigarette smoking

Data from a hospital based case-control study of lung cancer in Western Europe were used to examine changes in the risk of developing lung cancer after changes in habits of cigarette smoking. Only data for subjects who had smoked regularly at some time in their lives were included. The large size of the study population (7181 patients and 11 006 controls) permitted precise estimates of the effect of giving up smoking. Risks of developing lung cancer for people who had given up smoking 10 or more years before interview were less than half of those for people who continued to smoke. The reduction in risk was seen in men and women and in former smokers of both filter and non-filter cigarettes but varied by duration of smoking habit before giving up. The protective effect of giving up became progressively greater with shorter duration of smoking habit. The risks after not smoking for 10 years for both men and women who had previously smoked for less than 20 years were roughly the same as those for lifelong non-smokers. Reducing the number of cigarettes smoked a day or switching from non-filter to filter cigarettes also lowered the risk of developing lung cancer but not to the extent associated with giving up smoking.     

Dose-related effects of cigarette smoking on olfactory function

Little is known about the influence of cigarette smoking on the ability to smell; previous studies on this topic have led to contradictory findings and have failed to take into account smoking dose and duration. In the present study, the 40-odorant University of Pennsylvania Smell Identification Test was administered to 638 subjects for whom detailed smoking histories were available. Smoking was found to be adversely associated with odor identification ability in a dose-related manner in both current and previous cigarette smokers. Among previous smokers, improvement in olfactory function was related to the time elapsed since the cessation of smoking. Logistic regression analysis found current smokers to be nearly twice as likely to evidence an olfactory deficit than persons who have never smoked. Overall, the data suggest that (1) smoking causes long-term but reversible adverse effects on the ability to smell and (2) the failure of some studies to demonstrate smoking effects may be caused by the inclusion of persons with a history of smoking in the nonsmoking groups.     

Cigarette smoke and hypoxia induce acute changes in the testicular and cerebral microcirculation

The acute effects of cigarette smoking and hypoxia on the cerebral and testicular microcirculation were studied in anestethised adult rats. Smoking for 2 min did not influence arterial pO2, pCO2 or pH but it induced an increase in cerebral blood flow by 34% and inhibited vasomotion in the testis for about 1 h. One hour after smoke exposure apnea induced a slight increase in arterial pCO2, a significant decrease in pO2, and an increase in cerebral blood flow (CBF) by 54%. In animals not previously exposed to cigarette smoke apnea increased CBF by 121%, demonstrating that a short-term exposure to tobacco smoke influences the cerebrovascular reactivity for more than one hour. In the testis, apnea resulted in a decreased blood flow by 39% and a complete depression of vasomotion. Breathing 10% O2/90% N2 resulted in moderate hypoxia, a total disappearance of the vasomotion in the testis, a 24% decrease in testicular blood flow, but a 23% increase in CBF.     

Cigarette smoking among school children in Singapore. Part II--Development of the smoking habit

The second in this series on smoking among school children in Singapore aims to define the characteristics of young smokers. Results show that of respondents who had ever smoked, the median age of experimentation with smoking was 12 years. This was seen among boys as well as girls. The median age at which current smokers went on to smoke regularly was 14 years, approximately two years after trying their first cigarette. Friends and parents were the main sources of the first cigarette for all categories of smokers, whether they be ex smokers, experimenters or current smokers. Among the reasons as to why current smokers smoked, the leading two were "to relax" (46.4%) and "out of sheer curiosity" (22.3%). Boys tend more to smoke with friends of the same sex (40.6%) whilst girls preferred mixed company (45.5%) when they smoked. Fathers played a major role in the development and continuation of smoking among those who had ever smoked before--52.0% of boys and 51.6% of girls currently smoking reported that their fathers smoked as well.     

烟雾暴露小鼠肺部氧化应激与炎症的变化及戒烟的影响

目的：观察烟草暴露小鼠肺部氧化应激状态变化与炎症因子的关系及戒烟对其的影响。方法50只雄性Balb/ c 小鼠按随机数字表法分为对照组、烟雾暴露组、戒烟组。戒烟组小鼠烟雾暴露16周后戒烟,戒烟4、8、12周时处死小鼠留取支气管肺泡灌洗液（BALF）及肺组织标本。采用HE 法观察小鼠肺组织病理学形态改变,测量肺平均内衬间隔和平均肺泡数,收集 BALF 进行细胞计数,羟胺法测定肺组织匀浆中超氧化物歧化酶（SOD）活力,TBA 法测定肺匀浆中丙二醛（MDA）水平,ELISA 法测定 BALF 和肺匀浆中白细胞介素-8（IL-8）、肿瘤坏死因子-α（TNF-α）的浓度。结果与对照组比较,烟雾暴露组小鼠出现明显的肺气肿变化, BALF 中炎症细胞显著增多（P <0.05）,戒烟后明显减少（P<0.05）;肺组织匀浆中 SOD 活力和 MDA 水平增高（ P <0.05）,戒烟后逐渐下降。烟雾暴露组小鼠 BALF、肺组织匀浆中 IL-8和 TNF-α浓度显著增高（P <0.05）,戒烟后明显降低,并随戒烟时间延长更加明显,但未降至正常水平。SOD活力和 MDA 水平与炎症因子之间呈显著正相关性。结论吸烟可以导致小鼠肺部氧化应激异常和气道炎症,戒烟可减轻氧化应激和气道炎症,但未能恢复到完全正常,炎症持续存在。     

保定市2008年戒烟竞赛参赛人员情况分析

目的掌握保定市组织的2008年戒烟竞赛参赛人员的情况,为构建无烟单位和控制吸烟提供参考。方法 (18周岁至少吸烟1年以上的保定居民且目前继续吸烟者,均可报名参赛。按照调查表格对参赛人员的各种数据资料进行统计学处理。结果全市共4 616人参赛,平均年龄为37.56岁;平均每日吸烟量为13.76支;65.25%的参赛者以前从未戒过烟。结论通过开展戒烟竞赛活动,宣传了戒烟知识,提高了大众戒烟意识,为更好开展全市控烟工作具有重要的借鉴意义。     

Smoking cessation and risk of age-related cataract in men

CONTEXT: Although cigarette smoking has been shown to be a risk factor for age-related cataract, data are inconclusive on the risk of cataract in individuals who quit smoking. OBJECTIVE: To examine the association between smoking cessation and incidence of age-related cataract. DESIGN: Prospective cohort study conducted from 1982 through 1997, with an average follow-up of 13.6 years. SETTING AND PARTICIPANTS: A total of 20,907 US male physicians participating in the Physicians' Health Study I who did not have a diagnosis of age-related cataract at baseline and had reported their level of smoking at baseline. MAIN OUTCOME MEASURES: Incident age-related cataract defined as self-report confirmed by medical record review, diagnosed after study randomization and responsible for vision loss to 20/30 or worse, and surgical extraction of incident age-related cataract, in relation to smoking status and years since quitting smoking. RESULTS: At baseline, 11% were current smokers, 39% were past smokers, and 50% were never smokers. Average reported cumulative dose of smoking at baseline was approximately 2-fold greater in current than in past smokers (35.8 vs 20.5 pack-years). Two thousand seventy-four incident cases of age-related cataract and 1193 cataract extractions were confirmed during follow-up. Compared with current smokers, multivariate relative risks (RRs) of cataract in past smokers who quit smoking fewer than 10 years, 10 to fewer than 20 years, and 20 or more years before the study were 0.79 (95% confidence interval [CI], 0.64-0.98), 0.73 (95% CI, 0.61-0.88), and 0.74 (95% CI, 0.63-0.87), respectively, after adjustment for other risk factors for cataract and age at smoking inception. The RR for never smokers was 0.64 (95% CI, 0.54-0.76). The reduced risk in past smokers was principally due to a lower total cumulative dose (RR of cataract for increase of 10 pack-years of smoking, 1.07; 95% CI, 1.04-1.10). A benefit of stopping smoking independent of cumulative dose was suggested in some analyses. Results for cataract extraction were similar. CONCLUSION: These prospective data indicate that while some smoking-related damage to the lens may be reversible, smoking cessation reduces the risk of cataract primarily by limiting total dose-related damage to the lens. JAMA. 2000;284:713-716     

Cigarette smoking increases the risk of albuminuria among subjects with type I diabetes

The effect of cigarette smoking on diabetic renal and retinal complications was evaluated in 359 young subjects with insulin-dependent diabetes mellitus. The prevalence of increased albumin excretion rates was 2.8 times higher in smokers than nonsmokers. Mean glycohemoglobin levels and duration of diabetes were also significant factors in the development of diabetic nephropathy and retinopathy in a logistic regression model. Smoking remained a significant factor in the logistic regression model for albuminuria (but not retinopathy) when controlled for glycohemoglobin level, duration of diabetes, age, gender, and blood pressure. The progression of albuminuria and of retinopathy was also greater in smokers. Albuminuria improved significantly when subjects ceased smoking. It is concluded that cigarette smoking is an independent risk factor and is associated with the development and progression of early diabetic renal damage (albuminuria) and with the worsening of retinal disease in young subjects with diabetes.     

The effect of cessation of smoking on the accumulative survival rates of patients with symptomatic peripheral vascular disease

A study of the accumulative survival rates of 133 patients with symptomatic peripheral vascular disease was carried out comparing the survival rates of tobacco smokers and non-smokers. Within the smoking group, those who continued to smoke after the surgery were compared to those who ceased smoking. Of these patients with peripheral vascular disease, 86% were, or had been, smokers. Their survival rates were less than for those who had never been smokers. Of the smoking group, those who claimed to have ceased smoking had almost twice the chance of surviving five years than those who continued to smoke. From these data, we conclude that it is never too late to stop the smoking habit.