Meta-analysis of the effects of smoking and smoking cessation on triglyceride levels.

Smoking increases lipid levels, including triglycerides, leading to increased cardiovascular disease risk. We performed a meta-analysis to quantify the effects of smoking and smoking cessation on triglyceride levels. The PubMed and Scopus databases were searched to identify studies reporting either triglyceride levels in smokers and non-smokers or the effects of smoking cessation on triglyceride levels. Fixed- and random-effects models were used to perform the analyses when three or more studies/comparisons were available. We identified 169 and 21 studies evaluating the effects of smoking and smoking cessation, respectively, on triglyceride levels. Triglyceride levels were 0.50 mmol/L (95% confidence interval: 0.49-0.50 mmol/L) higher in smokers than non-smokers, but the effect differed widely across studies. No statistically significant effect was observed on triglyceride levels between baseline and 6 weeks (mean difference [MD] = 0.02 [-0.09, 0.12] mmol/L), 2 months (MD = 0.03 [-0.21, 0.27] mmol/L), 3 months (MD = 0.08 [-0.03, 0.21] mmol/L), or 1 year (MD = 0.04 [-0.06, 0.14] mmol/L) after quitting. However, a slightly significant decrease in triglyceride levels was observed at 1 month after cessation (MD = -0.15 [-0.15, -0.01] mmol/L). The results of this meta-analysis provide a basis for understanding the effects of smoking and smoking cessation on triglyceride levels, which could have important implications for public health.

Smoking and apolipoprotein levels: A meta-analysis of published data.

Background: Apolipoproteins are major components of lipoproteins such as high-density lipoprotein (HDL) and very-low-density lipoprotein and are considered nontraditional markers in the risk assessment for cardiovascular disease. The goal of this review was to quantify the effects of smoking and smoking cessation on serum levels of apolipoproteins AI, AII, and B and the ratio of apolipoproteins B and AI. Methods: PubMed and Scopus were searched up to June 2021 to identify publications that reported the levels of apolipoproteins AI, AII, and B and the apolipoprotein B/AI ratio in smokers and nonsmokers as well as articles reporting the effect of smoking cessation on the same endpoints. Meta-analyses were performed when a sufficient number (n ≥ 3) of articles evaluating the same outcome were available. Results: Forty-nine studies had assessed apolipoprotein levels in smokers and nonsmokers. The meta-analyses comparing the levels of apolipoproteins AI and AII showed decreased levels in smokers relative to nonsmokers. On the other hand, the apolipoprotein B levels and apolipoprotein B/AI ratio were increased in smokers relative to nonsmokers. Insufficient publications were available on which to perform meta-analyses on the effects of smoking cessation on apolipoprotein levels. Conclusions: Smoking is associated with reduced levels of apolipoproteins AI and AII (in line with reduced levels of HLD-cholesterol) and increased apolipoprotein B levels and apolipoprotein B/AI ratio, thereby confirming the negative impact of smoking on lipid metabolism, which contributes to increased cardiovascular risk. More data are needed to elucidate the effects of smoking cessation on these cardiovascular risk endpoints.

Impact of switching to a heat-not-burn tobacco product on CYP1A2 activity.

BACKGROUND: Cigarette smoking induces cytochrome P450 1A2 (CYP1A2) expression and activity, while smoking cessation normalizes the levels of this enzyme. The aim of this publication is to summarize the data on CYP1A2 gene expression and activity in preclinical and clinical studies on the Tobacco Heating System (THS), currently marketed as IQOS® with HEETs®, and to summarize the potential effects on CYP1A2 to be expected upon switching to reduced-risk products (RRPs). METHODS: We summarized PMI's preclinical and clinical data on the effects of switching from cigarette smoking to THS. RESULTS: Data from four preclinical mouse and rat studies showed that, upon either cessation of cigarette smoke exposure or switching to THS exposure, the upregulation of CYP1A2 observed with exposure to cigarette smoke reverted close to fresh-air levels. Data from four clinical studies yielded similar results on CYP1A2 activity within a time frame of five days. Furthermore, the effects of switching to THS were similar to those seen after smoking cessation. CONCLUSIONS: Because smoking cessation and switching to either electronic cigarettes or THS seem to have similar effects on CYP1A2 activity, the same measures taken for patients treated with narrow therapeutic index drugs that are metabolized by CYP1A2 and who quit smoking should be recommended for those switching to RRPs.

Reduced levels of biomarkers of exposure in smokers switching to the Carbon-Heated Tobacco Product 1.0: a controlled, randomized, open-label 5-day exposure trial.

In addition to smoking cessation, for those who would otherwise continue to smoke, replacing cigarettes with less harmful alternatives can reduce the harms of smoking. Heating instead of burning tobacco reduces, or eliminates, the formation of harmful and potentially harmful constituents (HPHC) that are found in cigarette smoke. The Carbon-Heated Tobacco Product (CHTP), a heat-not-burn tobacco product, mimics the cigarette smoking ritual. This randomized, open-label, two-arm, parallel-group, short-term confinement study tested the hypothesis that the geometric means of the BoExp levels for subjects switching to CHTP 1.0 for 5 days are lower relative to those continuing to smoke cigarettes. Biomarkers of exposure (BoExp), including nicotine, urinary excretion of mutagenic constituents (Ames test), and cytochrome P450 (CYP) 1A2 activity, were measured in blood and/or 24-h urine samples during ad libitum product use. Nicotine exposure remained at similar levels in individuals using CHTP as in those continuing to smoke cigarettes. Switching to CHTP resulted in marked decreases in all other urinary BoExp (56-97%), carboxyhemoglobin (59%), urinary mutagenic constituents, and CYP1A2 activity compared with continued cigarette smoking. Our results provide evidence of decreased exposure to 15 selected HPHCs in smokers switching from cigarettes to exclusive CHTP use.Trial registration ClinicalTrials.gov: NCT02503254; Date of first registration: 20/07/2015 https://www.clinicaltrials.gov/ct2/show/NCT02503254 .Study protocol Study protocol published at: https://www.clinicaltrials.gov/ProvidedDocs/54/NCT02503254/Prot_000.pdf .

Exposure to harmful and potentially harmful constituents decreased in smokers switching to Carbon-Heated Tobacco Product.

BACKGROUND: "Heat-not-burn" tobacco products are designed to heat processed tobacco instead of combusting it, thus significantly reducing the formation of harmful and potentially harmful constituents (HPHCs) found in cigarette smoke, and ultimately reducing the risk of smoking-related diseases. The Carbon-Heated Tobacco Product (CHTP), a heat-not-burn tobacco product similar in appearance and use ritual to cigarettes, has been developed for smokers who would otherwise continue smoking as an alternative to cigarettes. To evaluate reduced risk of harm potential of CHTP, it is critical to quantify exposure to HPHCs and consequent biological pathway disturbances involved in disease onset in smokers who switch to CHTP. METHODS: In this 2-arm, parallel-group study, adult healthy smokers, not willing to quit, were randomized to switch to CHTP 1.2 (n = 80) or to continue using cigarettes (n = 40) for 5 days in confinement followed by 85 days in an ambulatory setting. Endpoints included biomarkers of exposure (BoExp) to HPHCs, and to nicotine, urinary excretion of mutagenic constituents (Ames assay), CYP1A2 activity, biomarkers of effect, and safety. RESULTS: In switchers to CHTP, BoExp were 40%-95% lower compared to smokers after 5 days of product use, with sustained reductions (36%-93%) observed on Day 90. Urine mutagenicity and CYP1A2 activity were also lower in the CHTP group. Exposure to nicotine was higher in the CHTP group at Day 5, but was similar between the two groups at Day 90. Favorable changes in some biomarkers of effect were observed in the CHTP group showing reductions in white blood cell count, soluble intracellular adhesion molecule-1, and 11-dehydro-thromboxane B2, respectively, indicative of reduced inflammation, endothelial dysfunction, and platelet activation. CONCLUSIONS: Switching from cigarettes to CHTP resulted in significantly reduced exposure to HPHCs and was associated with observed improvements in some biomarkers of effect representative of pathomechanistic pathways underlying the development of smoking-related diseases.

Reduction in Exposure to Selected Harmful and Potentially Harmful Constituents Approaching Those Observed Upon Smoking Abstinence in Smokers Switching to the Menthol Tobacco Heating System 2.2 for 3 Months (Part 1).

INTRODUCTION: The Tobacco Heating System (THS) is a "heat-not-burn" tobacco product designed to generate significantly lower levels of harmful and potentially harmful constituents (HPHCs) and present lower risk of harm than cigarettes. This study assessed the exposure reduction to selected HPHCs in smokers switching to menthol Tobacco Heating System (mTHS) 2.2 compared with smokers continuing smoking menthol cigarettes (mCCs) and smoking abstinence (SA) for 5 days in a confined setting, followed by an 86-day ambulatory period. METHODS: A total of 160 healthy adult US smokers participated in this randomized, three-arm parallel group, controlled clinical study. Biomarkers of exposure to 16 HPHCs were measured in blood and 24-hour urine. Safety was monitored throughout the study. Information was also gathered on product evaluation, product use, subjective effects, and clinical risk markers (co-publication Part 2). RESULTS: Nicotine uptake was comparable in both exposure groups (mTHS:mCC ratio of 96% on day 90). On day 5, biomarker of exposure levels to other HPHCs were reduced by 51%-96% in the mTHS group compared with the mCC group, and these reductions were sustained for most biomarkers of exposure over ambulatory period. After 90 days of use, the level of satisfaction with mTHS and suppression of urge to smoke were comparable to mCC. CONCLUSION: Switching from mCCs to mTHS significantly reduced the exposure to HPHCs to levels approaching those observed in subjects who abstained from smoking for the duration of the study. IMPLICATIONS: This study compared the impact of switching to mTHS on biomarkers of exposure, relative to continued smoking or SA. TRIAL REGISTRATION: NCT01989156 (ClinicalTrials.gov).

Favorable Changes in Biomarkers of Potential Harm to Reduce the Adverse Health Effects of Smoking in Smokers Switching to the Menthol Tobacco Heating System 2.2 for 3 Months (Part 2).

INTRODUCTION: Tobacco Heating System (THS) 2.2, a candidate modified-risk tobacco product, aims at offering an alternative to cigarettes for smokers while substantially reducing the exposure to harmful and potentially harmful constituents found in cigarette smoke. METHODS: One hundred and sixty healthy adult US smokers participated in this randomized, three-arm parallel group, controlled clinical study. Subjects were randomized in a 2:1:1 ratio to menthol Tobacco Heating System 2.2 (mTHS), menthol cigarette, or smoking abstinence for 5 days in confinement and 86 subsequent ambulatory days. Endpoints included biomarkers of exposure to harmful and potentially harmful constituents (reported in our co-publication, Part 1) and biomarkers of potential harm (BOPH). RESULTS: Compliance (protocol and allocated product exposure) was 51% and 18% in the mTHS and smoking abstinence arms, respectively, on day 90. Nonetheless, favorable changes in BOPHs of lipid metabolism (total cholesterol and high- and low-density cholesterol), endothelial dysfunction (soluble intercellular adhesion molecule-1), oxidative stress (8-epi-prostaglandin F2α), and cardiovascular risk factors (eg, high-sensitivity C-reactive protein) were observed in the mTHS group. Favorable effects in other BOPHs, including ones related to platelet activation (11-dehydrothromboxane B2) and metabolic syndrome (glucose), were more pronounced in normal weight subjects. CONCLUSIONS: The results suggest that the reduced exposure demonstrated when switching to mTHS is associated with overall improvements in BOPHs, which are indicative of pathomechanistic pathways underlying the development of smoking-related diseases, with some stronger effects in normal weight subjects. IMPLICATIONS: Switching to mTHS was associated with favorable changes for some BOPHs indicative of biological pathway alterations (eg, oxidative stress and endothelial dysfunction). The results suggest that switching to mTHS has the potential to reduce the adverse health effects of smoking and ultimately the risk of smoking-related diseases. Switching to mTHS for 90 days led to reductions in a number of biomarkers of exposure in smokers, relative to those who continued smoking cigarettes, which were close to those observed when stopping smoking (reported in our co-publication, Part 1). Initial findings suggest reduced levels of 8-epi-prostaglandin F2α and intercellular adhesion molecule 1, when switching to mTHS for 90 days. These changes are comparable to what is observed upon smoking cessation. In normal weight subjects, additional favorable changes were seen in 11-dehydrothromboxane B2, fibrinogen, homocysteine, hs-CRP, percentage of predicted forced expiratory volume in 1 second, systolic blood pressure, diastolic blood pressure, glucose, high-density lipoprotein, apolipoprotein A1, and triglycerides. TRIAL REGISTRATION: NCT01989156.

Influence of smoking on levels of urinary 8-iso Prostaglandin F2α.

BACKGROUND: To evaluate the reduced-risk potential of alternative tobacco products, biomarkers that are involved in the biological pathways affected by cigarette smoking and smoking cessation are needed. Isoprostanes, a measure of oxidative stress, appear to be influenced by smoking and reversible upon smoking cessation and therefore could be a good biomarker. This review aims at quantifying the effect of smoking and smoking cessation on levels of urinary 8-iso prostaglandin F2α (8-epi-PGF2α), an isoprostane. METHODS: PubMed and Scopus databases were searched for publications that reported 8-epi-PGF2α levels in smokers and nonsmokers as well as articles reporting the effect of smoking cessation on 8-epi-PGF2α levels. RESULTS: Eighteen studies assessing 8-epi-PGF2α levels by smoking status were identified. Five of the papers reported the results as quantity excreted in 24-hour urine (µg/24 h), and 15 reported creatinine adjusted values. The meta-analyses show increased levels of 8-epi-PGF2α in current smokers compared with nonsmokers (mean difference = 0.16, 95% confidence interval [95%CI]: 0.14-0.19 µg/24 h with inconsistency statistic [I2] = 98%; mean difference = 172.38, 95%CI: 152.75-192.01 pg/mg creatinine with I2 = 89%, respectively). There were too few publications to perform a meta-analysis assessing the effects of smoking cessation on 8-epi-PGF2α levels. CONCLUSIONS: Due to the high heterogeneity among the studies included in these meta-analyses, it is difficult to generalize the results; however, our study indicates increased levels of 8-epi-PGF2α and therefore increased oxidative stress in smokers compared with nonsmokers. More studies are still needed to assess if 8-epi-PGF2α levels are reversible after cessation.

Influence of smoking and smoking cessation on levels of urinary 11-dehydro thromboxane B2.

BACKGROUND: Thromboxane is a key clinical risk endpoint of smoking-induced inflammation which has been associated in the pathogenesis of cardiovascular disease. The goal of this review is to quantify the effect of smoking and smoking cessation on one of its urinary metabolites, 11-dehydrothromboxaneB2. METHODS: PubMed and SCOPUS were searched to identify publications which report urinary 11-dehydrothromboxaneB2 levels in smokers and non-smokers, as well as articles reporting the effect of smoking cessation on urinary 11-dehydrothromboxaneB2 excretion. RESULTS: We found ten studies assessing urinary 11-dehydrothroboxaneB2 levels in smokers and non-smokers. Four papers reported the amount of urinary 11-dehydrothromboxaneB2 excreted in 24 h while six reported the amount excreted adjusted for creatinine. The meta-analyses comparing the excretion of urinary 11-dehydrothromboxane in current smokers to non-smokers report increased levels in current smokers (mean difference = 0.31 µg/24-h [95%CI: 0.27-0.34] and 166.45 pg/mg creatinine [95%CI: 120.51-212.40]). There were not enough publications to perform meta-analyses on the effects of smoking cessation on urinary 11-dehydrothromboxaneB2 excretion. CONCLUSIONS: Urinary 11-dehydrothromboxaneB2 levels are increased in cigarette smokers, however, more data are needed to elucidate the effects of smoking cessation on urinary 11-dehydrothromboxaneB2 excretion.

Biomarker of exposure level data set in smokers switching from conventional cigarettes to Tobacco Heating System 2.2, continuing smoking or abstaining from smoking for 5 days.

Levels of biomarkers of exposure to selected harmful and potentially harmful smoke constituents found in cigarette smoke, in addition to nicotine were measured in 160 smokers randomized for 5 days to continuing smoking conventional cigarettes (41 participants), switching to Tobacco Heating System 2.2 (THS 2.2) (80 participants), or abstaining from smoking (39 participants). The data reported here are descriptive statistics of the levels of each biomarker of exposure expressed as concentrations adjusted to creatinine; at baseline, and at the end of the study, and their relative change from baseline. Reductions in the levels of biomarkers of exposure when expressed as quantity excreted, are also reported. Detailed descriptions of bioanalytical assays used are also provided. The data presented here are related to the article entitled "Evaluation of the Tobacco Heating System 2.2. Part 8: 5-Day randomized reduced exposure clinical study in Poland" (Haziza et al., 2016) [1].

Evaluation of the Tobacco Heating System 2.2. Part 8: 5-Day randomized reduced exposure clinical study in Poland.

The Tobacco Heating System (THS) 2.2, a candidate Modified Risk Tobacco Product (MRTP), is designed to heat tobacco without burning it. Tobacco is heated in order to reduce the formation of harmful and potentially harmful constituents (HPHC), and reduce the consequent exposure, compared with combustible cigarettes (CC). In this 5-day exposure, controlled, parallel-group, open-label clinical study, 160 smoking, healthy subjects were randomized to three groups and asked to: (1) switch from CCs to THS 2.2 (THS group; 80 participants); (2) continue to use their own non-menthol CC brand (CC group; 41 participants); or (3) to refrain from smoking (smoking abstinence (SA) group; 39 participants). Biomarkers of exposure, except those associated with nicotine exposure, were significantly reduced in the THS group compared with the CC group, and approached the levels observed in the SA group. Increased product consumption and total puff volume were reported in the THS group. However, exposure to nicotine was similar to CC at the end of the confinement period. Reduction in urge-to-smoke was comparable between the THS and CC groups and THS 2.2 product was well tolerated.

Assessment of the reduction in levels of exposure to harmful and potentially harmful constituents in Japanese subjects using a novel tobacco heating system compared with conventional cigarettes and smoking abstinence: A randomized controlled study in confinement.

Smoking conventional cigarettes (CCs) exposes smokers to harmful and potentially harmful constituents (HPHCs). The Tobacco Heating System 2.2 (THS 2.2), a candidate modified risk tobacco product, was developed to reduce or eliminate the formation of HPHCs, while preserving as much as possible the taste, sensory experience, nicotine delivery profile and ritual characteristics of CC. This randomized, controlled, open-label study in confinement for 5 day exposure aimed to demonstrate the reduction in exposure to selected HPHCs, to assess nicotine uptake and subjective effects, in participants switching to THS 2.2 (n = 80) compared to participants continuing smoking CCs (n = 40) and abstaining from smoking (n = 40). The subjects were randomized according to sex and daily CC consumption. The levels of biomarkers of exposure to HPHCs were significantly reduced in participants switching to THS 2.2, compared to CC use. More importantly, the magnitude of exposure reduction observed was close to that which was seen in participants who abstained from smoking for 5 days, while nicotine uptake was maintained. Reduction in urge-to-smoke was comparable between THS and CC groups, however THS 2.2 was slightly less satisfactory than CCs. The new, alternative tobacco product THS 2.2 was well tolerated.

Open-label phase 1b study of FOLFIRI plus cetuximab plus IMO-2055 in patients with colorectal cancer who have progressed following chemotherapy for advanced or metastatic disease.

PURPOSE: The immune modulatory oligonucleotide IMO-2055 (EMD 1201081) is a phosphorothioate oligodeoxynucleotide agonist of Toll-like receptor 9. In preclinical studies, IMO-2055 was shown to activate natural killer cells and to support the antitumor activity of monoclonal antibodies. This phase 1b, open-label, 3 + 3 dose-escalation trial was performed to determine the recommended phase 2 dose of IMO-2055 combined with FOLFIRI/cetuximab in patients with previously treated, advanced/metastatic colorectal cancer (NCT00719199). METHODS: Patients received 14-day cycles of cetuximab (days 1/8; 400 mg/m(2) day 1 cycle 1, 250 mg/m(2) for subsequent days/cycles), irinotecan (day 1; 180 mg/m(2)), folinic acid (day 1; 400 mg/m(2) racemic or 200 mg/m(2) L-form), 5-fluorouracil (day 1; 400 mg/m(2) intravenous bolus, followed by 2,400 mg/m(2) as 46-h infusion), and escalating IMO-2055 doses (days 1/8; 0.16, 0.32, 0.48 mg/kg). Fifteen patients received IMO-2055, including six, three, and six patients who were treated at the dose levels 0.16, 0.32, and 0.48 mg/kg, respectively. RESULTS: One dose-limiting toxicity was observed (grade 3 fatigue; at dose level 0.16 mg/kg). The most common adverse events were injection site reactions, diarrhea, fatigue, hypomagnesemia, and stomatitis. One patient achieved a confirmed partial response; 12 had stable disease, including five with stable disease ≥4.0 months. CONCLUSIONS: IMO-2055 combined with FOLFIRI/cetuximab was well tolerated at all dose levels tested. IMO-2055 0.48 mg/kg was considered as the recommended phase 2 dose.

Antitumor activity and safety of combination therapy with the Toll-like receptor 9 agonist IMO-2055, erlotinib, and bevacizumab in advanced or metastatic non-small cell lung cancer patients who have progressed following chemotherapy.

BACKGROUND: IMO-2055 is a Toll-like receptor 9 (TLR9) agonist that potentially enhances the efficacy of antitumor agents through immune stimulation. The objective of this phase Ib dose-escalation trial (3 + 3 design) was to determine the recommended phase II dose (RP2D) of IMO-2055 when combined with erlotinib and bevacizumab in patients with advanced non-small cell lung cancer (NSCLC). METHODS: Patients with stage 3/4 NSCLC and progressive disease (PD) following chemotherapy received IMO-2055 0.08, 0.16, 0.32, or 0.48 mg/kg once weekly plus erlotinib 150 mg daily and bevacizumab 15 mg/kg every 3 weeks. Patients could receive treatment until PD or unacceptable toxicity. RESULTS: Thirty-six patients were enrolled; 35 received at least one treatment dose. Two dose-limiting toxicities were observed across the dose range (Grade 3 dehydration and fatigue) with neither suggestive of a consistent toxicity pattern. IMO-2055 0.32 mg/kg was adopted as RP2D based on clinical and pharmacodynamic data. The most common treatment-emergent adverse events (TEAEs) were diarrhea (74 %), nausea (51 %), fatigue (51 %), rash (51 %), and injection-site reactions (49 %). Four patients experienced serious TEAEs considered to be study drug related. Five patients died, all due to PD. High-grade neutropenia and electrolyte disturbances previously reported with TLR9 agonists combined with platinum-based therapy were not observed in this study. Five of 33 patients evaluable for response (15 %) achieved partial response; another 20 (61 %) had stable disease, including 13 with stable disease ≥4 months. CONCLUSIONS: IMO-2055 demonstrated good tolerability and possible antitumor activity in combination with erlotinib and bevacizumab in heavily pretreated patients with advanced NSCLC.