1
|
Benowitz NL, Nardone N, Dains KM, Hall SM, Stewart S, Dempsey D, Jacob P. Effect of reducing the nicotine content of cigarettes on cigarette smoking behavior and tobacco smoke toxicant exposure: 2-year follow up. Addiction 2015; 110:1667-75. [PMID: 26198394 PMCID: PMC4565734 DOI: 10.1111/add.12978] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 02/09/2015] [Accepted: 04/30/2015] [Indexed: 11/28/2022]
Abstract
BACKGROUND AND AIMS A broadly mandated reduction of the nicotine content (RNC) of cigarettes has been proposed in the United States to reduce the addictiveness of cigarettes, to prevent new smokers from becoming addicted and to facilitate quitting in established smokers. The primary aim of this study was to determine whether following 7 months of smoking very low nicotine content cigarettes (VLNC), and then returning to their own cigarettes, smokers would demonstrate persistently reduced nicotine intake compared with baseline or quit smoking. METHODS In a community-based clinic 135 smokers not interested in quitting were randomized to one of two groups. A research group smoked their usual brand of cigarettes, followed by five types of research cigarettes with progressively lower nicotine content, each for 1 month, followed by 6 months at the lowest nicotine level (0.5 mg/cigarette) (53 subjects) and then 12 months with no intervention (30 subjects completed). A control group smoked their usual brand for the same period of time (50 subjects at 6 months, 38 completed). Smoking behavior, biomarkers of nicotine intake and smoke toxicant exposure were measured. RESULTS After 7 months smoking VLNC, nicotine intake remained below baseline (plasma cotinine 149 versus 250 ng/ml, P<0.005) with no significant change in cigarettes per day or expired carbon monoxide (CO). During the 12-month follow-up, cotinine levels in RNC smokers rose to baseline levels and to those of control smokers. Quit rates among RNC smokers were very low [7.5 versus 2% in controls, not significant). CONCLUSIONS In smokers not interested in quitting, reducing the nicotine content in cigarettes over 12 months does not appear to result in extinction of nicotine dependence, assessed by persistently reduced nicotine intake or quitting smoking over the subsequent 12 months.
Collapse
Affiliation(s)
- Neal L. Benowitz
- Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine and Bioengineering & Therapeutic Sciences, University of California, San Francisco
| | - Natalie Nardone
- Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine and Bioengineering & Therapeutic Sciences, University of California, San Francisco
| | - Katherine M. Dains
- Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine and Bioengineering & Therapeutic Sciences, University of California, San Francisco
| | - Sharon M. Hall
- Department of Psychiatry, University of California, San Francisco
| | - Susan Stewart
- Department of Public Health Sciences, University of California Davis
| | - Delia Dempsey
- Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine and Bioengineering & Therapeutic Sciences, University of California, San Francisco
| | - Peyton Jacob
- Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine and Bioengineering & Therapeutic Sciences, University of California, San Francisco
- Department of Psychiatry, University of California, San Francisco
| |
Collapse
|
2
|
Abstract
BACKGROUND Water pipe tobacco smoking is spreading globally and is increasingly becoming popular in the United States, particularly among young people. Although many perceive water pipe smoking to be relatively safe, clinical experimental studies indicate significant exposures to tobacco smoke carcinogens following water pipe use. We investigated biomarkers of nicotine intake and carcinogen exposure from water pipe smoking in the naturalistic setting of hookah bars. METHODS Fifty-five experienced water pipe users were studied before and after smoking water pipe in their customary way in a hookah bar. Urine samples were analyzed for nicotine, cotinine, the tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), and mercapturic acid metabolites of volatile organic compounds (VOC). RESULTS We found an average 73-fold increase in nicotine, 4-fold increase in cotinine, 2-fold increase in NNAL, and 14% to 91% increase in VOC mercapturic acid metabolites immediately following water pipe smoking. We saw moderate to high correlations between changes in tobacco-specific biomarkers (nicotine, cotinine, and NNAL) and several mercapturic acid metabolites of VOCs. CONCLUSION Water pipe smoking in a hookah bar is associated with significant nicotine intake and carcinogen exposure. IMPACT Given the significant intake of nicotine and carcinogens, chronic water pipe use could place users at increased risk of cancer and other chronic diseases. Cancer Epidemiol Biomarkers Prev; 23(6); 1055-66. ©2014 AACR.
Collapse
Affiliation(s)
- Gideon St Helen
- Authors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, CaliforniaAuthors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, CaliforniaAuthors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, California
| | - Neal L Benowitz
- Authors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, CaliforniaAuthors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, CaliforniaAuthors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, CaliforniaAuthors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, California
| | - Katherine M Dains
- Authors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, CaliforniaAuthors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, CaliforniaAuthors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, California
| | - Christopher Havel
- Authors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, CaliforniaAuthors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, CaliforniaAuthors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, California
| | - Margaret Peng
- Authors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, CaliforniaAuthors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, CaliforniaAuthors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, California
| | - Peyton Jacob
- Authors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, CaliforniaAuthors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, CaliforniaAuthors' Affiliations: Center for Tobacco Control Research and Education, University of California, San Francisco; Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center; Departments of Medicine, and Bioengineering and Therapeutic Sciences, University of California, San Francisco, California
| |
Collapse
|
3
|
Benowitz NL, Dains KM, Hall SM, Stewart S, Wilson M, Dempsey D, Jacob P. Smoking behavior and exposure to tobacco toxicants during 6 months of smoking progressively reduced nicotine content cigarettes. Cancer Epidemiol Biomarkers Prev 2012; 21:761-9. [PMID: 22354905 PMCID: PMC3348427 DOI: 10.1158/1055-9965.epi-11-0644] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Recent federal legislation gives the U.S. Food and Drug Administration authority to regulate the nicotine content of cigarettes. A nationwide strategy for progressive reduction of the nicotine content of cigarettes is a potential way to reduce the addictiveness of cigarettes, to prevent new smokers from becoming addicted, and to facilitate quitting in established smokers. We conducted a trial of progressive nicotine content tapering over 6 months to determine the effects on smoking behaviors and biomarkers of tobacco smoke exposure and cardiovascular effects. METHODS One hundred and thirty-five healthy smokers were randomly assigned to one of two groups. A research group smoked their usual brand of cigarettes followed by five types of research cigarettes with progressively lower nicotine content, each smoked for one month. A control group smoked their own brand of cigarettes for the same period of time. RESULTS Nicotine intake, as indicated by plasma cotinine concentration, declined progressively as the nicotine content of cigarettes was reduced. Cigarette consumption and markers of exposure to carbon monoxide and polycyclic aromatic hydrocarbons, as well as cardiovascular biomarkers remained stable, whereas urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) excretion decreased. No significant changes in biomarkers of exposure or cardiovascular effects were observed in controls. CONCLUSIONS Our data support the proposition that the intake of nicotine from cigarettes of smokers can be substantially lowered without increasing exposure to other tobacco smoke toxins. IMPACT These findings support the feasibility and safety of gradual reduction of the nicotine content in cigarettes.
Collapse
Affiliation(s)
- Neal L Benowitz
- Division of Clinical Pharmacology and Experimental Therapeutics, San Francisco General Hospital Medical Center, Department of Medicine, University of California San Francisco, San Francisco, CA 94143-1220, USA.
| | | | | | | | | | | | | |
Collapse
|
4
|
Benowitz NL, Dains KM, Dempsey D, Wilson M, Jacob P. Racial differences in the relationship between number of cigarettes smoked and nicotine and carcinogen exposure. Nicotine Tob Res 2011; 13:772-83. [PMID: 21546441 DOI: 10.1093/ntr/ntr072] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
INTRODUCTION Black smokers are reported to have higher lung cancer rates and greater tobacco dependence at lower levels of cigarette consumption compared to non-Hispanic White smokers. We studied the relationship between cigarettes per day (CPD) and biomarkers of nicotine and carcinogen exposure in Black and White smokers. METHODS In 128 Black and White smokers, we measured plasma nicotine and its main proximate metabolite cotinine, urine nicotine equivalents, 4-(methylnitrosamino)-1-(3)pyridyl-1-butanol (NNAL), and polycyclic aromatic hydrocarbon (PAH) metabolites. RESULTS The dose-response between CPD and nicotine equivalents, and NNAL and PAH was flat for Black but positive for White smokers (Race × CPD interaction, all ps < .05). Regression estimates for the Race × CPD interactions were 0.042 (95% CI 0.013-0.070), 0.054 (0.023-0.086), and 0.028 (0.004-0.052) for urine nicotine equivalents, NNAL, and PAHs, respectively. In contrast there was a strong correlation between nicotine equivalents and NNAL and PAH independent of race. Nicotine and carcinogen exposure per individual cigarette was inversely related to CPD. This inverse correlation was stronger in Black compared to White smokers and stronger in menthol compared to regular cigarette smokers (not mutually adjusted). CONCLUSIONS Our data indicate that Blacks on average smoke cigarettes differently than White smokers such that CPD predicts smoke intake more poorly in Black than in White smokers.
Collapse
Affiliation(s)
- Neal L Benowitz
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143-1220, USA.
| | | | | | | | | |
Collapse
|
5
|
Benowitz NL, Dains KM, Dempsey D, Havel C, Wilson M, Jacob P. Urine menthol as a biomarker of mentholated cigarette smoking. Cancer Epidemiol Biomarkers Prev 2010; 19:3013-9. [PMID: 20962297 DOI: 10.1158/1055-9965.epi-10-0706] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVES Menthol cigarettes are smoked by 27% of U.S. smokers, and there are concerns that menthol might enhance toxicity of cigarette smoking by increasing systemic absorption of smoke toxins. We measured urine menthol concentrations in relation to biomarkers of exposure to nicotine and tobacco carcinogens. METHODS Concentrations of menthol glucuronide (using a novel analytical method), nicotine plus metabolites (nicotine equivalents, NE), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), and polycyclic aromatic hydrocarbon (PAH) metabolites were measured in the urine of 60 menthol and 67 regular cigarette smokers. RESULTS Urine menthol was measurable in 82% of menthol and 54% in regular cigarette smokers. Among menthol smokers, urine menthol was highly correlated with NE, NNAL, and PAHs. In a multiple regression model NE but not menthol was significantly associated with NNAL and PAHs. CONCLUSIONS Urine menthol concentration is a novel biomarker of exposure in menthol cigarette smokers, and is highly correlated with exposure to nicotine and carcinogens. Menthol is not independently associated with carcinogen exposure when nicotine intake is considered.
Collapse
Affiliation(s)
- Neal L Benowitz
- Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center, Department of Medicine, University of California, San Francisco, California 94143-1220, USA.
| | | | | | | | | | | |
Collapse
|
6
|
Benowitz NL, Dains KM, Dempsey D, Yu L, Jacob P. Estimation of nicotine dose after low-level exposure using plasma and urine nicotine metabolites. Cancer Epidemiol Biomarkers Prev 2010; 19:1160-6. [PMID: 20447913 DOI: 10.1158/1055-9965.epi-09-1303] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND We sought to determine the optimal plasma and urine nicotine metabolites, alone or in combination, to estimate the systemic dose of nicotine after low-level exposure. METHODS We dosed 36 nonsmokers with 100, 200, or 400 microg p.o. of deuterium-labeled nicotine (doses similar to exposure to secondhand smoke) daily for 5 days and then measured plasma and urine nicotine metabolites at various intervals over 24 hours. RESULTS The strongest correlations with nicotine dose were seen for the sum of four (cotinine+cotinine-glucuronide+trans-3'-hydroxycotinine+3HC-glucuronide) or six (including also nicotine+nicotine-glucuronide) of the major nicotine metabolites in 24-hour urine collection (r=0.96), with lesser correlations for these metabolites using spot urines corrected for creatinine at various times of day (r=0.72-0.80). The sum of plasma cotinine+trans-3'-hydroxycotine was more highly correlated with nicotine dose than plasma cotinine alone (r=0.82 versus 0.75). CONCLUSIONS Our results provide guidance for the selection of biomarkers to estimate the dose of nicotine taken in low-level (secondhand smoke) tobacco exposure. IMPACT This is probably relevant to active smoking as well.
Collapse
Affiliation(s)
- Neal L Benowitz
- Division of Clinical Pharmacology and Experimental Therapeutics, Medical Service, San Francisco General Hospital Medical Center, and Department of Medicine, University of California, San Francisco, Box 1220, San Francisco, CA 94143-1220, USA.
| | | | | | | | | |
Collapse
|
7
|
Benowitz NL, Schultz KE, Haller CA, Wu AHB, Dains KM, Jacob P. Prevalence of smoking assessed biochemically in an urban public hospital: a rationale for routine cotinine screening. Am J Epidemiol 2009; 170:885-91. [PMID: 19713287 DOI: 10.1093/aje/kwp215] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Cotinine, a metabolite of nicotine, has been used to study tobacco smoke exposure in population studies, but the authors are unaware of its use to screen hospitalized patients. The authors measured serum cotinine levels in 948 patients admitted to an urban public hospital in San Francisco, California, between September 2005 and July 2006. On the basis of cotinine levels, they classified patients as active smokers (cotinine > or = 14 ng/mL), recent smokers or significantly exposed to secondhand smoke (SHS) (0.5-13.9 ng/mL), lightly exposed to SHS (0.05-0.49 ng/mL), or unexposed (<0.05 ng/mL). In contrast to the 13% prevalence of smoking in the general population of San Francisco, 40% of patients were active smokers; 15% were recent smokers or heavily exposed to SHS; 25% had low-level exposure to SHS; and 20% were unexposed. Active smoking or heavy SHS exposure was particularly high among African Americans (77%), the uninsured (65%), self-reported alcohol drinkers (77%), and illicit drug users (90%). Of people who denied smoking, 32% were found to have had significant exposure. If serum cotinine measurement became part of routine screening at urban public hospitals, cotinine levels would be abnormal in many patients and would provide objective evidence of tobacco smoke exposure, probably resulting in more intensive intervention to encourage patients to stop smoking and avoid SHS.
Collapse
Affiliation(s)
- Neal L Benowitz
- Division of Clinical Pharmacology and Experimental Therapeutics, University of California San Francisco, San Francisco, CA 94143-1220, USA.
| | | | | | | | | | | |
Collapse
|
8
|
Benowitz NL, Dains KM, Dempsey D, Herrera B, Yu L, Jacob P. Urine nicotine metabolite concentrations in relation to plasma cotinine during low-level nicotine exposure. Nicotine Tob Res 2009; 11:954-60. [PMID: 19525206 DOI: 10.1093/ntr/ntp092] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
INTRODUCTION Plasma or saliva cotinine concentrations are used widely as biomarkers of secondhand smoke (SHS) exposure and have been associated with the risk of SHS-related disease. Concentrations of cotinine and other nicotine metabolites are considerably higher in urine than in plasma or saliva, making chemical analysis easier. In addition, urine is often more convenient to collect in some SHS exposure studies. The optimal use of nicotine metabolites in urine, singly or in combination, with or without correction for urine creatinine concentration, to estimate plasma cotinine concentration with low-level nicotine exposure has not been determined. METHODS We dosed 36 nonsmokers with 100, 200, or 400 microg deuterium-labeled nicotine (simulating exposure to SHS) by mouth daily for 5 days and then measured plasma and urine cotinine and metabolites at various intervals over 24 hr. RESULTS A plasma cotinine concentration of 1 ng/ml corresponds on average to a daily intake of 100 microg nicotine. Cotinine concentrations in urine averaged four to five times those in plasma. Correction of urine cotinine for creatinine concentration improved the correlation between urine and plasma cotinine. Measuring multiple cotinine metabolites in urine did not improve the correlation with plasma cotinine, compared with the use of urine cotinine alone. DISCUSSION Measurement of urine cotinine corrected for creatinine concentration appears to be the best predictor of plasma cotinine.
Collapse
Affiliation(s)
- Neal L Benowitz
- Division of Clinical Pharmacology and Experimental Therapeutics, Department of Medicine, San Francisco General Hospital Medical Center, University of California, San Francisco, Box 1220, San Francisco, CA 94143-1220, USA.
| | | | | | | | | | | |
Collapse
|
9
|
Benowitz NL, Dains KM, Hall SM, Stewart S, Wilson M, Dempsey D, Jacob P. Progressive commercial cigarette yield reduction: biochemical exposure and behavioral assessment. Cancer Epidemiol Biomarkers Prev 2009; 18:876-83. [PMID: 19258480 PMCID: PMC2802575 DOI: 10.1158/1055-9965.epi-08-0731] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Mandated reduction of exposure to nicotine and other cigarette toxins has been proposed as a possible national regulatory strategy. However, tapering using lower yield commercial cigarettes may not be effective in reducing nicotine or tar exposure due to compensatory smoking behavior. We examined the effects of gradual reduction of nicotine yield in commercial cigarettes on smoking behavior, with an assessment of nicotine intake and exposure to tobacco smoke toxins. METHODS This 10-week longitudinal study of 20 smokers involved smoking the usual brand followed by different brands with progressively lower machine-determined yields, ranging from 0.9 to 0.1 mg nicotine, each smoked for 1 week. Subjects were followed for 4 weeks after returning to smoking the usual brand (or quitting). Smoking behaviors, biomarkers of tobacco smoke exposure, and cardiovascular effects were measured. FINDINGS Cotinine and other biomarkers of smoke exposure remained unchanged comparing the usual brand with the 0.4 mg nicotine brands. A 30% to 40% decrease in nicotine, carbon monoxide, and carcinogen exposure comparing 0.1 mg nicotine cigarettes with baseline was observed. Self-efficacy was significantly increased and dependence decreased after tapering. IMPLICATIONS We confirm prior cross-sectional population and experimental studies showing complete compensation for cigarettes down to the 0.4 mg nicotine range. Nicotine and tobacco toxin exposure were substantially reduced while smoking 0.1 mg nicotine cigarettes. Our data suggest that the degree of nicotine dependence of smokers may be lowered with progressive yield tapering. Gradual tapering of smokers from regular to ultralow nicotine yield commercial cigarettes might facilitate smoking cessation and warrants future research.
Collapse
Affiliation(s)
- Neal L Benowitz
- Medical Service, San Francisco General Hospital Medical Center, and Department of Medicine, University of California at San Francisco, San Francisco, CA 94143-1220, USA.
| | | | | | | | | | | | | |
Collapse
|
10
|
Bodnar JS, Chatterjee A, Castellani LW, Ross DA, Ohmen J, Cavalcoli J, Wu C, Dains KM, Catanese J, Chu M, Sheth SS, Charugundla K, Demant P, West DB, de Jong P, Lusis AJ. Positional cloning of the combined hyperlipidemia gene Hyplip1. Nat Genet 2002; 30:110-6. [PMID: 11753387 PMCID: PMC2846781 DOI: 10.1038/ng811] [Citation(s) in RCA: 170] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Familial combined hyperlipidemia (FCHL, MIM-144250) is a common, multifactorial and heterogeneous dyslipidemia predisposing to premature coronary artery disease and characterized by elevated plasma triglycerides, cholesterol, or both. We identified a mutant mouse strain, HcB-19/Dem (HcB-19), that shares features with FCHL, including hypertriglyceridemia, hypercholesterolemia, elevated plasma apolipoprotein B and increased secretion of triglyceride-rich lipoproteins. The hyperlipidemia results from spontaneous mutation at a locus, Hyplip1, on distal mouse chromosome 3 in a region syntenic with a 1q21-q23 FCHL locus identified in Finnish, German, Chinese and US families. We fine-mapped Hyplip1 to roughly 160 kb, constructed a BAC contig and sequenced overlapping BACs to identify 13 candidate genes. We found substantially decreased mRNA expression for thioredoxin interacting protein (Txnip). Sequencing of the critical region revealed a Txnip nonsense mutation in HcB-19 that is absent in its normolipidemic parental strains. Txnip encodes a cytoplasmic protein that binds and inhibits thioredoxin, a major regulator of cellular redox state. The mutant mice have decreased CO2 production but increased ketone body synthesis, suggesting that altered redox status down-regulates the citric-acid cycle, sparing fatty acids for triglyceride and ketone body production. These results reveal a new pathway of potential clinical significance that contributes to plasma lipid metabolism.
Collapse
MESH Headings
- Animals
- Animals, Congenic
- Carbon Dioxide/metabolism
- Carrier Proteins/genetics
- Carrier Proteins/metabolism
- Chromosomes, Artificial, Bacterial/genetics
- Chromosomes, Human, Pair 1/genetics
- Citric Acid Cycle/genetics
- Cloning, Molecular
- Codon/genetics
- Codon, Nonsense
- Contig Mapping
- Cosmids/genetics
- Cricetinae
- Crosses, Genetic
- Disease Models, Animal
- Energy Metabolism/genetics
- Exons/genetics
- Fatty Acids/metabolism
- Haplotypes/genetics
- Humans
- Hybrid Cells
- Hyperlipidemia, Familial Combined/genetics
- Hyperlipidemia, Familial Combined/metabolism
- Ketone Bodies/biosynthesis
- Mice
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Molecular Sequence Data
- Oxidation-Reduction
- Thioredoxins/antagonists & inhibitors
- Triglycerides/blood
Collapse
Affiliation(s)
- Jackie S Bodnar
- Department of Medicine, University of California, Los Angeles, 47-123 CHS, UCLA School of Medicine, Los Angeles, California 90095, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Iakoubova OA, Olsson CL, Dains KM, Ross DA, Andalibi A, Lau K, Choi J, Kalcheva I, Cunanan M, Louie J, Nimon V, Machrus M, Bentley LG, Beauheim C, Silvey S, Cavalcoli J, Lusis AJ, West DB. Genome-tagged mice (GTM): two sets of genome-wide congenic strains. Genomics 2001; 74:89-104. [PMID: 11374905 DOI: 10.1006/geno.2000.6497] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
An important approach for understanding complex disease risk using the mouse is to map and ultimately identify the genes conferring risk. Genes contributing to complex traits can be mapped to chromosomal regions using genome scans of large mouse crosses. Congenic strains can then be developed to fine-map a trait and to ascertain the magnitude of the genotype effect in a chromosomal region. Congenic strains are constructed by repeated backcrossing to the background strain with selection at each generation for the presence of a donor chromosomal region, a time-consuming process. One approach to accelerate this process is to construct a library of congenic strains encompassing the entire genome of one strain on the background of the other. We have employed marker-assisted breeding to construct two sets of overlapping congenic strains, called genome-tagged mice (GTMs), that span the entire mouse genome. Both congenic GTM sets contain more than 60 mouse strains, each with on average a 23-cM introgressed segment (range 8 to 58 cM). C57BL/6J was utilized as a background strain for both GTM sets with either DBA/2J or CAST/Ei as the donor strain. The background and donor strains are genetically and phenotypically divergent. The genetic basis for the phenotypic strain differences can be rapidly mapped by simply screening the GTM strains. Furthermore, the phenotype differences can be fine-mapped by crossing appropriate congenic mice to the background strain, and complex gene interactions can be investigated using combinations of these congenics.
Collapse
Affiliation(s)
- O A Iakoubova
- Pfizer Global Research and Development, 1501 Harbor Bay Parkway, Alameda, California 94502, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Iakoubova OA, Olsson CL, Dains KM, Choi J, Kalcheva I, Bentley LG, Cunanan M, Hillman D, Louie J, Machrus M, West DB. Microsatellite marker panels for use in high-throughput genotyping of mouse crosses. Physiol Genomics 2000; 3:145-8. [PMID: 11015609 DOI: 10.1152/physiolgenomics.2000.3.3.145] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Several microsatellite genotyping panel sets have been developed that are polymorphic between C57BL/6J and CAST/Ei mice, or C57BL/6J and DBA/2J. One set of markers for each strain pair has an intermarker distance of approximately 20 cM, and a second set has an intermarker distance of 5 cM. The 20-cM set contains 105 markers for C57BL/6J x DBA/2J and 108 for C57BL/6J x CAST/Ei, divided into 13 panels. Each 5-cM set includes 350 markers arranged into 45 panels. A panel contains a number of primer pairs whose fluorescently labeled PCR products can be pooled together and separated on one lane of a polyacrylamide gel. The sets are arranged by the size of the PCR product and by the type of fluorescent dye; 5-cM sets are also arranged by chromosomal region. The 20-cM sets are most useful for full-genome scans, the 5-cM sets are useful for full-genome and/or for region-specific chromosome screens. Both sets were proven as useful tools for speed congenic development, quantitative trait loci (QTL) analysis and physical mapping. These panel sets provide a throughput of 1,536-2,304 mouse genotypes daily per one gel-based system. Whole genome scans of one animal require 13 or 48 gel lanes, with 20 cM or 5 cM density, respectively.
Collapse
Affiliation(s)
- O A Iakoubova
- Pfizer Global Research and Development Alameda Laboratories, Alameda 94502, Deltagen, Inc., Menlo Park, California 94025, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|