Smoking cessation and body mass index of occupationally active men: the Israeli CORDIS Study

OBJECTIVES: This study estimated weight gain after smoking cessation and identified factors attenuating this gain. METHODS: We conducted a prospective follow-up of 1209 male factory workers for 2 to 4 years. The independent variables were smoking habits. age, sports activity, education, alcohol consumption, ethnicity, duration of follow-up, and body mass index (BMI, kg/m2) at entry. The dependent variable was increase in BMI during follow-up. RESULTS: The mean age-adjusted BMI at entry into the study was 26.6 kg/m2 among past smokers and 25.4 kg/m2 among current smokers. There were no differences in BMI between those who quit less than 3 years before entry and those who quit more than 6 years before entry. During follow-up, the average increase in BMI was 0.07 kg/m2 among never smokers, 0.19 kg/m2 among smokers who had stopped smoking before entry, 0.24 kg/m2 among current smokers, and 0.99 kg/m2 among those who stopped smoking after entry. Cessation of smoking after entry predicted an increased gain in BMI; older age, a higher BMI at entry, sports activity, and alcohol consumption attenuated this gain. CONCLUSIONS: The increased rate of weight gain after smoking cessation is transient. However, the weight gained is retained for at least 6 years.     

Underweight and overweight in relation to mortality among men aged 40-59 and 50-69 years: the Seven Countries Study

This study investigated the relation between body mass index (BMI) and the all-cause mortality rate among 7,985 European men. Starting around 1960, when all men were aged 40-59 years, mortality was followed for 15 years (1960-1975); starting around 1970, the survivors were followed for an additional 15 years (1970-1985). For the first and second follow-up periods, a BMI of 18.5-25 kg/m2 around 1960 and 1970, respectively, was considered the reference category. The authors found that the hazard ratios of mortality for a BMI of <18.5 kg/m2 was 2.1 (95% confidence interval (CI): 1.5, 2.8) for the first follow-up period and 1.7 (95% CI: 1.3, 2.2) for the second. A BMI of 25-30 kg/m2 was not related to increased mortality. Among never smokers, the hazard ratios for a BMI of >30 kg/m2 were 1.8 (95% CI: 1.2, 2.8) for the 1960-1975 follow-up period and 1.4 (95% CI: 1.0, 1.9) for the 1970-1985 follow-up period. A BMI of >30 kg/m2 was not related to increased mortality among current smokers. When mortality was followed for more than 15 years, the hazard ratio for a BMI of <18.5 kg/m2 declined and the hazard ratios for a BMI of >30 kg/m2 did not change. Underweight among those in all smoking categories and severe overweight in never smokers remained predictors of increased mortality when middle-aged men became older.     

Cross-sectional study on the relationship between body mass index and smoking, and longitudinal changes in body mass index in relation to change in smoking status: the Tromso Study

AIMS: To evaluate the effects of smoking and other lifestyle factors on body mass index (BMI), and changes in BMI in relation to changes in smoking status. METHODS: A cross-sectional study was performed on 10,920 males (3937 smokers) and 12,090 females (4343 smokers) who participated in the fourth Troms? Study (performed in 1994-95). A longitudinal study was performed on 2364 males (732 smokers in 1994-95) and 2738 females (942 smokers in 1994-95) who participated in both the fourth and the fifth Troms? studies (performed in 2001). RESULTS: In the cross-sectional study, current smokers of both genders had a lower BMI (25.0+/-3.4 vs. 25.5+/-3.2 kg/m(2) in males, and 23.9+/-3.9 vs. 25.3+/-4.6 kg/m( 2) in females, p<0.01), a lower degree of physical activity, and a higher consumption of coffee and alcohol than never-smokers. We found a U-shaped relationship between number of cigarettes smoked per day and BMI, with the lowest BMI in those smoking 6- 10 cigarettes per day. Heavy smokers and never-smokers had similar BMI. In the longitudinal study, continuing smokers had a smaller increase in BMI than those who gave up smoking. In those who gave up smoking, there was a significant, positive relationship between number of cigarettes smoked in 1994-95 and increase in BMI. CONCLUSIONS: There is a U-shaped relationship between number of cigarettes smoked per day and BMI. Smoking cessation is associated with an increase in weight as compared to those who continue smoking.     

Cigarette smoking and the risk of the metabolic syndrome in middle-aged Japanese male office workers

To examine the association between cigarette smoking and the risk of the metabolic syndrome (MS), 3649 Japanese male office workers aged 35-59 yr who did not have a history of cardiovascular disease were enrolled in this study. 2994 men without the MS at entry were followed up over a 7-yr period. A modified National Cholesterol Education Program definition with body mass index instead of waist circumference was used for the MS. With adjustment for age, family history of diabetes, alcohol intake, and regular physical activity, the odds ratios of the MS were 1.0 (referent), 1.30 (95% confidence interval (CI), 1.00-1.68), 1.07 (95% CI, 0.82-1.39), 1.17 (95% CI, 0.88-1.56), and 1.66 (95% CI, 1.24-2.20) for never smokers, ex-smokers, and those who smoked 1-20 cigarettes/d, 21-30 cigarettes/d, and > or =31 cigarettes/d, respectively (P for trend for current smokers only =0.006). As for the risk of developing the MS, the respective multivariate-adjusted hazard ratios of developing the MS were 1.0 (referent), 1.43 (95% CI, 1.14-1.79), 1.14 (95% CI, 0.91-1.44), 1.45 (95% CI, 1.14-1.84), and 1.59 (95% CI, 1.24-2.05) (P for trend for current smokers only =0.001). Among men without the MS at entry, body weight gain over 7 yr, compared with never smokers, was significantly higher in smokers who quit smoking. It is important for the prevention of the MS not only to quit smoking but also to prevent weight gain after smoking cessation.     

Weight gain and risk of impaired fasting glucose after smoking cessation

Background

Observation of early changes in fasting plasma glucose level induced by post-smoking cessation weight gain is useful in predicting the risks of diabetes mellitus (DM) and impaired fasting glucose (IFG). We investigated the effect of post-smoking cessation weight gain on early changes in the risk of a high fasting plasma glucose (IFG) level (≥100 mg/dL).

Methods

In 946 subjects who underwent repeated health examinations after smoking cessation, changes in body mass index (BMI) and the odds ratio (OR) for IFG risk (adjusted for sex, age, BMI, fasting plasma glucose at year 1, and alcohol consumption) were calculated every year for 3 years after smoking cessation.

Results

After smoking cessation, the rate of BMI increase significantly increased in quitters: 2.36% at year 2 (never smokers: 0.22%, current smokers: 0.39%) and 0.46% at year 3 (never smokers: 0.14%, current smokers: 0.32%). However, it decreased by 0.15% at year 4 (never smokers: 0.12%, current smokers: 0.26%). The ORs for quitters did not significantly increase at any time during the follow-up period. However, among quitters who had smoked at least 20 cigarettes per day, it was significantly higher (OR 1.51, 95% confidence interval 1.1–2.01 at year 1 and 1.71, 1.23–2.38 at year 2).

Conclusions

The time course of the risk of IFG after smoking cessation was similar to that for the rate of BMI increase. In contrast to the findings of previous reports, the increase in IFG risk after smoking cessation was brief and disappeared in the absence of a significant increase in BMI.Key words: smoking cessation, fasting, glucose tolerance, weight gain     

Smoking cessation and long-term weight gain in the Framingham Heart Study: an application of the parametric g-formula for a continuous outcome

Weight gain after smoking cessation can lessen the health benefits of, and reduce the incentives for, quitting smoking. Randomized clinical trials of smoking cessation have estimated this weight gain only over short periods of follow-up. We provide an estimate of long-term post-cessation weight gain in the Framingham Heart Study, a prospective observational study. We identified 2001 smokers free of diabetes, cancer, and cardiovascular disease in 1952. Using the parametric g-formula we estimated mean weight in 1972 if all smokers had quit at baseline versus if all had continued smoking. Our estimates were adjusted for demographic, socio-economic, and clinical factors at baseline and during follow-up. The estimated mean weight (95 % CI) at 20 years if all smokers had quit smoking was 75.2 kg (73.5, 76.6), compared with 70.2 kg (68.7, 71.8) if they had smoked 20 cigarettes/day and 73.4 kg (71.9, 74.6) if they had smoked 5 cigarettes/day (i.e., an estimated mean weight gain of 5.1 kg (3.1, 6.6) and 1.8 kg (0.8, 2.8), respectively). Smokers who were overweight or obese at baseline had a greater post-cessation weight gain on average. Our estimates suggest that smoking cessation can result in increases in body weight over 20 years. While the benefits of smoking cessation outweigh the risks due to post-cessation weight gain, our results highlight the need for long-term weight management interventions in combination with smoking cessation.     

Smoking reduction in a population-based cohort

OBJECTIVE: To describe the factors associated with smoking reduction in a population-based cohort study in Cornella de Llobregat (Barcelona, Spain). MATERIAL AND METHODS: We used data from the Cornella Health Interview Survey Follow-up Study (n = 2,500). We included for the analysis those subjects who declared to be daily smokers at baseline (1994) and continued smoking after eight years of follow-up (n = 234). We considered as operational definition of reduction to reduce > or = 10 cigarettes/day. We calculated the relative risk (RR) of smoking reduction vs. maintain or increase tobacco consumption and 95% confidence intervals (CI) by means of a Breslow-Cox regression model. RESULTS: The average reduction on number of cigarettes among subjects who reduced their tobacco consumption was similar in men and women (13 cigarettes/day). The consumption intensity and self-perceived health are the characteristics associated with reduction: smoking reduction was associated with being a smoker > 20 cigarettes/day (RR = 3.25; 95% CI: 1.69-6.25) and individuals who declared having a suboptimal health showed a 3-fold risk of reducing smoking (RR = 3.13; 95% CI: 1.52-6.43). CONCLUSION: Heavy smokers and smokers with poor health are those smokers more likely to reduce their tobacco consumption. Specific actions targeting them could lead to increase reduction and even smoking cessation.     

上海市区中老年男性吸烟状况与肥胖关系的横断面研究

目的 评价上海市区中老年男性吸烟状况与肥胖的关系.方法 利用2002-2006年开展的上海市男性健康队列基线调查资料,分析61 491名40～74岁研究对象的吸烟情况与身体测量数据、体重变化等的关联.吸烟状况和体重变化数据采用问卷方式进行收集,身高、体重、腰围、臀围由调查员面访时对被访者进行测量而得.多元回归模型用于估计吸烟与肥胖间的关联强度,并调整可能的混杂因素.结果 调整年龄等可能的混杂因素后,吸烟组的体质指数(BMI)(23.4±3.1)和成人期体重增加值[(11.6±9.7)kg]均低于从未吸烟者组的BMI(24.0±2.9)和成人期体重增加值[(12.7±8.9)kg],两组平均BMI相差0.60(95%CI:-O.67～-0.54),体重增加相差1.46 kg(95%CI:-1.65～-1.27).吸烟组腰围臀围比(WHO)高于不吸烟组,平均差值达0.006 08(95%CI:0.005 08～0.007 09),差异均有统计学意义(P＜0.01).开始吸烟年龄越早,日吸烟支数越多,吸烟年数越长,总吸烟包年数越高,两组WHR的差值越大(趋势检验,P＜0.05).戒烟者的BMI、WHR和体重增加z值在戒烟的头几年均高于从未吸烟者,但随后可恢复至未吸烟者的水平.结论 吸烟与体重呈负相关,但可能加重中心性肥胖.戒烟虽伴暂时的体重上升,但随戒烟时间的延长,该效应消失.     

Smoking and risk of incident psoriasis among women and men in the United States: a combined analysis

The authors evaluated the association between smoking and the incidence of psoriasis among 185,836 participants from a cohort of older women (the Nurses' Health Study, 1996-2008), a cohort of younger women (the Nurses' Health Study II, 1991-2005), and a cohort of men (Health Professionals' Follow-up Study, 1986-2006). Information on smoking was collected biennially during follow-up. The authors identified a total of 2,410 participants with incident psoriasis. Compared with never smokers, past smokers had a relative risk of incident psoriasis of 1.39 (95% confidence interval (CI): 1.27, 1.52) and current smokers had a relative risk of 1.94 (95% CI: 1.64, 2.28). For current smokers who smoked 1-14 cigarettes/day, the relative risk was 1.81 (95% CI: 1.38, 2.36); for those who smoked 15-24 cigarettes/day, the relative risk was 2.04 (95% CI: 1.68, 2.47); and for those who smoked 25 or more cigarettes/day, the relative risk was 2.29 (95% CI: 1.74, 3.01). There was a trend toward an increased risk of psoriasis with increasing pack-years or duration of smoking (P(trend) < 0.0001). The risk was highest among smokers who had 65 or more pack-years of smoking (relative risk = 2.72, 95% CI: 2.05, 3.60) and among those with a smoking duration of 30 or more years (relative risk = 1.99, 95% CI: 1.75, 2.25). The authors observed a graded reduction of risk with an increase in time since smoking cessation (P(trend) <0.0001). In this study, smoking was found to be an independent risk factor for psoriasis in both women and men. Psoriasis risk was particularly augmented for heavy smokers and persons with longer durations of smoking.     

The impact of body weight on smoking cessation in German adults

OBJECTIVE: To assess the relevance of pre-existing body weight for successful smoking cessation among women and men. METHODS: We carried out a retrospective cohort analysis among 4270 ever smoking participants of a general health screening examination in Germany recruited from July 2000 to June 2002 aged 50 to 74, who provided lifetime histories of both body weight and smoking. RESULTS: In the extended Cox model, the relative cessation rate (RCR) increased significantly with increasing body mass index (BMI) among both genders (test for trend: P < 0.01 for women and P < 0.0001 for men). In women, this effect was mainly due to a lower cessation rate in low-weight (BMI <20) smokers (adjusted RCR = 0.76, 95% confidence interval (CI) 0.62-0.95), whereas in men, the effect was mainly due to a higher cessation rate among overweight and obese smokers (adjusted RCR = 1.26, 95% CI 1.11-1.35, and 1.38, 95% CI 1.17-1.63, respectively) compared to normal-weight smokers. CONCLUSIONS: While in men, overweight and obesity are associated with increased smoking cessation, possibly related to increased health concerns, in women, low weight is associated with decreased smoking cessation, possibly related to increased fear of weight gain.     

Food habits, physical activity and body mass index in relation to smoking status in 40-42 year old Norwegian women and men

BACKGROUND: The aim of the study was to examine the associations between smoking habits, and dietary habits, physical activity and body mass index (BMI) in Norway in 1997-1999. METHODS: The study was cross-sectional. Data on smoking habits, consumption of selected foods and physical activity were collected by questionnaire while body height and weight were measured in 59,361 subjects 40-42 years in 11 Norwegian counties. RESULTS: In both genders, nearly twice as many never smokers than current smokers had fruit or vegetables at least twice a day; 25.5% versus 13.3% for women and 10.5% versus 4.6% for men. The proportion of non-smoking women with a high intake of fish and fruit/vegetables was considerably higher than that of non-smoking men. Mean BMI (95% confidence interval (CI)) was higher for never smokers than for current smokers; 25.2 (25.1-25.3) versus 24.7 (24.6-24.8) kg/m2 for women and 26.6 (26.5-26.7) versus 26.1 (26.0-26.2) kg/m2 for men. The prevalence of obesity (BMI > or =30 kg/m2) (mean and 95% CI) was 12.5% (11.9-13.1%) and 14.4% (13.7-15.1%) among never-smoking women and men, respectively, whereas in smokers, the prevalence of obesity was 10.3% (9.8-10.8%) in women and 12.3% (11.7-12.9%) in men. The prevalence of performing strenuous physical activity at least 1 h a week was approximately 10% lower among current smokers than among non-smokers for both men and women. CONCLUSION: We found that non-smokers had healthier eating habits and higher levels of physical activity than did smokers, whereas the prevalence of obesity was lower in smokers. On the other hand, there were considerable gender differences, and female smokers' eating habits were as healthy as non-smoking males' eating habits.     

Heavy smoking raises risk for type 2 diabetes mellitus in obese men; but, light smoking reduces the risk in lean men: a follow-up study in Japan

PURPOSE: To investigate interactive effects of cigarette smoking and body mass index (BMI, measured in kilograms per square meter) on the risk for type 2 diabetes mellitus (DM). METHODS: We conducted a follow-up study in 16,829 apparently healthy men 30 to 59 years of age. At baseline, 23.1%, 24.6%, 24.0%, and 28.4% of the men were 'never' smokers, ex-smokers, light smokers (20 cigarettes/d), respectively. BMI was expediently categorized into quartiles (Q1: <21.3; Q2: 21.3-22.9; Q3: 23.0-24.7; and Q4: >24.7 kg/m2). Incident DM was identified by a fasting serum glucose level of 7.00 mmol/L or higher or the criterion 'under treatment for DM.' The risk ratio for incident DM, hazard ratio (HR) and the 95% confidence interval (CI), according to smoking and BMI, were estimated by using Cox proportional hazard models. Age, drinking, exercise, and education were computed as confounders. RESULTS: During mean follow-up of 7.4 years, 869 men developed DM. In Q4 of BMI, heavy smoking raised the risk against 'never smoking' (multivariate-adjusted HR (95%CI): 1.37 [1.05-1.80]), but neither light smoking nor ex-smoking did. In Q1 of BMI, light and heavy smoking reduced the risk (multivariate-adjusted HR (95% CI): 0.45 (0.23-0.88) and 0.74 (0.41-1.33), respectively). CONCLUSIONS: Smoking and BMI interactively influence risk for DM and the interaction is considerably complex. Heavy smoking moderately increases the risk for DM in obese men. But, light smoking reduces the risk in lean men.     

Can physical activity minimize weight gain in women after smoking cessation?

OBJECTIVES. The purpose of this study was to examine prospectively whether exercise can modify weight gain after smoking cessation in women. METHODS. Data were analyzed from a 2-year follow-up period (1986-1988) in the Nurses' Health Study, an ongoing cohort of 121,700 US women aged 40 to 75 in 1986. RESULTS. The average weight gain over 2 years was 3.0 kg in the 1474 women who stopped smoking, and 0.6 kg among the 7832 women who continued smoking. Among women smoking 1 to 24 cigarettes per day, those who quit without changing their levels of exercise gained an average of 2.3 kg more (95% confidence interval [CI] = 1.9, 2.6) than women who continued smoking. Women who quit and increased exercise by between 8 to 16 MET-hours (the work metabolic rate divided by the resting metabolic rate) per week gained 1.8 kg (95% CI = 1.0, 2.5), and the excess weight gain was only 1.3 kg (95% CI = 0.7, 1.9) in women who increased exercise by more than 16 MET-hours per week. CONCLUSIONS. Smoking cessation is associated with a net excess weight gain of about 2.4 kg in middle-aged women. However, this weight gain is minimized if smoking cessation is accompanied by a moderate increase in the level of physical activity.     

Weight concerns and smoking in a general population: the Inter99 study

OBJECTIVE: No previous studies have explored weight concerns in relation to smoking habits, or investigated how weight concerns affect smoking cessation in a general population. METHOD: Inter99 is a population-based lifestyle interventional study, conducted in 1999-2001 in Copenhagen, Denmark, comprising 30-60 year old men and women. All daily smokers (N=2408) were offered help to quit. The baseline investigation (N=6784) was used for analysing associations of smoking status with weight concerns (cross-sectional design). To analyse how weight concerns affected smoking cessation we included the 1387 daily smokers attending 1-year follow-up; 221 of these were verified quitters (longitudinal design). RESULTS: Daily smoking men and women had a significantly lower body mass index than never smokers (men: 3%, women 5%) but reported to be significantly less concerned of their weight (men: OR=0.64, 95%CI=0.4-0.9), women: 0.78(0.6-1.0)). Ex-smoking normal weight women were significantly more likely to be frequently concerned of their weight than never smoking normal weight women (OR=2.06, 95CI%=1.6-2.7). Fifty-two percent of the women and 32% of the men with a previous quit attempt reported that weight gain was a reason for relapse. Neither weight concerns nor eating patterns were predictive of point abstinence at 1-year follow-up. CONCLUSION: Smokers are believed to be very concerned of their weight but in this population-based study, daily smokers more frequently ate what they wanted, had a lower BMI and were significantly less concerned of their weight than never smokers. Weight concerns and eating patterns did not predict abstinence at 1-year follow-up. It seems that weight gain and weight concerns are independent factors.     

Body mass index and mortality from ischaemic heart disease in a lean population: 10 year prospective study of 220,000 adult men

BACKGROUND: Increased body mass index (BMI) is known to be related to ischaemic heart disease (IHD) in populations where many are overweight (BMI>or=25 kg/m2) or obese (BMI>or=30). Substantial uncertainty remains, however, about the relationship between BMI and IHD in populations with lower BMI levels. METHODS: We examined the data from a population-based, prospective cohort study of 222,000 Chinese men aged 40-79. Relative and absolute risks of death from IHD by baseline BMI were calculated, standardized for age, smoking, and other potential confounding factors. RESULTS: The mean baseline BMI was 21.7 kg/m2, and 1942 IHD deaths were recorded during 10 years of follow-up (6.5% of all such deaths). Among men without prior vascular diseases at baseline, there was a J-shaped association between BMI and IHD mortality. Above 20 kg/m2 there was a positive association of BMI with risk, with each 2 kg/m2 higher in usual BMI associated with 12% (95% CI 6-19%, 2P=0.0001) higher IHD mortality. Below this BMI range, however, the association appeared to be reversed, with risk ratios of 1.00, 1.09, and 1.15, respectively, for men with BMI 20-21.9, 18-19.9, and <18 kg/m2. The excess IHD risk observed at low BMI levels persisted after restricting analysis to never smokers or excluding the first 3 years of follow-up, and became about twice as great after allowing for blood pressure. CONCLUSIONS: Lower BMI is associated with lower IHD risk among people in the so-called normal range of BMI values (20-25 kg/m2), but below that range the association may well be reversed.     

Smoking cessation and lung cancer mortality in a cohort of middle-aged Canadian women

PURPOSE: To determine the impact of smoking cessation on lung cancer mortality among women. METHODS: Survival analysis is used to assess the effect of smoking cessation on lung cancer death in the dietary cohort of 49,165 women aged 40 to 59 years enrolled in the Canadian National Breast Screening Study. RESULTS: During an average of 10.3 years of follow-up, 106 women died of lung cancer. The risk of lung cancer mortality among women who quit before age 50 (HR=0.26; 95% CI, 0.13-0.55 among women who quit at ages 40-49) or quit in the previous 10 years (HR=0.39; 95% CI, 0.22-0.69) is substantially lower than the risk among current smokers. Women who quit after age 40 or have quit for less than 20 years are at substantially higher risk of lung cancer mortality compared with never smokers. Both duration of smoking cessation and age at quitting have independent effects on lung cancer mortality, after controlling for number of cigarettes smoked per day and number of years smoked, as well as other potential confounding variables. CONCLUSION: These findings suggest that programs and policies to promote early cessation of smoking and prevention of relapse should be a public health priority.     

Differences in resting energy expenditure between black and white smokers: implications for postcessation weight gain

OBJECTIVE: To examine differences in resting energy expenditure (REE) between black and white smokers in order to determine whether REE might contribute to postcessation weight gain. DESIGN: Cross-sectional and prospective investigation of ethnic differences in REE. Differences in REE between black and white smokers were examined at baseline while all participants were smoking, and again during 2 weeks of abstinence from smoking. SETTING: Memphis, Tennessee, USA. SUBJECTS: Sixty-six black and 112 white smokers (age 30.4 y; cigarettes per day 21.4; weight 71.7 kg; body mass index 24.5 kg/m2). RESULTS: Black smokers had a significantly lower baseline REE after adjusting for gender and body weight. Changes in REE following smoking cessation did not differ by ethnicity. CONCLUSIONS: These results suggest that black smokers may be more energy efficient, which could contribute to ethnic differences in postcessation weight gain.     

Active Smoking,Passive Smoking,and Risk of Nonalcoholic Fatty Liver Disease (NAFLD): A Population-Based Study in China

Background

The effect of active smoking on development of nonalcoholic fatty liver disease (NAFLD) is controversial, and there are limited clinical data on the relationship between passive smoking and NAFLD. We investigated whether active and passive smoking are associated with NAFLD.

Methods

A total of 8580 subjects (2691 men) aged 40 years or older participated in a community-based survey in Shanghai, China. Information on active and passive smoking was collected using a validated questionnaire. NAFLD was diagnosed by abdominal B-mode ultrasound testing and serum liver enzymes.

Results

NAFLD prevalence was 29.4% in never smokers, 34.2% in former smokers, 27.8% in light smokers (<20 cigarettes/day), 30.8% in moderate smokers (20–39 cigarettes/day), and 43.5% in heavy smokers (≥40 cigarettes/day). Fully adjusted logistic regression analyses revealed that, as compared with never smoking, former and heavy smoking were associated with increased risk of prevalent NAFLD, with odds ratios of 1.45 (95% CI 1.05–2.00) and 2.29 (95% CI 1.30–4.03), respectively. Active smoking and body mass index (BMI) had a synergistic effect on the risk of prevalent NAFLD; the combination of these risk factors was associated with the highest observed odds ratio for NAFLD: 8.58. In never-smoking women, passive smoking during both childhood and adulthood was associated with a 25% increase in the risk of prevalent NAFLD (OR = 1.25, 95% CI 1.05–1.50) as compared with no passive smoking.

Conclusions

Passive smoking and heavy active smoking are associated with prevalent NAFLD in middle-aged and elderly Chinese. Active smoking and BMI have a synergistic effect on prevalent NAFLD.Key words: active tobacco smoking, passive tobacco smoking, fatty liver     

吸烟与帕金森病关系的病例对照研究

目的　探讨吸烟与帕金森病 (PD)的关系。方法　采用以人群为基础的病例对照研究 ,调查在北京地区 55岁以上PD患病率调查中确诊及 2 0 0 2年 8月至 2 0 0 3年 1月在北京协和医院帕金森研究中心诊治的病例共 1 1 4例 ;以及性别、民族及居住地与其匹配的对照 2 0 5名。结果　吸烟与PD呈显著负相关联。以非吸烟者为对照 ,曾经吸烟者、现在吸烟者和过去吸烟者患PD的危险性低于对照 ,OR值分别为 0 .49(95 %CI:0 .30～ 0 .79)、0 .44(95 %CI :0 .2 3～ 0 .86)和 0 .54(95 %CI:0 .30～0 .96)。此外 ,对吸烟者分别按吸烟年限≥ 2 0年和 <2 0年、戒烟年限≥ 2 0年和 <2 0年以及吸烟量分层和logistic回归分析 ,其负相关联依然存在并具有剂量反应关系的趋势 (P <0 .0 5)。结论　吸烟与PD存在负相关联 ,今后应着重开展有关生物学依据的研究     

The Effect of Smoking Status upon Occurrence of Impaired Fasting Glucose or Type 2 Diabetes in Korean Men

OBJECTIVES: To investigate whether smoking and the smoking status are predictors of the incident impaired fasting glucose (IFG) or type 2 diabetes in Korean men. METHODS: A cohort of 1,717 Korean men without IFG or diabetes, who underwent annual periodic health examinations for 4 years (2002-2006), were retrospectively investigated. IFG and diabetes were defined as a serum fasting glucose concentration of 100-125 mg/dL and more than 126 mg/dL, respectively. Cox's proportional hazards model was used to evaluate the association between smoking and development of IFG or type 2 diabetes. RESULTS: A total of 558 cases (32.5%) of incident IFG and 50 cases (2.9%) of diabetes occurred. After controlling for the potential predictors of diabetes, the relative risk for IFG, compared with the never smokers, was 1.02 (95% CI=0.88 to 1.19) for the ever-smokers, 0.96 (95% CI=0.79-1.16) for those who smoked 1-9 cigarettes/d, 1.15 (95% CI=1.01 to 1.30) for those who smoked 10-19 cigarettes/d, and 1.31 (95% CI=1.10 to 1.57) for those who smoked 20 or more cigarettes/d (the P value for the current smokers was only p<0.002). The respective multivariate adjusted relative risks for type 2 diabetes, compared with the neversmokers, were 1.07 (95% CI=0.64 to 1.92), 1.47 (95% CI=0.71 to 3.04), 1.84 (95% CI=0.92-3.04), and 1.87 (95% CI=1.13-3.67), respectively (the P value for the current smokers was only p=0.004). CONCLUSIONS: The smoking status and the number of cigarettes smoked daily are associated with an increased risk for developing IFG or type 2 diabetes in Korean men.