Cigarette Pack-years Research Articles

Are female smokers at higher risk for lung cancer than male smokers? A case-control analysis by histologic type.

A case-control study of male-female differences in cigarette smoking and lung cancer was conducted during 1981-1985 in Toronto, St. Catharine's, and Niagara Falls, Ontario, Canada. In total, 442 female and 403 male histologically verified cancer cases were individually matched by age and area of residence to each other and to 410 female and 362 male randomly selected population controls. Subjects were interviewed concerning their exposures to various life-style factors, and in particular, they received detailed questioning regarding their lifelong histories of usage of tobacco products. It was found that, for both sexes, a greatly elevated risk of developing lung cancer was associated with cigarette consumption, increasing with pack-years of cigarettes smoked and declining with duration of time since quitting smoking. Furthermore, the association was significantly (p = 0.010) and appreciably stronger for females than for males. At a history of 40 pack-years relative to lifelong nonsmoking, the odds ratio for women was 27.9 (95% confidence interval (CI) 14.9-52.0) and that for men was 9.60 (95% CI 5.64-16.3). Higher odds ratios for females were also seen within each of the major histologic groupings. Thus, the higher elevated risk of lung cancer currently observed in other studies for female ever smokers compared with male ever smokers, while possibly attributable in part to greater smoking cessation among males, may be due to higher susceptibility among females.

Occupational exposure to dust and lung disease among sheet metal workers.

A previous large medical survey of active and retired sheet metal workers with 20 or more years in the trade indicated an unexpectedly high prevalence of obstructive pulmonary disease among both smokers and non-smokers. This study utilised interviews with a cross section of the previously surveyed group to explore occupational risk factors for lung disease. Four hundred and seven workers were selected from the previously surveyed group on the basis of their potential for exposure to fibreglass and asbestos. Selection was independent of health state, and excluded welders. A detailed history of occupational exposure was obtained by telephone interview for 333 of these workers. Exposure data were analysed in relation to previously collected data on chronic bronchitis, obstructive lung disease, and personal characteristics. Assessment of the effects of exposure to fibreglass as distinct from the effects of exposure to asbestos has been difficult in previous studies of construction workers. The experienced workers studied here have performed a diversity of jobs involving exposure to many different types of materials, and this enabled exposure to each dust to be evaluated separately. The risk of chronic bronchitis increased sharply by pack-years of cigarettes smoked; current smokers had a double risk compared with those who had never smoked or had stopped smoking. The occurrence of chronic bronchitis also increased with increasing duration of exposure to asbestos. Workers with a history of high intensity exposure to fibreglass had a more than doubled risk of chronic bronchitis. Obstructive lung disease, defined by results of pulmonary function tests at the medical survey, was also related to both smoking and occupational risk factors. Number of pack years smoked was the strongest predictor of obstructive lung disease. Duration of direct and indirect exposure to welding fume was also a positive predictor of obstructive lung disease. Duration of exposure to asbestos was significantly associated with obstructive lung disease but the dose-response relation was inconsistent, especially for those with higher pack-years of smoking exposure. Exposure to fibreglass was not a risk factor for obstructive lung disease.

The relation of hearing in the elderly to the presence of cardiovascular disease and cardiovascular risk factors.

Hearing loss with age (presbycusis) is a substantial problem for the elderly. To investigate the possible relation of presbycusis to cardiovascular disease (CVD), the hearing status of a cohort of 1662 elderly men and women was determined and compared with their 30-year prevalence of cardiovascular disease. Age-adjusted multivariate logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) to describe the relation of hearing to cardiovascular disease events, cardiovascular disease risk factors, and both events and risk factors separately for the 676 men and for the 996 women. Cardiovascular disease events were the sum of coronary heart disease, stroke, and intermittent claudication. Five groups of risk factors were studied: hypertension and blood pressure; diabetes, glucose intolerance, and blood glucose level; smoking status and number of pack-years of cigarettes; relative weight; and serum lipid levels, including cholesterol, triglycerides, and lipoprotein fractions. Low-frequency hearing (low pure-tone average, 0.25 to 1.0 kHz) was related to cardiovascular disease events in both genders but more in the women. For women, the OR of having any cardiovascular disease event for a low pure-tone average of 40 dB hearing level was 3.06 (95% CI, 1.84 to 5.10); for a high pure-tone average (average of 4 to 8 kHz) of 40-dB hearing level, the OR for any cardiovascular disease event was 1.75 (95% CI, 1.28 to 2.40). In men with a low pure tone average of 40-dB hearing level, the OR for stroke was 3.46 (95% CI, 1.60 to 7.45) and for coronary heart disease the OR was 1.68 (95% CI, 1.10 to 2.57).(ABSTRACT TRUNCATED AT 250 WORDS)

Reliability of passive smoke exposure histories in a case-control study of lung cancer.

Despite the growing number of studies on the health effects of passive smoke exposure, few data exist on the quality of questionnaire data on passive smoking. To measure the reliability of passive smoking histories, re-interviews were conducted for 110 subjects (37 cases and 73 controls) as part of a larger study of lung cancer among non-smoking women in Missouri. Agreement was high both for parental smoking status (94% concordance; kappa = 0.82) and for spousal smoking status (84% concordance; kappa = 0.67). Concordance also was relatively high for cigarette pack-years of exposure due to the parents or spouse. Reliability tended to be somewhat higher among controls than among cases, and for exposure due to a parent or spouse than for that due to other household members. Questions on the perceived harmfulness of passive smoke exposure showed no differences between cases and controls. These findings indicate a high degree of repeatability in responses regarding passive smoking, but also suggest the potential for misclassification of passive smoke exposure status, the desirability of standardized questions on passive smoking, and the need for additional studies of reliability and validity.

High stored iron levels are associated with excess risk of myocardial infarction in eastern Finnish men.

Iron can induce lipid peroxidation in vitro and in vivo in humans and has promoted ischemic myocardial injury in experimental animals. We tested the hypothesis that high serum ferritin concentration and high dietary iron intake are associated with an excess risk of acute myocardial infarction. Randomly selected men (n = 1,931), aged 42, 48, 54, or 60 years, who had no symptomatic coronary heart disease at entry, were examined in the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD) in Eastern Finland between 1984 and 1989. Fifty-one of these men experienced an acute myocardial infarction during an average follow-up of 3 years. On the basis of a Cox proportional hazards model adjusting for age, examination year, cigarette pack-years, ischemic ECG in exercise test, maximal oxygen uptake, systolic blood pressure, blood glucose, serum copper, blood leukocyte count, and serum high density lipoprotein cholesterol, apolipoprotein B, and triglyceride concentrations, men with serum ferritin greater than or equal to 200 micrograms/l had a 2.2-fold (95% CI, 1.2-4.0; p less than 0.01) risk factor-adjusted risk of acute myocardial infarction compared with men with a lower serum ferritin. An elevated serum ferritin was a strong risk factor for acute myocardial infarction in all multivariate models. This association was stronger in men with serum low density lipoprotein cholesterol concentration of 5.0 mmol/l (193 mg/dl) or more than in others. Also, dietary iron intake had a significant association with the disease risk in a Cox model with the same covariates. Our data suggest that a high stored iron level, as assessed by elevated serum ferritin concentration, is a risk factor for coronary heart disease.

Nass use, cigarette smoking, alcohol consumption and risk of oral and oesophageal precancer.

In a cross sectional study, conducted in Uzbekistan, an area with a high incidence of oral and oesophageal cancer, 1569 men were interviewed regarding use of nass quid, cigarette smoking and alcohol drinking. All subjects in the study had an oral examination, and oesophagoscopy was performed in 1344 men. Nass use and cigarette smoking emerged as independent risk factors for oral leukoplakia. The prevalence odds ratio (OR) for life-time nass intake equivalent rose from 1.0 in never-users to 5.17 [95% confidence interval (CI), 3.10-8.61] in the highest category; for total pack-years of cigarettes smoked the risk rose from 1.0 in never-smokers to 10.03 (95% CI, 4.9-20.6) in the highest category. There was a significant trend in risk (P < 0.001), for both factors. In the group with oral leukoplakia, the effect of nass use and cigarette smoking appeared to be additive. Cigarette smoking was also found to be an independent risk factor for oesophageal lesions and was significantly associated with chronic oesophagitis. The risk of chronic oesophagitis in the group with the highest pack-years of cigarettes smoked was approximately double that among non-smokers [Odds ratio (OR) = 2.47; 95% CI 1.34-4.56]. There was a weak association between nass use and oesophageal pathology: the highest life-time intake equivalent was associated with an OR of 1.56 (95% CI 1.09-2.23). Alcohol intake was not found to be independently associated with the presence of oral and oesophageal precancerous lesions.

The Lung Health Study: Airway Responsiveness to Inhaled Methacholine in Smokers with Mild to Moderate Airflow Limitation

As part of a multicenter clinical trial (Lung Health Study), methacholine inhalation challenge testing was performed in 5,877 current cigarette smokers, ages 35 to 59 yr (mean 48.5 +/- 6.8 yr), with borderline to moderate airflow limitation (FEV1/FVC ratio 63.0 +/- 5.5). The test was successfully completed in 96.4% of subjects, of whom 63% were male and 95.9% were white. Symptomatic reactions to methacholine were rarely severe enough to require evaluation by a trial physician. Nonspecific airways hyperresponsiveness (AHR) was defined as a greater than or equal to 20% decline in FEV1 from the post-diluent control value after inhalation of less than or equal to 25 mg/ml methacholine. AHR was noted in a significantly higher percentage of women (85.1%) than men (58.9%). Moreover, nearly twice as many women as men (46.6 and 23.9%, respectively) responded to less than or equal to 5 mg/ml of methacholine. In both men and women, baseline degree of airways obstruction and clinical center were strongly associated with AHR (p less than 0.001), whereas age was not. Additional associations with AHR were analyzed in men and women separately using logistic regression after adjustment for baseline lung function, age, and center-to-center differences. In men, AHR was significantly related to symptoms of wheeze, chronic cough and/or sputum, and a history of asthma or hay fever (p less than 0.004), but not to current or lifetime tobacco use. By contrast, among women, AHR was not significantly associated with chronic cough and/or phlegm (p greater than 0.05) or a past history of asthma or hay fever (p greater than 0.1) and was only weakly related to wheeze and current asthma (p = 0.04), as well as to cigarette pack-years (p = 0.044). These results indicate that most continuing smokers with functional evidence of early chronic obstructive pulmonary disease have nonspecific AHR that is strongly related to gender and baseline lung function and, to a lesser extent, to respiratory symptoms. The reason for the striking effect of gender on AHR in early chronic obstructive pulmonary disease is unclear but cannot be attributed to male-female differences in age, cigarette use, presence of asthma, or baseline degree of airflow obstruction.

Lower limb arterial disease: assessment of risk factors in an elderly population

Doppler ultrasound measurement of ankle/brachial systolic blood pressure ratio was carried out in 295 elderly (mean 77.3, SEM +/- 0.3, range 68-92 years; males = 180) subjects. Of these, 49.8% (n = 147; males = 86) had evidence of lower limb arterial disease (ankle/brachial systolic blood pressure ratio less than 0.96). On multivariate analyses, excluding ischaemic heart disease as an independent variable, systolic blood pressure and current cigarette pack years were positively related to lower limb arterial disease while BMI and serum high density lipoprotein cholesterol were inversely related (multiple correlation coefficient = 0.277; P less than 0.0001). On including ischaemic heart disease as an independent variable, this was positively associated with lower limb arterial disease; the relationships of the other variables were similar except for a weaker (P = 0.055) relationship with serum high density lipoprotein cholesterol (multiple correlation coefficient = 0.296; P less than 0.0001). While the relationships demonstrated were relatively weak, the findings suggest that reversible risk factors are still relevant in the development of lower limb arterial disease in the elderly.

The associations of race, cigarette smoking, and smoking cessation to measures of the immune system in middle-aged men

To estimate the association between the immunologic responses of the cell-mediated and humoral systems and race or tobacco smoking, we used data from the Vietnam Experience Study conducted by the Centers for Disease Control. That study, done from 1985 to 1986, was based on a random sample of 4462 male, Vietnam-era, U.S. veterans. Racial groups were white, black, Hispanic, Asian, and American Indian. We used linear regression to evaluate how (i) the race of the subjects, (ii) the number of pack-years of cigarettes the subjects smoked, and (iii) the smoking cessation of certain subjects were associated with their relative and absolute T, B, CD4, and CD8 lymphocyte counts and immunoglobulin A (IgA), IgM, and IgG levels. The results indicated that immune status was associated with race and smoking history and that, generally, the associations remained after adjustment for covariates. For example, the average IgA level and absolute CD8 lymphocyte count for blacks were, respectively, 19 and 16% higher than those for whites. On the other hand, smokers had lower immunoglobulin levels and relative CD8 cell counts and higher counts for other lymphocytes of the cell-mediated system than nonsmokers. For example, the average absolute B count of heavy smokers was 37% higher than that of nonsmokers. The pattern after cigarette smoking cessation was consistent with a reversible effect of smoking and a return toward immune levels of nonsmokers.

Predictive value of current cigarette smoking, pack years and tar exposure in the estimation of lung cancer risk

Predictive value of current cigarette smoking, pack years and tar exposure in the estimation of lung cancer risk

Are Respiratory Symptoms and Chronic Airflow Limitation Really Associated with an Increased Risk of Respiratory Cancer?

The relationship between respiratory symptoms, chronic airflow limitation and respiratory cancer was examined in a random population sample of 876 middle-aged men. All men were examined in 1974 with interview and lung function tests. Information on respiratory cancer from 1974 to June 1985 was obtained from the Danish Cancer Register. Using a multivariate Cox regression model including age as the underlying time scale and controlling for pack-years of cigarettes, cough and breathlessness were found to be significantly related to cancer--relative risks (RRs) 2.5 (95% confidence interval (CI): 1.3-5.0) and 2.2 (95% CI: 1.0-4.9), respectively. Phlegm, chronic phlegm, and chronic bronchitis were not related to respiratory cancer after controlling for age and smoking. Forced expiratory volume in one second (FEV1) was related to respiratory cancer, RR = 2.1 (95% CI: 1.3-3.4) per litre under the expected FEV1 given height. Thus, our study demonstrates some relationship between respiratory symptoms and FEV1 and respiratory cancer; however, the study at the same time questions the previously demonstrated relationship between phlegm and respiratory cancer.

A case‐control study of serum vitamins A, E, and C in lung cancer patients

In a case-control study, serum levels of vitamins E, C, and A, carotenoids, total cholesterol, and retinol-binding protein along with smoking levels were studied on 59 persons newly diagnosed with lung cancer and also on matched hospitalized controls. The relative risk for smoking increased with the number of pack years of cigarettes smoked. Cases had significantly lower serum levels of carotenoids, vitamin E, and total cholesterol. Adjustment for serum cholesterol levels diminished the case-control difference for serum carotenoid levels and reduced the case-control difference for serum vitamin E levels. The results indicate that serum vitamin E may also be associated with lung cancer, possibly to a greater degree than serum retinol (vitamin A) is associated with lung cancer.

Passive Smoking, Air Pollution, and Acute Respiratory Symptoms in a Diary Study of Student Nurses

A cohort of approximately 100 student nurses in Los Angeles was recruited for a diary study of the acute effects of air pollution. Smoking histories and presence of asthma and other allergies were determined by questionnaire. Diaries were completed daily and collected weekly for as long as 3 yr. Air pollution was measured at a monitoring location within 2.5 miles of the school. Incidence and duration of a symptom were modeled separately. Pack-years of cigarettes were predictive of the number of episodes of coughing (p less than 0.0001) and of bringing up phlegm (p less than 0.0001). Current smoking, rather than cumulative smoking, was a better predictor of the duration of a phlegm episode (p less than 0.0001). Controlling for personal smoking, a smoking roommate increased the risk of an episode of phlegm (odds ratio [OR] = 1.41, p less than 0.001), but not of cough. Excluding asthmatics (who may be medicated), increased the odds ratio for passive smoking to 1.76 (p less than 0.0001). In logistic regression models controlling for temperature and serial correlation between days, an increase of 1 SD in carbon monoxide exposure (6.5 ppm) was associated with increased risk of headache (OR = 1.09, p less than 0.001), photochemical oxidants (7.4 pphm) were associated with increased risk of chest discomfort (OR = 1.17, p less than 0.001) and eye irritation (OR = 1.20 p less than 0.001), and nitrogen dioxide (9.1 pphm) was associated with increased risk of phlegm (OR = 1.08 p less than 0.01), sore throats (OR = 1.26, p less than 0.001), and eye irritation (OR = 1.16, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Peripheral arterial disease in large vessels is epidemiologically distinct from small vessel disease. An analysis of risk factors.

The authors used noninvasive techniques, including flow velocity by Doppler ultrasound, to accurately assess and distinguish between large and small vessel peripheral arterial disease in a population study in southern California, 1978-1981. In 565 men and women aged 38-82 years, there were 69 cases of large vessel peripheral arterial disease, 19 of which were severe, and 90 cases of isolated small vessel peripheral arterial disease. In cross-sectional multivariate analysis in men, large vessel peripheral arterial disease was significantly associated with age, pack-years of cigarettes smoked, systolic blood pressure, fasting plasma glucose, and marginally with obesity. Similar analysis in women revealed significant associations only for age and systolic blood pressure, although the associations for pack-years of cigarettes, obesity, and low density lipoprotein cholesterol were suggestive. By contrast, isolated small vessel peripheral arterial disease was not significantly associated with any of the major cardiovascular disease risk factors, including two measures of carbohydrate metabolism, fasting plasma glucose and glycosylated hemoglobin. These findings, coupled with our earlier report that large vessel peripheral arterial disease but not isolated small vessel peripheral arterial disease was independently predictive of subsequent mortality, suggest that large vessel peripheral arterial disease and isolated small vessel peripheral arterial disease are epidemiologically, as well as pathophysiologically, distinct entities.

Dietary and alcohol intake, smoking pattern, occupational risk, and family history in lung cancer patients: results of a case-control study in males.

In a case-control study of 71 consecutive new male cases of lung cancer and 71 male hospital control patients, previous dietary and alcohol intake, smoking pattern, occupation, dust exposure, and family history of lung cancer were investigated. The cases and controls were similar in age, country of origin, area of residence, and marital status. Using a frequency-based assessment of previous dietary intake, broad food groups were similar for cases and controls. Cases had a significantly lower intake of fish than controls did (odds ratio = 0.5, confidence interval = 0.2-1.0, p = 0.05). A protective effect for fish consumption in lung cancer has not been previously reported. The dietary intake of foods containing retinol and beta-carotene and the intake of alcohol were not significantly different between cases and controls. For cases, smoking duration was longer and the time since cessation for exsmokers was shorter, cigarette pack years were longer, and the number of cigarettes smoked per day was greater. The factors of occupation, dust exposure, and family history of cancer (including lung cancer) were similarly distributed between cases and controls.

Prevalence, Trends, and Correlates of Alcohol Use, Nonmedical Drug Use, and Tobacco Use Among U.S. Military Personnel

This paper presents data on substance use by military personnel from a series of worldwide surveys conducted in 1985, 1982, and 1980 with primary emphasis on the 1985 survey. Estimates are based on responses from participants serving on active duty in the Army, Navy, Marine Corps, and Air Force. Results for 1985 indicate pervasive use of alcohol, substantial use of tobacco, and low nonmedical use of drugs among military personnel. Average daily consumption of alcohol declined significantly from 1.4 ounces in 1982 to 1.2 ounces in 1985, but the patterns of use remained relatively constant. Nonmedical drug use during the past 30 days declined significantly, from 27.0% in 1980, to 19.0% in 1982, to 8.9% in 1985. Cigarette smoking declined significantly from 51.4% in 1982 to 46.2% in 1985. Current alcohol and drug use is concentrated among younger, less educated, unmarried, and junior and mid-career enlisted personnel. Cigarette pack years are higher among males, whites, those with less than a high school education, and senior enlisted personnel. Results show progress in reducing drug use and smoking in the military, but little change in patterns of alcohol use. New initiatives and approaches by the military to further reduce substance abuse are discussed.

Predictors of Dyspnea Intensity In Asthma

Predictors of dyspnea were studied during induced airflow obstruction or cough in an attempt to increase understanding of factors related to observed variability in the descriptions of the experience of dyspnea. Thirty-one adult subjects with asthma participated in a 2-day protocol using a laboratory analog of asthma. Air flow obstruction and dyspnea were induced on Day 1 with inhalations of methacholine in doubling concentrations from 0.063 to 2.0 mg/ml. Cough was induced on Day 2 with inhalations of 3% sodium gluconate solution. Dyspnea was assessed on both days by a visual analog technique. The magnitude of dyspnea was not related to airway caliber. There was a significant negative relationship between age and magnitude of dyspnea and between cigarette pack years and dyspnea intensity. Dyspnea at baseline was positively related to dyspnea intensity during induced bronchoconstriction. Dyspnea during cough was not related to airway caliber, but there was a significant difference between males and females in the intensity of dyspnea at cough threshold. These findings may explain some of the variability observed in the experience of dyspnea in asthma.

The Copenhagen case-control study of bladder cancer: role of smoking in invasive and non-invasive bladder tumours.

A population based study of 388 cases of bladder cancer including papillomas and 787 controls in Greater Copenhagen confirmed the role of smoking in the aetiology of bladder cancer. Significantly increased relative risks were found for persons who had smoked only cigarettes (RR = 2.9; both sexes combined) and for mixed smokers including cigarettes (RR = 3.6; both sexes combined). Multiple logistic regression analysis showed significant influences of the amount (pack years) of cigarettes smoked and a reduced risk among persons who had stopped smoking. No significant effects of smoking pipe or cigars/cigarillos were apparent, and the present study does not confirm previous suggestions of associations between the smoking of cigars/cigarillos and bladder cancer in Denmark. Only a slight increase in relative risk with the amount smoked was found. The influence of smoking on bladder cancer risk was similar for tumours in stages T1 and T2-4 at diagnosis and also for tumours of grades 1-2 and grades 3-4 at diagnosis.

Maximum oxygen uptake capacity of smokers of different age groups.

Eighty-four healthy asymptomatic sedentary smokers and 92 healthy sedentary non-smokers of the age range 20-59 years were investigated for their maximum oxygen uptake capacity (VO2max) and related cardiorespiratory parameters at the level of maximal exercise by bicycle ergometry. The subjects were blocked into four age decades of 20-29, 30-39, 40-49, and 50-59 years to show the effect of smoking on VO2max of smokes of different age groups. The physical characteristics of smokers and non-smokers of comparable age groups did not show any significant difference. The smokers of each subsequent age group consumed 5.9 +/- 4.1, 6.3 +/- 5.7, 12.7 +/- 7.1, and 11.5 +/- 9.1 pack years of cigarettes, respectively (pack year = number of packets of cigarettes per day X number of years of smoking). VO2max of smokers (38.9 +/- 4.6 ml.kg-1.min-1) was significantly lower (p less than 0.05) than that of nonsmokers (42.1 +/- 3.2 ml.kg-1.min-1) only in the young age group of 20-29 years. VO2max expressed in per kg of the body weight (VO2max/BW) was found to be significantly (p less than 0.01) and negatively correlated with number of cigarettes smoked per day (-0.36, p less than 0.01), number of years through which smoked (-0.38, p less than 0.01), and pack years (-0.42, p less than 0.01). In other age groups, though non-smokers predominated over smokers in VO2max, the differences were not statistically significant. Also, in these age groups, smoking histories failed to reveal any significant correlation with VO2max. This suggests that smoking impairs VO2max only in the young ages. By increasing age, VO2max was diminished by 13% from 20 to 59 years in non-smokers and 15.5% from 20 to 59 years in smokers. Age also diminished HRmax and VEmax of smokers in the same manner as in the case of non-smokers. The VO2max of Indian sedentary non-smokers was found to be lower than those of Caucasians, Kurds, Yemenites, Europeans, and Africans. Values reported on Asians were found to be comparable with those of the present study.

Importance of risk factors in the angiographic progression of coronary artery disease

Although specific risk factors correlate with the development of clinical coronary events, little Is known about their Importance in patients with established coronary artery disease (CAD). A numerical scaring system was used to assess serial coronary anglograms in subjects who had detailed risk factor determinations. Strong linear correlations were demonstrated between the extent of progression of CAD and diastolic blood pressure (BP) (p = 0.002), systolic BP (p = 0.094), the number of cigarette pack-years smoked among current smokers (p = 0.022), fasting blood glucose level (p = 0.017) and low levels of physical activity at leisure (p = 0.097). This analysis of sequential coronary anglograms identifies SP, cigarette smoking, diabetes mellitus and physical activity as important risk factors in the progression of CAD. These variables merit attention in the management of patients with symptomatic CAD and in secondary coronary prevention trials investigating risk factor modification.