Smoking and risk of all-cause mortality: the Jichi Medical School (JMS) Cohort Study

Motivational support intervention to reduce smoking and increase physical activity in smokers not ready to quit: the TARS RCT

Background

Physical activity can support smoking cessation for smokers wanting to quit, but there have been no studies on supporting smokers wanting only to reduce. More broadly, the effect of motivational support for such smokers is unclear.

Objectives

The objectives were to determine if motivational support to increase physical activity and reduce smoking for smokers not wanting to immediately quit helps reduce smoking and increase abstinence and physical activity, and to determine if this intervention is cost-effective.

Design

This was a multicentred, two-arm, parallel-group, randomised (1 : 1) controlled superiority trial with accompanying trial-based and model-based economic evaluations, and a process evaluation.

Setting and participants

Participants from health and other community settings in four English cities received either the intervention (n = 457) or usual support (n = 458).

Intervention

The intervention consisted of up to eight face-to-face or telephone behavioural support sessions to reduce smoking and increase physical activity.

Main outcome measures

The main outcome measures were carbon monoxide-verified 6- and 12-month floating prolonged abstinence (primary outcome), self-reported number of cigarettes smoked per day, number of quit attempts and carbon monoxide-verified abstinence at 3 and 9 months. Furthermore, self-reported (3 and 9 months) and accelerometer-recorded (3 months) physical activity data were gathered. Process items, intervention costs and cost-effectiveness were also assessed.

Results

The average age of the sample was 49.8 years, and participants were predominantly from areas with socioeconomic deprivation and were moderately heavy smokers. The intervention was delivered with good fidelity. Few participants achieved carbon monoxide-verified 6-month prolonged abstinence [nine (2.0%) in the intervention group and four (0.9%) in the control group; adjusted odds ratio 2.30 (95% confidence interval 0.70 to 7.56)] or 12-month prolonged abstinence [six (1.3%) in the intervention group and one (0.2%) in the control group; adjusted odds ratio 6.33 (95% confidence interval 0.76 to 53.10)]. At 3 months, the intervention participants smoked fewer cigarettes than the control participants (21.1 vs. 26.8 per day). Intervention participants were more likely to reduce cigarettes by ≥ 50% by 3 months [18.9% vs. 10.5%; adjusted odds ratio 1.98 (95% confidence interval 1.35 to 2.90] and 9 months [14.4% vs. 10.0%; adjusted odds ratio 1.52 (95% confidence interval 1.01 to 2.29)], and reported more moderate-to-vigorous physical activity at 3 months [adjusted weekly mean difference of 81.61 minutes (95% confidence interval 28.75 to 134.47 minutes)], but not at 9 months. Increased physical activity did not mediate intervention effects on smoking. The intervention positively influenced most smoking and physical activity beliefs, with some intervention effects mediating changes in smoking and physical activity outcomes. The average intervention cost was estimated to be £239.18 per person, with an overall additional cost of £173.50 (95% confidence interval -£353.82 to £513.77) when considering intervention and health-care costs. The 1.1% absolute between-group difference in carbon monoxide-verified 6-month prolonged abstinence provided a small gain in lifetime quality-adjusted life-years (0.006), and a minimal saving in lifetime health-care costs (net saving £236).

Conclusions

There was no evidence that behavioural support for smoking reduction and increased physical activity led to meaningful increases in prolonged abstinence among smokers with no immediate plans to quit smoking. The intervention is not cost-effective.

Limitations

Prolonged abstinence rates were much lower than expected, meaning that the trial was underpowered to provide confidence that the intervention doubled prolonged abstinence.

Future work

Further research should explore the effects of the present intervention to support smokers who want to reduce prior to quitting, and/or extend the support available for prolonged reduction and abstinence.

Trial registration

This trial is registered as ISRCTN47776579.

Funding

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 4. See the NIHR Journals Library website for further project information.

Stroke Risk Due to Smoking Characterized by Sex Differences in Japan: The Jichi Medical School Cohort Study

OBJECTIVES

Smoking is a risk factor for stroke. The relationship between smoking and the risk of different subtypes of stroke has not been fully elucidated. We investigated the relationship between smoking and the incidence of stroke in the Japanese population.

MATERIALS AND METHODS

This prospective, population-based cohort study included 11,324 participants (4447 men; 6877 women) from 12 districts in Japan, between April 1992 and July 1995. Participants were stratified according to smoking status (non-smoker [never smoked]/ex-smoker/current smoker). Male current smokers were further stratified according to the number of cigarettes smoked per day (1-14, 15-29, or ≥ 30). The non-smoking group was used as a reference. Cox proportional hazards analysis was used to determine the risk of stroke due to smoking.

RESULTS

Four hundred and seventeen new stroke events (212 men; 205 women) were recorded during a mean follow-up of 10.7 years, including 95 intracerebral hemorrhages (48 men; 47 women), 267 cerebral infarctions (152 men; 115 women), and 54 subarachnoid hemorrhages (12 men; 42 women). In multivariable analysis, the hazard ratios (95% confidence intervals) for male current smokers (≥ 30 cigarettes/day) were 1.89 (1.08-3.31) and 3.41 (1.22-9.57) for all strokes and intracerebral hemorrhages, respectively; those for female current smokers were 2.78 (1.62-4.74), 3.14 (1.51-6.54), and 4.03 (1.64-9.93) for all strokes, cerebral infarctions, and subarachnoid hemorrhages, respectively.

CONCLUSIONS

Smoking ≥ 30 cigarettes/day is a risk factor for stroke, especially intracerebral hemorrhage in men. Furthermore, smoking increases the risk of cerebral infarction and subarachnoid hemorrhage in women.

Possible burden of hyperuricaemia on mortality in a community-based population: a large-scale cohort study

Hyperuricaemia is a risk for premature death. This study evaluated the burden of hyperuricaemia (serum urate > 7 mg/dL) for all-cause and cardiovascular mortality in 515,979 health checkup participants using an index of population attributable fraction (PAF). Prevalence of hyperuricaemia at baseline was 10.8% in total subjects (21.8% for men and 2.5% for women). During 9-year follow-up, 5952 deaths were noted, including 1164 cardiovascular deaths. In the Cox proportional hazard analysis adjusted for confounding factors, hyperuricaemia was independently associated with all-cause and cardiovascular mortality (adjusted hazard ratios [95% confidence interval]; 1.36 [1.25–1.49] and 1.69 [1.41–2.01], respectively). Adjusted PAFs of hyperuricaemia for all-cause and cardiovascular deaths were 2.9% and 4.4% (approximately 1 in 34 all-cause deaths and 1 in 23 cardiovascular deaths), respectively. In the subgroup analysis, the association between hyperuricaemia and death was stronger in men, smokers, and subjects with renal insufficiency. Adjusted PAFs for all-cause and cardiovascular deaths were 5.3% and 8.1% in men; 5.8% and 7.5% in smokers; and 5.5% and 7.3% in subjects with renal insufficiency. These results disclosed that a substantial number of all-cause and cardiovascular deaths were statistically relevant to hyperuricaemia in the community-based population, especially men, smokers, and subjects with renal insufficiency.

Impact of smoking on mortality and life expectancy in Japanese smokers: a prospective cohort study

OBJECTIVE

To investigate the impact of smoking on overall mortality and life expectancy in a large Japanese population, including some who smoked throughout adult life.

DESIGN

The Life Span Study, a population-based prospective study, initiated in 1950.

SETTING

Hiroshima and Nagasaki, Japan.

PARTICIPANTS

Smoking status for 27,311 men and 40,662 women was obtained during 1963-92. Mortality from one year after first ascertainment of smoking status until 1 January 2008 has been analysed.

MAIN OUTCOME MEASURES

Mortality from all causes in current, former, and never smokers.

RESULTS

Smokers born in later decades tended to smoke more cigarettes per day than those born earlier, and to have started smoking at a younger age. Among those born during 1920-45 (median 1933) and who started smoking before age 20 years, men smoked on average 23 cigarettes/day, while women smoked 17 cigarettes/day, and, for those who continued smoking, overall mortality was more than doubled in both sexes (rate ratios versus never smokers: men 2.21 (95% confidence interval 1.97 to 2.48), women 2.61 (1.98 to 3.44)) and life expectancy was reduced by almost a decade (8 years for men, 10 years for women). Those who stopped smoking before age 35 avoided almost all of the excess risk among continuing smokers, while those who stopped smoking before age 45 avoided most of it.

CONCLUSIONS

The lower smoking related hazards reported previously in Japan may have been due to earlier birth cohorts starting to smoke when older and smoking fewer cigarettes per day. In Japan, as elsewhere, those who start smoking in early adult life and continue smoking lose on average about a decade of life. Much of the risk can, however, be avoided by giving up smoking before age 35, and preferably well before age 35.

Cigarette smoking and its association with serum lipid/lipoprotein among Chinese nonagenarians/centenarians

Objective

Cigarette smoking had been confirmed as an increased risk for dyslipidemia, but none of the evidence was from long-lived population. In present study, we detected relationship between cigarette smoking habits and serum lipid/lipoprotein (serum Triglyceride (TG), Total cholesterol (TC), Low-density lipoprotein (LDL) and high-density lipoprotein (HDL)) among Chinese Nonagenarians/Centenarian.

Methods

The present study analyzed data from the survey that was conducted on all residents aged 90 years or more in a district, there were 2,311,709 inhabitants in 2005. Unpaired Student’s t test, χ² test, and multiple logistic regression were used to analyze datas.

Results

The individuals included in the statistical analysis were 216 men and 445 women. Current smokers had lower level of TC (4.05 ± 0.81 vs. 4.21 ± 0.87, t = 2.403, P = 0.017) and lower prevalence of hypercholesteremia (9.62% vs. 15.13%, χ² = 3.018,P = 0.049) than nonsmokers. Unadjusted and adjusted multiple logistic regressions showed that cigarette smoking was not associated with risk for abnormal serum lipid/lipoprotein.

Conclusions

In summary, we found that among Chinese nonagenarians/centenarians, cigarette smoking habits were not associated with increased risk for dyslipidemia, which was different from the association of smoking habits with dyslipidemia in general population.

Attributable fractions of risk factors for cardiovascular diseases

Background

Cardiovascular disease (CVD) is a leading cause of death in Japan. To reduce the threat of CVD, it is important to identify its major risk factors. The population attributable fraction (PAF) is calculated from the prevalence and relative risk of risk factors and can be used to estimate the burden of these factors with respect to CVD. We analyzed the findings from several prospective studies to determine the PAFs of CVD.

Methods

PAF was calculated as pd × (multiadjusted relative risk − 1)/multiadjusted relative risk, where pd is the proportion of patients exposed to that risk factor category, according to data from the Ohsaki Cohort Study, EPOCH-JAPAN, NIPPON DATA80, Miyagi Cohort Study, CARDIA Study, and ARIC Study.

Results

Nonoptimal blood pressure explained 47% and 26% of CVD mortality in middle-aged and elderly Japanese, respectively. Cigarette smoking explained 34% of all-cause mortality in middle-aged men. The combination of hypertension and cigarette smoking explained 57% and 44% of CVD mortality in younger men and women, respectively. Furthermore, the presence of at least 1 nonoptimal risk factor explained most CVD deaths and all-cause deaths.

Conclusions

Established CVD risk factors, especially high blood pressure and cigarette smoking, explained a large proportion of CVD mortality and all-cause mortality. Prevention, early detection, and treatment of these conventional risk factors are required to reduce mortality risk.

Relationship of smoking and smoking cessation with oral health status in Japanese men

BACKGROUND AND OBJECTIVE

Smoking has been associated with the number of natural teeth a person has and with the likelihood of periodontitis. The purpose of this study was to determine the relationships between the number of teeth present and periodontal diseases with smoking habits in a cohort of Japanese men.

MATERIAL AND METHODS

The study group comprised 1088 men, 40-75 years of age. Oral examinations were conducted in dental clinics. Information on smoking status and on oral health behavior was collected from self-administered questionnaires. The relationship between oral health status and smoking status was estimated using adjusted odds ratios.

RESULTS

Compared with those whom had never smoked, the odds ratios of having more than eight missing teeth and having periodontitis, among current smokers, were 1.67 and 1.74, respectively. In those who had stopped smoking for 11 years or longer, there was no increase in the odds ratio of having more than eight missing teeth and periodontitis, compared with those whom had never smoked.

CONCLUSION

Smoking has a positive association with missing teeth and periodontitis. However, smoking cessation is beneficial for oral health. The odds of having more than eight missing teeth, or of having periodontitis, in those who had never smoked was similar to that of individuals who reported that they had stopped smoking for 11 years or more.

Plasma adiponectin level and myocardial infarction: the JMS Cohort Study

Background

Adiponectin is associated with many cardiovascular risk factors. Thus, a relation between adiponectin and subsequent coronary heart disease has been hypothesized. However, the results of prospective studies have been conflicting.

Methods

In this nested case-control study, blood samples were collected from 5243 of 12 490 community residents enrolled in the Jichi Medical School Cohort Study. The samples were taken between 1992 and 1995 and stored until 2007, at which point the plasma adiponectin level was measured.

Results

During an average of 9.4 years of follow-up, 38 patients with myocardial infarction and 89 controls matched for age, sex, and community were identified. Plasma adiponectin concentration did not significantly differ between cases and controls (geometric mean 7.6 [interquartile range, 5.0–12.2] versus 7.4 [5.4–11.0] mg/L, respectively, P = 0.57). The odds of myocardial infarction in the lowest tertile of adiponectin concentration was not significantly different from that in the highest tertile, after adjustment for age and sex (OR 1.33; 95% CI, 0.50–3.55) or after further adjustment for other cardiovascular risk factors (OR 1.68; 95% CI, 0.45–6.25). Similarly, there was no significant difference in odds of myocardial infarction between the lowest and highest quartiles of adiponectin concentration.

Conclusion

The results do not support an association between hypoadiponectinemia and myocardial infarction.

Dental caries in 3-year-old children and smoking status of parents

An association has been suggested between environmental tobacco smoke and oral disease. The present study examined the relationship between early childhood caries (ECC) and parental smoking, particularly paternal smoking, using records of 711 36-month-old children. The smoking status of parents as an independent variable was entered in the multivariable logistic regression model for caries experience as the dependent variable with confounders: sex, residential location, and possible risks of ECC such as order of birth, type of main drink, frequency of daily intake of sugar-containing snacks, daily toothbrushing by parents and use of fluoridated toothpaste. About 65% of children were caries free. Children whose parents did not smoke (CN), those in whom only the father smoked (CF), and those whose mother smoked regardless of the smoking status of the father (CM) comprised 33%, 33% and 34% respectively. The adjusted mean number [95% CI] of decayed teeth and caries experience prevalence for CN, CF and CM were 1.2 [0.8, 1.6], 1.6 [1.2, 2.0] and 2.1 [1.7, 2.5], and 25.6%, 35.3% and 45.7% respectively. The relationship between caries experience and parental smoking was significant on multivariable analysis. The adjusted OR [95% CI] of CF and CM relative to CN was 1.52 [1.01, 2.30] and 2.25 [1.51, 3.37] respectively. These results indicate the association of ECC with parental smoking, although the association with paternal smoking was weaker than with maternal smoking.

Relationship between smoking status and tooth loss: findings from national databases in Japan

Background

A causal association between cigarette smoking and periodontal disease has been established. The present study examined the association between smoking and tooth loss using national databases in Japan.

Methods

Records of the Survey of Dental Diseases and the National Nutrition Survey in 1999 were linked electronically using common identification. Records of 3,999 subjects aged older than 40 years were analyzed using logistic regression models, controlling for confounding factors, such as age, frequency of tooth brushing, body mass index, alcohol consumption, and intakes of vitamin C and E.

Results

Prevalence of tooth loss in terms of having less than 19 existing teeth was 37.3% overall. Smoking rates differed in males (45.6%) and females (7.8%). The prevalence of tooth loss in nonsmokers, former, and current smokers was 28.5%, 38.6%, and 36.9% in males, and 38.6%, 34.3% and 38.9% in females, respectively. Adjusted means of existing teeth controlling for confounders by smoking status were 21.5, 19.7 and 18.2 in males and 19.0, 19.2 and 16.4 in females, respectively. The association of tooth loss was non-significant in former smokers but significant in current smokers: adjusted odds ratios (95% confidence intervals) relative to nonsmokers in males and females were 1.29 (0.92-1.80) and 0.86 (0.46, 1.60) for former smokers and 2.22 (1.61-3.06) and 2.14 (1.45-3.15) for current smokers, respectively. A dose-response relationship between lifetime exposure and tooth loss was seen (P for trend <0.0001).

Conclusion

The findings of this cross-sectional study of a nationwide population of Japanese indicated an association between smoking and tooth loss.

Mortality attributable to cigarette smoking in a cohort study in Japan

We conducted this study to estimate the association and population attributable risk (PAR) of smoking with all-cause and cause-specific mortality based on a general prospective cohort study in Japan. A total of 8,129 subjects (3,996 males and 4,133 females) aged 40 or over were analyzed. The follow-up period was from 1986 to 2003. Smoking habit was classified into three categories of never smoker, former smoker, and current smoker. The Cox proportional hazard model was used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI). We also estimated the PAR of smoking, and calculated the 95% CI of PAR based on the bootstrap procedure. A total of 112,151 person-years were counted for 8,129 subjects over an average of 13.7 years of follow-up. The results showed that smoking increased the risk of dying from all cancers, cardiovascular, and respiratory diseases in both sexes. For all causes of death, smokers had a HR of 1.30 (95% CI: 1.09, 1.54), PAR of 13.1% (95% CI: 7.6, 22.3) in males, and HR of 1.81 (95% CI: 1.43, 2.29), and PAR of 6.1% (95% CI: 3.1, 9.3) in females compared to never smokers. These results confirm an increased risk of mortality from all causes, as well as from all cancers, cardiovascular disease, and respiratory disease in relation to smoking habit. Smoking is responsible for a considerable proportion of deaths due to all causes as well as cause-specific deaths. Population-based antismoking programs should be implemented to reduce such avoidable deaths.

Association of Smoking in Household and Dental Caries in Japan

OBJECTIVES

The study investigated the relationship between smoking in the household and dental caries in Japanese children using nationally representative cross-sectional data.

METHODS

This study included 925 children aged 1-14 years. A child was considered to have decayed and/or filled teeth if a dentist diagnosed these conditions in deciduous or permanent teeth. Smoking in the household was defined as positive if someone in the household reported smoking cigarettes.

RESULTS

No statistically significant relationship was observed between household smoking and caries experience. However, smoking in the household was independently associated with an increased prevalence of decayed teeth. The adjusted mean of filled teeth among children exposed to household smoking was higher than that among non-exposed children.

CONCLUSIONS

The results of the study failed to substantiate a positive association between passive smoking and caries experience in Japanese children.