Decline in the risk of myocardial infarction among women who stop smoking

To assess the relation of smoking cessation to the risk of a first myocardial infarction in women, we compared the smoking habits of 910 patients who had had their first myocardial infarction with those of 2375 controls in a hospital-based case-control study of women from 25 to 64 years of age. The estimate of relative risk among current smokers as compared with women who had never smoked was 3.6 (95 percent confidence interval, 3.0 to 4.4). Among exsmokers overall, the corresponding estimate of relative risk was 1.2 (95 percent confidence interval, 1.0 to 1.7). Among exsmokers, the estimate of relative risk was significantly elevated among women who had stopped smoking less than two years previously (relative risk, 2.6; 95 percent confidence interval, 1.8 to 3.8). Most of the increase in the risk had dissipated among the women who had stopped smoking two to three years previously, and the estimate of relative risk among the women who had not smoked for three or more years was virtually indistinguishable from that among the women who had never smoked. The same pattern of decline was apparent regardless of the amount smoked, the duration of smoking, the age of the women, or the presence of other predisposing factors. These data suggest that in women, as in men, the increase in the risk of a first myocardial infarction among cigarette smokers declines soon after the cessation of smoking and is largely dissipated after two or three years.     

Cigarette smoking and risk of stroke in middle-aged women

It is known that cigarette smoking is associated with increased risk of both thrombotic and hemorrhagic stroke among men. To test for such an association among women, we examined the incidence of stroke in relation to cigarette smoking in a prospective cohort study of 118,539 women 30 to 55 years of age and free from coronary heart disease, stroke, and cancer in 1976. During eight years of follow-up (908,447 person-years), we identified 274 strokes, comprising 71 subarachnoid hemorrhages, 26 intracerebral hemorrhages, 122 thromboembolic strokes, and 55 strokes about which information was insufficient to permit classification. The number of cigarettes smoked per day was associated positively with the risk of stroke. Compared with the women who had never smoked, those who smoked 1 to 14 cigarettes per day had an age-adjusted relative risk of 2.2 (95 percent confidence interval, 1.5 to 3.3), whereas those who smoked 25 or more cigarettes per day had a relative risk of 3.7 (95 percent confidence interval, 2.7 to 5.1). For women in this latter group, the relative risk of subarachnoid hemorrhage was 9.8 (95 percent confidence interval, 5.3 to 17.9), as compared with those who had never smoked. Adjustment for the effects of relative weight, hypertension, diabetes, history of high cholesterol, previous use of oral contraceptives, postmenopausal estrogen therapy, and alcohol intake did not appreciably alter the association between cigarette use and incidence of stroke. These prospective data support a strong causal relation between cigarette smoking and stroke among young and middle-aged women.     

Effect of cigar smoking on the risk of cardiovascular disease, chronic obstructive pulmonary disease, and cancer in men.

BACKGROUND: The sale of cigars in the United States has been increasing for the past six years. Cigar smoking is a known risk factor for certain cancers and for chronic obstructive pulmonary disease (COPD). However, unlike the relation between cigarette smoking and cardiovascular disease, the association between cigar smoking and cardiovascular disease has not been clearly established. METHODS: We performed a cohort study among 17,774 men 30 to 85 years of age at base line (from 1964 through 1973) who were enrolled in the Kaiser Permanente health plan and who reported that they had never smoked cigarettes and did not currently smoke a pipe. Those who smoked cigars (1546 men) and those who did not (16,228) were followed from 1971 through the end of 1995 for a first hospitalization for or death from a major cardiovascular disease or COPD, and through the end of 1996 for a diagnosis of cancer. RESULTS: In multivariate analysis, cigar smokers, as compared with nonsmokers, were at higher risk for coronary heart disease (relative risk, 1.27; 95 percent confidence interval, 1.12 to 1.45), COPD (relative risk, 1.45; 95 percent confidence interval, 1.10 to 1.91), and cancers of the upper aerodigestive tract (relative risk, 2.02; 95 percent confidence interval, 1.01 to 4.06) and lung (relative risk, 2.14; 95 percent confidence interval, 1.12 to 4.11), with evidence of dose-response effects. There appeared to be a synergistic relation between cigar smoking and alcohol consumption with respect to the risk of oropharyngeal cancers and cancers of the upper aerodigestive tract. CONCLUSIONS: Independently of other risk factors, regular cigar smoking can increase the risk of coronary heart disease, COPD, and cancers of the upper aerodigestive tract and lung.     

Smoking cessation and severity of weight gain in a national cohort

BACKGROUND. Many believe that the prospect of weight gain discourages smokers from quitting. Accurate estimates of the weight gain related to the cessation of smoking in the general population are not available, however. METHODS. We related changes in body weight to changes in smoking status in adults 25 to 74 years of age who were weighed in the First National Health and Nutrition Examination Survey (NHANES I, 1971 to 1975) and then weighed a second time in the NHANES I Epidemiologic Follow-up Study (1982 to 1984). The cohort included continuing smokers (748 men and 1137 women) and those who had quit smoking for a year or more (409 men and 359 women). RESULTS. The mean weight gain attributable to the cessation of smoking, as adjusted for age, race, level of education, alcohol use, illnesses related to change in weight, base-line weight, and physical activity, was 2.8 kg in men and 3.8 kg in women. Major weight gain (greater than 13 kg) occurred in 9.8 percent of the men and 13.4 percent of the women who quit smoking. The relative risk of major weight gain in those who quit smoking (as compared with those who continued to smoke) was 8.1 (95 percent confidence interval, 4.4 to 14.9) in men and 5.8 (95 percent confidence interval, 3.7 to 9.1) in women, and it remained high regardless of the duration of cessation. For both sexes, blacks, people under the age of 55, and people who smoked 15 cigarettes or more per day were at higher risk of major weight gain after quitting smoking. Although at base line the smokers weighed less than those who had never smoked, they weighed nearly the same at follow-up. CONCLUSIONS. Major weight gain is strongly related to smoking cessation, but it occurs in only a minority of those who stop smoking. Weight gain is not likely to negate the health benefits of smoking cessation, but its cosmetic effects may interfere with attempts to quit. Effective methods of weight control are therefore needed for smokers trying to quit.     

The risk of myocardial infarction after quitting smoking in men under 55 years of age

We assessed the effect of quitting cigarette smoking on the incidence of nonfatal myocardial infarction in men under the age of 55 in a case-control study of 1873 men with first episodes of myocardial infarction and 2775 controls. For "current" smokers (men who had smoked in the previous year) as compared with those who had never smoked, the estimated relative risk of myocardial infarction, adjusted for age, was 2.9 (95 per cent confidence interval, 2.4 to 3.4). Among exsmokers (those who had last smoked at least one year previously), the relative-risk estimate declined to a value close to unity for those who had abstained for at least two years; the estimate was 2.0 (1.1 to 3.8) for men who had abstained for 12 to 23 months, and the estimates were about 1.0 for men who had abstained for longer intervals. The results were unchanged by allowance for multiple potential confounding factors. A similar pattern was apparent among exsmokers who had smoked heavily for many years; among those predisposed to a myocardial infarction because of family history, hypertension, or other risk factors; and among those with no apparent predisposition. The results suggest that the risk of myocardial infarction in cigarette smokers decreases within a few years of quitting to a level similar to that in men who have never smoked.     

The influence of gestational age and smoking habits on the risk of subsequent preterm deliveries.

BACKGROUND: Previous preterm delivery and maternal smoking are associated with increased risks of preterm delivery. It is not known whether gestational age at the time of a preterm delivery is correlated with gestational age in successive preterm deliveries and whether changes in smoking habits influence the subsequent risk of preterm delivery. METHODS: We studied the associations among smoking habits, previous very preterm or moderately preterm delivery (before 32 weeks and at 32 to 36 weeks, respectively), and the risk of a subsequent very preterm or moderately preterm delivery in a population-based cohort of 243,858 women in Sweden between 1983 and 1993. The results were adjusted for covariates known to be associated with preterm delivery. RESULTS: The odds ratios for very or moderately preterm delivery in a subsequent pregnancy among women with a previous very preterm delivery, as compared with women who had a previous term delivery, were 12.4 (95 percent confidence interval, 9.1 to 17.0) and 7.1 (95 percent confidence interval, 6.0 to 8.4), respectively. Among women with a previous moderately preterm delivery, the corresponding odds ratios were 2.3 (95 percent confidence interval, 1.9 to 3.0) and 5.9 (95 percent confidence interval, 5.5 to 6.3), respectively. The odds ratios for a very preterm second delivery among the women who smoked 1 to 9 cigarettes per day and those who smoked 10 or more cigarettes per day, as compared with nonsmokers, were 1.4 (95 percent confidence interval, 1.1 to 1.7) and 1.6 (95 percent confidence interval, 1.3 to 2.0), respectively. The corresponding odds ratios for moderate preterm delivery were 1.3 (95% confidence interval, 1.2 to 1.4) and 1.5 (95 percent confidence interval, 1.4 to 1.6). The women who quit smoking between pregnancies were not at increased risk for very or moderately preterm delivery, whereas the women who started to smoke in the second pregnancy had the same risk as those who continued to smoke. CONCLUSIONS: The risk of a very preterm delivery in successive pregnancies is increased primarily among women with a previous very preterm delivery. Changes in smoking habits influence the risk of preterm delivery as well.     

Associations between smoking, screening, and death caused by cervical cancer in Korean women

PURPOSE: Cervical cancer is a major women's health problem in the world today. The purpose of this study was to estimate the incidence and mortality rates and to investigate risk factors for cervical cancer in Korean women. MATERIALS AND METHODS: Reproductive factors, cigarette smoking, as well as the risk of incidence and death from cervical cancer were examined in a 12-year prospective cohort study of 475,398 Korean women aged 30 to 95 years who received health insurance from the National Health Insurance Corporation and who had a medical evaluation in 1992. Relative risks (RR) and 95% confidence intervals (CI) were calculated using the Cox proportional hazards model after adjusting for age, body mass index, cigarette smoking, alcohol use, menarche, parity, and Papanicolaou test status. RESULTS: This study showed that the RR of death due to cervical cancer among current smokers was two times higher compared with non- smokers (RR=2.00; 95% CI, 1.23-2.91). In addition, the RR of death due to cervical cancer among all women who smoked > or = 10 cigarettes/day was 2.4 times higher than the RR among women that had never smoked. More interestingly, those who had never been screened by Papanicolaou smears had twice the risk of death due to cervical cancer (RR =2.00; 95% CI, 1.37-1.81). CONCLUSION: Our prospective study concluded that current smokers had an increased risk of death due to cervical cancer. We suggest that the target age group for cervical cancer screening tests be reconsidered and should begin as early as possible.     

"Low yield" cigarettes and the risk of nonfatal myocardial infarction in women

Newer brands of cigarettes with reduced yields of nicotine and carbon monoxide have been promoted as being less hazardous than others. We evaluated the effect of smoking "low yield" cigarettes on the risk of nonfatal myocardial infarction in women under 65 years of age. The data were obtained in a case-control study of 910 women with a first myocardial infarction and 2375 hospital controls. The estimated relative risk for current smokers as compared with those who had never smoked increased with the number of cigarettes smoked. The estimated overall relative risk was 3.7 (95 percent confidence interval, 3.0 to 4.7). The estimated risks did not vary according to the nicotine or carbon monoxide yield of the cigarette. The estimated relative risk (4.7) in women who smoked brands with the lowest levels of nicotine (less than 0.40 mg per cigarette) was similar to that (4.2) in smokers of the higher-yield brands (greater than 1.30 mg). For exsmokers, the estimated relative risk was 1.4 (95 percent confidence interval, 1.0 to 1.8). These data suggest that women who smoke low-yield cigarettes do not have a lower risk of a first nonfatal myocardial infarction than women who smoke higher-yield brands. For smokers who wish to reduce their risk, switching to low-yield brands is a poor alternative to quitting.     

Genetic influence on smoking--a study of male twins.

BACKGROUND. The results of twin and family studies suggest that heredity has a small influence on smoking behavior. METHODS. We conducted a genetic analysis of several aspects of smoking behavior among subjects in the National Academy of Sciences-National Research Council Twin Registry. The registry includes male twins who were born in the United States between 1917 and 1927 and who were members of the armed services during World War II. Information on smoking history was available for 4775 pairs of twins, who were first surveyed in 1967 through 1969, when they were 40 to 50 years old, and then re-surveyed in 1983 through 1985, when they were 56 to 66. Eighty percent of the subjects in this cohort had smoked at some time in their lives, 60 percent were smokers in 1967 through 1969, and 39 percent were smoking in 1983 through 1985. Similarities between twins in smoking habits at base line and at the second follow-up 16 years later were examined. The comparison of concordance for smoking between monozygotic and dizygotic twins was used to assess the relative contribution of familial and genetic factors. RESULTS. In 1967-1969 survey the ratio of observed to expected concordance for smoking was higher among the monozygotic twins than among the dizygotic twins for those who had never smoked (overall rate ratio, 1.38; 95 percent confidence interval, 1.25 to 1.54), for former smokers (overall rate ratio, 1.59; 95 percent confidence interval, 1.35 to 1.85), for current cigarette smokers (overall rate ratio, 1.18; 95 percent confidence interval, 1.11 to 1.26), and for current cigar or pipe smokers (overall rate ratio, 1.60; 95 percent confidence interval, 1.22 to 2.06). The data also suggest genetic influences on quitting smoking. Monozygotic twins were more likely than dizygotic twins to be concordant for quitting smoking (overall rate ratio, 1.24; 95 percent confidence interval, 1.06 to 1.45). CONCLUSIONS. In this cohort of adult male twins, there were moderate genetic influences on lifetime smoking practices.     

Body-mass index and mortality in a prospective cohort of U.S. adults.

BACKGROUND: Body-mass index (the weight in kilograms divided by the square of the height in meters) is known to be associated with overall mortality. We investigated the effects of age, race, sex, smoking status, and history of disease on the relation between body-mass index and mortality. METHODS: In a prospective study of more than 1 million adults in the United States (457,785 men and 588,369 women), 201,622 deaths occurred during 14 years of follow-up. We examined the relation between body-mass index and the risk of death from all causes in four subgroups categorized according to smoking status and history of disease. In healthy people who had never smoked, we further examined whether the relation varied according to race, cause of death, or age. The relative risk was used to assess the relation between mortality and body-mass index. RESULTS: The association between body-mass index and the risk of death was substantially modified by smoking status and the presence of disease. In healthy people who had never smoked, the nadir of the curve for body-mass index and mortality was found at a body-mass index of 23.5 to 24.9 in men and 22.0 to 23.4 in women. Among subjects with the highest body-mass indexes, white men and women had a relative risk of death of 2.58 and 2.00, respectively, as compared with those with a body-mass index of 23.5 to 24.9. Black men and women with the highest body-mass indexes had much lower risks of death (1.35 and 1.21), which did not differ significantly from 1.00. A high body-mass index was most predictive of death from cardiovascular disease, especially in men (relative risk, 2.90; 95 percent confidence interval, 2.37 to 3.56). Heavier men and women in all age groups had an increased risk of death. CONCLUSIONS: The risk of death from all causes, cardiovascular disease, cancer, or other diseases increases throughout the range of moderate and severe overweight for both men and women in all age groups. The risk associated with a high body-mass index is greater for whites than for blacks.     

Postmenopausal estrogen therapy and cardiovascular disease. Ten-year follow-up from the nurses' health study

BACKGROUND. The effect of postmenopausal estrogen therapy on the risk of cardiovascular disease remains controversial. Our 1985 report in the Journal, based on four years of follow-up, suggested that estrogen therapy reduced the risk of coronary heart disease, but a report published simultaneously from the Framingham Study suggested that the risk was increased. In addition, studies of the effect of estrogens on stroke have yielded conflicting results. METHODS. We followed 48,470 postmenopausal women, 30 to 63 years old, who were participants in the Nurses' Health Study, and who did not have a history of cancer or cardiovascular disease at base line. During up to 10 years of follow-up (337,854 person-years), we documented 224 strokes, 405 cases of major coronary disease (nonfatal myocardial infarctions or deaths from coronary causes), and 1263 deaths from all causes. RESULTS. After adjustment for age and other risk factors, the overall relative risk of major coronary disease in women currently taking estrogen was 0.56 (95 percent confidence interval, 0.40 to 0.80); the risk was significantly reduced among women with either natural or surgical menopause. We observed no effect of the duration of estrogen use independent of age. The findings were similar in analyses limited to women who had recently visited their physicians (relative risk, 0.45; 95 percent confidence interval, 0.31 to 0.66) and in a low-risk group that excluded women reporting current cigarette smoking, diabetes, hypertension, hypercholesterolemia, or a Quetelet index above the 90th percentile (relative risk, 0.53; 95 percent confidence interval, 0.31 to 0.91). The relative risk for current and former users of estrogen as compared with those who had never used it was 0.89 (95 percent confidence interval, 0.78 to 1.00) for total mortality and 0.72 (95 percent confidence interval, 0.55 to 0.95) for mortality from cardiovascular disease. The relative risk of stroke when current users were compared with those who had never used estrogen was 0.97 (95 percent confidence interval, 0.65 to 1.45), with no marked differences according to type of stroke. CONCLUSIONS. Current estrogen use is associated with a reduction in the incidence of coronary heart disease as well as in mortality from cardiovascular disease, but it is not associated with any change in the risk of stroke.     

Sex-based differences in early mortality after myocardial infarction. National Registry of Myocardial Infarction 2 Participants.

BACKGROUND: There is conflicting information about whether short-term mortality after myocardial infarction is higher among women than among men after adjustment for age and other prognostic factors. We hypothesized that younger, but not older, women have higher mortality rates during hospitalization than their male peers. METHODS: We analyzed data on 384,878 patients (155,565 women and 229,313 men) who were 30 to 89 years of age and who had been enrolled in the National Registry of Myocardial Infarction 2 between June 1994 and January 1998. Patients who had been transferred from or to other hospitals were excluded. RESULTS: The overall mortality rate during hospitalization was 16.7 percent among the women and 11.5 percent among the men. Sex-based differences in the rates varied according to age. Among patients less than 50 years of age, the mortality rate for the women was more than twice that for the men. The difference in the rates decreased with increasing age and was no longer significant after the age of 74 (P< 0.001 for the interaction between sex and age). Logistic-regression analysis showed that the odds of death were 11.1 percent greater for women than for men with every five-year decrease in age (95 percent confidence interval, 10.1 to 12.1 percent). Differences in medical history, the clinical severity of the infarction, and early management accounted for only about one third of the difference in the risk. After adjustment for these factors, women still had a higher risk of death for every five years of decreasing age (increase in the odds of death, 7.0 percent; 95 percent confidence interval, 5.9 to 8.1 percent). CONCLUSIONS: After myocardial infarction, younger women, but not older women, have higher rates of death during hospitalization than men of the same age. The younger the age of the patients, the higher the risk of death among women relative to men. Younger women with myocardial infarction represent a high-risk group deserving of special study.     

Impact of high-normal blood pressure on the risk of cardiovascular disease.

BACKGROUND: Information is limited regarding the absolute and relative risk of cardiovascular disease in persons with high-normal blood pressure (systolic pressure of 130 to 139 mm Hg, diastolic pressure of 85 to 89 mm Hg, or both). METHODS: We investigated the association between blood-pressure category at base line and the incidence of cardiovascular disease on follow-up among 6859 participants in the Framingham Heart Study who were initially free of hypertension and cardiovascular disease. RESULTS: A stepwise increase in cardiovascular event rates was noted in persons with higher baseline blood-pressure categories. The 10-year cumulative incidence of cardiovascular disease in subjects 35 to 64 years of age who had high-normal blood pressure was 4 percent (95 percent confidence interval, 2 to 5 percent) for women and 8 percent (95 percent confidence interval, 6 to 10 percent) for men; in older subjects (those 65 to 90 years old), the incidence was 18 percent (95 percent confidence interval, 12 to 23 percent) for women and 25 percent (95 percent confidence interval, 17 to 34 percent) for men. As compared with optimal blood pressure, high-normal blood pressure was associated with a risk-factor-adjusted hazard ratio for cardiovascular disease of 2.5 (95 percent confidence interval, 1.6 to 4.1) in women and 1.6 (95 percent confidence interval, 1.1 to 2.2) in men. CONCLUSIONS: High-normal blood pressure is associated with an increased risk of cardiovascular disease. Our findings emphasize the need to determine whether lowering high-normal blood pressure can reduce the risk of cardiovascular disease.     

A long-term study of mortality in men who have undergone vasectomy.

BACKGROUND. Vasectomy is a reliable and widely accepted method of contraception, but there is some uncertainty and few data about a possible long-term adverse effect on health. METHODS. We examined the relation between vasectomy and mortality rates from cardiovascular disease, cancer, and all causes in a retrospective cohort of husbands of members of the Nurses' Health Study. In 1989 we obtained data by questionnaire on 14,607 men who had undergone vasectomy as of 1976 and 14,607 men who had not. RESULTS. Among the men who were free of cancer at the start of the study, 1052 died: 446 of cardiovascular disease, 341 of cancer, and 265 of other causes. Vasectomy was associated with reductions in mortality from all causes (age-adjusted relative risk, 0.85; 95 percent confidence interval, 0.76 to 0.96) and mortality from cardiovascular disease (relative risk, 0.76; 95 percent confidence interval, 0.63 to 0.92). Vasectomy was unrelated to mortality from all forms of cancer (relative risk, 1.01; 95 percent confidence interval, 0.82 to 1.25). Among men who had a vasectomy at least 20 years earlier, the procedure had no relation to mortality from all causes (relative risk, 1.11; 95 percent confidence interval, 0.92 to 1.33) or that from cardiovascular disease (relative risk, 0.85; 95 percent confidence interval, 0.63 to 1.16). However, mortality from cancer was increased in men who had a vasectomy at least 20 years earlier (relative risk, 1.44; 95 percent confidence interval, 1.07 to 1.92). The excess risk of cancer in these men was due primarily to lung cancer. None of the observed associations were confounded by smoking habits, body-mass index, alcohol consumption, or educational level. CONCLUSIONS. Vasectomy is not associated with an increase in overall mortality or mortality from cardiovascular disease. Our study also found no increase in overall mortality from cancer after vasectomy, but there was an apparent increase in the risk of cancer 20 or more years after vasectomy that requires further study.     

Mortality over a period of 10 years in patients with peripheral arterial disease.

BACKGROUND. Previous investigators have observed a doubling of the mortality rate among patients with intermittent claudication, and we have reported a fourfold increase in the overall mortality rate among subjects with large-vessel peripheral arterial disease, as diagnosed by noninvasive testing. In this study, we investigated the association of large-vessel peripheral arterial disease with rates of mortality from all cardiovascular diseases and from coronary heart disease. METHODS. We examined 565 men and women (average age, 66 years) for the presence of large-vessel peripheral arterial disease by means of two noninvasive techniques--measurement of segmental blood pressure and determination of flow velocity by Doppler ultrasound. We identified 67 subjects with the disease (11.9 percent), whom we followed prospectively for 10 years. RESULTS. Twenty-one of the 34 men (61.8 percent) and 11 of the 33 women (33.3 percent) with large-vessel peripheral arterial disease died during follow-up, as compared with 31 of the 183 men (16.9 percent) and 26 of the 225 women (11.6 percent) without evidence of peripheral arterial disease. After multivariate adjustment for age, sex, and other risk factors for cardiovascular disease, the relative risk of dying among subjects with large-vessel peripheral arterial disease as compared with those with no evidence of such disease was 3.1 (95 percent confidence interval, 1.9 to 4.9) for deaths from all causes, 5.9 (95 percent confidence interval, 3.0 to 11.4) for all deaths from cardiovascular disease, and 6.6 (95 percent confidence interval, 2.9 to 14.9) for deaths from coronary heart disease. The relative risk of death from causes other than cardiovascular disease was not significantly increased among the subjects with large-vessel peripheral arterial disease. After the exclusion of subjects who had a history of cardiovascular disease at base line, the relative risks among those with large-vessel peripheral arterial disease remained significantly elevated. Additional analyses revealed a 15-fold increase in rates of mortality due to cardiovascular disease and coronary heart disease among subjects with large-vessel peripheral arterial disease that was both severe and symptomatic. CONCLUSIONS. Patients with large-vessel peripheral arterial disease have a high risk of death from cardiovascular causes.     

Cigarette smoking and invasive pneumococcal disease. Active Bacterial Core Surveillance Team

BACKGROUND: Approximately half of otherwise healthy adults with invasive pneumococcal disease are cigarette smokers. We conducted a population-based case-control study to assess the importance of cigarette smoking and other factors as risk factors for pneumococcal infections. METHODS: We identified immunocompetent patients who were 18 to 64 years old and who had invasive pneumococcal disease (as defined by the isolation of Streptococcus pneumoniae from a normally sterile site) by active surveillance of laboratories in metropolitan Atlanta, Baltimore, and Toronto. Telephone interviews were conducted with 228 patients and 301 control subjects who were reached by random-digit dialing. RESULTS: Fifty-eight percent of the patients and 24 percent of the control subjects were current smokers. Invasive pneumococcal disease was associated with cigarette smoking (odds ratio, 4.1; 95 percent confidence interval, 2.4 to 7.3) and with passive smoking among nonsmokers (odds ratio, 2.5; 95 percent confidence interval, 1.2 to 5.1) after adjustment by logistic-regression analysis for age, study site, and independent risk factors such as male sex, black race, chronic illness, low level of education, and living with young children who were in day care. There were dose-response relations for the current number of cigarettes smoked per day, pack-years of smoking, and time since quitting. The adjusted population attributable risk was 51 percent for cigarette smoking, 17 percent for passive smoking, and 14 percent for chronic illness. CONCLUSIONS: Cigarette smoking is the strongest independent risk factor for invasive pneumococcal disease among immunocompetent, nonelderly adults. Because of the high prevalence of smoking and the large population attributable risk, programs to reduce both smoking and exposure to environmental tobacco smoke have the potential to reduce the incidence of pneumococcal disease.     

Beneficial six-year outcome of smoking cessation in older men and women with coronary artery disease. Results from the CASS registry

We investigated the effects of cigarette smoking and cessation of smoking in a cohort of 1893 men and women from the Coronary Artery Surgery Study (CASS) registry who were 55 years of age or older and had angiographically documented coronary artery disease. The six-year mortality rate was greater among continuing smokers (n = 1086) than among those who quit smoking during the year before enrollment in the study and abstained throughout the study (n = 807) (relative risk, 1.7 [95 percent confidence limits, 1.4, 2.0]). Continuing smokers were also at higher risk of either myocardial infarction or death (1.5 [1.2, 1.7]). There was no diminution of the beneficial effect with increasing age. The relative risks of death were 1.7 (1.4, 2.1) and 1.6 (1.1, 2.3) for the groups 55 to 64 years old and 65 or older, respectively, and 1.6 (1.4, 1.9) for comparable subgroups among CASS subjects 35 to 54 years of age. When subjects were arrayed according to risk quartile, the benefits of smoking cessation were greatest in those at moderate risk. We conclude that smoking cessation lessens the risk of death or myocardial infarction in older as well as younger persons with coronary artery disease.     

Breast cancer and cigarette smoking

It has been suggested that cigarette smoking may reduce the incidence of breast cancer, perhaps by as much as 20 per cent. To evaluate the relation between breast-cancer risk and smoking, we studied 2160 women with breast cancer and 717 controls who had been admitted to the hospital for cancer of the ovary, cancer of the colon or rectum, malignant melanoma, or lymphoreticular cancers. As compared with women who had never smoked, the estimated relative risk of breast cancer was 1.1 for current smokers of any amount (95 per cent confidence interval, 0.9 to 1.3), and 1.0 (0.8 to 1.3) for heavy smokers (15 or more cigarettes per day). Allowance for all identified potential confounding factors did not materially alter the results. There was no indication that age at commencement of smoking was related to the risk, nor was there evidence of an effect of smoking within the categories of age at first pregnancy or age at menopause. The data provide evidence against the hypothesis that smoking may reduce the incidence of breast cancer by 20 per cent.     

Prognostic implications of echocardiographically determined left ventricular mass in the Framingham Heart Study

A pattern of left ventricular hypertrophy evident on the electrocardiogram is a harbinger of morbidity and mortality from cardiovascular disease. Echocardiography permits the noninvasive determination of left ventricular mass and the examination of its role as a precursor of morbidity and mortality. We examined the relation of left ventricular mass to the incidence of cardiovascular disease, mortality from cardiovascular disease, and mortality from all causes in 3220 subjects enrolled in the Framingham Heart Study who were 40 years of age or older and free of clinically apparent cardiovascular disease, in whom left ventricular mass was determined echocardiographically. During a four-year follow-up period, there were 208 incident cardiovascular events, 37 deaths from cardiovascular disease, and 124 deaths from all causes. Left ventricular mass, determined echocardiographically, was associated with all outcome events. This relation persisted after we adjusted for age, diastolic blood pressure, pulse pressure, treatment for hypertension, cigarette smoking, diabetes, obesity, the ratio of total cholesterol to high-density lipoprotein cholesterol, and electrocardiographic evidence of left ventricular hypertrophy. In men, the risk factor-adjusted relative risk of cardiovascular disease was 1.49 for each increment of 50 g per meter in left ventricular mass corrected for the subject's height (95 percent confidence interval, 1.20 to 1.85); in women, it was 1.57 (95 percent confidence interval, 1.20 to 2.04). Left ventricular mass (corrected for height) was also associated with the incidence of death from cardiovascular disease (relative risk, 1.73 [95 percent confidence interval, 1.19 to 2.52] in men and 2.12 [95 percent confidence interval, 1.28 to 3.49] in women). Left ventricular mass (corrected for height) was associated with death from all causes (relative risk, 1.49 [95 percent confidence interval, 1.14 to 1.94] in men and 2.01 [95 percent confidence interval, 1.44 to 2.81] in women). We conclude that the estimation of left ventricular mass by echocardiography offers prognostic information beyond that provided by the evaluation of traditional cardiovascular risk factors. An increase in left ventricular mass predicts a higher incidence of clinical events, including death, attributable to cardiovascular disease.     

Alcohol, caffeine and smoking in relation to age at menopause

OBJECTIVES: Exposures which might influence age at natural menopause have been extensively studied but, with the exception of cigarette smoking, results have been inconsistent. We sought to determine: (i) whether alcohol and caffeine intake are associated with age at menopause; (ii) whether the association of cigarette smoking with age at menopause is confined to current smokers. METHODS: Analyses drew on longitudinal data from 494 women, aged 44-60 in 1993, of whom 159 experienced menopause before intake or during follow-up. We used parametric logistic survival analysis to estimate shifts in median age at menopause for women who drink alcohol or caffeine or who smoke cigarettes. RESULTS: The estimated median age at menopause was 2.2 (95% confidence interval (CI) 0.5, 3.9) years later for women who drank alcohol 5-7 days/week (13% of the sample) than for women who did not drink alcohol (54%). For women who drank at least 1 day/week, the estimated shift was 1.3 (95% CI 0.2, 2.3) years. Caffeine intake in approximate quartiles of mg/day-0-100, >100-200, >200-400, 400+-was not related to age at menopause. Current smokers of 14+cigarettes/day (6%) experienced menopause 2.8 (95% CI -4.8, -0.8) years earlier than women who never smoked (51%). Current smokers of 1-13 cigarettes/day (5%) and former smokers (38%) experienced menopause at about the same age as women who never smoked. CONCLUSIONS: The results are compatible with a pro-estrogenic effect of moderate alcohol intake and an anti-estrogenic effect of current cigarette smoking of 14+cigarettes/day.