Net Effect of Short-Term Smoking Cessation on Mental Health Changes:Inverse Probability of Treatment Weighting and Difference-in-Differences Method

Background:In response to the need for research clearly demonstrating the net effect of smoking cessation on mental health status,considering the causal relationship between smoking cessation and changes in mental health status,this study was undertaken.Thus,this study aimed to examine the net effect of short-term smoking cessation on five specific mental health metrics and the overall mental health status score.Methods:We used data from the first wave of the Korean Health Panel(KHP)Survey(2011–2013,2016–2018)and focused on men aged 19 years and older,to explore the effects of smoking cessation.We compared mental health status before and after cessation among current non-smokers who had quit smoking and continuous smokers.We ensured homogeneity between the two groups via inverse probability of treatment weighting(IPTW)and employed a difference-in-differences(DID)analysis to assess changes in mental health status.This study controlled for factors that could influence mental health and explored the net effect of short-term smoking cessation through difference-in-differences model using multiple regression analysis.Results:The results showed that short-term smoking cessation significantly alleviated mental and physical stress(p<0.1),reduced experiences of frustration(p<0.01),and improved the overall mental health status score(p<0.1).Conclusion:Thus,these results highlight a meaningful link between positive health behavior changes,such as smoking cessation,and enhanced mental health.Moreover,the application of temporal variables further improved the understanding of the causal relationship between health behaviors and mental health.

Smoking cessation prior to elective total joint arthroplasty results in sustained abstinence postoperatively

BACKGROUND Tobacco use is a well-documented modifiable risk factor for perioperative complications.AIM To determine the tobacco abstinence rates of patients who made cessation efforts prior to a total joint arthroplasty(TJA)procedure.METHODS A retrospective evaluation was performed on 88 self-reported tobacco users who underwent TJA between 2014-2022 and had tobacco cessation dates within 3 mo of surgery.Eligible patients were contacted via phone survey to understand their tobacco use pattern,and patient reported outcomes.A total of 37 TJA patients participated.RESULTS Our cohort was on average 61-years-old,60%(n=22)women,with an average body mass index of 30 kg/m^(2).The average follow-up time was 2.9±1.9 years.A total of 73.0%(n=27)of patients endorsed complete abstinence from tobacco use prior to surgery.Various cessation methods were used perioperatively including prescription therapy(13.5%),over the counter nicotine replacement(18.9%),cessation programs(5.4%).At final follow up,43.2%(n=16)of prior tobacco smokers reported complete abstinence.Patients who were able to maintain cessation postoperatively had improved Patient-Reported Outcomes Measurement Information System(PROMIS)-10 mental health scores(49 vs 58;P=0.01),and hip dysfunction and osteoarthritis outcome score for joint replacement(HOOS.JR)scores(63 vs 82;P=0.02).No patients in this cohort had a prosthetic joint infection or required revision surgery.CONCLUSION We report a tobacco cessation rate of 43.2%in patients undergoing elective TJA nearly 3 years postoperatively.Patients undergoing TJA who were able to remain abstinent had improved PROMIS-10 mental health scores and HOOS.JR scores.The perioperative period provides clinicians a unique opportunity to assist active tobacco smokers with cessation efforts and improve postoperative outcomes.

Effect of smoking on the risk of gastrointestinal cancer after cholecystectomy: A national population-based cohort study

BACKGROUND The role of smoking in the incidence of colorectal cancer(CRC)or gastric cancer(GC)in populations undergoing cholecystectomy has not been investigated.AIM To evaluate the effect of smoking on CRC or GC development in cholecystectomy patients.METHODS A total of 174874 patients who underwent cholecystectomy between January 1,2010 and December 31,2017 were identified using the Korean National Health Insurance Service claims database.These patients were matched 1:1 with mem-bers of a healthy population according to age and sex.CRC or GC risk after cholecystectomy and the association between smoking and CRC or GC risk in cholecystectomy patients were evaluated using adjusted hazard ratios(HRs)and 95%CIs.RESULTS The risks of CRC(adjusted HR:1.15;95%CI:1.06-1.25;P=0.0013)and GC(adjusted HR:1.11;95%CI:1.01-1.22;P=0.0027)were significantly higher in cholecystectomy patients.In the population who underwent cholecystectomy,both CRC and GC risk were higher in those who had smoked compared to those who had never smoked.For both cancers,the risk tended to increase in the order of non-smokers,ex-smokers,and current smokers.In addition,a positive correlation was observed between the amount of smoking and the risks of both CRC and GC.CONCLUSION Careful follow-up and screening should be performed,focusing on the increased risk of gastrointestinal cancer in the cholecystectomy group,particularly considering the individual smoking habits.

Does Smoking Weaken the Immune System: A Narrative Review

Smoking has a complex impact on the immune system, affecting both innate and adaptive immunity. It can exacerbate pathogenic immune responses and attenuate defensive immunity, leading to a higher susceptibility to infections and certain diseases. The chemicals in cigarette smoke, such as nicotine and carbon monoxide, can alter immune cell functions and inflammatory responses. Smoking can also have long-term effects on the immune system, with some changes persisting even after quitting [1]. According to a Penn Medicine Physician, the Medical Oncologist Dr. David Porter, “People who are smokers tend to get sicker from infections”, “It may be that smoking impacts the immune system’s ability to respond appropriately”. Thus, such individuals within smoking exposure history might be considered as immunocompromised due to the altered and weakened immune system. Cigarette smoking is a prevalent habit with far-reaching health implications. Among its many adverse effects, smoking significantly alters the immune system’s functionality [1].

Exploring the Impact of Alcohol Consumption and Smoking on Primary Open Angle Glaucoma: A Mendelian Randomization Study

Objective: Utilizing Mendelian Randomization, this study employs Single Nucleotide Polymorphisms (SNPs) as instrumental variables to explore the causal relationships between bibulosity, smoking, and Primary Open Angle Glaucoma (POAG). Methods: GWAS data for bibulosity, smoking, and POAG were obtained from the Social Science Genetic Association Consortium website and the IEU OpenGWAS Project website, respectively. Using a P-value threshold of −8, a linkage disequilibrium coefficient (r2) of 0.001, and a linkage disequilibrium region width of 10,000 kb, the data were aggregated, resulting in 6 SNPs for bibulosity and 253 SNPs for smoking. Three regression models, MR-Egger, Weighted Median Estimator (WME), and Random-Effects Inverse-Variance Weighted (IVW) were applied to analyze the causal impact of bibulosity and smoking on POAG. Results: The GWAS data for alcohol consumption and smoking were derived from European populations, while the GWAS data for Primary Open-Angle Glaucoma (POAG) were sourced from East Asian populations, with no gender restrictions. Analysis using three different regression models revealed that neither excessive alcohol consumption nor smoking significantly increased the risk of developing POAG. Specifically, the odds ratios with 95% confidence intervals for the alcohol consumption group were 0.854 (0.597 - 1.221) in MR-Egger regression, 0.922 (0.691 - 1.231) in WME regression, and 0.944 (0.711 - 1.252) in IVW regression. For the smoking group, the odds ratios were 1.146 (0.546 - 2.406) in MR-Egger regression, 0.850 (0.653 - 1.111) in WME regression, and 0.939 (0.780 - 1.131) in IVW regression. Given the significant heterogeneity in the SNPs associated with smoking, the focus was primarily on the results from the IVW regression model. Conclusion: Alcohol consumption and smoking are not significant risk factors for the development of POAG.

The Prevalence of Smoking in Caribbean Towns and Correlation with Disease States: A Survey

Background: Smoking continues to be one of the most popular recreational practices despite its known harmful effects. Aim: The purpose of this survey was to assess the prevalence of smoking in the Caribbean and the correlation of smoking with the disease states of high blood pressure, diabetes and high cholesterol whose risk is known to be higher among smokers. Findings: Our study found a smoking prevalence of 22% in the population, similar to that reported by the World Health Organization (20%) and a positive correlation between smoking and diabetes. Conclusion: The survey shows that smoking numbers within the population are still high and that smoking increases the risk of certain disease states within smokers. Aggressive global efforts to reduce smoking should continue so as to minimize the negative impact of smoking on health.

Persuasive Technology for the Future of Smoking Cessation*

This paper explores the integration of persuasive technology into smoking cessation efforts through the development and evaluation of a mobile app, “No-Smoke.” Leveraging compelling features like social support, tracking, planning, and motivation, the app aims to augment user engagement and support the process of quitting smoking. The efficacy of these features has been substantiated through both automated testing and user feedback, highlighting their potential to enhance awareness, motivation, and behavior modification. Despite notable successes, limitations, including a limited user base and uncertainties regarding long-term efficacy, have been acknowledged, stemming from the inherent complexities of smoking cessation. Nevertheless, based on user experiences and feedback, “No-Smoke” represents a promising advancement in the use of technology for public health interventions, particularly in the realm of smoking cessation. To address existing challenges, future research is recommended to encompass a comprehensive, long-term study involving a larger and more diverse user base. Additionally, further investigation should focus on personalization enhancements and the integration of machine learning algorithms to better understand and respond to user behavior.

Lung Cancer Risk Attributable to Active Smoking in China:A Systematic Review and Meta-Analysis

Objective No consensus exists on the relative risk(RR)of lung cancer(LC)attributable to active smoking in China.This study aimed to evaluate the unified RR of LC attributable to active smoking among the Chinese population.Methods A systematic literature search of seven databases was conducted to identify studies reporting active smoking among smokers versus nonsmokers in China.Primary articles on LC providing risk estimates with their 95%confidence intervals(CIs)for“ever”“former”or“current”smokers from China were selected.Meta-analysis was used to estimate the pooled RR of active smoking.Results Forty-four unique studies were included.Compared with that of nonsmokers,the pooled RR(95%CI)for“ever”“former”and“current”smokers were 3.26(2.79–3.82),2.95(1.71–5.08),and 5.16(2.58–10.34)among men,3.18(2.78–3.63),2.70(2.08–3.51),and 4.27(3.61–5.06)among women,and2.71(2.12–3.46),2.66(2.45–2.88),and 4.21(3.25–5.45)in both sexes combined,respectively.Conclusion The RR of LC has remained relatively stable(range,2–6)over the past four decades in China.Early quitting of smoking could reduce the RR to some extent;however,completely refraining from smoking is the best way to avoid its adverse effects.

An Efficient ResNetSE Architecture for Smoking Activity Recognition from Smartwatch

Smoking is a major cause of cancer,heart disease and other afflictions that lead to early mortality.An effective smoking classification mechanism that provides insights into individual smoking habits would assist in implementing addiction treatment initiatives.Smoking activities often accompany other activities such as drinking or eating.Consequently,smoking activity recognition can be a challenging topic in human activity recognition(HAR).A deep learning framework for smoking activity recognition(SAR)employing smartwatch sensors was proposed together with a deep residual network combined with squeeze-and-excitation modules(ResNetSE)to increase the effectiveness of the SAR framework.The proposed model was tested against basic convolutional neural networks(CNNs)and recurrent neural networks(LSTM,BiLSTM,GRU and BiGRU)to recognize smoking and other similar activities such as drinking,eating and walking using the UT-Smoke dataset.Three different scenarios were investigated for their recognition performances using standard HAR metrics(accuracy,F1-score and the area under the ROC curve).Our proposed ResNetSE outperformed the other basic deep learning networks,with maximum accuracy of 98.63%.

Relationship between anal cancer recurrence and cigarette smoking

BACKGROUND The incidence of anal cancer has been increasing in the United States.Smoking is a well-established risk factor;however,the impact of smoking on disease recurrence and outcome has not been well studied.The aim of this study was to assess the association between anal cancer recurrence and cigarette smoking.AIM To investigate the relationship between cigarette smoking status and anal cancer treatment outcome.METHODS The cancer registry from a single,community hospital was screened for patients with anal cancer between 2010 and 2021.The following characteristics were gathered from the database:Age;sex;cigarette smoking history;American Joint Committee on Cancer Clinical Stage Group;response to therapy;recurrence;time to recurrence;mortality;time to death;and length of follow-up.Patients were divided into the following groups:Current smokers;former smokers;and never smokers.SPSSv25.0 software(IBM Corp.,Armonk,NY,United States)was used for statistical analysis.RESULTS A total of 95 patients from the database met the screening criteria.There were 37 never smokers,22 former smokers,and 36 current smokers.There was no difference between groups in regards to race or sex.There was no difference in the American Joint Committee on Cancer Clinical Stage Group between groups.The former smokers were significantly older when compared to never smokers and current smokers(66.5±13.17 vs 57.4±7.82 vs 63.7±13.80,P=0.011).Former smokers and current smokers had a higher recurrence rate compared to never smokers(30.8%and 20.8%compared to zero,P=0.009).There was not a significant difference in recurrence between former smokers and current smokers.There was no difference in the mortality,non-response rate,or time to death between the groups.CONCLUSION Our data contributes evidence that cigarette smoking status is associated with increased recurrence for patients with anal cancer.

Reproductive outcomes of water pipe smoking:A scoping review

Objective:To present an overview of the adverse effects of water pipe smoking on various aspects of reproduction and perinatal complications,covering all the most relevant studies,from descriptive findings to clinical trials.Methods:We reviewed the literature and included full publications in English provided by international biomedical databases,including PubMed,Science Direct,EBSCO,Scopus,and Google Scholar,and Cochrane Library over the last 38 years(May 1985 to June 2023).Search terms(Water pipe,Narghile,Shisha,Dokha,etc.,and Reproduction,Fertility,etc.)were adopted from Medical Subheading(MeSH)and Boolean operators were utilized to improve sensitivity.Results:133 Papers were identified in the initial search,of which 29 were excluded due to duplication.Eliminating search overlap and irrelevant records by reviewing titles and abstracts reduced 42 papers.62 Full-publication articles met the inclusion criteria.We summarized the effects of waterpipe smoke exposure on reproductive health based on three main categories:male and female fertility,fetal and neonatal outcomes,and pregnancy complications.Conclusions:Water pipe smoking has potential adverse effects on different aspects of human reproductive health,including semen parameters,male and female fertility,and fetal and neonatal health,and contributes to many maternal complications and morbidities.

The Prevalence, Pattern, and Factors Affecting Cigarette Smoking among Undergraduate Students in a Tertiary Institution in Plateau State, Nigeria

Background: Cigarette smoking is a modern health hazard, and it is preventable. It starts in adolescence for 90% of adults with an average age of onset ranging between 13 - 15 years and is commoner among males. This study is aimed at the prevalence, pattern, and factors affecting Cigarette smoking among undergraduate students in a tertiary institution in Plateau State. Method: A cross-sectional descriptive study involving 290 undergraduate students of the University of Jos was selected using the multistage sampling method. Results: The prevalence of cigarette use was 5.3%. Seven (70.0%) of students smoke daily, 6 (60.0%), smoke cigarettes before Lecture Hours, and 90.0% are unwilling to stop smoking. Smoking was done to experience the highness feeling, 8 (80.0%), peer smoking 8 (80.0%), to reduce stress and tension 5 (50.0%), and Smoking for Fun 7 (70.0%). Most students first smoked a cigarette when with friends 6 (60.0%). Factors significantly associated with the current use of cigarettes among the respondents were religion (χ2 = 4.167, p = 0.041) Level/year of study (χ2 = 32.266, p ≤ 0.001), and type of family (χ2 = 6.271, p = 0.043). Conclusion: Most students smoke daily, smoke before lectures start, and are unwilling to stop smoking. Health-promotion program to help smoking cessation and prevent initiation of smoking is recommended.

The effects of smoking on blood lipids, C-reactive protein, and homocysteine in young patients with ischemic stroke

Objective:To investigate clinical significance of the effects of smoking on blood lipids, C-reactive protein,and homocysteine in young ischemic stroke patients.Methods:The clinical data of 423 young stroke patients in the department of neurology at Taihe Hospital in Shiyan City, China were retrospectively analyzed, including age,gender,drinking history,family history,and atrial fibrillation history. Patients were divided into two groups according to whether they smoked,and the blood lipids, C-reactive protein, and homocysteine were compared between groups.Results:The proportion of smokers was 41.83%.The levels of total cholesterol,triglycerides (TG), low density lipoprotein (LDL), and homocysteine were higher in patients who smoked than in those who did not(P < 0.05). High density lipoprotein (HDL) was lower in the smoking group (P < 0.05). C-reactive protein test results were divided into groups according to whether the levels exceeded the normal range or not, and no correlation was found between C-reactive protein levels and smoking(P>0.05). Conclusion:Total cholesterol, TG, LDL, HDL, and homocysteine were significantly different between stroke patients who smoked and those who did not. We therefore suggest that smoking cessation take place as soon as possible and that it be avoided entirely in order to reduce the incidence of atherosclerosis and stroke.

Incidence of Haematoma Formation in Relation to Smoking in Abdominoplasty Cases

Objective: This study aims at assessing the relation between smoking and the incidence of haematoma formation in abdominoplasty surgery cases. Patients and Methods: This is a 4 years retrospective study involving the patients who underwent abdominoplasty surgery between the period of May 2015 and April 2019 in Zayed Military Hospital, Abu Dhabi, United Arab of Emirates. The incidence of haematoma formation was assessed in relation to tobacco use in these patients. Results: 164 patients met the inclusion criteria of the study. 35 patients were smokers (21.3%) and 129 patients were non-smokers (78.7%). The mean age was 38.4 (21 - 59 years). The mean BMI was 27 kg/m2 (21.4 - 34.7 kg/m2) and the mean hospital stay was 6.5 days (4 - 19). 23 patients in the study developed haematoma (14%). 11 of them had surgical evacuation of the haematoma (6.7%) while the rest were aspirated in the out-patient clinic. Out of the 23 patients who developed haematoma, 17 patients were smokers and 6 were non-smokers. The incidence of haematoma among smokers was 48.6% (17 out of 35 cases) while its incidence among nonsmokers was 4.7% (6 out of 129 cases) showing a clear relationship between smoking and hematoma formation (p Conclusion: Our study shows a direct relationship between smoking and haematoma formation in abdominoplasty cases. Cessation of smoking during the perioperative period is required before embarking on such a procedure.

Mining twitter to understand the smoking cessation barriers

Smoking cessation is challenging and lack of positive support is a known major barrier to quitting cigarettes.Previous studies have suggested that social influences might increase smokers' awareness of social norms for appropriate behavior,which might lead to smoking cessation.Although social media use is increasing among young adults in the United States,research on the relationship between social media use and smoking cessation is lacking.Twitter has provided a rich source of information for researchers,but no overview exists as to how the field uses Twitter in smoking cessation research.To the best of our knowledge,this study conducted a data mining analysis of Twitter to assess barriers to smoking cessation.In conclusion,Twitter is a cost-effective tool with the potential to disseminate information on the benefits of smoking cessation and updated research to the Twitter community on a global scale.

The Effects of Smoking Ban in Closed Public Spaces on the Status of Smoking

Smoking Ban in Closed Public Spaces went into effect in Turkey on May 19, 2008. We aimed at investigating the status of smoking among hospital staff following the ban. The study was conducted with the staff of the university hospital other than physicians. A questionnaire form investigating the status of smoking among hospital staff, the effects of the ban on smoking in closed public spaces, their thoughts that might affect their decisions to quit smoking or to decrease the number of cigarettes smoked was implemented. Prior to each interview, the participants read and signed the informed consent form. Mean and percentage distributions were used in the evaluation of the data. Of 60 individuals, 68% were female, mean age was 40.72 ~ 7.25. Of them 50% were active smokers. After the ban 55% of the smokers declared a decrease in the number of cigarettes they smoked, 37% said no change. The ban had no effect on smokers＇ decisions about quitting smoking. Social leadership and role model characteristics of healthcare professionals should be taken into consideration and the habit of smoking should be handled as a disease, and medical approaches including behavioral therapy should be given the necessary significance they deserve.

Difference analysis of the influence of smoking on LDL,Cys-C,and hs-CRP in patients with cerebral infarction

Objective:To compare the effects of smoking on low-density lipoprotein(LDL),cystatin C(Cys-C)and C-reactive protein(hs-CRP)in patients with cerebral infarction.Methods:The clinical data of acute stroke patients classified as large atherosclerosis by the trial of Org 10172 in acute stroke treatment(TOAST)classification were collected,and the differences of gener-al data and results of LDL,Cys-C and hs-CRP in smoking and nonsmoking patients were compared to search for rel-evant clinical data with statistical significance.Results:A total of 116 patients with acute stroke classified as large atherosclerotic by TOAST were collected and divid-ed into groups according to smoking status.Among the smoking patients,gender,age,occupation,drinking,hy-pertension,and diabetes were used as influencing factors to compare whether LDL was greater than or equal to 1.3 mmol/L,Cys-C≥0.8 mg/L and hs-CRP≥4 mg/L,with P values greater than 0.05.There was no statistical differ-ence.Among non-smoking patients,occupation,alcohol consumption,and high blood pressure had statistical sig-nificance for whether LDL was greater than 1.3 mmol/L.Age,occupation,and diabetes had statistical significance for whether Cys-C was greater than 0.8 mg/L.Conclu-sion:In this study,there was no statistically significant impact on the test results of LDL,Cys-C,and CRP whether the patients with ischemic stroke were smokers or nonsmokers.

Impacts of Preoperative Smoking and Smoking Cessation Time on Preoperative Peripheral Blood Inflammatory Indexes and Postoperative Hospitalization Outcome in Male Patients with Lung Cancer and Surgery Treatment

Objectives To investigate the effects of preoperative smoking and smoking cessation time on preoperative peripheral blood inflammatory indexes and postoperative hospitalization outcomes in male patients with lung cancer and surgery therapy.Methods We retrospectively enrolled 637 male patients who underwent curative-intent lung cancer resection between January 2014 and December 2016.Patients were classified as the current smokers,the never smokers,and the ex-smokers based on their smoking history,and the ex-smokers were allocated into five subgroups according to their smoking cessation times(CeT):CeT W6 weeks,6weeks<CeT W lyear,lyear<CeT<5years,5years<CeT<lOyears,CeT>10years.The preoperative peripheral blood white blood cells(WBCs),albumin,neutrophil to lymphocyte ratio(NLR),platelet to lymphocyte ratio(PLR),intraoperative blood loss,30-day mortality,in-hospital days,hospitalization costs,intensive care un辻(ICU),admission days and placement time of closed thoracic drainage tube were compared among difTerent groups.Results There were significant differences in WBC(F=S.275,P<0.001)and albumin(F=2,470,P<0.05)among patients of current smokers,ex-smokers with different smoking cessation time,and never-smokers.The blood WBC count in current smokers(7.7 X 109/L)was significantly higher than that in ex・smokers(7.0 X 109/L)and never-smokers(5.9 X 109/L)(t=-2.145,P<0.05;t=-6.073,P<0.01,respectively).The level of peripheral blood albumin in current smokers(41.1 g/L)was lower than that in ex・smokers(42.1 g/L)and neve—smokers(43.2 g/L)(t=2.323,P<0.05;t=3.995,P<0.01,respectively).The level of peripheral blood NLR in current smokers(3.7)was higher than that in ex-smokers(3.1)and never smokers(2.8)(t—-1.836,P<0.05;t=-2.889,P<0.01,respectively).There was no significant difference in WBC,albumin and NLR among five subgroups of different smoking cessation time.No significant difference was observed in intraoperative blood loss,30-day mortality,hospitalization costs,hospital stay,ICU stay and placement time of closed thoracic drainage tube among groups either.Conclusion Smoking increases the preoperative inflammatory indexes in peripheral blood of lung cancer patients.Smoking cessation has beneficial effect on reducing levels of these inflammatory indexes,which may be not impacted by the time length of smoking cessation.Therefore,lung cancer patients should be encouraged to quit smoking at any time.

Impact of Smoking Status on Lipoprotein Subfractions： Data from an Untreated Chinese Cohort

Objective Cigarette smoking is one of the established risk factors of atherosclerotic cardiovascular disease, however, its impact on lipids is not completely understood, especially in the Chinese population. Therefore, this study evaluated the impact of smoking status （non, former, and current smoking） on the distribution of lipoprotein subfractions in untreated patients with angina-like chest pain. Methods A total of 877 patients were consecutively enrolled and divided into nonsmoking （n = 528）, former smoking （n = 103）, and current smoking （n = 256） groups. Both low- and high-density lipoprotein cholesterol （LDL-C and HDL-C） subfractions were measured using the Quantimetrix Lipoprint System. The distributions of lipoprotein subfractions were evaluated among the groups. Results Compared with nonsmoking subjects, the current smoking group had significantly lower large/medium HDL-C （both P 〈 0.001） concentration and large HDL subfraction percentage but higher small HDL-C and medium LDL-C concentrations as well as medium LDL subfraction percentage. Importantly, former smoking subjects showed elevated levels of large HDL-C concentration, large HDL particle percentage, and mean LDL particle size and attenuation in small HDL/LDL percentages and small LDL-C concentration, but these levels did not reach the optimal status compared with those of the non-smoking group （data not shown）. Conclusion Smoking has an adverse impact on the lipoprotein subfractions, presented as lower large HDL particles besides higher small HDL and medium LDL particles, whereas smoking cessation could reverse these change to a certain degree.

Effects of Different Yellowing Conditions on Neutral Aroma Components and Smoking Quality of Flue-cured Upper Leaves

A heated air circulation standard curing barn was used for baking tobacco leaves, and the effects of different yellowing conditions during the baking process on contents of neutral aroma components and smoking quality of upper leaves were studied by setting different yellowing time and color-fixing time. The results showed that during the baking process, only by prolonging the yellowing time by 24 h on the basis of control, the content of every kind of neutral aroma components in- creased obviously and the content of solanone increased by nearly 2.20 times. It was unfavorable for the degradation and accumulation of aroma components when only prolonging color-fixing time by 24 h. Prolonging both yellowing time and color- fixing time by 24 h mainly promoted the accumulation of chlorophyll degradation product neophytadiene, which increased by 33.24%, while the degradation and ac- cumulation of some aroma components were inhibited, indicating that only prolonging the yellowing time by 24 h could promote the accumulation of various kinds of neu- tral aroma components and improve the quality of tobacco leaves. The regression models were established of neutral aroma components in the first and second prin- cipal components to total aroma content, which were y=x＋0.053 47 （R^2=0.919 7） and y=x＋0.147 5 （R^2=0.698 4）, respectively, and they were verified to be feasible.