Standardization of definitions concerning smoking behavior among Japanese adolescents--results from the Japan Adolescent Smoking Survey (JASS)]

The aim of the Japan Adolescent Smoking Survey (JASS) is to standardize the definitions of smoking behavior among Japanese adolescents together with measurement methods and questionnaires concerned. A study of 9921 school children aged 9 to 18 years in 17 elementary schools, 16 junior high schools and 18 senior high schools in 9 prefectures, was conducted between June and July of 1989, to determine the relationship between actual smoking behavior during the past month or year and the "self-referent label" concerning their smoking status. The main results were as follows: 1) The percentage of those who smoked at least one cigarette during the past month showed a high degree of similarity to the percentage of those who referred to themselves as "regular smokers" or "occasional smokers". 2) Less than 10% of students who identified themselves as "never smokers" or "ex-smokers" smoked at least one cigarette during the past month, while more than 80% of students who referred to themselves as "regular smokers" or "occasional smokers" smoked during the past month. 3) On the whole, those who smoked 20 or more cigarettes during the past month referred to themselves as "regular smokers"; those who smoked between 2 and 19 cigarettes as "occasional smokers"; those who smoked 1 cigarette as "ex-smokers"; those who did not smoke during the past month as "never smokers". 4) The definition where students who smoked one cigarette during the past month are classified as a category of smoker, displayed a high level of sensitivity and specificity for all school-level groups and for both sexes.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cigarette smoking and increased risk of mucinous epithelial ovarian cancer

Several studies have reported that cigarette smoking is associated with an increased risk of mucinous ovarian cancer, but other studies have failed to find such a relation. Using data from the Case-Control Surveillance Study, begun in four US cities in 1976, the authors conducted a case-control study (1976-2001) to examine the association between cigarette smoking and the risk of ovarian cancer of different cell types. Among 709 incident cases of epithelial ovarian cancer, 402 were serous, 74 were mucinous, 106 were endometrioid, and 127 were of other cell types. For mucinous ovarian cancer, the odds ratios were 1.5 (95% confidence interval (CI): 0.7, 3.4) among women who smoked less than one pack of cigarettes per day, 1.4 (95% CI: 0.6, 3.5) among women who smoked one pack per day, and 2.9 (95% CI: 1.2, 7.5) among women who smoked more than one pack per day, relative to never smokers. The odds ratios were 2.5 (95% CI: 1.1, 5.4) for ex-smokers and 1.4 (95% CI: 0.7, 2.9) for current smokers. While women with up to 15 pack-years of smoking had an almost 2.5 times' increased risk of mucinous ovarian cancer, such an increased risk was not found among those with more than 15 pack-years of smoking. There was no association between cigarette smoking and epithelial ovarian cancer of other cell types. Despite inconsistencies in the data, these results strengthen the evidence that cigarette smoking may play a role in the development of mucinous ovarian cancer but not ovarian cancer of other cell types.     

Smoking and life expectancy among U.S. veterans.

Life expectancies were estimated for selected groups of smokers, ex-smokers, and nonsmokers based on the results of a 16-year mortality follow-up of 198,820 U.S. veterans. Life expectancy varied inversely with number of cigarettes smoked per day. The most pronounced differences were between nonsmokers and heavy cigarette smokers (40+ per day). These differences in life expectancy were greatest at the younger ages--nearly 9 years at ages 35 and 40. Life expectancies for cigarette smokers varied directly with age began smoking. For all ages, differences in life expectancy between nonsmokers and ex-cigarette smokers who stopped for other than doctor's orders were less than those between nonsmokers and current cigarette smokers. Results in the present study clearly confirmed Hammond's earlier findings.     

The epidemiology of cigarette smoking in Hong Kong Chinese women

BACKGROUND: Smoking in women is a well-recognized public health problem. In many developed countries, cigarette smoking is now the single most important preventable cause of premature death in women. There are relatively few data on the epidemiology of cigarette smoking in Asian women, and this study examined the prevalence of and factors predisposing Chinese women to smoke cigarettes in Hong Kong. METHOD: A territory-wide random telephone survey of 26,716 households in Hong Kong was conducted. A total of 1064 current smokers and 291 ex-smokers were identified in these household, and in-depth interviews of 791 current smokers, 221 ex-smokers, and 1012 controls were conducted. RESULTS: The prevalence of cigarette smoking was 4.5% in women who were 25 years or younger, 2.6% in women aged 46-65 years, and 2.2% in women aged 65 years or older. Sixty-four percent of current smokers started when they were 19 years or younger. The main reasons for the initiation of cigarette smoking were the influence of friends, curiosity, feeling bored, or being idle. Current smokers and ex-smokers tended to have positive images of women who smoked. The following risk factors were found to be significant for cigarette smoking: less than university education, unemployment, being divorced, having a husband who smoked, and a low score on the perceived harms of cigarette smoking. CONCLUSION: Cigarette smoking is more prevalent in younger women in Hong Kong; and psychosocial issues should be addressed to prevent future epidemics.     

THE SMOKING HABITS AND ATTITUDES OF NURSES

The demographic and social characteristics, attitudes to smokers and smoking, and knowledge about smoking were surveyed in 988 (81.3%) of 1,215 trainee and trained nurses in four locations in Perth, Western Australia. Male and female nurses were similar with 51% never having smoked regularly, 17% being ex-smokers and 32% current smokers. In comparison with Australian woman in general, there were less current smokers and more ex-smokers among female nurses. Female nurses smoked substantially more than Australian female doctors. The majority of nurses who had ever smoked (68%) began smoking between ages 15 and 19 years, 26% began in the first year of their nursing training and 26% smoked their first cigarette in the nurses' quarters. The knowledge of nurses about the health effects of smoking was similar to that of Australian doctors as were their opinions regarding their role in setting a non-smoking example to others. A substantial majority supported either a complete ban on smoking, or its restriction to especially segregated areas in aeroplanes, buses, trains, hospitals and cinemas.     

Nonspecific inflammatory bowel disease and smoking

The authors assessed the relation between cigarette smoking and nonspecific inflammatory bowel disease in a case-control study of 124 cases of ulcerative colitis, 109 cases of Crohn's disease, and 250 age- and sex-matched control subjects in hospital for acute nongastric or intestinal conditions unrelated to smoking. For ulcerative colitis, the risk for current smoking compared with never smoking was 0.5, with a 95% confidence interval (Cl) of 0.3-1.0. They observed decreasing risk with increasing number of cigarettes smoked. The risk for ex-smokers, however, was greater than that for never smokers (relative risk = 2.7; 95% Cl = 1.5-4.9). The elevated risk of ulcerative colitis in ex-smoking in the presence of an overall lack of association with ever-smoking may plausibly be attributed to either 1) brief induction time of a protective effect of smoking on ulcerative colitis or 2) selective cessation of smoking due perhaps to very early symptoms of the disease. If time at first onset of bowel symptoms, instead of clinical diagnosis, is considered as the index date, the negative association between ulcerative colitis and current smoking would have weakened in men and disappeared in the overall series. There was clear evidence of a positive association between cigarette smoking and Crohn's disease (relative risk for ever smokers vs. never smokers = 4.0; 95% Cl = 2.2-7.3). The risk estimates increased with the number of cigarettes smoked per day and duration of habit. The association between current smoking and Crohn's disease was even stronger when age at first onset of bowel symptoms was considered as the index date, but the risk for ex-smokers fell below unity.     

The interaction of cigarette smoking, oral contraceptive use, and cardiovascular risk factor variables in children: the Bogalusa Heart Study.

Two separate surveys were conducted in a total biracial population of children ages 8-17 years to determine the effects of cigarette smoking and oral contraceptive use on blood pressure and serum lipids and lipoproteins. Information regarding smoking habits and oral contraceptive use was obtained from detailed questionnaires. For White boys and White and Black girls, a small but statistically significant decrease in diastolic blood pressure levels for cigarette smokers when compared to non-smokers was noted. A significant increase among cigarette smokers in beta-lipoprotein cholesterol, pre-beta-lipoprotein cholesterol, and triglycerides as well as a decrease in alpha-lipoprotein cholesterol was noted, especially for White girls. This change in lipoprotein levels for cigarette smokers was noted in both surveys. Oral contraceptive users had higher total cholesterol and beta-lipoprotein cholesterol and lower alpha-lipoprotein cholesterol than nonusers. After adjusting for oral-contraceptive use, particularly among White girls, cigarette smokers still demonstrated high pre-beta-lipoprotein cholesterol and lower alpha-lipoprotein cholesterol levels than non-smokers. These results suggest that the lipid and lipoprotein response to cigarette smoking and oral contraceptive use is to increase cardiovascular risk.     

Does switching from cigarettes to pipes or cigars reduce tobacco smoke exposure?

Cigarette smoking histories, reported depth of inhalation, number of pipe and cigars (PC) smoked, serum thiocyanate (SCN) and expired air carbon monoxide (CO) levels were examined in PC male smokers enrolled in the Multiple Risk Factor Intervention Trial (MRFIT). Serum SCN levels for all PC smokers were higher than for non-smokers and lower than for current cigarette smokers. Levels were related to the amount of product smoke. Prior cigarette smokers had higher SCN levels when compared to PC users who had never smoked cigarettes, smoked a larger number of tobacco products per day, and reported inhaling into the chest more often. Prospective data on baseline cigarette smokers demonstrated that smokers who stopped all tobacco products had a greater drop in SCN and CO than those who switched to PC. The findings strongly suggest that cessation of all tobacco products is the best strategy for decreasing exposure to tobacco smoke.     

Black-white differences in serum cotinine levels among pregnant women and subsequent effects on infant birthweight.

OBJECTIVES. Higher levels of serum cotinine (a metabolite of nicotine) have been found in Black smokers than in White smokers even after self-reported cigarette dose was controlled. It is unknown whether higher cotinine levels in Black pregnant smokers may increase the risk of delivering an infant of reduced birthweight. METHODS. We analyzed serum cotinine levels of 374 Black and 829 White women who smoked during pregnancy and who delivered between April 1964 and April 1967. Racial differences in the relationship between cotinine and birthweight were examined. RESULTS. Cotinine levels were 27.4 ng/mL higher in Black smokers after cigarette dose and confounding variables were controlled. Blacks had higher cotinine levels than Whites at each dose. No significant racial differences in the rate of decrease in birthweight per nanogram of cotinine per milliliter were found. CONCLUSIONS. Our results confirm previous research showing higher cotinine levels at each smoking dose in Black smokers than in White smokers. Because there was no difference in the rate of decrease in birthweight due to cotinine, our results suggest that cigarette smoking among Blacks may have a greater effect on birthweight than it does among Whites.     

Associations between white blood cell count and features of the metabolic syndrome in Japanese male office workers

We assessed the association of white blood cell (WBC) count with different components of the metabolic syndrome (MS) in 5275 Japanese male office workers aged 23-59 years. There was a significantly crude correlation between WBC count and body mass index, systolic and diastolic blood pressures, total cholesterol, high-density lipoprotein cholesterol (negative), triglycerides, fasting plasma glucose, and uric acid (all P<0.001). After controlling for potential confounding factors, the adjusted means of WBC count were significantly higher in subjects with each feature of the MS (obesity, hypertension, hypercholesterolemia, low high-density lipoprotein cholesterol levels, hypertriglyceridemia, high fasting plasma glucose levels, and hyperuricemia) (all P<0.005). The adjusted WBC count increments in subjects with 1, 2, 3, 4, and > or = 5 features of the MS were 0.28, 0.45, 0.68, 0.76, and 1.40 x 10(9) cells/l, respectively, compared with the subjects without features of the MS (P for trend<0.001). The adjusted means of WBC count increased significantly with the increasing number of features of the MS in both non-smokers and smokers (both P<0.001). These data indicate a strong association between WBC count and a number of disorders characterizing the MS independent of cigarette smoking among Japanese men.     

Effects of smoking and stopping smoking on serum high-density lipoprotein cholesterol levels in a representative population sample

Serum high-density lipoprotein (HDL) cholesterol levels were assessed in a random sample of 939 men and 853 women ages 14-65 years in eastern Finland. Amount of daily smoking measured by serum thiocyanate concentration was negatively and independently associated with serum HDL cholesterol level and HDL/total cholesterol ratio in men. This negative association seemed largely to be due to low HDL cholesterol levels in heavy smokers. Both male and female current smokers had lower HDL cholesterol levels and HDL/total cholesterol ratios than those who had never smoked. This difference was found even after adjustment for age, body mass index, and beer drinking. The reduction of HDL cholesterol level seemed to be reversible, because those who had recently stopped smoking had higher HDL cholesterol levels and higher HDL/total cholesterol ratios than current smokers.     

Host and environmental factors influencing the peripheral blood leukocyte count.

The peripheral leukocyte count is an important predictor of mortality. Hence, host and environmental factors influencing the peripheral leukocyte count are of interest. The authors studied 8,635 subjects, aged 30-74 years, who were seen as part of the National Health and Nutrition Examination Survey II in 1976-1980, and sought to assess the relation of age, sex, obesity (body mass index), alcohol use, and various parameters of cigarette smoking to the peripheral leukocyte count using multiple regression analysis. Various parameters of cigarette smoking were statistically significant independent predictors of the peripheral leukocyte count with higher leukocyte counts seen among current smokers, relative to former or never smokers. Among current smokers, a dose-response relation was seen for cigarettes/day and total pack-years smoked. A dose-response relation with pack-years and years since quitting was seen in former smokers. Other variables that were statistically significant independent predictors of a higher peripheral blood leukocyte count were younger age, male sex, increased body mass index, and decreased alcohol consumption. Although the specific cell or cells responsible for these relations are not defined by this analysis, the results support the suggestion that a number of host and environmental factors can influence cellular markers of inflammation.     

Tobacco smoking as a risk factor for colon polyps.

BACKGROUND: Data from a cancer screening project among pattern makers were used to evaluate the association between tobacco smoking and prevalence of colon polyps. METHODS: From 1981-1983, 549 White men were examined by flexible sigmoidoscopy and completed self-administered questionnaires including smoking histories. RESULTS: One or more colon polyps were detected in 76 men. Standardized prevalence rates (SPR) for polyps increased by smoking category (never smoked = 0.094; ex-smokers = 0.118, current smokers = 0.214) and by cigarettes per day, years of smoking, and pack-years among both current and ex-smokers. Both adenomatous and hyperplastic polyps showed an association with smoking while other types of polyps and polyps with unspecified histology did not. The risk associated with smoking was greater for polyps greater than one centimeter in diameter. An interaction with occupational exposures was suggested by a greater increase in the SPR for polyps among current smokers employed as pattern makers for more than 10 years than among current smokers similarly employed for 10 years or less. CONCLUSIONS: Since at least some colon polyps are considered precursor lesions to colon cancer, one of the most common cancers in the United States, this report suggests that the possible link between colon polyps and smoking deserves further evaluation.     

Response error in self-reported current smoking frequency by black and white established smokers

As compared with white smokers, black smokers, although they report using fewer cigarettes per day, are at higher risk for most smoking-related diseases. Among black smokers serum cotinine levels are also higher in proportion to cigarettes per day; this observation has led to suggestions of bias in self-reporting. The purpose of this study was to evaluate and compare the extent of errors in self-reported smoking patterns among black and white established smokers. Ninety-seven white and 66 black smokers participated in structured telephone interviews, filled out two self-administered questionnaires one week apart, and collected all of their cigarette butts for a week. Group differences in the validity of self-reported smoking patterns were assessed by comparison with cigarette butt counts and the measured butt lengths. Both black and white smokers significantly overestimated smoking on our measure of smoking frequency (both P < 0.001); the group difference in bias was not significant (P = 0.13). There was no evidence that underreporting was more common among blacks than among whites (P = 0.67). Test-retest reliability was not significantly different in the two groups (P = 0.09). Both groups performed poorly when asked to categorize their smoking frequency according to the cutpoints of the Fagerström Test for Nicotine Dependence. Black smokers smoked more of each cigarette and smoked longer cigarettes, but they smoked fewer total millimeters of cigarettes per day (all P < 0.001). Contrary to an earlier report, the disproportionately high cotinine levels could not be attributed to reporting error.     

Multiple Correlates of Cigarette Use Among High School Students

A cross-sectional survey research design measured factors related to cigarette use among 2,212 senior high school students. Results showed 14.3% of the sample smoked cigarettes at least occasionally, with 5.3% reporting they were daily smokers. About 12.8% indicated they were ex-smokers. Males and females smoked at almost equal rates, and the percentage of 10th grade student smokers was slightly higher (16.4%) than the percentage of juniors and seniors who smoked. Approximately 22% of Hispanic students, 15% of Caucasian students, and 4.5% of African-American students reported smoking cigarettes at least occasionally. An initial regression analysis used 21 variables to predict cigarette smoking. A more parsimonious regression model (R2 = .28), using variables from the initial regression analysis with significance levels of .01 or less, indicated the most important predictors of cigarette use were ethnic group, attitude toward females who smoke, close friends' use of cigarettes, personal use of marijuana, best friend's use of cigarettes, personal use of alcohol, and school self-esteem. Implications for school health programs are addressed.     

Determinants of quitting smoking.

Factors associated with quitting smoking were examined in 3,778 male and 1,486 female ever-smoking patients hospitalized with non-tobacco-related conditions interviewed between 1977 and 1985. Quitters were defined as those who had stopped smoking at least one year prior to admission. More than 80 per cent of male and female quitters had stopped more than five years prior to diagnosis. The lifetime quit rate (no. ex-smokers/no. ever smokers) X 100 was higher in males than in females, and in both sexes the quit rate increased with increasing age, education level, and occupational level. Jews had higher quit rates compared to non-Jews, and Whites had higher quit rates than Blacks. Those who were divorced or separated had lower quit rates than those who were not. In both sexes, light smokers and heavy smokers had elevated quit rates. The quit rate also increased with increasing interval between waking and smoking the first cigarette of the day. Logistic regression models were used to adjust simultaneously for the role of different variables.     

Risks of lung cancer, chronic bronchitis, ischaemic heart disease, and stroke in relation to type of cigarette smoked.

In a case control study of over 12 000 inpatients aged 35-74, risk of lung cancer, chronic bronchitis, and, particularly in those aged 35-54, ischaemic heart disease was positively associated with the number of manufactured cigarettes smoked daily and was negatively associated with long term giving up. Risk of stroke was not clearly related to smoking. Among manufactured cigarette smokers, lung cancer risk tended to be lowest in those who had always smoked filter cigarettes. This pattern was, however, evident only in men who additionally smoked pipes, cigars or handrolled cigarettes and in women, not being seen in men who smoked only manufactured cigarettes. Risk of lung cancer was not clearly related to time of switch to filter cigarettes. A markedly lower risk of chronic bronchitis was seen in men, but not women, who smoked filter rather than plain cigarettes. Heart disease risk did not vary by type of cigarette smoked 10 years before admission, but, compared with those who had never smoked filter cigarettes, those who had ever smoked filter cigarettes had a higher risk in men and a lower risk in younger women. Compared with the general population, markedly more controls were ex-smokers, suggesting incipient disease, whether or not smoking related, may alter smoking habits, thus affecting the interpretability of the findings. Control smokers were also relatively much more likely to report smoking plain cigarettes than expected. This comparison, not made in other studies relating risk to type of cigarette smoked, indicates that great care must be taken in verifying validity of reported smoking habits. While our findings are compatible with other evidence that risk of lung cancer and chronic bronchitis is probably reduced by switching from plain to filter cigarettes, they underline the difficulties in obtaining valid evidence from epidemiological studies.     

Smoking habits and risk of fatal stroke: 18 years follow up of the Oslo Study.

STUDY OBJECTIVE: To examine the risk of fatal stroke in relation to smoking habits in men screened for the Oslo study. DESIGN: The Oslo study is a prospective, cohort study of the epidemiology and preventive aspects of cardiovascular diseases in middle aged men. Screening started in May 1972 and results after 18 years of follow up are reported. PARTICIPANTS: There were 16209 men aged 40-49 years, of whom 16173 had no stroke history. Eighty five men died from stroke, of whom 48 were daily cigarettes smokers, 7 were pipe and cigar smokers, 15 smoked cigarettes and pipe or cigars daily, 11 were previous cigarette smokers, and 4 had never smoked cigarettes. MAIN RESULTS: Results of proportional hazards regression analysis adjusted for age, diastolic blood pressure, and glucose concentration showed the following rate ratios (RR) (95% confidence interval) of smoking groups compared with those who had never smoked or had previously smoked: combined cigarette and cigar or pipe smokers, RR = 6.1 (3.0, 12.5); cigarettes only, RR = 4.1 (2.3,7.4); and pipe and/or cigars only RR = 2.2 (0.9,5.5). The overall, age adjusted risk of smoking cigarettes daily was 3.5 and was found to increase with increasing cigarette consumption. Regardless of their smoking group, stroke cases had increased diastolic (DBP) and systolic blood pressure (SBP) when compared with men who had not had a stroke. The absolute differences in DBP and SBP between stroke cases and others for never and previous cigarette smokers versus daily smokers were twice as large: DBP, 12.1 mmHg versus 6.5 mmHg respectively and SBP, 16.0 mmHg versus 7.1 mmHg respectively. A high BMI increased the risk of fatal stroke of never and previous cigarette smokers. Men being treated for hypertension at the time of screening had three times the crude risk of fatal stroke of men who were not taking hypertensive treatment. CONCLUSIONS: Daily cigarette smoking increased the risk of fatal stroke three and a half times. Combined cigarette and pipe or cigar smoking had a higher risk than smoking cigarettes only. An increased risk was found in relation to increased daily cigarette consumption.     

Cigarette smoking and small irregular opacities.

A survey of chemical workers by chest roentgenograms was designed to determine whether exposure to acrylic dust and/or cigarette smoking was associated with diffuse abnormalities suggestive of pneumoconiosis. The films were examined without knowledge of dust exposure or smoking habits. The International Labour Office (ILO) classification and standard films were used. Workers with exposure to asbestos were excluded. There was no relation between prevalence of abnormalities and exposure to dust. Among 181 workers 28 had s and/or t small irregular opacities with profusion of 0/1 (23), 1/0 (three), or 1/1 (two). These findings were present in 20% of smokers compared with 2.2% of non-smokers. The prevalence increased with increasing age to 31.6% among smokers aged 50-64. Prevalence was 10% among ex-smokers of cigarettes. Among current cigarette smokers, prevalence was 5.3% in those who smoked less than one pack per day, 31.3% in heavier cigarette smokers, and 52.9% in 17 heavy cigarette smokers aged 50-64. Profusions of 0/1 and 1/0 are classified as "suspect" pneumoconiosis according to the ILO guidelines. The data in this study indicate that such abnormalities are directly related to age and smoking habits among workers not exposed to hazardous dust.     

The association between amount of cigarettes smoked and overweight, central obesity among Chinese adults in Nanjing, China

OBJECTIVES: To examine the association between overweight, central obesity and cigarette smoking (total amount of cigarettes smoked [TACS] and status). DESIGN: Population-based cross-sectional study. Setting: Administrative villages and neighborhoods (n=45) randomly selected from three urban districts and two rural counties in Nanjing City, China. SUBJECTS AND METHODS: A representative sample (n=13,463) of permanent local male residents aged 35 years or older; 66.5% were urban residents. The response rate was 90.1%. Overweight (BMI>=24) and central obesity (waist circumference>=85 in men) were defined according to the new Chinese standard. The association between smoking (amount and status) and obesity was examined using logistic and linear regression analysis. RESULTS: The overall prevalence of overweight was 36.1% (29.7% with 24<=BMI<28 and 6.4% with BMI>=28). After adjusted for age, residence, education, occupation, family income, alcohol drinking, dietary intake, occupational and leisure-time physical activity, the prevalence was significantly lower among current smokers (33.0%) than in non-smokers (39.9%) and ex-smokers (39.2%), respectively (p<0.05). The amount of cigarette smoked was reversely associated with BMI (compared to non-smokers, ORs and 95%CIs for smokers with low-, medium- and high-TACS were 0.88 [0.79, 0.98], 0.77 [0.69, 0.86], and 0.77 [0.69, 0.86], respectively). The prevalence of central obesity was 35.9%. Compared to nonsmokers, only male ex-smokers were at increased risk of central obesity (OR=1.38, 95%CI=1.10, 1.74), while there was no significant association with current- smokers (OR=1.02 [0.92, 1.12]). The amount of cigarette smoked was not significantly associated with central obesity. CONCLUSIONS: Cigarette smoking was negatively associated with body weight indicated by BMI but not with central obesity indexed by waist circumference in Chinese men. Cessation of smoking may increase the risk of gaining overall body weight and developing central obesity. Cigarette smoking prevention and cessation should be a public health priority in China.