Longitudinal Follow-Up of Participants With Tobacco Exposure and Preserved Spirometry.

Importance: People who smoked cigarettes may experience respiratory symptoms without spirometric airflow obstruction. These individuals are typically excluded from chronic obstructive pulmonary disease (COPD) trials and lack evidence-based therapies. Objective: To define the natural history of persons with tobacco exposure and preserved spirometry (TEPS) and symptoms (symptomatic TEPS). Design, Setting, and Participants: SPIROMICS II was an extension of SPIROMICS I, a multicenter study of persons aged 40 to 80 years who smoked cigarettes (>20 pack-years) with or without COPD and controls without tobacco exposure or airflow obstruction. Participants were enrolled in SPIROMICS I and II from November 10, 2010, through July 31, 2015, and followed up through July 31, 2021. Exposures: Participants in SPIROMICS I underwent spirometry, 6-minute walk distance testing, assessment of respiratory symptoms, and computed tomography of the chest at yearly visits for 3 to 4 years. Participants in SPIROMICS II had 1 additional in-person visit 5 to 7 years after enrollment in SPIROMICS I. Respiratory symptoms were assessed with the COPD Assessment Test (range, 0 to 40; higher scores indicate more severe symptoms). Participants with symptomatic TEPS had normal spirometry (postbronchodilator ratio of forced expiratory volume in the first second [FEV1] to forced vital capacity >0.70) and COPD Assessment Test scores of 10 or greater. Participants with asymptomatic TEPS had normal spirometry and COPD Assessment Test scores of less than 10. Patient-reported respiratory symptoms and exacerbations were assessed every 4 months via phone calls. Main Outcomes and Measures: The primary outcome was assessment for accelerated decline in lung function (FEV1) in participants with symptomatic TEPS vs asymptomatic TEPS. Secondary outcomes included development of COPD defined by spirometry, respiratory symptoms, rates of respiratory exacerbations, and progression of computed tomographic-defined airway wall thickening or emphysema. Results: Of 1397 study participants, 226 had symptomatic TEPS (mean age, 60.1 [SD, 9.8] years; 134 were women [59%]) and 269 had asymptomatic TEPS (mean age, 63.1 [SD, 9.1] years; 134 were women [50%]). At a median follow-up of 5.76 years, the decline in FEV1 was -31.3 mL/y for participants with symptomatic TEPS vs -38.8 mL/y for those with asymptomatic TEPS (between-group difference, -7.5 mL/y [95% CI, -16.6 to 1.6 mL/y]). The cumulative incidence of COPD was 33.0% among participants with symptomatic TEPS vs 31.6% among those with asymptomatic TEPS (hazard ratio, 1.05 [95% CI, 0.76 to 1.46]). Participants with symptomatic TEPS had significantly more respiratory exacerbations than those with asymptomatic TEPS (0.23 vs 0.08 exacerbations per person-year, respectively; rate ratio, 2.38 [95% CI, 1.71 to 3.31], P < .001). Conclusions and Relevance: Participants with symptomatic TEPS did not have accelerated rates of decline in FEV1 or increased incidence of COPD vs those with asymptomatic TEPS, but participants with symptomatic TEPS did experience significantly more respiratory exacerbations over a median follow-up of 5.8 years.

Does weight mediate the effect of smoking on coronary heart disease? Parametric mediational g-formula analysis.

BACKGROUND: In settings in which there are time-varying confounders affected by previous exposure and a time-varying mediator, natural direct and indirect effects cannot generally be estimated unbiasedly. In the present study, we estimate interventional direct effect and interventional indirect effect of cigarette smoking as a time-varying exposure on coronary heart disease while considering body weight as a time-varying mediator. METHODS: To address this problem, the parametric mediational g-formula was proposed to estimate interventional direct effect and interventional indirect effect. We used data from the Multi-Ethnic Study of Atherosclerosis to estimate effect of cigarette smoking on coronary heart disease, considering body weight as time-varying mediator. RESULTS: Over a 11-years period, smoking 20 cigarettes per day compared to no smoking directly (not through weight) increased risk of coronary heart disease by an absolute difference of 1.91% (95% CI: 0.49%, 4.14%), and indirectly decreased coronary heart disease risk by -0.02% (95% CI: -0.05%, 0.04%) via change in weight. The total effect was estimated as an absolute 1.89% increase (95% CI: 0.49%, 4.13%). CONCLUSION: The overall absolute impact of smoking to incident coronary heart disease is modest, and we did not discern any important contribution to this effect relayed through changes to bodyweight. In fact, changes in weight because of smoking have no meaningful mediating effect on CHD risk.

Hemoglobin and adult height loss among Japanese workers: A retrospective study.

Height loss starting in middle age is reported to be associated with increased all-cause and cardiovascular mortality later in life. However, the mechanisms underlying this association are unclear. Hypoxia and oxidative stress, which are known causes of cardiovascular disease, could be reduced by hemoglobin. Therefore, hemoglobin could be inversely associated with height loss. However, high body mass index (BMI) is a known risk factor for intervertebral disc disorder, a known cause of height loss in adults. High BMI might confound the association between hemoglobin and height loss. Therefore, we performed analyses stratified by BMI status. To clarify the association between hemoglobin and height loss, we conducted a retrospective study of Japanese workers (6,471 men and 3,180 women) aged 40-74 years. Height loss was defined as being in the highest quintile of height decrease per year. In men overall and men with BMI <25 kg/m2, hemoglobin was significantly inversely associated with height loss; but no association was observed for men with high BMI (BMI ≥25 kg/m2) and for women. For men, after adjusting for known cardiovascular risk factors, adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for height loss with each 1 standard deviation (SD) increase in hemoglobin (1.0 g/dL for men and 0.8g/dL for women) were 0.89 (0.83, 0.95) for men overall, 0.82 (0.75, 0.89) for men who do not have high BMI, and 1.01 (0.92, 1.12) for men with high BMI. For women, the corresponding values were 0.97 (0.89, 1.06), 0.98 (0.89, 1.09), and 0.93 (0.75, 1.15) respectively. Hemoglobin is significantly inversely associated with height loss in men who do not have high BMI, but not in men with high BMI or women. These results help clarify the mechanisms underlying height loss, which has been reported to be associated with a higher risk of mortality in adults.

Cigarette Smoke Stimulates SARS-CoV-2 Internalization by Activating AhR and Increasing ACE2 Expression in Human Gingival Epithelial Cells.

A large body of evidence shows the harmful effects of cigarette smoke to oral and systemic health. More recently, a link between smoking and susceptibility to coronavirus disease 2019 (COVID-19) was proposed. COVID-19 is due to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which uses the receptor ACE2 and the protease TMPRSS2 for entry into host cells, thereby infecting cells of the respiratory tract and the oral cavity. Here, we examined the effects of cigarette smoke on the expression of SARS-CoV-2 receptors and infection in human gingival epithelial cells (GECs). We found that cigarette smoke condensates (CSC) upregulated ACE2 and TMPRSS2 expression in GECs, and that CSC activated aryl hydrocarbon receptor (AhR) signaling in the oral cells. ACE2 was known to mediate SARS-CoV-2 internalization, and we demonstrate that CSC treatment potentiated the internalization of SARS-CoV-2 pseudovirus in GECs in an AhR-dependent manner. AhR depletion using small interference RNA decreased SARS-CoV-2 pseudovirus internalization in CSC-treated GECs compared with control GECs. Our study reveals that cigarette smoke upregulates SARS-CoV-2 receptor expression and infection in oral cells. Understanding the mechanisms involved in SARS-CoV-2 infection in cells of the oral cavity may suggest therapeutic interventions for preventing viral infection and transmission.

Cigarette Smoking and Longitudinal Associations With Blood Pressure: The CARDIA Study.

Background The associations of chronic cigarette smoking with blood pressure (BP) remain mixed. It is unclear whether a lack of examination of racial differences contributed to the mixed findings in previous studies. Black smokers metabolize nicotine at a slower rate than White smokers and racial discrimination contributes to nicotine dependence and higher BP among Black smokers. Methods and Results We studied the association between cigarette smoking and longitudinal (30-year) changes in systolic BP, diastolic BP, and pulse pressure (PP) in 4786 Black and White individuals from the CARDIA (Coronary Artery Risk Development in Young Adults) study using repeated-measures regression models. Neither systolic BP, nor diastolic BP differed between Black consistent smokers compared with Black never smokers, although Black consistent smokers had higher PP than Black never smokers (ß=1.01 mm Hg, P=0.028). White consistent smokers had similar systolic BP, but lower diastolic BP (ß=-2.27 mm Hg, P<0.001) and higher PP (ß=1.59 mm Hg, P<0.001) compared with White never smokers. There were no differences in systolic BP, diastolic BP, or PP between Black or White long-term former smokers compared with never smokers (all P>0.05). Conclusions Although the associations of cigarette smoking with alterations in BP are small, the greater PP observed in consistent smokers may contribute in part to the higher cardiovascular disease risk observed in this group because PP is a strong predictor of cardiovascular disease risk after middle age.

Sex Differences in the Association of Cigarette Craving With Insula Structure.

BACKGROUND: Cigarette craving, which can negatively impact smoking cessation, is reportedly stronger in women than in men when they initiate abstinence from smoking. Identifying approaches to counteract craving in people of different sexes may facilitate the development of personalized treatments for Tobacco Use Disorder, which disproportionately affects women. Because cigarette craving is associated with nicotine dependence and structure of the insula, this study addressed whether a person's sex influences these associations. METHODS: The research participants (n = 99, 48 women) reported daily cigarette smoking and provided self-reports of nicotine dependence. After overnight abstinence from smoking, they underwent structural magnetic resonance imaging scanning to determine cortical thickness of the left and right anterior circular insular sulcus, and self-rated their cigarette craving before and after their first cigarette of the day. RESULTS: Women reported stronger craving than men irrespective of smoking condition (i.e., pre- and post-smoking) (P = .048), and smoking reduced craving irrespective of sex (P < .001). A 3-way interaction of sex, smoking condition, and right anterior circular insular sulcus thickness on craving (P = .033) reflected a negative association of cortical thickness with pre-smoking craving in women only (P = .012). No effects of cortical thickness in the left anterior circular insular sulcus were detected. Nicotine dependence was positively associated with craving (P < .001) across groups and sessions, with no sex differences in this association. CONCLUSIONS: A negative association of right anterior insula thickness with craving in women only suggests that this region may be a relevant therapeutic target for brain-based smoking cessation interventions in women.

Structural and functional remodeling of the female Apoe-/- mouse aorta due to chronic cigarette smoke exposure.

Despite a decline in popularity over the past several decades, cigarette smoking remains a leading cause of cardiovascular morbidity and mortality. Yet, the effects of cigarette smoking on vascular structure and function are largely unknown. To evaluate changes in the mechanical properties of the aorta that occur with chronic smoking, we exposed female apolipoprotein E-deficient mice to mainstream cigarette smoke daily for 24 wk, with room air as control. By the time of euthanasia, cigarette-exposed mice had lower body mass but experienced larger systolic/diastolic blood pressure when compared with controls. Smoking was associated with significant wall thickening, reduced axial stretch, and circumferential material softening of the aorta. Although this contributed to maintaining intrinsic tissue stiffness at control levels despite larger pressure loads, the structural stiffness became significantly larger. Furthermore, the aorta from cigarette-exposed mice exhibited decreased ability to store elastic energy and augment diastolic blood flow. Histological analysis revealed a region-dependent increase in the cross-sectional area due to smoking. Increased smooth muscle and extracellular matrix content led to medial thickening in the ascending aorta, whereas collagen deposition increased the thickness of the descending thoracic and abdominal aorta. Atherosclerotic lesions were larger in exposed vessels and featured a necrotic core overlaid by a thinned fibrous cap and macrophage infiltration, consistent with a vulnerable phenotype. Collectively, our data indicate that cigarette smoking decreases the mechanical functionality of the aorta, inflicts morphometric alterations to distinct segments of the aorta, and accelerates the progression of atherosclerosis.NEW & NOTEWORTHY We studied the effects of chronic cigarette smoking on the structure and function of the aorta in a mouse model of nose-only aerosol inhalation. Our data indicated that exposure to cigarette smoke impairs vascular function by reducing the ability of the aorta to store elastic energy and by decreasing aortic distensibility. Combined with a more vulnerable atherosclerotic phenotype, these findings reveal the biomechanical mechanisms that support the development of cardiovascular disease due to cigarette smoking.

Perceptions, symptoms, and practices of electronic cigarette users: Descriptive analysis and validation of Arabic short form vaping consequences questionnaire.

BACKGROUND: E-cigarette (EC) use is increasing worldwide. Understanding the practices and perceptions of e-cigarette users and profiling the symptoms they experience is essential for regulating the use of such products. This study aims to investigate the practices and perceptions of e-cigarette users in Jordan and examine the symptoms (e.g. respiratory) they associate with e-cigarette use. METHODS: A cross-sectional online survey was conducted to assess EC use and tobacco smoking behaviors and the corresponding health symptoms among EC users in Jordan. EC use expectancies were also assessed using the Short Form Vaping Consequences Questionnaire, which was first translated into Arabic and tested for validity and reliability. RESULTS: Out of the 400 EC users surveyed, 95.5% were male, 76.2% used nicotine-containing juice, and 56.8% were concurrent tobacco smokers. Further, the participants had a mean age of 28.9 years (±10.2). Among dual EC/cigarette users, 88.6% reported that they tried to quit cigarette smoking, with e-cigarette use being the most commonly tried method of smoking cessation. The smoking-related symptoms reported by regular cigarette smokers mainly included sputum production (77.5%). The participants reported that using e-cigarettes instead of tobacco cigarettes had led to improvements in their sputum production (60.8%), breathing (59%), and general wellbeing (52%). Pleasant taste, enjoyable taste sensation, and flavor were significantly stronger (P-value < 0.05) among e-cigarette users compared to dual users. Dual EC/cigarette users reported stronger perceptions in the negative consequences scale, particularly with regards to the hazardous effects of smoking on health (P-value < 0.05). CONCLUSION: Dual daily use of e-cigarettes and regular cigarettes is a common practice among EC users. We recommend that further research is conducted on dual EC/cigarette use and the potential health risks this may have (e.g. higher nicotine intake as compared to the single use of either products).

Smoking status and endothelial function in Japanese men.

It is established that smoking is a major risk factor of atherosclerosis. Endothelial dysfunction occurs in the initial step in the pathogenesis of atherosclerosis and plays a critical role in the development of atherosclerosis. The purpose of this study was to evaluate the association between smoking status and endothelial function in detail in men. We measured flow-mediated vasodilation (FMD) in 2209 Japanese men including 1181 men who had never smoked and 1028 current smokers. All of the participants were divided into five groups by smoking pack-years: never smoker group (= 0), light smoker group (> 0 to 10), moderate smoker group (> 10 to 20), heavy smoker group (> 20 to 30) and excessive smoker group (> 30). FMD significantly decreased in relation to pack-years (6.6 ± 3.4% in the never smoker group, 6.8 ± 3.0% in the light smoker group, 6.5 ± 2.9% in the moderate smoker group, 5.9 ± 2.9% in the heavy smoker group, and 4.9 ± 2.7% in the excessive smoker group; P < 0.001). After adjustment for age (≥ 65 years), body mass index, systolic blood pressure, low-density lipoprotein cholesterol, glucose, and year of recruitment, FMD was significantly smaller in the excessive smoker group than in the never smoker group as a reference group (OR 1.95, 95% CI 1.42 to 2.67; P < 0.001). These findings suggest that FMD decreases with an increase in the number of cigarettes smoked and that excessive smoking is associated with endothelial dysfunction. Cigarette smoking is harmful to vascular function in men who are heavy smokers.

Lack of Smoking Effects on Pharmacokinetics of Oral Paliperidone-analysis of a Naturalistic Therapeutic Drug Monitoring Sample.

INTRODUCTION: Major smoking effects have been reported for a series of psychotropic agents, mainly including substrates of CYP450 1A2, although smoking may also affect alternative metabolic pathways. To our knowledge, smoking effects on paliperidone pharmacokinetics have not been assessed yet. METHODS: We compared plasma concentrations of paliperidone as well as dose-corrected-plasma concentrations (C/D) from a naturalistic database between smokers and nonsmokers using nonparametrical tests, such as the Mann-Whitney U-test (MWU). Additionally, we compared light and heavy smokers with nonsmokers separately. RESULTS: Comparing 55 smokers with 37 nonsmokers treated with oral paliperidone, no differences in the percentage of females, age, body weight, body mass index, and daily paliperidone dose were reported (p=0.709 for χ2, p=0.26, p=0.38, p=0.67, and p=0.8 for MWU). No differences were detected in plasma concentrations or C/D values (p=0.50 and p=0.96 for MWU). Likewise, differences in daily dose, plasma concentrations, or C/D values were not significant between light smokers (n=17) and nonsmokers (p=0.61, p=0.81, and p=0.33 for MWU) or heavy smokers (n=22) and nonsmokers (p=0.874, p=0.38, and p=0.59; MWU in all cases). DISCUSSION: Paliperidone is not affected by smoking, and paliperidone dose-adjustments in smokers may not be necessary. This may be seen as an essential difference to risperidone, whose cytochrome-mediated metabolism might be affected by smoking.

Matrix metalloproteinase (MMP)-1 and MMP-3 gene variations affect MMP-1 and -3 serum concentration and associates with breast cancer.

Matrix metallopeptidases (MMPs) 1 and 3 have been shown to contribute to the initiation, and progression of different cancers, including breast cancer (BC). In this study, we aimed to examine the relations between polymorphisms of MMP1 (rs1799750) and MMP3 (rs632478) and their circulating levels with BC. The polymorphisms were genotyped by PCR-based Restriction Fragment Length Polymorphism (RFLP) and Allele-Specific PCR (AS-PCR) among 100 patients and 100 controls. MMP1 and MMP3 serum levels were measured by enzyme-linked immunosorbent assay (ELISA). Genotype distributions of MMP1 and MMP3 genes showed significant difference between patients and controls. The distribution of 2G/2G, 1G/2G and 1G/1G genotypes for MMP1 was 74%, 2% and 24% in the patients and 38%, 2% and 60% in the controls, respectively (P = 0.0001). For MMP3 the distribution of C/C, A/C and A/A genotypes was 28%, 54% and 18% in patients and 48%, 40% and 12% in controls, respectively (P = 0.01). For MMP1, the 2G/2G genotype was linked with a higher risk of BC when compared with that of the 1G/1G genotype (OR = 4.86; 95% CI = 2.63-8.99; P = 0.0001). For MMP3, in co-dominant model, there was a higher risk of BC in A/A and A/C genotype carriers (A/A: OR = 2.57; 95% CI = 1.08-6.11; P = 0.03) (A/C: OR = 2.31 95% CI = 1.24-4.30; P = 0.008). We also showed that MMP1 and MMP3 serum level was significantly increased in BC patients compared to controls. MMP1 and MMP3 genetic variations and their circulating levels are both significantly related to BC.

Mediation by differential DNA methylation of known associations between single nucleotide polymorphisms and bladder cancer risk.

BACKGROUND: Though bladder cancer has been the subject of many well-powered genome-wide association studies, the mechanisms involving bladder-cancer-associated single nucleotide polymorphisms (SNPs) remain largely unknown. This study focuses on rs798766, rs401681, rs2294008, and rs8102137, which have been associated with bladder cancer and are also cis-acting methylation quantitative loci (mQTL). METHODS: Among 412 bladder cancer cases and 424 controls from the Women's Health Initiative (WHI), we assessed whether the effects of these SNPs on bladder cancer are mediated through proximal DNA methylation changes in pre-diagnostic blood at mQTL-associated CpG sites, which we refer to as natural indirect effects (NIEs). We used a multiple-mediator mediation model for each of the four mQTL adjusted for matching variables and potential confounders, including race/ethnicity, smoking status, and pack-years of smoking. RESULTS: While not statistically significant, our results suggest that substantial proportions of the modest effects of rs401681 (ORNIE = 1.05, 95% confidence interval (CI) = 0.89 to 1.25; NIE percent = 98.5%) and rs2294008 (ORNIE = 1.10, 95% CI = 0.90 to 1.33; NIE percent = 77.6%) on bladder cancer risk are mediated through differential DNA methylation at nearby mQTL-associated CpG sites. The suggestive results indicate that rs2294008 may affect bladder cancer risk through a set of genes in the lymphocyte antigen 6 family, which involves genes that bind to and modulate nicotinic acetylcholine receptors. There was no suggestive evidence supporting mediation for rs8102137 and rs798766. CONCLUSIONS: Though larger studies are necessary, the methylation changes associated with rs401681 and rs2294008 at mQTL-associated CpG sites may be relevant for bladder carcinogenesis, and this study demonstrates how multi-omic data can be integrated to help understand the downstream effects of genetics variants.

Epigallocatechin gallate diminishes cigarette smoke-induced oxidative stress, lipid peroxidation, and inflammation in human bronchial epithelial cells.

Cigarette smoke (CS), the major risk factor of chronic obstructive pulmonary disease (COPD), contains numerous free radicals that can cause oxidative stress and exaggerated inflammatory responses in the respiratory system. Lipid peroxidation which is oxidative degradation of polyunsaturated fatty acids and results in cell damage has also been associated with COPD pathogenesis. Increased levels of lipid peroxidation as well as its end product 4-hydroxynonenal have indeed been detected in COPD patients. Additionally, reactive oxygen species such as those contained in CS can activate nuclear factor-κB signaling pathway, initiating cascades of proinflammatory mediator expression. As emerging evidence attests to the antioxidative and anti-inflammatory properties of tea catechins, we sought to determine whether epigallocatechin gallate, the most abundant tea catechin, can provide protection against oxidative stress, lipid peroxidation, and inflammatory responses caused by CS. We found that EGCG treatment blocked cigarette smoke extract (CSE)-induced oxidative stress as indicated by decreased production and accumulation of reactive oxygen species in airway epithelial cells (AECs). Likewise, lipid peroxidation in CSE-stimulated AECs was suppressed by EGCG. Our findings further suggest that EGCG sequestered 4-hydroxynonenal and interfered with its protein adduct formation. Lastly, we show that EGCG inhibited nuclear factor-κB activation and the downstream expression of proinflammatory mediators. In summary, our study describing the antioxidative and anti-inflammatory effects of EGCG in CSE-exposed AECs provide valuable information about the therapeutic potential of this tea catechin for COPD.

Resistance training prevents right ventricle hypertrophy in rats exposed to secondhand cigarette smoke.

Exposure to secondhand cigarette smoke is associated with the development of diverse diseases. Resistance training has been considered one of the most useful tools for patients with pulmonary disease, improving their quality of life. This study aimed to evaluate the effect of resistance training (RT) on the prevention of thickening of the right ventricle wall of rats exposed to secondhand cigarette smoke. Thirty-two Wistar rats were divided into four groups: Control (C), Smoker (S), Exercised (E) and Exercised Smoker (ES). The smoker groups were exposed to the smoke of four cigarettes for 30 min, twice daily, five days a week, for 16 weeks. The exercised groups climbed on a vertical ladder with progressive load, once a day, five days a week, for 16 weeks. The heart, trachea, lung, liver and gastrocnemius muscle were removed for histopathological analysis. Pulmonary emphysema (S and ES vs C and E, P < 0.0001) and pulmonary artery thickness enlargement (S vs C and E, P = 0.003, ES vs C, P = 0.003) were detected in the smoking groups. There was an increase in the right ventricle thickness in the S group compared with all other groups (P < 0.0001). An increase in resident macrophages in the liver was detected in both smoking groups compared with the C group (P = 0.002). Additionally, a relevant reduction of the diameter of the muscle fibers was detected only in ES compared with the C, S and E groups (P = 0.0002), impairing, at least in part, the muscle mass in exercised smoking rats. Therefore, it was concluded that resistance training prevented the increase of thickness of the right ventricle in rats exposed to secondhand cigarette smoke, but it may be not so beneficial for the skeletal muscle of smoking rats.

Differential effects of tobacco cigarettes and electronic cigarettes on endothelial function in healthy young people.

Tobacco cigarette (TC) smoking has never been lower in the United States, but electronic cigarette (EC) vaping has reached epidemic proportions among our youth. Endothelial dysfunction, as measured by flow-mediated vasodilation (FMD) is a predictor of future atherosclerosis and adverse cardiovascular events and is impaired in young TC smokers, but whether FMD is also reduced in young EC vapers is uncertain. The aim of this study in otherwise healthy young people was to compare the effects of acute and chronic tobacco cigarette (TC) smoking and electronic cigarette (EC) vaping on FMD. FMD was compared in 47 nonsmokers (NS), 49 chronic EC vapers, and 40 chronic TC smokers at baseline and then after EC vapers (n = 31) and nonsmokers (n = 47) acutely used an EC with nicotine (ECN), EC without nicotine (EC0), and nicotine inhaler (NI) at ~4-wk intervals and after TC smokers (n = 33) acutely smoked a TC, compared with sham control. Mean age (NS, 26.3 ± 5.2 vs. EC, 27.4 ± 5.45 vs. TC, 27.1 ± 5.51 yr, P = 0.53) was similar among the groups, but there were more female nonsmokers. Baseline FMD was not different among the groups (NS, 7.7 ± 4.5 vs. EC:6.6 ± 3.6 vs. TC, 7.9 ± 3.7%∆, P = 0.35), even when compared by group and sex. Acute TC smoking versus control impaired FMD (FMD pre-/postsmoking, -2.52 ± 0.92 vs. 0.65 ± 0.93%∆, P = 0.02). Although the increase in plasma nicotine was similar after EC vapers used the ECN versus TC smokers smoked the TC (5.75 ± 0.74 vs. 5.88 ± 0.69 ng/mL, P = 0.47), acute EC vaping did not impair FMD. In otherwise healthy young people who regularly smoke TCs or ECs, impaired FMD compared with that in nonsmokers was not present at baseline. However, FMD was significantly impaired after smoking one TC, but not after vaping an equivalent "dose" (estimated by change in plasma nicotine) of an EC, consistent with the notion that non-nicotine constituents in TC smoke mediate the impairment. Although it is reassuring that acute EC vaping did not acutely impair FMD, it would be dangerous and premature to conclude that ECs do not lead to atherosclerosis.NEW & NOTEWORTHY In our study of otherwise healthy young people, baseline flow-mediated dilation (FMD), a predictor of atherosclerosis and increased cardiovascular risk, was not different among tobacco cigarette (TC) smokers or electronic cigarette (EC) vapers who had refrained from smoking, compared with nonsmokers. However, acutely smoking one TC impaired FMD in smokers, whereas vaping a similar EC "dose" (as estimated by change in plasma nicotine levels) did not. Finally, although it is reassuring that acute EC vaping did not acutely impair FMD, it would be premature and dangerous to conclude that ECs do not lead to atherosclerosis or increase cardiovascular risk.

The effect of cigarette smoking on the semen parameters of infertile men.

INTRODUCTION: 36.9% of men worldwide use tobacco. Previous studies suggest a negative effect of cigarette smoking on semen quality, but the results are contradictory. We have studied the effects of smoking on the semen characteristics such as sperm concentration, semen volume, sperm motility, sperm vitality and sperm morphology in a large group of infertile men. METHODS: This retrospective study was conducted on a total of 5146 infertile men with at least one year of idiopathic infertility, who admitted to the Centre for Reproductive medicine (CRG) at the Brussels University Hospital, Belgium between 2010 and 2017. The smokers were classified as mild (1-10 cigarettes/d), moderate (11-20 cigarettes/d) or heavy smokers (> 20 cigarettes/d). Semen analysis was performed for all patients. Statistical analysis was performed using the R software package and t-test or Mann-Whitney U tests were used, group comparisons were performed using ANOVA, ANCOVA or Kruskal-Wallis tests as appropriate. A p-value <0.05 was considered as statistically significant. RESULTS: Comparing the semen parameters in the two global groups showed that smoking had a significant decrease in semen volume (p=0.04074) and sperm concentration (p=0.029). ANOVA testing on the different smoking groups versus non-smoking group showed a significant decrease in sperm concentration (p=0.0364). After adjusting for the confounders, age and testosterone, ANCOVA testing showed significant effect on the sperm concentration (p=0.03871) in smokers versus non-smokers. No significant correlation was detected between the other semen characteristics. CONCLUSION: We concluded that smoking had a significant and independent effect on the sperm concentration in a semen analysis. Other parameters, like semen volume, sperm motility, sperm vitality and sperm morphology were not influenced by smoking.

Examining sex, adverse childhood experiences, and oxytocin on neuroendocrine reactivity in smokers.

Adverse childhood experiences (ACE) are associated with greater neuroendocrine responses to social stress in substance users. The neuropeptide oxytocin might attenuate this relationship. Given sex differences in ACE exposure and neuroendocrine stress reactivity, it is unknown whether this association is similar for males and females. Therefore, this secondary analysis evaluated the interactive effect of sex, ACE, and acute oxytocin administration on neuroendocrine stress responses in adult cigarette smokers (N = 144). Participants completed the Adverse Childhood Experiences Questionnaire at screening and were randomized to receive intranasal oxytocin or placebo before undergoing the Trier Social Stress Task (TSST). Cortisol levels were assessed at pre- and post-medication administration and at 20 and 40 min following the TSST. Generalized linear mixed models were developed to predict post-TSST cortisol levels. Predictors included treatment assignment (placebo vs. oxytocin), sex (male vs. female), ACE (0-10 total score), pre-medication cortisol levels, and minutes since medication administration. The hypothesized three-way interaction between sex, oxytocin, and ACE scores was significant. Linear associations between ACE scores and cortisol reactivity indicated higher ACE scores were associated with attenuated cortisol response in females, regardless of treatment condition. For males, higher ACE scores were associated with heightened cortisol response, an effect that was attenuated by oxytocin. Results indicate that the association between ACE and neuroendocrine reactivity to social stress, as well as the attenuating effect of oxytocin, is differentially impacted by sex. Males with greater childhood adversity may be more likely to benefit from oxytocin's anxiolytic properties.

The α7 and ß2 nicotinic acetylcholine receptor subunits regulate apoptosis in the infant hippocampus, and in sudden infant death syndrome (SIDS).

Apoptosis is increased in the hippocampus of infants who died of sudden infant death syndrome (SIDS), yet it is not known via which mechanism this has occurred. Following existing support for a role of the α7 and ß2 nicotinic acetylcholine receptor (nAChR) subunits in apoptotic regulation, we aimed to determine whether these subunits are altered in the SIDS hippocampus and if they are correlated with cell death markers of active caspase-3 (Casp-3) and TUNEL. Further analyses were run according to the presence of major SIDS risk factors related to hypoxia (bed-sharing and prone sleeping), infection (presence of an upper respiratory tract infection (URTI)), cigarette smoke exposure and gender. Immunohistochemical expression of the markers was studied in 4 regions of the hippocampus (Cornu Ammonis (CA)1, CA2, CA3, CA4) and subiculum amongst 52 infants (aged 1-7 months) who died suddenly and unexpectedly (SUDI) and for whom the cause of death was explained (eSUDI; n = 9), or not and characterised as SIDS I (n = 8) and SIDS II (n = 35) according to the San Diego diagnostic criteria. Results showed that SIDS II infants had widespread increases in TUNEL compared with eSUDI and SIDS I infants, as well as increased α7 and Casp-3 in CA2 compared to eSUDI infants, although these changes were predominant amongst infants who did not bed-share. Cigarette smoke exposure had minimal effects on the markers, while an URTI was associated with changes in all markers (after accounting for bed-sharing). Our findings support the role of nAChRs in regulating apoptosis in the SIDS hippocampus, and highlight the need for separate analysis according to risk factors.

Cigarette smoking blocks the benefit from reduced weight gain for insulin action by shifting lipids deposition to muscle.

Cigarette smoking (CS) is known to reduce body weight and this often masks its real effect on insulin action. The present study tested the hypothesis that CS can divert lipid deposition to muscles to offset the supposed benefit of reduced body weight gain on insulin signalling in this major site for glucose tolerance (or insulin action). The study was conducted in mice exposed to chronic CS followed by either a chow (CH) diet or a high-fat (HF) diet. CS increased triglyceride (TG) levels in both plasma and muscle despite a reduced body weight gain and adiposity. CS led to glucose intolerance in CH-fed mice and they retained the glucose intolerance that was induced by the HF diet. In adipose tissue, CS increased macrophage infiltration and the mRNA expression of TNFα but suppressed the protein expression of adipose triglyceride lipase and PPARγ. While CS increased hormone-sensitive lipase and suppressed the mRNA expression of leptin, these effects were blunted in HF-fed mice. These results imply that CS impairs insulin signalling in skeletal muscle via accumulated intramuscular lipids from lipolysis and lipodystrophy of adipose tissues. This may explain why smokers may not benefit from insulin sensitising effects of reduced body weight gain.

No effect of repetitive tDCS on daily smoking behaviour in light smokers: A placebo controlled EMA study.

INTRODUCTION: The effectiveness of repetitive transcranial Direct Current Stimulation (tDCS) on reducing smoking behaviour has been studied with mixed results. Smoking behaviour is influenced by affect and context, therefore we choose to use mobile ecological momentary assessments (EMA) to measure changes in smoking behaviour after tDCS. METHODS: In a randomized, placebo-controlled, between subject study, we applied tDCS bilaterally with the anodal electrode targeting the right DLPFC (https://clinicaltrials.gov/ct2/show/NCT03027687). Smokers were allocated to six sessions of either active tDCS (n = 35) or sham tDCS (n = 36) and received two sessions on three different days in one week. They were asked to keep track of their daily cigarette consumption, craving and affect in an application on their mobile phones for three months starting one week before the first tDCS session. RESULTS: Number of smoked cigarettes a day progressively decreased up to one week after the last tDCS session in both conditions. Active treatment had no additional effect on cigarette consumption, craving and affect. CONCLUSIONS: In this exploratory study, repetitive bilateral tDCS over the DLPFC had no effect on daily smoking behaviour. Future research needs to investigate how motivation to quit smoking and the number of tDCS sessions affect the efficacy of repetitive tDCS.