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Barth J, Jacob T, Daha I, Critchley JA. Psychosocial interventions for smoking cessation in patients with coronary heart disease. Cochrane Database Syst Rev 2015; 2015:CD006886. [PMID: 26148115 PMCID: PMC11064764 DOI: 10.1002/14651858.cd006886.pub2] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND This is an update of a Cochrane review previously published in 2008. Smoking increases the risk of developing atherosclerosis but also acute thrombotic events. Quitting smoking is potentially the most effective secondary prevention measure and improves prognosis after a cardiac event, but more than half of the patients continue to smoke, and improved cessation aids are urgently required. OBJECTIVES This review aimed to examine the efficacy of psychosocial interventions for smoking cessation in patients with coronary heart disease in short-term (6 to 12 month follow-up) and long-term (more than 12 months). Moderators of treatment effects (i.e. intervention types, treatment dose, methodological criteria) were used for stratification. SEARCH METHODS The Cochrane Central Register of Controlled Trials (Issue 12, 2012), MEDLINE, EMBASE, PsycINFO and PSYNDEX were searched from the start of the database to January 2013. This is an update of the initial search in 2003. Results were supplemented by cross-checking references, and handsearches in selected journals and systematic reviews. No language restrictions were applied. SELECTION CRITERIA Randomised controlled trials (RCTs) in patients with CHD with a minimum follow-up of 6 months. DATA COLLECTION AND ANALYSIS Two authors independently assessed trial eligibility and risk of bias. Abstinence rates were computed according to an intention to treat analysis if possible, or if not according to completer analysis results only. Subgroups of specific intervention strategies were analysed separately. The impact of study quality on efficacy was studied in a moderator analysis. Risk ratios (RR) were pooled using the Mantel-Haenszel and random-effects model with 95% confidence intervals (CI). MAIN RESULTS We found 40 RCTs meeting inclusion criteria in total (21 trials were new in this update, 5 new trials contributed to long-term results (more than 12 months)). Interventions consist of behavioural therapeutic approaches, telephone support and self-help material and were either focused on smoking cessation alone or addressed several risk factors (eg. obesity, inactivity and smoking). The trials mostly included older male patients with CHD, predominantly myocardial infarction (MI). After an initial selection of studies three trials with implausible large effects of RR > 5 which contributed to substantial heterogeneity were excluded. Overall there was a positive effect of interventions on abstinence after 6 to 12 months (risk ratio (RR) 1.22, 95% confidence interval (CI) 1.13 to 1.32, I² 54%; abstinence rate treatment group = 46%, abstinence rate control group 37.4%), but heterogeneity between trials was substantial. Studies with validated assessment of smoking status at follow-up had similar efficacy (RR 1.22, 95% CI 1.07 to 1.39) to non-validated trials (RR 1.23, 95% CI 1.12 to 1.35). Studies were stratified by intervention strategy and intensity of the intervention. Clustering reduced heterogeneity, although many trials used more than one type of intervention. The RRs for different strategies were similar (behavioural therapies RR 1.23, 95% CI 1.12 to 1.34, I² 40%; telephone support RR 1.21, 95% CI 1.12 to 1.30, I² 44%; self-help RR 1.22, 95% CI 1.12 to 1.33, I² 40%). More intense interventions (any initial contact plus follow-up over one month) showed increased quit rates (RR 1.28, 95% CI 1.17 to 1.40, I² 58%) whereas brief interventions (either one single initial contact lasting less than an hour with no follow-up, one or more contacts in total over an hour with no follow-up or any initial contact plus follow-up of less than one months) did not appear effective (RR 1.01, 95% CI 0.91 to 1.12, I² 0%). Seven trials had long-term follow-up (over 12 months), and did not show any benefits. Adverse side effects were not reported in any trial. These findings are based on studies with rather low risk of selection bias but high risk of detection bias (namely unblinded or non validated assessment of smoking status). AUTHORS' CONCLUSIONS Psychosocial smoking cessation interventions are effective in promoting abstinence up to 1 year, provided they are of sufficient duration. After one year, the studies showed favourable effects of smoking cessation intervention, but more studies including cost-effectiveness analyses are needed. Further studies should also analyse the additional benefit of a psychosocial intervention strategy to pharmacological therapy (e.g. nicotine replacement therapy) compared with pharmacological treatment alone and investigate economic outcomes.
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Affiliation(s)
- Jürgen Barth
- University of BernInstitute of Social and Preventive MedicineNiesenweg 6BernSwitzerlandCH‐3012
| | - Tiffany Jacob
- University of BernInstitute of Social and Preventive MedicineNiesenweg 6BernSwitzerlandCH‐3012
| | - Ioana Daha
- Carol Davila University of Medicine and Pharmacy, Colentina Clinical HospitalDepartment of Cardiology19‐21, Stefan cel MareBucharestRomania020142
| | - Julia A Critchley
- St George's, University of LondonPopulation Health Sciences InstituteCranmer TerraceLondonUKSW17 0RE
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Forey BA, Fry JS, Lee PN, Thornton AJ, Coombs KJ. The effect of quitting smoking on HDL-cholesterol - a review based on within-subject changes. Biomark Res 2013; 1:26. [PMID: 24252691 PMCID: PMC4177613 DOI: 10.1186/2050-7771-1-26] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 08/22/2013] [Indexed: 12/11/2022] Open
Abstract
A higher concentration of high density lipoprotein cholesterol (HDL-C) in ex-smokers than smokers has consistently been observed. Better evidence of quitting effects comes from within-subject changes. We extend an earlier meta-analysis to quantify the reduction, and investigate variation by time quit and other factors. We conducted Medline and Cochrane searches for studies measuring HDL-C in subjects while still smoking and later having quit. Using unweighted and inverse-variance weighted regression analysis, we related changes (in mmol/l) to intra-measurement period, and estimated time quit, and to study type, location and start year, age, sex, product smoked, validation of quitting, baseline HDL-C, baseline and change in weight/BMI, and any study constraints on diet or exercise. Forty-five studies were identified (17 Europe, 16 North America, 11 Asia, 1 Australia). Thirteen were observational, giving changes over at least 12 months, with most involving >1000 subjects. Others were smoking cessation trials, 12 randomized and 20 non-randomized. These were often small (18 of <100 subjects) and short (14 of <10 weeks, the longest a year). Thirty studies provided results for only one time interval. From 94 estimates of HDL-C change, the unweighted mean was 0.107 (95% CI 0.085-0.128). The weighted mean 0.060 (0.044 to 0.075) was lower, due to smaller estimates in longer term studies. Weighted means varied by time quit (0.083, 0.112, 0.111, 0.072, 0.058 and 0.040 for <3, 3 to <6, 6 to <13, 13 to <27, 27 to <52 and 52+ weeks, p=0.006). After adjustment for time quit, estimates varied by study constraint on diet/exercise (p=0.003), being higher in studies requiring subjects to maintain their pre-quitting habits, but no other clear differences were seen, with significant (p<0.05) increases following quitting being evident in all subgroups studied, except where data were very limited. For both continuing and never smokers, the data are (except for two large studies atypically showing significant HDL-C declines in both groups, and a smaller decline in quitters) consistent with no change, and contrast markedly with the data for quitters. We conclude that quitting smoking increases HDL-C, and that this increase occurs rapidly after quitting, with no clear pattern of change thereafter.
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Affiliation(s)
| | - John S Fry
- P.N. Lee Statistics and Computing Ltd, Surrey, UK
| | - Peter N Lee
- P.N. Lee Statistics and Computing Ltd, Surrey, UK
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Suwazono Y, Dochi M, Oishi M, Tanaka K, Morimoto H, Sakata K. Longitudinal effect of smoking cessation on physical and laboratory findings. Am J Prev Med 2010; 38:192-200. [PMID: 20117576 DOI: 10.1016/j.amepre.2009.09.040] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Revised: 08/10/2009] [Accepted: 09/21/2009] [Indexed: 11/25/2022]
Abstract
BACKGROUND Detailed information on the expected physiologic changes after smoking cessation is practically useful to encourage people to stop smoking. Furthermore, weight increase after cessation may affect such physiologic changes. PURPOSE This article aims to evaluate the effect of smoking cessation on annual changes in body weight, blood pressure, and blood biochemistry. METHODS This study analyzed the results of annual health examinations from 1991 to 2005 in male Japanese workers in 2009. Subjects classified as stopping smoking (n=445) responded initially as smokers in a self-administered questionnaire (baseline year) and then answered consistently as nonsmokers for 3 subsequent years. Of the 2672 smokers identified in the study, 2403 subjects who had data available for at least 4 successive years were selected as controls. The time course of physiologic and laboratory data was analyzed using a linear mixed model. RESULTS Data adjusted for age, type of job schedule, drinking and physical activity showed that subjects who stopped smoking had significantly greater increases in weight, BMI, systolic and diastolic blood pressure, total cholesterol, high-density lipoprotein cholesterol, and uric acid and a greater decrease in hemoglobin in the 3 years following smoking cessation than continuing smokers. Additional adjustment for change in BMI from baseline negated the significant deterioration in systolic and diastolic blood pressure and total cholesterol that occurred following smoking cessation. CONCLUSIONS Increase in body weight, blood pressure, and blood biochemistry can continue for at least 3 years after smoking cessation. This study also indicated that these increases were related to the weight increase that occurred after smoking cessation.
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Affiliation(s)
- Yasushi Suwazono
- Department of Occupational and Environmental Medicine (A2), Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuoku, Chiba 260-8670, Japan.
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Barth J, Critchley J, Bengel J. Psychosocial interventions for smoking cessation in patients with coronary heart disease. Cochrane Database Syst Rev 2008:CD006886. [PMID: 18254119 DOI: 10.1002/14651858.cd006886] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Quitting smoking improves prognosis after a cardiac event, but many patients continue to smoke, and improved cessation aids are urgently required. OBJECTIVES To assess the effectiveness of psychosocial interventions such as behavioural therapeutic intervention, telephone support and self-help interventions in helping people with coronary heart disease (CHD) to quit smoking. SEARCH STRATEGY The Cochrane Central Register of Controlled Trials (issue 2 2003), MEDLINE, EMBASE, PsycINFO and PSYNDEX were searched from the start of the database to August 2003. Results were supplemented by cross-checking references, and handsearches in selected journals and systematic reviews. SELECTION CRITERIA Randomised controlled studies (RCTs) in patients with CHD with a minimum follow-up of 6 months. After initial selection of the studies three trials with methodological flaws (e.g. high drop out) were excluded. DATA COLLECTION AND ANALYSIS Abstinence rates were computed according to an intention to treat analysis if possible, or if not on follow-up results only. MAIN RESULTS We found 16 RCTs meeting inclusion criteria. Interventions consist of behavioural therapeutic approaches, telephone support and self-help material and were either focused on smoking cessation alone or addressed several risk factors. The trials mostly included older male patients with CHD, predominantly myocardial infarction. Overall there was a positive effect of interventions on abstinence after 6 to 12 months (odds ratio (OR) 1.66, 95% confidence interval (CI) 1.25 to 2.22), but substantial heterogeneity between trials. Studies with validated assessment of smoking status at follow-up had lower efficacy (OR 1.44, 95% CI 0.99 to 2.11) than non-validated trials (OR 1.92, 95% CI 1.26 to 2.93). Studies were clustered by intervention strategy and intensity of the intervention. Clustering reduced heterogeneity, although many trials used more than one type of intervention. The ORs for different strategies were similar (behavioural therapies OR 1.69, 95% CI 1.33 to 2.14; telephone support OR 1.58, 95% CI 1.28 to 1.97; self-help OR 1.48, 95% CI 1.11 to 1.96). More intense interventions showed increased quit rates (OR 1.98, 95% CI 1.49 to 2.65) whereas brief interventions did not appear effective (OR 0.92, 95% CI 0.70 to 1.22). Two trials had longer term follow-up, and did not show any benefits after 5 years. AUTHORS' CONCLUSIONS Psychosocial smoking cessation interventions are effective in promoting abstinence at 1 year, provided they are of sufficient duration. Further studies, with longer follow-up, should compare different psychosocial intervention strategies, or the addition of a psychosocial intervention strategy to pharmacological therapy (e.g. nicotine replacement therapy) compared with pharmacological treatment alone.
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Affiliation(s)
- J Barth
- University Berne, Institute of Social and Preventive Medicine, Department of Social and Preventive Medicine, Niesenweg 6, Berne, Switzerland, 3012.
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Bernaards CM, Twisk JWR, Snel J, van Mechelen W, Kemper HCG. In a prospective study in young people, associations between changes in smoking behavior and risk factors for cardiovascular disease were complex. J Clin Epidemiol 2005; 58:1165-71. [PMID: 16223660 DOI: 10.1016/j.jclinepi.2005.02.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2002] [Revised: 02/27/2004] [Accepted: 02/14/2005] [Indexed: 11/30/2022]
Abstract
OBJECTIVE This study investigates how voluntary changes in tobacco consumption are related to changes in biological risk factors for cardiovascular disease in 21- to 36-year-old men and women. STUDY DESIGN AND SETTING Data of the Amsterdam Growth and Health Longitudinal Study (AGAHLS) were used to study the association between voluntary changes in tobacco consumption and changes in biological risk factors for cardiovascular disease (CVD) during 4-6 years of follow-up in 165 men and 195 women aged 21-36 years. We used multiple linear regression analyses with corrections for age and changes in other lifestyles. RESULTS In both sexes, we found trends for a reduction in blood pressure, high-density lipoprotein cholesterol (HDL-C), body weight, and waist-to-hip ratio (WHR) and a rise in the ratio between total serum cholesterol (TC) and HDL-C (TC/HDL-C) with increasing tobacco consumption. Opposite trends were found with reducing tobacco consumption. In women, body weight, WHR, and waist circumference reduced significantly and independently with increasing tobacco consumption and increased significantly with decreasing tobacco consumption. CONCLUSION These results suggest that voluntary changes in tobacco consumption go together with both healthy and unhealthy changes in biological risk factors for CVD.
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Affiliation(s)
- Claire M Bernaards
- Institute for Research in Extramural Medicine (EMGO Institute), VU University Medical Center (VUMC), Amsterdam, The Netherlands
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Hendrickson A, McKinstry LA, Lewis JK, Lum J, Louie A, Schellenberg GD, Hatsukami TS, Chait A, Jarvik GP. Ex vivo measures of LDL oxidative susceptibility predict carotid artery disease. Atherosclerosis 2004; 179:147-53. [PMID: 15721021 DOI: 10.1016/j.atherosclerosis.2004.09.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2004] [Revised: 08/26/2004] [Accepted: 09/24/2004] [Indexed: 11/27/2022]
Abstract
AIM The purpose of the study was to assess whether ex vivo measures of low-density lipoprotein (LDL) oxidation improved prediction of carotid artery disease (CAAD) case-control status compared to standard lipid and smoking measures. METHODS One hundred and forty cases with a high degree of carotid artery stenosis aged 40-83 years and an equal number of controls without stenosis or other vascular disease were matched by censored age within 2 years. Matched logistic regression evaluated the significance of copper-induced oxidative measures with and without covariates. The relationship of LDL oxidation measures with statin use and current smoking was also evaluated. RESULTS Logistic regression demonstrated a significant effect of the three correlated measures of oxidative susceptibility (lag time, oxidation rate and maximal rate of oxidation) separately on disease prediction (all p<0.05). These oxidative measures remained significant predictors of case-control status when other cardiovascular disease predictors (age; LDL-C, HDL-C and ApoAI levels; current smoking, ever smoking and pack-years smoked) were jointly considered. This relationship was not attributable to the effects of statin use on LDL oxidation. CONCLUSIONS Ex vivo measures of oxidation improved the prediction of carotid artery disease status, suggesting that this is an important determinant of atherosclerotic risk in this older population.
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Affiliation(s)
- Audrey Hendrickson
- Division of Medical Genetics, The University of Washington Department of Medicine, Seattle, WA 98195, USA
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Hong CC, Tang BK, Rao V, Agarwal S, Martin L, Tritchler D, Yaffe M, Boyd NF. Cytochrome P450 1A2 (CYP1A2) activity, mammographic density, and oxidative stress: a cross-sectional study. Breast Cancer Res 2004; 6:R338-51. [PMID: 15217501 PMCID: PMC468635 DOI: 10.1186/bcr797] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2003] [Revised: 02/18/2004] [Accepted: 03/31/2004] [Indexed: 02/05/2023] Open
Abstract
Introduction Mammographically dense breast tissue is a strong predictor of breast cancer risk, and is influenced by both mitogens and mutagens. One enzyme that is able to affect both the mitogenic and mutagenic characteristics of estrogens is cytochrome P450 1A2 (CYP1A2), which is principally responsible for the metabolism of 17β-estradiol. Methods In a cross-sectional study of 146 premenopausal and 149 postmenopausal women, we examined the relationships between CYP1A2 activity, malondialdehyde (MDA) levels, and mammographic density. In vivo CYP1A2 activity was assessed by measuring caffeine metabolites in urine. Levels of serum and urinary MDA, and MDA–deoxyguanosine adducts in DNA were measured. Mammograms were digitized and measured using a computer-assisted method. Results CYP1A2 activity in postmenopausal women, but not in premenopausal women, was positively associated with mammographic density, suggesting that increased CYP1A2 activity after the menopause is a risk factor for breast cancer. In premenopausal women, but not in postmenopausal women, CYP1A2 activity was positively associated with serum and urinary MDA levels; there was also some evidence that CYP1A2 activity was more positively associated with percentage breast density when MDA levels were high, and more negatively associated with percentage breast density when MDA levels were low. Conclusion These findings provide further evidence that variation in the activity level of enzymes involved in estrogen metabolism is related to levels of mammographic density and potentially to breast cancer risk.
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Affiliation(s)
- Chi-Chen Hong
- Division of Epidemiology and Statistics, Ontario Cancer Institute, Toronto, Ontario, Canada
| | - Bing-Kou Tang
- Department of Pharmacology, University of Toronto, Toronto, Ontario, Canada
| | - Venketeshwer Rao
- Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Sanjiv Agarwal
- Department of Nutritional Sciences, University of Toronto, Toronto, Ontario, Canada
| | - Lisa Martin
- Division of Epidemiology and Statistics, Ontario Cancer Institute, Toronto, Ontario, Canada
| | - David Tritchler
- Division of Epidemiology and Statistics, Ontario Cancer Institute, Toronto, Ontario, Canada
| | - Martin Yaffe
- Medical Imaging Research Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario, Canada
| | - Norman F Boyd
- Division of Epidemiology and Statistics, Ontario Cancer Institute, Toronto, Ontario, Canada
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Maeda K, Noguchi Y, Fukui T. The effects of cessation from cigarette smoking on the lipid and lipoprotein profiles: a meta-analysis. Prev Med 2003; 37:283-90. [PMID: 14507483 DOI: 10.1016/s0091-7435(03)00110-5] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Cross-sectional studies revealed that cigarette smokers have lower high-density lipoprotein cholesterol (HDL-C) levels and higher levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) than nonsmokers. But prospective studies on the effects of cigarette smoking cessation on lipid profile have yielded inconclusive results. METHODS Relevant English articles were retrieved by keyword searches of MEDLINE (1966-October 2000), Cochrane Library (2000, Issue 2), and cited references. Twenty-seven studies met the following inclusion criteria: (1) prospective cohort study including clinical trials, (2) measuring smoking status and lipid profile of HDL-C, TC, LDL-C, and TG, (3) reporting the changes of lipid concentrations in abstinent smokers, and (4) not using adjuvant antihyperlipidemic drugs. RESULTS Overall Q statistics for net change of HDL-C, TC, LDL-C, and TG showed heterogeneity. Using a random-effects model, HDL-C level increased significantly [0.100 (CI 0.074 to 0.127) mmol/L] after smoking cessation. However, levels of TC [+0.003 (CI -0.042 to 0.048)], LDL-C [-0.064 (CI -0.149 to 0.021)], and TG [+0.028 (CI -0.014 to 0.071)] did not change significantly after smoking cessation. CONCLUSIONS Cigarette smoking cessation increases serum levels of HDL-C but not of TC, LDL-C, and TG.
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Affiliation(s)
- Kenji Maeda
- Department of General Medicine and Clinical Epidemiology, Kyoto University Graduate School of Medicine, Kyoto, Japan
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Toobert DJ, Strycker LA, Glasgow RE, Bagdade JD. If you build it, will they come? Reach and Adoption associated with a comprehensive lifestyle management program for women with type 2 diabetes. PATIENT EDUCATION AND COUNSELING 2002; 48:99-105. [PMID: 12401412 DOI: 10.1016/s0738-3991(02)00120-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This paper describes recruitment and participation of physicians and patients in a randomized study to evaluate the effects of a moderately intensive (2-year) lifestyle management intervention for post-menopausal women with type 2 diabetes at risk for coronary heart disease (CHD). The purpose of this report is to answer two practical public health questions: (1) "Will physicians refer their patients with type 2 diabetes to such an intensive lifestyle change program?" and, if so, (2) "Will these patients participate?" Results showed high (70%) acceptance among physicians. About 51% of eligible patients agreed to participate, which was encouraging given the substantial time commitment involved. Main reasons for refusal were lack of eligible patients (among physicians) and lack of time (among patients). Patient participants and non-participants did not differ significantly on age, body mass, and other demographic and medical variables. Based on these results, it appears that appropriate recruitment procedures will yield a representative sample of women willing to participate in intensive lifestyle management programs.
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Affiliation(s)
- Deborah J Toobert
- Oregon Research Institute, 1715 Franklin Blvd., 97403-1983, Eugene, OR, USA.
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van den Berkmortel FW, Demacker PN, Wollersheim H, Thien T, Stalenhoef AF. Smoking or its cessation does not alter the susceptibility to in vitro LDL oxidation. Eur J Clin Invest 2000; 30:972-9. [PMID: 11114959 DOI: 10.1046/j.1365-2362.2000.00739.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Enhanced induction of low density lipoprotein (LDL) oxidation may play a role in the increased cardiovascular risk in smokers. We determined LDL oxidisability in vitro in non-smokers, smokers and in subjects after smoking cessation. PATIENTS AND METHODS Plasma lipids and copper induced LDL oxidation in vitro were measured in 31 persistent smokers, 47 smokers who tried to stop smoking and 25 non-smokers. In the smoking cessation group, blood was collected before then 1, 3, 6 and 12 months after smoking cessation, and in the persistent smoking and non-smoking groups at baseline and after 12 months. Plasma thiobarbituric acid reactive substances (TBARS) were measured 3 times (at baseline then after 1 and 3 months) in all subjects who refrained from smoking (controlled by urinary cotinine concentrations) for at least 3 months. RESULTS At baseline, no differences in mean age, body mass index and lipid profiles between groups were present. Seventeen subjects of the smoking cessation group (36%) managed to quit during 12 months. Smoking cessation was associated with an increase in mean weight (P </= 0.001) and waist-hip ratio (P </= 0.001). No major differences in LDL oxidisability were found between groups. A significant transient increase in high density lipoprotein (HDL) cholesterol was seen (from 1.20 +/- 0.39 to 1.34 +/- 0.42 mmol L-1) after 1 month of smoking cessation that disappeared after 3 months. However, after 1 month of smoking cessation, plasma TBARS decreased significantly (P < 0.05). CONCLUSIONS Neither the previously observed increased cardiovascular risk in smokers nor the decreased risk in those who stopped smoking seem to be mediated by permanent changes in lipid profiles or by alterations in the susceptibility to in vitro oxidation of LDL.
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Affiliation(s)
- F W van den Berkmortel
- Department of Medicine, Division of General Internal Medicine, University Hospital Nijmegen, The Netherlands.
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Poulsen HE, Loft S, Prieme H, Vistisen K, Lykkesfeldt J, Nyyssonen K, Salonen JT. Oxidative DNA damage in vivo: relationship to age, plasma antioxidants, drug metabolism, glutathione-S-transferase activity and urinary creatinine excretion. Free Radic Res 1998; 29:565-71. [PMID: 10098460 DOI: 10.1080/10715769800300601] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Oxidative DNA modification has been implicated in development of certain cancers and 8-oxodG, the most abundant and mutagenic DNA modification, has for some time been considered a biomarker of this activity. Urinary excretion of 8-oxodG over 24h has been used to estimate the rate of damage to DNA, and animal studies have supported this rationale. Reported determinants include tobacco smoking, heavy exercise, environmental pollution and individual oxygen consumption. Samples from three published studies were used to determine the association of urinary 8-oxodG excretion with age, plasma antioxidants, the glutathione-S-transferase phenotype and the activity of the xenobiotic metabolising enzyme CYP1A2. In the age range 35-65 years, age was not related to urinary 8-oxodG excretion, and there were no relations to either the glutathione-S-transferase phenotype or to the plasma antioxidants: vitamin C, alpha-tocopherol, beta-carotene, lycopene or coenzyme Q10. The activity of CYP1A2 showed a significant correlation in two of the three studies, as well as a significant correlation of 0.26 (p < 0.05) in the pooled data set. Regression analysis of CYP1A2 activity on 8-oxodG indicated that 33% increase in CYP1A2 activity would correspond to a doubling of 8-oxodG excretion. This finding needs to be confirmed in independent experiments. Spot morning urine samples can under certain circumstances be used to estimate 8-oxodG excretion rate provided that creatinine excretion is unchanged (in paired experiments) or comparable (in un-paired experiments), as evaluated from the correlation between 8-oxodG excretion in 24 h urine samples and in morning spot urine samples corrected for creatinine excretion (r = 0.50, p < 0.05). We conclude that 8-oxodG excretion is determined by factors like oxygen consumption and CYP1A2 activity rather than by factors like plasma antioxidant concentrations.
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Affiliation(s)
- H E Poulsen
- Department of Clinical Pharmacology, Rigshospitalet, University Hospital Copenhagen, Denmark.
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