Acute changes in Atherogenic and Thrombogenic Factors with Cessation of Smoking

Tobacco smoking and binge alcohol use are associated with incident venous thromboembolism in an HIV cohort

BACKGROUND

People with HIV (PWH) are at increased risk of cardiovascular comorbidities and substance use is a potential predisposing factor. We evaluated associations of tobacco smoking and alcohol use with venous thromboembolism (VTE) in PWH.

METHODS

We assessed incident, centrally adjudicated VTE among 12 957 PWH within the Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) cohort between January 2009 and December 2018. Using separate Cox proportional hazards models, we evaluated associations of time-updated alcohol and cigarette use with VTE, adjusting for demographic and clinical characteristics. Smoking was evaluated as pack-years and never, former, or current use with current cigarettes per day. Alcohol use was parameterized using categorical and continuous alcohol use score, frequency of use, and binge frequency.

RESULTS

During a median of 3.6 years of follow-up, 213 PWH developed a VTE. One-third of PWH reported binge drinking and 40% reported currently smoking. In adjusted analyses, risk of VTE was increased among both current (HR: 1.44, 95% CI: 1.02-2.03) and former (HR: 1.44, 95% CI: 0.99-2.07) smokers compared to PWH who never smoked. Additionally, total pack-years among ever-smokers (HR: 1.10 per 5 pack-years; 95% CI: 1.03-1.18) was associated with incident VTE in a dose-dependent manner. Frequency of binge drinking was associated with incident VTE (HR: 1.30 per 7 days/month, 95% CI: 1.11-1.52); however, alcohol use frequency was not. Severity of alcohol use was not significantly associated with VTE.

CONCLUSIONS

Current smoking and pack-year smoking history were dose-dependently associated with incident VTE among PWH in CNICS. Binge drinking was also associated with VTE. Interventions for smoking and binge drinking may decrease VTE risk among PWH.

Predictive risk factors of venous thromboembolism (VTE) associated with peripherally inserted central catheters (PICC) in ambulant solid cancer patients: retrospective single Centre cohort study

Aims

Peripherally inserted central catheters(PICC) lines are becoming increasingly popular in solid cancer patients for the administration of chemotherapy. This study aims looking at the incidence of PICC line related and distant thromboembolism associated with these catheters and exploring risk factors.

Methods

Records were reviewed for 158 patients who underwent PICC line insertion over the two years period in the medical oncology unit, Milton Keynes University Hospital. The Incidence PICC line related Deep Venous Thrombosis (DVT) which is defined as upper extremity DVT at the site of PICC line insertion was documented after checking reports of ultrasound Doppler of all symptomatic patients to confirm the presence of thrombo-embolism and Computed Tomography(CT)scan or Computed Tomography Pulmonary Angiography (CTPA) to confirm the presence Pulmonary Embolism(PE).

Results

23(13%) symptomatic patients with confirmed diagnosis by ultrasound Doppler were found to have PICC line related DVT and similar number of patients developed distant VTE, namely PE and lower limbs DVT. Average time to thrombo-embolism from the insertion of PICC line was 13 days and 51 days in distant VTE. Statistically significant results have been identified in the term of risk factors leading to VTE events during the period of PICC line insertion.

Conclusions

VTE is a common complication in medical oncology patients who underwent insertion PICC line insertion for chemotherapy. Risk of distant VTE is high as well as the PICC line related DVT and the risk of the PICC line related DVT is higher in the first two weeks after PICC insertion. We concluded that high BMI,high PLTs count and Fluropyrimidine containing chemotherapy are all significant risk factors for VTE events recorded while smoking and high BMI are significantly contributing to the high rate of the PICC line related DVT.

Venous thromboembolism has the same risk factors as atherosclerosis: A PRISMA-compliant systemic review and meta-analysis

BACKGROUND

Previous studies have shown that idiopathic pulmonary embolism is positively associated with other cardiovascular events, such as myocardial infarction and stroke, suggesting a potentially important association between atherosclerosis risk factors and venous thromboembolism (VTE). We performed a meta-analysis to evaluate the correlation between risk factors for atherosclerosis and VTE.

METHODS

In December 2014, we searched MEDLINE and EMBASE for studies evaluating the associations between VTE and risk factors for atherosclerosis and pooled outcome data using random-effects meta-analysis. In addition, we analyzed publication bias.

RESULTS

Thirty-three case-control and cohort studies with a total of 185,124 patients met the inclusion criteria. We found that participants with body mass index (BMI) ≥30 kg/m had a significantly higher prevalence of VTE than those with BMI <30 kg/m in both case-control studies (odds ratio [OR] = 2.45, 95% confidence interval [CI]: 1.78-3.35) and cohort studies (relative risk [RR] = 2.39, 95% CI: 1.79-3.17). VTE was more prevalent in patients with hypertension than without hypertension (OR = 1.40, 95% CI: 1.06-1.84; RR = 1.36, 95% CI: 1.11-1.67). The findings were similar for VTE prevalence between patients with and without diabetes (OR = 1.78, 95% CI: 1.17-2.69; RR = 1.41, 95% CI: 1.20-1.66). Current smoking was significantly associated with VTE prevalence in case-control studies (OR = 1.34, 95% CI: 1.01-1.77), but not in cohort studies (RR = 1.29, 95% CI: 0.96-1.72). In addition, we found that total cholesterol and triglyceride concentrations were significantly higher in patients with VTE than without VTE (weighted mean differences [WMD] = 8.94 mg/dL, 95% CI: 3.52-14.35 mg/dL, and WMD = 14.00 mg/dL, 95% CI: 8.85-19.16 mg/dL, respectively). High-density lipoprotein cholesterol concentrations were significantly lower in patients with VTE than without VTE (WMD = -2.03 mg/dL, 95% CI: -3.42 to -0.63 mg/dL). Higher quality studies were more homogeneous, but confirmed the same significant associations.

CONCLUSIONS

Based on our systematic review and meta-analysis, we observed a significant association between VTE and the risk factors for atherosclerosis. These results may make an important contribution to clinical practice regarding VTE treatment.

Distribution, genetic and cardiovascular determinants of FVIII:c - Data from the population-based Gutenberg Health Study

BACKGROUND

Elevated levels of

FVIII

c are associated with risk for both venous and arterial thromboembolism. However, no population-based study on the sex-specific distribution and reference ranges of plasma

FVIII

c and its cardiovascular determinants is available.

METHODS

FVIII

c was analyzed in a randomly selected sample of 2533 males and 2440 females from the Gutenberg Health Study in Germany. Multivariable regression analyses for

FVIII

c were performed under adjustment for genetic determinants, cardiovascular risk factors and cardiovascular disease.

RESULTS AND CONCLUSIONS

Females (126.6% (95% CI: 125.2/128)) showed higher

FVIII

c levels than males (121.2% (119.8/122.7)).

FVIII

c levels increased with age in both sexes (ß per decade: 5.67% (4.22/7.13) male, 6.15% (4.72/7.57) female; p<0.001). Sex-specific reference limits and categories indicating the grade of deviation from the reference were calculated, and nomograms for

FVIII

c were created.

FVIII

c was approximately 25% higher in individuals with non-O blood type. Adjusted for sex and age, ABO-blood group accounted for 18.3% of

FVIII

c variation. In multivariable analysis,

FVIII

c was notably positively associated with diabetes mellitus, obesity, hypertension and dyslipidemia and negatively with current smoking. In a fully adjusted multivariable model, the strongest associations observed were of elevated

FVIII

c with diabetes and peripheral artery disease in both sexes and with obesity in males. Effects of SNPs in the vWF, STAB2 and SCARA5 gene were stronger in females than in males. The use of nomograms for valuation of

FVIII

c might be useful to identify high-risk cohorts for thromboembolism. Additionally, the prospective evaluation of

FVIII

c as a risk predictor becomes feasible.

The effect of quitting smoking on HDL-cholesterol - a review based on within-subject changes

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.

Blood viscosity as a forgotten factor and its effect on pulmonary flow

Background

The effect of smoking on blood viscosity is widely known. There are, however, few studies on the effect of blood viscosity on pulmonary circulation.

Methods

We aimed to observe the relationship between blood viscosity and pulmonary circulation among smokers and non-smokers. The study comprised 114 subjects in three groups: group 1, ex-smokers; group 2, smoked at least 10 packs/year and still smoking; group 3, never smoked. Blood viscosity (BV), pulmonary blood flow (PBF), and right ventricular systolic pressure (RVSP) were measured in all subjects.

Results

PBF was significantly lower in group 1 compared with group 3 (p < 0.05). BV in group 1 was significantly higher than group 3 (p < 0.05) while BV in group 2 was significantly higher than group 3 (p < 0.05). PBF in group 2 was significantly lower than group 3 (p = 0.01).

Conclusions

We believe that BV is a significant and forgotten factor that plays an important role in pulmonary and cardiovascular diseases. BV may affect PF even during the course of smoking, and before the clinical onset of chronic obstructive pulmonary disease (COPD). Therefore, individuals at risk of pulmonary hypertension could be detected earlier with a simple blood test.

Current and former smoking and risk for venous thromboembolism: a systematic review and meta-analysis

BACKGROUND

Smoking is a well-established risk factor for atherosclerotic disease, but its role as an independent risk factor for venous thromboembolism (VTE) remains controversial. We conducted a meta-analysis to summarize all published prospective studies and case-control studies to update the risk for VTE in smokers and determine whether a dose-response relationship exists.

METHODS AND FINDINGS

We performed a literature search using MEDLINE (source PubMed, January 1, 1966 to June 15, 2013) and EMBASE (January 1, 1980 to June 15, 2013) with no restrictions. Pooled effect estimates were obtained by using random-effects meta-analysis. Thirty-two observational studies involving 3,966,184 participants and 35,151 VTE events were identified. Compared with never smokers, the overall combined relative risks (RRs) for developing VTE were 1.17 (95% CI 1.09-1.25) for ever smokers, 1.23 (95% CI 1.14-1.33) for current smokers, and 1.10 (95% CI 1.03-1.17) for former smokers, respectively. The risk increased by 10.2% (95% CI 8.6%-11.8%) for every additional ten cigarettes per day smoked or by 6.1% (95% CI 3.8%-8.5%) for every additional ten pack-years. Analysis of 13 studies adjusted for body mass index (BMI) yielded a relatively higher RR (1.30; 95% CI 1.24-1.37) for current smokers. The population attributable fractions of VTE were 8.7% (95% CI 4.8%-12.3%) for ever smoking, 5.8% (95% CI 3.6%-8.2%) for current smoking, and 2.7% (95% CI 0.8%-4.5%) for former smoking. Smoking was associated with an absolute risk increase of 24.3 (95% CI 15.4-26.7) cases per 100,000 person-years.

CONCLUSIONS

Cigarette smoking is associated with a slightly increased risk for VTE. BMI appears to be a confounding factor in the risk estimates. The relationship between VTE and smoking has clinical relevance with respect to individual screening, risk factor modification, and the primary and secondary prevention of VTE. Please see later in the article for the Editors' Summary.

Weight gain and insulin resistance during nicotine replacement therapy

BACKGROUND

Although the cessation of smoking reduces the increased risk for ischemic heart disease, it is associated with marked weight gain and presumably insulin resistance, both of which heighten the risk of coronary heart disease.

HYPOTHESIS

We investigated the isolated effect of nicotine on body weight and insulin resistance during smoking cessation.

METHODS

Eleven healthy, middle-aged heavy smokers were studied. Insulin sensitivity was assessed by an insulin-enhanced, frequently sampled intravenous glucose tolerance test with minimal model analysis. The subjects were studied at baseline (last day of smoking) (phase 1), at the end of the 6-week nicotine replacement program (phase 2), and after 8 weeks without smoking or nicotine replacement (phase 3).

RESULTS

The subjects started to gain weight during nicotine replacement (phase 2) (0.3 +/- 0.2 kg/week, mean +/- standard deviation) and continued to do so at a steady rate after nicotine replacement was stopped (0.2 +/- 0.2 kg/week) (p = 0.3). Insulin sensitivity decreased by 14 +/- 2.6% during nicotine replacement but increased by 16 +/- 5.1% (compared with phase 2) during phase 3, even though the weight gain continued (p = 0.047; 95% confidence interval: 0.05-5.73).

CONCLUSIONS

Smoking cessation is associated with weight gain and improvement in insulin resistance. Nicotine is the main ingredient in cigarette smoke causing insulin resistance, but the withdrawal of another, unknown ingredient in cigarette smoke is responsible for the weight gain associated with smoking cessation.

The smoker's paradox and the real risk of smoking

No satisfactory explanations have been offered for the smoker's paradox, the greater short-term survival of smokers after a myocardial infarction nor for the large variations in the coronary risk rate for smoking ranging between 1 and 5.9. These discrepancies as well as the smoker's paradox may be caused by different baseline characteristics of smokers and nonsmokers, whereas the usually quoted coronary risk of 2 is derived from studies based on the assumption of equal baseline characteristics. As neither this assumption nor the possibility of unequal starting conditions have been tested, we examined the main cardiovascular risk factors in smoking and nonsmoking boys as near as possible to baseline, at the age of fourteen. This age appeared to be best suited, because boys starting to smoke early are most likely to become regular and heavy smokers. Of 336 boys, 39 had smoked 8.3+/-6.0 cigarettes/day for 15.5+/-11.2 months. Compared to nonsmokers, boys who started to smoke early had lower LDL cholesterol and alpha2-antiplasmin, greater handgrip strength, vital capacity and forced expiratory volume, better perfomance on bicycle ergometry and higher testosterone. The differences in total cholesterol, LDL cholesterol, vital capacity, handgrip strength, testosterone and alpha2-antiplasmin persisted after adjustment for age, body mass, and testosterone. In addition, the differences in perfomance on bicycle ergometry and forced expiratory volume persisted after adjustment for age. These favourable baseline characteristics of those starting to smoke early can explain the smoker's paradox. In addition, they suggest that the individual coronary risk in smokers is considerably higher than 2, because the assumption of equal baseline characteristics of smokers and nonsmokers cannot be upheld.

The effects of cessation from cigarette smoking on the lipid and lipoprotein profiles: a meta-analysis

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.

Smoking diminishes the beneficial effect of statins: observations from the landmark trials

The landmark statin trials showed a significant reduction in morbidity and mortality associated with ischemic heart disease. However, it may not be widely appreciated that smoking had a marked adverse effect on outcome in these trials. In both the primary and secondary prevention setting, the effect of smoking was broadly similar. Smoking markedly increased the risk of events in the placebo and treatment groups. For example, in the primary prevention trials, this risk was 74-86% higher when smokers were compared with nonsmokers in the placebo groups. The corresponding figures for the secondary prevention trials were 23-61%. The risk of events in untreated nonsmokers was of a similar order to that seen in smokers taking statins. Although statin treatment was associated with a significant reduction in events in smokers, the best outcome was observed in nonsmokers treated with statins (primary prevention: lovastatin or pravastatin; secondary prevention: pravastatin or simvastatin). The highest risk of events in any group was in the smokers on placebo. This information may increase clinician and patient awareness as to the marked harmful effect of smoking relative to effective, evidence-based treatment (ie, the use of statins).

Effects of nicotine nasal spray on atherogenic and thrombogenic factors during smoking cessation

OBJECTIVES

To investigate changes in cardiovascular risk factor parameters when stopping smoking and to identify any impact of nicotine nasal spray on these factors.

DESIGN AND SUBJECTS

In a placebo-controlled, double-blind 3-month prospective study, nicotine nasal spray (NNS) or a placebo was given to 157 subjects attending a smoking cessation programme. Blood samples from 46 subjects who remained abstinent for 3 months were analysed. Nasal spray use was given on an ad libitum basis.

RESULTS

The haemoglobin (Hb) decreased from 149.0 to 143.2 g L(-1) (P<0.001). The haematocrit (Hct) decreased from 44.6 to 42.4% (P<0.001). The mean corpuscular volume (MCV) decreased from 93.4 to 92.3 fl (P<0.001). The mean corpuscular haemoglobin concentration (MCHC) increased from 333.9 to 338.1 g L(-1) (P = 0.029). The white blood cell count (WBC) decreased from 8.4 to 6.6x10(9) L(-1) (P<0.001). The total cholesterol decreased from 5.92 to 5.65 mmol L(-1) (P = 0.015). The high-density lipoprotein cholesterol (HDL) increased from 1.29 to 1.44 mmol L(-1) (P = 0.48) and low-density lipoprotein cholesterol (LDL) decreased from 4.00 to 3.54 mmol L(-1) (P = 0.004). The HDL/LDL ratio increased from 0.36 to 0.46 (P = 0.011).

CONCLUSION

Stopping smoking resulted in positive effects on cardiovascular risk factors. Nicotine treatment for as long as 3 months did not have any significant effect on these 'stopping smoking changes'. In smoking cessation, nicotine substitution up to 3 months seems to be safe.

von Willebrand factor, fibrinogen and other plasma proteins as determinants of plasma viscosity

Plasma viscosity and fibrinogen are risk factors for cardiovascular disease and on rheological grounds, it is widely believed that the latter is a major determinant of the former. However, other plasma constituents may also be important determinants of plasma viscosity. Our aim was to determine whether or not levels of von Willebrand factor contributed to plasma viscosity. We measured plasma viscosity, fibrinogen, von Willebrand factor, immunoglobulins G, A and M, total, HDL- and LDL-cholesterol, triglycerides and albumin in 95 patients with peripheral arterial disease and in 120 healthy controls. A stepwise multivariate analysis was performed to determine the major influences of plasma viscosity. We also measured fibrinogen, von Willebrand factor, immunoglobulins G, A and M, total, HDL- and LDL-cholesterol, triglycerides, albumin and viscosity in 32 smokers as they successfully progressed to being non-smokers. The level of von Willebrand factor was an independent influence on plasma viscosity in the controls (P < 0.05), patients (P < 0.01) and in the combined group (P < 0.001). von Willebrand factor, fibrinogen and plasma viscosity, but not the immunoglobulins, lipoproteins or albumin, fell (P < 0.05) in smokers as they became non-smokers. We find that von Willebrand factor contributes to plasma viscosity, hence a reduction in levels of von Willebrand factor should result in a reduction in viscosity. These data may have implications for the pathogenesis of cardiovascular disease.

Is transdermal nicotine associated with cardiovascular risk?

We had the unique opportunity to study the effects of transdermal nicotine on markers of haemostasis and serum lipids in patients with ulcerative colitis; all were non-smokers and were given transdermal nicotine to assess its value in maintenance therapy for colitis. In a controlled double-blind trial, 45 patients with ulcerative colitis in remission on 5-aminosalicylic acid, were randomly allocated to receive transdermal nicotine (20) or placebo (25) patches. Markers of haemostasis, including platelet activation (platelet volume and surface expression of P selectin), endothelial damage (plasma von Willebrand factor antigen) and plasma fibrinogen were measured at the beginning and after 12 weeks of treatment. The white cell count and serum lipids were also measured. Nicotine significantly lowered plasma fibrinogen but did not affect markers of platelet activation, endothelial damage, white cell count and serum lipids. The possibility that transdermal nicotine may beneficially influence cardiovascular risk factors warrants further exploration.

Association between fibrinogen and other risk factors for cardiovascular disease in men and women. Results from the Göteborg MONICA survey 1985

Plasma fibrinogen and its association to other risk factors for cardiovascular disease was investigated in a random sample of 691 men and 739 women, aged 25 to 64 years, participating in the Göteborg MONICA survey. In both genders univariate analyses revealed significantly positive correlations between plasma fibrinogen and age, body mass index (BMI), waist/hip ratio (WHR), systolic blood pressure, serum cholesterol and triglycerides and a negative correlation to high-density lipoprotein (HDL) cholesterol; however, the degree of relationship varied between men and women. Smoking was significantly correlated to fibrinogen (P < 0.001) in men, whereas the association was weaker in women. Multivariate analysis showed that plasma fibrinogen in both genders was significantly correlated to age, smoking, and BMI. The influence of smoking was stronger in men and BMI was stronger in women. Furthermore, the association of fibrinogen to HDL cholesterol was significant only in men and to triglycerides only in women. Plasma fibrinogen was significantly related to gender; when all other significant variables were taken into account, women had higher fibrinogen levels than men.

Exposure to environmental tobacco smoke increases myocardial infarct size in rats

BACKGROUND

Exposure to environmental tobacco smoke (ETS) has been epidemiologically linked to death from ischemic heart disease in nonsmokers. In this study, we evaluated the influence of 3 days, 3 weeks, and 6 weeks of ETS exposure on myocardial infarct size in a rat ischemia/reperfusion model.

METHODS AND RESULTS

Sprague-Dawley rats exposed to ETS (four Marlboro cigarettes per 15 minutes, 6 hours per day, 5 days per week) for 3 days (n = 24), 3 weeks (n = 21), or 6 weeks (n = 12) and control rats (n = 24, n = 21, and n = 12, respectively) were subjected to 35 minutes of left coronary artery occlusion and 2 hours of reperfusion. Infarct size and risk area were determined by triphenyltetrazolium chloride and phthalocyanine blue staining, respectively. Air nicotine, carbon monoxide, and total particulates were measured during ETS exposure. Serum lipids, plasma carbon monoxide hemoglobin (COHb), nicotine, and cotinine concentrations were measured in additional groups (6 to 13 rats each) exposed to 3 days, 3 weeks, or 6 weeks of ETS and controls. Average air nicotine, carbon monoxide, and total particulate concentrations were 1103 micrograms/m3, 92 ppm, and 60 mg/m3 for the ETS-exposed rats. Infarct size (infarct mass/risk area x 100%) increased significantly in the ETS groups compared with the control groups in a dose-dependent manner (P = .023), with longer exposure associated with larger infarct size. Infarct size nearly doubled with 6 weeks of ETS exposure (61 +/- 5% versus 34 +/- 3% for control, mean +/- SEM). Plasma COHb, nicotine, and cotinine levels increased significantly in the ETS groups in a dose-dependent manner (all P < .001).

CONCLUSIONS

Exposure to passive smoking increases myocardial infarct size in a rat model of ischemia and reperfusion. This increase of infarct size exhibited a dose-response relation. These results are consistent with epidemiological studies demonstrating that ETS increases the risk of heart death.

Standard and alternative adjunctive treatments in cardiac rehabilitation

Cardiovascular rehabilitation is the process of restoring functional abilities degraded by a serious cardiovascular event or by a surgical procedure to preempt such an event. Cardiovascular rehabilitation also includes attempts to reverse risk factors that have contributed initially to the disease process. Rehabilitation programs generally comprise disease-related educational components, supervised prescriptive physical exercise, diet counseling and modification, cessation of tobacco use, psychoeducational interventions aimed at adjustment and coping, and relaxation and stress management to lower nonexertion-related sympathetic drive. The presence of so-called coronary-prone behavior patterns can be detected, and special behavioral modifications may be indicated to mitigate these putative risk factors. This paper reviews the roles of these behavioral adjuncts in treating cardiovascular disease and its aftermath, and notes new and unusual approaches to these components of treatment, such as alternative exercises, biofeedback, yoga, and other relaxation methods. Barriers to compliance are acknowledged, and enhancement of compliance is discussed briefly.

Environmental influences on hemostasis and thrombosis. Diet and smoking

High levels of factor VII coagulant activity (VIIc) and fibrinogen concentration are independently associated with an increased risk of acute coronary heart disease in middle-aged men. Studies have, therefore, been undertaken to determine the responsiveness of these hemostatic factors to changes in diet and smoking habit. Plasma VIIc increases acutely with an increase in total fat intake, but fibrinogen is unaffected. In the general community, men who have a high total fat intake for their body size tend to have a high VIIc level. Changes in the dietary ratio of saturated to polyunsaturated fat of up to 14 days' duration have no effect on factor VIIc or fibrinogen (there are conflicting reports on the influence of dietary very-long-chain polyunsaturated fatty acids on fibrinogen concentration). Cigarette smokers have a higher fibrinogen concentration than do nonsmokers, but their levels slowly revert toward those of nonsmokers when the habit is relinquished.

Acute Changes in Haematological Parameters on Cessation of Smoking

Cigarette smoking is known to affect many haematological parameters but little is known of their rate of return to normal on withdrawal of cigarettes. Two groups of chronic smokers were studied whilst smoking and in the 2 weeks after cessation. A rapid return towards normal was found in the elevated haemoglobm concentration, packed cell volume, red cell count, white cell count, neutrophil count, lymphocyte count and platelet count, indicating that at least some of the abnormalities in these parameters are an acute, reversible effect of cigarette smoking rather than being a response to tissue damage.

Lowering of plasma viscosity by the oral administration of the glycosaminoglycan sulodexide in patients with peripheral vascular disease

The aim of the double-blind, crossover, placebo-controlled study was to evaluate whether oral administration of sulodexide, a medium molecular weight glycosaminoglycan, had an effect on whole blood, plasma and serum viscosity, and/or plasma fibrinogen concentrations. The drug was administered orally at a dose of 500 lipoproteinlipase releasing units twice daily for 1 month to two groups of 20 patients with peripheral vascular disease; one group was administered a placebo--drug sequence and the other a drug--placebo sequence. Orally administered sulodexide had a marked effect on plasma viscosity and on plasma fibrinogen concentrations, whereas there were no effects on whole blood viscosity. No significant side-effects were observed. The fact that sulodexide was highly effective, even after oral administration, suggests it may be useful for the treatment of patients with atheromatous vascular diseases of the lower limbs requiring chronic therapy.

Doxazosin therapy in the treatment of diabetic hypertension

The incidence of cardiovascular disease in non-insulin-dependent diabetes mellitus (NIDDM) has not been reduced by the control of hyperglycemia alone. Hypertension and dyslipidemia may be the major determinants of macrovascular disease in these patients. With the high prevalence of hypertension in NIDDM, antihypertensive drugs are likely to be important determinants of an atherogenic lipid profile. To date, there is no completed major randomized controlled trial of antihypertensive treatment outcome in a diabetic population, and as such, drug choice for the treatment of diabetic hypertension is often based on evidence extrapolated from studies in nondiabetic groups. However, two short-term studies have assessed the effects of doxazosin antihypertensive therapy in subjects with NIDDM. Both studies showed that the significant reduction in blood pressure with doxazosin treatment was associated with favorable effects on the serum lipid profile. In one study, contrasting adverse effects of atenolol treatment on glycemic control, lipids, and lipoproteins were observed. Doxazosin therapy was associated with a trend toward correcting the disturbances of lipoprotein metabolism characteristic of NIDDM. These metabolic effects, combined with effective lowering of blood pressure by doxazosin, may be important determinants of cardiovascular disease in the long term.