Nicotine yields of cigarettes,plasma nicotine in smokers,and public health

Previous research by M. A. H. Russell, M. Jarvis, R. Iyer, and C. Feyerabend (Brit. Med. J.280, 972–976 (1980)) concluded (a) that standard nicotine yields of cigarettes are very poor indicators of plasma nicotine concentrations in smokers, and therefore, (b) that the presumed health advantage of lower-yield cigarettes was likely not due to reduced “tar” intake by smokers of these cigarettes. The laboratory data, however, were not analyzed in a way that permits direct generalization to the epidemiological findings. A reanalysis of the data shows that the odds of deriving high yields increases substantially as the standard nicotine yield increases: lower risks associated with lower-yield cigarettes may be attributable to reduced nicotine (tar) yields to smokers. Implications for public health and the special risks of ventilated-filter cigarettes are discussed.     

Attitudes and practices of physicians regarding hypertension and smoking: The Stanford Five City Project

A survey was sent to 318 physicians in Monterey County, California, to assess their attitudes and practices regarding hypertension and cigarette smoking. After three mailings, 62% returned completed questionnaires. Eight percent of the respondents were smokers, 5% were women, and 34% were in primary care specialties. Older physicians and primary care specialists were less aggressive in their treatment of high blood pressure, but none of the assessed attitudes was significantly associated with treatment practice. Only half of the sample advised all patients to quit smoking. Physicians who doubted the effectiveness of their anti-smoking advice or who did not know what to say to smoking patients were less likely to provide advice. Most physicians felt that their smoking patients lacked sufficient motivation to quit. Programs to encourage physicians to increase smoking cessation activities should address these attitudes.     

Multivariate prediction of smoking cessation following physician advice to quit smoking: A validation study

A multivariate predictive model was developed to classify patients with respiratory disease as to their smoking status following physician advice to quit (L. L. Pederson, J. C. Baskerville, and J. M. Wanklin, Prev. Med.11, 536–549 (1982)). The purpose of this study was to validate this model on a new group of patients by comparing their predicted smoking behavior with their actual behavior. Using a probability of 0.50 as the cutoff for prediction, overall accuracy was 89.6%. However, the sensitivity for detecting those who would actually quit was low. By reducing the cutoff probability to 0.20, overall accuracy remained high and sensitivity was increased. A discussion of the implications of different types of classification errors is presented based on cost-effectiveness considerations. The clinical usefulness of prediction models is discussed.     

Spirometric "lung age" estimation for motivating smoking cessation

Motivation for smoking cessation benefits from physician counseling. To further improve this educational process, spirometry can demonstrate ventilatory impairment to the smoker. In addition to comparing a person's spirometric results with predicted reference values for normal subjects, estimation of "lung age" can be used to demonstrate the effects of cigarette smoking. Equations were developed from reference linear regression equations permitting lung age estimation in terms of ventilatory function. This age can then be compared with the individual's chronological lung age. Normal and abnormal groups determined by a respiratory health questionnaire and pulmonary function testing were used to compare the value of single and combination spirometric tests. The forced expiratory volume at 1 sec proved superior to any other single test or combination for best separation of the two groups and had the lowest standard error for estimated lung age. Both spirometry and estimated lung age calculation may be useful for motivating cessation of cigarette smoking.     

The influence of passive smoking on pulmonary function—A study of 1,351 office workers

Until now it has been difficult to ascertain how much passive inhalation of tobacco smoke affects bronchopulmonary function. To answer this question, an investigation involving 1,351 white collar workers was carried out. Information about active and passive tobacco smoke exposure was obtained by a standardized questionnaire. This made it possible to subdivide the overall group into five subgroups: Never smokers, passive smokers, ex-smokers, current smokers, and other smokers. Forced expiratory vital capacity (FVC) and maximal expiratory flow-volume (MEFV) curves were used for lung function analysis. From these curves FVC, forced mid-expiratory flow (FEF 25/75), forced end-expiratory flow (FEF 75/85), and maximal mid-expiratory flow (MEF 25/75) were determined and standardized for sex, age, height, and body weight. Passive smokers evaluated by this method showed essentially no decrease in parameters describing ventilatory function. It is concluded from the dose-and time-effect relationships obtained in active smokers between the lung function parameters and the duration of tobacco smoke exposure on the one hand and the daily consumption of cigarettes on the other that passive smoking in small doses may have no essential effect on pulmonary function.     

Evaluating an early secondary smoking prevention intervention

Given the documented link between smoking and later debilitating health conditions, a need exists to investigate educational programs aimed at reducing rates of smoking among school-age children. The present study involved an entire class of ninth graders in a treatment condition featuring either role-playing and discussion, or only discussion. While both treatments effectively reduced levels of smoking among early smokers, few changes were noted for youngsters manifesting long-term, more entrenched habits. Levels of smoking for children monitored in a control school remained about the same. These data suggest that early preventive programs might be most efficacious in curtailing smoking among school-age children.     

The multiple risk factor intervention trial (MRFIT): V. Intervention on smoking

The development, implementation, and results of the smoking cessation program of the Multiple Risk Factor Intervention Trial (MRFIT) are presented. The MRFIT is a 6-year clinical trial designed to investigate the effects of reducing cardiovascular risk factors—elevated cholesterol, hypertension, and cigarette smoking—in a group of asymptomatic men at high risk of cardiovascular disease. The men participated in an integrated intervention program that offered both group and individual formats, a structured maintenance program for those who stopped smoking, and an extended intervention program for those unable to quit initially. Results among the original 4,103 smokers included a 47.3% quit rate 4 months after program initiation and a 45.9% quit rate after 4 years. Of those reporting no smoking at 4 months, 56% were abstinent at all visits through 48 months. Most recidivism occurred soon after initial cessation, with 17% of the men who reported quitting at 4 months reporting smoking 4 months later. The quit rates were strongly associated with the initial level of smoking, with light smokers reporting higher quit rates and lower recidivism rates at all visits through 4 years. Results exceed trial goals whether measured by self-reports or by thiocyanate levels, an objective assessment of smoking behavior. Discussion focuses on understanding the variables contributing to smoking cessation and to achieving the goals of reduction of risk of cardiovascular disease.     

Physical, psychological, and sociodemographic differences among smokers, exsmokers, and nonsmokers in a working population

Nonsmokers, exsmokers, cigarette smokers, and other smokers were compared for a variety of psychological, physiological, and sociodemographic characteristics. A total of 183 white men and 284 white women, 17 to 65 years of age, who were home office employees of the Liberty Life Insurance Company participated in the study. Age-adjusted comparisons indicated that nonsmokers differed from smokers in that they attended church more frequently and had more education; were less likely to have spouses who smoked; were less active physically on the job; were more likely to eat breakfast and desserts; consumed fewer soft drinks, alcoholic beverages, and coffee; and had lower pulse rates (men only) and thinner skinfolds. The differences among smoking categories for job-related factors, coping techniques, leisure time physical activity, and personality characteristics were generally unremarkable. In light of the numerous comparisons made, it was surprising how few differences were observed. Although the discriminant function was only modestly successful in classifying smokers and nonsmokers (78% accuracy), differences in diet, behavior, spouse characteristics, religious habits, and health orientations may prove useful in designing smoking prevention and cessation programs.     

Cigarette smoking, tumor recurrence, and survival from bladder cancer

Results are presented from an investigation into the effects of cigarette smoking on tumor recurrence and survival in a group of 302 patients with bladder cancer. A regression analysis using Cox's proportional hazards model was done to evaluate the effect of cigarette smoking status, stage of disease at diagnosis, histology, race, sex, and the patient's age at diagnosis on length of survival. Results showed that younger patients, those with less extensive disease, and those with transitional cell tumors showed the best survival. Cigarette smoking was unrelated to survival. The effects of cigarette smoking on tumor recurrence were examined in patients with localized disease. Smoking status was not associated with either recurrence-free survival or the number of tumor recurrences. These findings suggest that cigarette smoking is not an important prognostic factor for patients with bladder cancer.     

The stress concept as a problem for a ‘theoretical pathology’

Theoretical pathology' is defined as the conceptual foundation of medicine. Research in this area is concerned with the analysis of explicit and implicit patterns of thought dominating research and practice. Using the example of the stress concept, it is suggested that it is a 'key word' with denotative and connotative meanings accessible to professional and laymen, contributing to explore the 'gray zone' between 'health' and 'disease' by linking psychological, social and biological determinants of 'well-being' and 'discomfort'. Examples of current research illustrate possible expansions of medical theorization.     

The effects of chronic administration of LH-RH agonists and antagonists on the menstrual cycle and endometrium of the rhesus monkey

Regularly cycling rhesus monkeys (Macaca mulatta) were used to study the effects of prolonged administration of LH-RH analogs on the menstrual cycle and the endometrium. According to the treatment, animals were divided into: Group 1, vehicle; Group 2, LH-RH agonist (D-Trp6 LH-RH, 20 micrograms/day); and Group 3, LH-RH antagonist [( N-Ac-D-Trp1,3, D-p-Cl-Phe2,D-Arg6,D- Ala10 ]-LH-RH,200 micrograms/day) for 90 days. Follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2) and progesterone (P) were measured every second day until thirty days past the discontinuation of drug administration. Endometrial biopsies were obtained on days 10, 40, 90 and 120 and processed for histologic exam and determination of estrogen (E) and progesterone receptors. Animals of Group 1 presented regular cycles, while those in Groups 2 and 3 remained anovulatory throughout the treatment. Animals of Group 2 presented different degrees of endometrial hyperplasia during treatment and animals of Group 3 showed either resting or atrophic endometrium. Administration of LH-RH agonist produced a marked increase in E and P endometrial receptors and the antagonist produced a decrease in P receptors. In both instances, reversal of the effects on the menstrual cycle and in the endometrium was observed 30 days after discontinuation of drug administration.     

The multiple risk factor intervention trial (MRFIT).: II. The development of the protocol

The detailed development of the MRFIT protocol is discussed, beginning with the general plan outlined by the National Heart and Lung Institute in the initial solicitation of contract proposals. The protocol is designed to test the hypothesis that lowering serum cholesterol by diet, reducing high blood pressure by diet and drugs, and cessation of cigarette smoking will result in a reduced risk of (a) death from coronary heart disease (CHD), (b) combined fatal CHD and nonfatal myocardial infarction, (c) deaths from all cardiovascular disease, and (d) death from all causes, over a period of 6 years among men aged 35–57 without initial evidence of CHD. After screening 361,662 men, from 1974 to early 1976, 12,866 from the upper end of the risk spectrum of CHD on the basis of serum cholesterol, blood pressure, and smoking habits, were randomly assigned either to a program of Special Intervention (SI) directed toward altering these risk factors or to their usual source of medical care (UC). Men in the UC group have been evaluated once each year in the clinic without direct intervention on the risk factors. Men in the SI group participated in an initial intensive series of group sessions designed to assist in modification of behavior relating to the three risk factors. The SI men have since been invited to the clinic at least three times each year to maintain and increase risk factor change. Changes in the intervention protocol have resulted mainly from difficulty in achieving the expected response in serum cholesterol. These changes have included greater emphasis on control of body weight, the recommendation of more rigorous dietary specifications for those with persistently elevated levels of serum cholesterol, and advice to increase physical activity.     

The independent contributions of socioeconomic status and health practices to health status

The objective of this study was to determine whether the much-repeated finding of a relationship between socioeconomic status and health status is explained by individuals' health practices. The investigation was carried out using data tapes from the 1977 Health Interview Survey in which a one-third subsample of adults was asked a series of questions related to the seven nonmedical health practices identified in the Alameda County Study. The group selected for analysis comprised 15,892 white, responding adults. With age controlled statistically, perceived health status was found to be associated with socioeconomic status, whether the indicator was educational level, family income, or occupation, and to number of positive health practices. When number of health practices, in addition to age and other socioeconomic indicators was controlled for, the association was still positive and significant. The finding of an independent contribution by socioeconomic status to health status emphasizes that individual health habits are not the only influence on health status.     

Variability and reliability of diastolic blood pressure during adolescence: The Philadelphia blood pressure project

This paper reports results of diastolic blood pressure studies done as part of the Philadelphia Blood Pressure Project (PBPP), a 3-year longitudinal study of black adolescents, initially ages 11–15, who were enrolled originally in the Philadelphia Collaborative Perinatal Project (CPP). Three samples were studied by the PBPP: a representative sample of over 500 black adolescents stratified by age and sex, a smaller sample of adolescents who had blood pressures elevated beyond one standard deviation of the CPP population mean at age 7, and a sample of adolescents born of toxemic pregnancies. We found, for the representative sample, consistent differences in the means of diastolic blood pressure phases IV and V and between diastolic blood pressures taken in supine and seated positions. Supine diastolic blood pressures were more variable at every age and were lower than the comparable seated diastolic blood pressures. In addition, we estimated on a random subsample from all three samples diastolic blood pressure reliability for supine readings taken sequentially by the same (N = 96) and different (N = 55) examiners. We also estimated measurement reliability simultaneously (N = 91 supine, N = 96 seated) using a double-listening stethoscope. We found that although diastolic phase IV blood pressure was more reproducible or less variable over short periods of time (5–15 min) when reliability measures were taken sequentially, two examiners simultaneously could not measure phase IV with significantly greater accuracy than phase V. We concluded that the fourth and fifth Korotkoff sounds should not be used interchangeably during adolescence and that postural position is an important contributor to diastolic blood pressure variance during adolescence. Also, since it has not yet been established which is more statistically predictive of adult blood pressure levels, whenever possible, both phase IV and V should be recorded for adolescents.     

The description and initial evaluation of an intensive live-in program in risk reduction

Drawing upon the epidemiological, clinical, and behavioral studies suggesting the importance and feasibility of multidisciplinary efforts to reduce levels of risk variables for cardiovascular and other chronic diseases, a short-term live-in intervention program was developed. The program includes efforts to reduce smoking, weight, blood lipids, blood pressure, and stress through improving habits of exercise, nutrition, weight management, and stress control delivered to individuals with varying levels of health risk based on measurable biochemical and physiological variables and medical history. Major changes occurred during the 24-day program in 459 individuals enrolled in the program: 68% of smokers ceased, average cholesterol fell from 240 to 200 mg%, ideal body weight fell from 134 to 129% (82 to 79 kg), systolic blood pressure (BP) fell from 131 to 119 mm Hg, diastolic BP fell from 81 to 73 mm Hg, and reported feelings of general well-being increased. Greater changes were observed in the high-risk groups. Follow-up results at 1 year (48% of patients reporting) for those defined as high risk were a net decrease of 22 mg% in cholesterol, 7 mm Hg in systolic BP, 6 mm Hg in diastolic BP, and 6.8% of ideal body weight; 45% of those smoking at admission were still not smoking at 1 year (32% reporting). For those at lower risk there was a general return of risk levels toward baseline values.     

Synergism between radiation and other risk factors for breast cancer

The question of whether the risk of radiation-induced breast cancer is additive or multiplicative (synergistic) with other risk factors for breast cancer has important implications for determining optimal guidelines for mammographic screening. Data from a follow-up study of 571 women given X-ray therapy for acute postpartum mastitis in Rochester, New York, and 993 control women were analyzed to examine this question. No synergism was found between breast irradiation and family history of breast cancer, late parity, oral contraceptive use, menopausal hormone use, or a composite of ovarian-related factors. Results indicated that women with a history of breast irradiation who develop benign breast disease, particularly cystic disease, are at high risk for breast cancer and should be carefully monitored. Women who were irradiated at the time of their first childbirth are also at especially high risk for breast cancer.     

The relationship between vasectomy and angiographically determined atherosclerosis in men

Long-term prospective studies in monkeys have shown that vasectomy is associated with an increase in atherosclerotic disease. The purpose of the present investigation is to evaluate whether vasectomy in men is associated with atherosclerotic disease in the coronary arteries. In this study information was obtained on the vasectomy status in a series of 7,420 men who had previously been referred for coronary angiography because of cardiovascular symptomatology and have been followed for as long as 9 years to evaluate coronary artery bypass surgery and the natural history of the disease. It was found that 5.0% had a vasectomy prior to angiography. Two different data analysis procedures were used to determine whether the vasectomized men had a greater degree of angiographically determined coronary occlusive disease than the nonvasectomized men. Subgroups with minimal and extensive coronary artery disease were also analyzed. Results of all analyses show that the vasectomized men did not have more coronary occlusive disease. Possible patient selection biases in this study are discussed.     

Obesity and external sexual maturation—The bogalusa heart study

We explored the relation between amount of adipose tissue and maturation in 3,524 boys and girls ages 5–14 years examined in 1973–1974, and 4,074 children ages 5–17 years (re)examined in 1976–1977. Subjects were drawn from a total, geographically defined, biracial community as part of a cardiovascular risk factor screening. Height, weight, triceps skinfold thickness, external sexual maturation according to Reynolds—Tanner, status of menarche, and visible gynecomastia were assessed. We observed that adiposity was positively correlated with acceleration of maturation. This positive correlation was stronger in girls than boys, and stronger in whites than blacks. Visible gynecomastia was more prevalent at ages 13–15 years than other ages. These boys were markedly more obese than all others. Gynecomastia was negatively associated with sexual maturation (after controlling for the positive effect of adiposity), in white boys more than in black. Adiposity may have some feedback sex-hormonal effect, in girls more directly, toward accelerated maturation. In boys adiposity enhances gynecomastia which in turn is likely related to a deceleration in male maturation. The observed effects of adiposity on sex-hormonal function could have implications for the known association between adiposity and incidence of sex hormone-related female cancers, especially mammary cancer.