Influence of smoking combined with another risk factor on the risk of mortality from coronary heart disease and stroke: pooled analysis of 10 Japanese cohort studies

Spatiotemporal distribution characteristics and influencing factors of the rate of cardiovascular hospitalization in Ganzhou city of China

Aims

The objective of this study was to analyze hospitalization rates for cardiovascular diseases (CVD) in Ganzhou City, Jiangxi Province of China from 2015 to 2020 and to uncover the spatiotemporal distribution characteristics and influencing factors, and thus to provide reference for the prevention and control of CVD and public health resources planning.

Methods

The hospitalization data for CVDs from 2016 to 2020 was obtained from the First Affiliated Hospital of Gannan Medical University, and ArcGIS 10.8, SaTScan 9.5, and Matlab 20.0 were used to analyze the spatial autocorrelation, spatiotemporal scan statistics, and potential affecting factors of the hospitalization rates.

Results

The hospitalization rate for CVDs in Ganzhou City showed a slightly increasing trend from 2016 to 2020, with higher rates in winter and summer than that in spring and autumn, and the individuals aged 61 and above constitute a higher proportion compared to other age groups. Additionally, there was a positive correlation between hospitalization rates for CVDs and the counties and districts in Ganzhou City, with high-high aggregation areas mainly distributed in Nankang District, the western urban area of Ganzhou City. The spatial scan analysis identified three different types of significant aggregation areas: high-risk, low-risk, and middle-risk areas. The high-risk area was mainly centered around Zhanggong District or Shangyu County in the central and western regions, with a disease hospitalization rate 2-3 times higher than the rest areas. The study also found that environmental meteorological factors such as the annual average concentration of NO2, O3, average annual temperature, and annual maximum temperature diurnal range had a significant positive effect on hospitalization rates for CVDs in Ganzhou City, with O3 concentration and average annual temperature having significant positive indirect spatial spillover effects.

Conclusion

Winter and summer are the seasons with high hospitalization rate of cardiovascular diseases. County residents aged 61 and above are the higher-risk population that needs to pay more attention on for prevention and control of CVD in Ganzhou City, which exhibits significant spatiotemporal clustering. The urban areas of Zhanggong and Nankang in Ganzhou City are the key areas for prevention and control of CVD. The hospitalization rate of CVD in Ganzhou City is influenced by the aforementioned four environmental meteorological factors, with the annual maximum temperature diurnal range showing the most significant positive direct effect.

Obesity and hypertension from a public health perspective in a small remote island of Okinawa, Japan

This study investigated the relationship between obesity and hypertension from a public health perspective in a small remote island of Okinawa where obesity is prevalent. A cross-sectional study was conducted in 456 residents aged ≥18 years in Yonaguni island who underwent an annual health check-up and the Yonaguni dietary survey in 2022. Each participant responded to our original questionnaire and provided further dietary survey data via the Yonaguni municipal government. The odds ratio for hypertension was calculated in the obese group, using a logistic regression model with the non-obese group serving as the reference. Hypertension was defined as a systolic blood pressure ≥140 mmHg, a diastolic blood pressure ≥90 mmHg measured on an automated sphygmomanometer, and/or taking anti-hypertensive agents, while obesity was defined as a body mass index ≥25 kg/m2. The proportion of hypertension associated with obesity among all hypertensive subjects was calculated. The prevalence of obesity and hypertension was 54.3% and 49.0% in the 208 male subjects and 32.3% and 43.6% in the 248 female subjects, respectively. The odds ratio for hypertension in the obese group was 3.73 (95% confidence interval, 1.93-7.20) for men and 4.13 (2.06-8.29) for women after adjusting for age, alcohol drinking habit, behavior for lowering salt intake, and smoking habit. Hypertension in 49.5% (95% confidence interval, 29.4%-63.9%) of males and 37.9% (22.6%-50.2%) of females was associated with obesity in this island. Some areas of Japan could be urgently required to address obesity for preventing cardiovascular disease. A community-based, cross-sectional study in 456 residents aged ≥18 years in Yonaguni island, Okinawa prefecture, Japan.

Prevalence and Risk Factors of Hypertension in Hargeisa, Somaliland: A Hospital-Based Cross-Sectional Study

Hypertension is the leading risk factor for cardiovascular diseases and represents a major public health challenge worldwide. There is a paucity of information regarding the hypertension status of adults in Somaliland. We aimed to assess the magnitude of, and factors associated with, hypertension among adult patients seeking care at Hargeisa group hospital in Hargeisa city, Somaliland. We conducted a health facility-based cross-sectional study enrolling adult outpatients. We used the World Health Organization (WHO) STEPwise surveillance approach to obtain patient information. A total of 319 participants (54.2% males; mean age 40.4 ± 14.0 years) had complete data records. The prevalence of hypertension was 22.6% (95% confidence interval; 18.2-27.6%). The prevalence of hypertension increased with age and was higher in males (24.9%) than in females (19.9%). Age, cholesterolaemia and obesity were significantly associated with hypertension. Separate analyses for females and males revealed that obesity was significantly associated with hypertension in females but not in males. On the contrary, cholesterolaemia was significantly associated with hypertension in males but not in females. We found a high prevalence of hypertension and multiple risk factors for non-communicable diseases (NCDs) in outpatients seeking care in Hargeisa. Our findings emphasise the need for enhanced focus on the prevention and management of NCDs in Somaliland.

Knowledge, Prevention Practice and Associated Factors of Stroke Among Hypertensive and Diabetic Patients - A Systematic Review

INTRODUCTION

Because of the inadequate level of public awareness of the disease, the incidence of stroke has been sharply rising. Eventually, due to the prehospital delay, many stroke cases could not be eligible for thrombolysis thereby poor rehabilitative outcome has been tremendously increased. Thus, this study aimed to review the level of knowledge, prevention practice, and associated factors of stroke among hypertensive and diabetic patients.

METHODS

A systematic review of primarily published articles (2010-2020) related to knowledge and prevention practices of stroke was performed by searching online electronic databases like PubMed, Google Scholar, Refseek, Science direct, ResearchGate, and manual Google search by using the keywords and MeSH terms. Studies conducted on knowledge and prevention practices amongst hypertensive and/or diabetic patients were included.

RESULTS

Out of 531 searched studies, 42 articles were identified to be reviewed. The reported overall knowledge of stroke was ranging from 4.4% to 79%. Knowledge to the signs/symptoms of stroke was 23.6% to 87%. However, 15% to 77% of subjects were also reported that they did not know any sign of stroke. The range of risk factor knowledge was 10.5% to 86.6%. The reported level of stroke prevention practice was 2.4% to 72% but physical activity and weight reduction practice were relatively low. Inadequate level of knowledge and prevention practice of stroke was related to elderly, female gender, uneducated, unmarried, rural residents, economically low, comorbidity and unemployed individuals.

CONCLUSION

The current finding revealed that the level of knowledge and prevention practice of stroke was inadequate. Hence, the finding highlights health educational programs should be planned as an important avenue to enhance stroke awareness among the high-risk populations.

Smoking is associated with impaired verbal learning and memory performance in women more than men

Vascular contributions to cognitive impairment and dementia (VCID) include structural and functional blood vessel injuries linked to poor neurocognitive outcomes. Smoking might indirectly increase the likelihood of cognitive impairment by exacerbating vascular disease risks. Sex disparities in VCID have been reported, however, few studies have assessed the sex-specific relationships between smoking and memory performance and with contradictory results. We investigated the associations between sex, smoking, and cardiovascular disease with verbal learning and memory function. Using MindCrowd, an observational web-based cohort of ~ 70,000 people aged 18-85, we investigated whether sex modifies the relationship between smoking and cardiovascular disease with verbal memory performance. We found significant interactions in that smoking is associated with verbal learning performance more in women and cardiovascular disease more in men across a wide age range. These results suggest that smoking and cardiovascular disease may impact verbal learning and memory throughout adulthood differently for men and women.

Increased risk of ischemic heart disease in patients with bipolar disorder: A population-based study

OBJECTIVE

This study investigated the national prevalence and incidence of ischemic heart disease and associated factors among Taiwanese patients with bipolar disorder.

METHODS

We used a random sample of 766,427 subjects who were ≥18 years old from the National Health Research Institute database in 2005. Subjects with at least one primary diagnosis of bipolar disorder or ischemic heart disease were identified. We compared the prevalence and incidence of ischemic heart disease in bipolar patients and the general population in 2005 and the same cohort from 2006 to 2010. These associated factors with respect to ischemic heart disease among patients with bipolar disorder were also analyzed.

RESULTS

The prevalence of ischemic heart disease in patients with bipolar disorder was 1.69 times higher than in the general population (7.85% vs 4.67%; odds ratio 1.69; 95% confidence interval, 1.41-2.03) in 2005. The average annual incidence of ischemic heart disease in patients with bipolar disorder was also 1.60 times higher than in the general population (2.02% vs 1.24; risk ratio 1.60; 95% confidence interval, 1.36-1.90) from 2006 to 2010. The higher prevalence of ischemic heart disease among bipolar patients was associated with increased age, diabetes, hypertension, and antidepressant use.

CONCLUSIONS

Patients with bipolar disorder had a significantly higher prevalence and incidence of ischemic heart disease than the general population in both sexes, especially at younger ages. Among patients with bipolar disorder, older age, and hyperlipidemia were risk factors of ischemic heart disease.

Impact of secondhand smoke exposure in former smokers on their subsequent risk of coronary heart disease: evidence from the population-based cohort of the Tehran Lipid and Glucose Study

OBJECTIVES

Cigarette smoking is an established, strong, and modifiable risk factor for coronary heart disease (CHD). However, little research has investigated CHD risk in former smokers who continue to be exposed to others’ cigarette smoke (former & secondhand smokers).

METHODS

In the Tehran Lipid and Glucose Study, a prospective population-based cohort (n=20,069) was followed up for a median period of 14.6 years. A subset of 8,050 participants of 30 years of age and older was analyzed, with first CHD events as the study outcome. Participants were categorized as never, former, current, secondhand, and former & secondhand smokers. Data on smoking intensity (cigarette/d) were also collected. A Cox proportional hazards regression model was applied to estimate the risk of CHD, taking into account the main potential confounders.

RESULTS

The mean age of participants was 46.10 ±11.38 years, and they experienced 1,118 first CHD events (with most CHD cases in former smokers) during the follow-up period. The risk of CHD was highest in current smokers, followed in order by former & secondhand, former, and secondhand smokers (hazard ratio [HR], 1.99; 95% confidence interval [CI], 1.65 to 2.39; HR, 1.55; 95% CI, 1.15 to 2.08; HR, 1.39; 95% CI, 1.12 to 1.72; HR, 1.27; 95% CI, 1.07 to 1.51, respectively), compared to never smokers. The risk of CHD increased with smoking intensity, which has been proposed as a preferable measure of smoking, indicating a dose-response pattern.

CONCLUSIONS

The elevated risk of CHD in former & secondhand smokers was a noteworthy finding, with possible implications for health policy; however, further research is needed.

Key Points of the 2019 Japanese Society of Hypertension Guidelines for the Management of Hypertension

The new 2019 Japanese Society of Hypertension (JSH) guidelines for the management of hypertension are now available; these update the previous guidelines published in 2014. The primary objective of the guideline is to provide all healthcare professionals with a standard management strategy and appropriate antihypertensive treatments to prevent hypertension-related target organ damage and cardiovascular events. The major changes in the new guideline relate to the definition of normal blood pressure (BP) and target BP. The terms 'normal BP' and 'high normal BP' used in the JSH 2014 guidelines are replaced with terms 'high normal BP' and 'elevated BP,' respectively. There was no change to the office BP diagnostic threshold for hypertension (140/90 mmHg). Recommended target office and home BP values for patients with hypertension aged <75 years and/or high-risk patients are <130/80 mmHg and <125/75 mmHg, respectively. Corresponding targets for elderly patients with hypertension (age≥75 years) are 140/90 and 135/85 mmHg, respectively. The goal is that these changes will contribute to reducing cardiovascular events, especially stroke and heart failure, in Japan. The dissemination of the JSH 2019 guidelines and implementation of a home BP-based approach by all general practitioners in Japan might be facilitated by digital hypertension management using health information technology.

Survival to Age 90 in Men: The Tromsø Study 1974-2018

The 738 oldest men who participated in the first survey of the population-based Tromsø Study (Tromsø 1) in Norway in 1974 have now had the chance to reach the age of 90 years. The men were also invited to subsequent surveys (Tromsø 2–7, 1979–2016) and have been followed up for all-cause deaths. This study sought to investigate what could be learned from how these men have fared. The men were born in 1925–1928 and similar health-related data from questionnaires, physical examination, and blood samples are available for all surveys. Survival curves over various variable strata were applied to evaluate the impact of individual risk factors and combinations of risk factors on all-cause deaths. At the end of 2018, 118 (16.0%) of the men had reached 90 years of age. Smoking in 1974 was the strongest single risk factor associated with survival, with observed percentages of men reaching 90 years being 26.3, 25.7, and 10.8 for never, former, and current smokers, respectively. Significant effects on survival were also found for physical inactivity, low income, being unmarried, high blood pressure, and high cholesterol. For men with 0–4 of these risk factors, the percentages reaching 90 years were 33.3, 24.9, 12.4, 14.4, and 1.5, respectively. Quitting smoking and increasing physical activity before 55 years of age improved survival significantly. Men should refrain from smoking and increase their physical activity, especially those with low income, those who are unmarried, and those with high blood pressure and high cholesterol.

Cardiovascular risk and blood pressure lowering treatment among elderly individuals: Evidence for Cardiovascular Prevention from Observational Cohorts in Japan

OBJECTIVE

There is little evidence to support an increased risk of blood pressure (BP) elevation among elderly individuals receiving antihypertensive drug treatment.

METHODS

To clarify the impact on BP level and residual cardiovascular risk in treated elderly individuals, we analysed individual participant data of 26 133 residents aged 60-89 years from seven Japanese general populations and cross-classified participants by age category, 60-74 (young-old) versus 75-89 years (old-old), and by usage of antihypertensive medication at baseline survey (1980-1995).

RESULTS

During a median follow-up period of 12.7 years, 2451 cardiovascular deaths were observed. Multivariable-adjusted hazard ratios of cardiovascular mortality in treated participants compared with untreated participants were 1.30 [95% confidence intervals, 1.16-1.46) and 1.35 (95% confidence interval, 1.16-1.56) in young-old and old-old participants, respectively. Irrespective of antihypertensive medication, the risk increase of total cardiovascular and stroke mortality with elevation of BP was significant among young-old (P ≤ 0.0013), but not significant among old-old participants (P ≥ 0.061).

CONCLUSION

Although impact on BP was more evident among young-old than old-old individuals, clinicians who prescribe antihypertensive medication to elderly patients should consider that such patients require further monitoring.

Association Between Body Mass Index and All-Cause Death in Japanese Population: Pooled Individual Participant Data Analysis of 13 Cohort Studies

BACKGROUND

We sought to investigate the optimal values of BMI for the lowest risk of all-cause death and whether the optimal BMI differs according to smoking status in large-scale pooled analysis of 13 Japanese cohorts.

METHODS

Data from 179,987 participants of 13 well-qualified cohort studies conducted throughout Japan were used for our analysis. A cohort-stratified Cox proportional hazard model was used. P values for interactions were calculated based on the cross product of BMI and age, sex, or smoking status.

RESULTS

In the entire study population, all-cause mortality risk was lowest when the BMI was 22.0-24.9 kg/m². This was also the case for selected healthy participants (never smoked, baseline total cholesterol level ≥4.1 mmol/L; the first 5 years of follow-up data were excluded). No effect modification of age, sex, or smoking status was observed. Regardless of their BMI, never smokers always had a lower all-cause mortality risk than did current smokers even with an ideal BMI in terms of mortality risk.

CONCLUSION

A BMI of 22-24.9 kg/m² correlated with the lowest risk of mortality, regardless of whether all participants or selected healthy participants were analyzed. The fact that smoking was more strongly associated with mortality than obesity emphasizes the urgency for effective anti-smoking programs.

Pooled Analysis of the Associations between Body Mass Index, Total Cholesterol, and Liver Cancer-related Mortality in Japan

Objective: We employed a large-scale pooled analysis to investigate the association of liver cancer-related mortality with being overweight/obese and total cholesterol (TC) levels, since limited and inconsistent data on these associations exist in Japan. Methods: A total of 59,332 participants (23,853 men and 35,479 women) from 12 cohorts without a history of cancer who were followed for a median of 14.3 years were analyzed. A sex-specific stratified Cox proportional hazards model adjusted for age and other potential confounders was used to calculate hazard ratios (HRs) and 95% confidence intervals (CI) for liver cancer-related mortality. Results: A total of 447 participants (266 men and 181 women) died of liver cancer within the follow-up period. Individuals classified as having a high BMI (≥25.0 kg/m2) and low TC levels (<160 mg/dL) had a significantly increased risk for liver cancer-related mortality (HR 7.05, 95% CI 4.41–11.26 in men; HR 8.07, 95% CI 4.76–13.67 in women) when compared with those in the intermediate BMI (18.5–24.9 kg/m2) and TC (160–219 mg/dL) categories. These associations remained after limiting the follow-up duration to >5 years. Conclusion: Being overweight/obese, combined with low TC levels, was strongly associated with liver cancer-related mortality in the EPOCH-JAPAN.

The Influence of the Japanese Nationwide Cardiovascular Prevention System Health Guidance on Smoking Cessation Among Smokers: A Propensity Score Matching Analysis

Aim: We investigated whether 2 types of personalized health guidance (repeated and single counseling) in the Japanese nationwide cardiovascular prevention system promoted smoking cessation among smokers.

Methods: The study included 47,745 Japanese smokers aged 40 to 74 years classified into 2 personalized health guidance schemes. After a 1-year follow-up, we compared the rates of smoking cessation between individuals who had received counseling (“supported”) and those who had not received counseling (“unsupported”). Using propensity score matching analysis, we estimated the average treatment effect (ATE) of each approach on smoking cessation after balancing out the characteristics between the supported and unsupported groups. The propensity score regression model included age, medical insurance type, weight gain since the age of 20 years, exercise, eating habits, alcohol intake, quality of sleep, readiness to modify lifestyle, willingness to receive support, and body mass index.

Results: In the repeated counseling scheme, the age-adjusted rates of smoking cessation in the supported and unsupported groups were 8.8% and 6.3% for males, and 9.8% and 9.1% for females respectively. In the single counseling scheme, the corresponding rates were 8.4% and 7.3% for supported and unsupported males, and 11.0% and 11.7% for supported and unsupported females respectively. The ATE of repeated counseling was + 2.64% (95% confidence interval: + 1.51% to + 3.77%) for males and + 3.11% (−1.85% to +8.07%) for females. The ATE of single counseling was +0.61% (−1.17% to +2.38%) for males and −1.06% (−5.96% to +3.85%) for females.

Conclusions: In the Japanese cardiovascular prevention system, repeated counseling may promote smoking cessation among male smokers.

Smoking, leisure-time exercise and frequency of self-reported common cold among the general population in northeastern China: a cross-sectional study

Background

Physical activity (PA) and smoking have been reported to be associated with the duration and severity of common cold symptoms. However, few studies have addressed the associations between the frequency of leisure-time exercise, cigarette smoking status and the frequency of the common cold in a cold area. This study was designed to investigate these issues in northeastern China.

Methods

This cross-sectional study included individuals who participated in a regular health examination conducted in Jilin Province, China. Information on episodes of the common cold, the frequency of leisure-time exercise and cigarette smoking status in the past year were collected by self-administered health questionnaires. Ordinal logistic regression models were used to analyse the associations between the frequency of leisure-time exercise, cigarette smoking status and the retrospective frequency of common cold.

Results

A total of 1413 employees participated in the study, with an average age of 38.92 ± 9.04 years and 44.4% of them were male. Of all participants, 80.8% reported having experienced the common cold in the past year. After adjustment, the risk of suffering from the common cold more than once (odds ratios (ORs), 1.59; 95% confidence interval (CI), 1.27–1.99) in passive smokers was 1.59 times as high as that in non-smokers. Nevertheless, the results of the adjusted analysis showed no statistically significant relation between current smoking and the frequency of the common cold. A high frequency of leisure-time exercise (≥3 days/week) was associated with a 26% reduced risk of having at least one episode of the common cold (OR, 0.74; 95% CI, 0.55–0.98) compared with a low frequency group (< 4 days/month). For current and passive smokers, the protective effect of a high frequency of leisure-time exercise appears not to be obvious (current smokers: OR, 0.68; 95% CI, 0.33–1.43; passive smokers: OR, 1.15; 95% CI, 0.69–1.93).

Conclusion

Passive smoking was associated with a higher risk of having self-reported common cold at least once, while a high frequency of leisure-time exercise was related to a lower risk of reporting more than one episode of the disease in Chinese.

The relationship of cigarette smoking in Japan to lung cancer, COPD, ischemic heart disease and stroke: A systematic review

Background:  To present up-to-date meta-analyses of evidence from Japan relating smoking to major smoking-related diseases.  Methods:  We restricted attention to lung cancer, chronic obstructive pulmonary disease (COPD), ischemic heart disease (IHD) and stroke, considering relative risks (RRs) for current and ex-smokers relative to never smokers.  Evidence by amount smoked and time quit was also considered.  For IHD and stroke only, studies had to provide age-adjusted RRs, with age-specific results considered.  For each disease we extended earlier published databases to include more recent studies.  Meta-analyses were conducted, with random-effects RRs and tests of heterogeneity presented.  Results:  Of 40 studies, 26 reported results for lung cancer and 7 to 9 for each other disease.  For current smoking, RRs (95%CIs) were lung cancer 3.59 (3.25-3.96), COPD 3.57 (2.72-4.70), IHD 2.21 (1.96-2.50) and stroke 1.40 (1.25-1.57).  Ex-smoking RRs were lower.  Data for lung cancer and IHD showed a clear tendency for RRs to rise with increasing amount smoked and decrease with increasing time quit.  Dose-response data were unavailable for COPD and unclear for stroke, where the association was weaker.  Conclusions:  Compared to studies in other Asian and Western countries, current smoking RRs were quite similar for IHD and stroke.  The comparison is not clear for COPD, where the Japanese data, mainly from cross-sectional studies, is limited.  For lung cancer, the RRs are similar to those in other Asian countries, but substantially lower than in Western countries.  Explanations for this are unclear, but less accurate reporting of smoking by Japanese may contribute to the difference.

Nicotine cut-off value in human hair as a tool to distinguish active from passive smokers: A cross-sectional study in Japanese men

BACKGROUND

Nicotine concentration in hair is a useful marker of tobacco exposure. Detection of nicotine in the hair of non-smokers indicates passive smoking. Accurate measurement of nicotine among active and passive smokers can help in smoking cessation programs or programs designed to prevent secondhand smoke exposure.

OBJECTIVE

To establish, using high-performance liquid chromatography-ultraviolet detection (HPLC/UV), a hair nicotine cut-off value to distinguish active from passive smokers.

METHODS

Hair samples were collected from randomly chosen Japanese men (n= 192) between 2009 and 2011. Nicotine and cotinine levels in hair were measured using HPLC/UV with column-switching. T-tests and chi-square tests were performed to compare active and passive smokers, while receiver operating characteristic curves were used to evaluate the effectiveness of the cut-off value.

RESULTS

There were 69 active smokers and 123 passive smokers. The nicotine and cotinine concentrations in hair were significantly higher in active than in passive smokers (p< 0.01). The area under the curve for nicotine was 0.92. A hair nicotine cut-off value of 5.68 ng/mg, with a sensitivity of 94.2% and specificity of 87.0%, was identified as the optimal cut-off value for separating active from passive smokers.

CONCLUSION

Nicotine and cotinine concentrations in hair clearly distinguished active from passive smokers.

Synergistic and Non-synergistic Associations for Cigarette Smoking and Non-tobacco Risk Factors for Cardiovascular Disease Incidence in the Atherosclerosis Risk In Communities (ARIC) Study

INTRODUCTION

Cigarette smoking, various metabolic and lipid-related factors and hypertension are well-recognized cardiovascular disease (CVD) risk factors. Since smoking affects many of these factors, use of a single imprecise smoking metric, for example, ever or never smoked, may allow residual confounding and explain inconsistencies in current assessments of interactions.

METHODS

Using a comprehensive model in pack-years and cigarettes/day for the complex smoking-related relative risk (RR) of CVD to reduce residual confounding, we evaluated interactions with non-tobacco risk factors, including additive (non-synergistic) and multiplicative (synergistic) forms. Data were from the prospective Atherosclerosis Risk in Communities (ARIC) Study from four areas of the United States recruited in 1987-1989 with follow-up through 2008. Analyses included 14 127 participants, 207 693 person-years and 2857 CVD events.

RESULTS

Analyses revealed distinct interactions with smoking: including statistical consistency with additive (body mass index [BMI], waist to hip ratio [WHR], diabetes mellitus [DM], glucose, insulin, high density lipoproteins [HDL] and HDL(2)); and multiplicative (hypertension, total cholesterol [TC], low density lipoproteins [LDLs], apolipoprotein B [apoB], TC to HDL ratio and HDL(3)) associations, as well as indeterminate (apolipoprotein A-I [apoA-I] and triglycerides) associations.

CONCLUSIONS

The forms of the interactions were revealing but require confirmation. Improved understanding of joint associations may help clarify the public health burden of smoking for CVD, links between etiologic factors and biological mechanisms, and the consequences of joint exposures, whereby synergistic associations highlight joint effects and non-synergistic associations suggest distinct contributions.

IMPLICATIONS

Joint associations for cigarette smoking and non-tobacco risk factors were distinct, revealing synergistic/multiplicative (hypertension, TC, LDL, apoB, TC/HDL, HDL(3)), non-synergistic/additive (BMI, WHR, DM, glucose, insulin, HDL, HDL(2)) and indeterminate (apoA-I and TRIG) associations. If confirmed, these results may help better define the public health burden of smoking on CVD risk and identify links between etiologic factors and biologic mechanisms, where synergistic associations highlight joint impacts and non-synergistic associations suggest distinct contributions from each factor.

Age-specific impact of diabetes mellitus on the risk of cardiovascular mortality: An overview from the evidence for Cardiovascular Prevention from Observational Cohorts in the Japan Research Group (EPOCH-JAPAN)

Background

Diabetes mellitus is a strong risk factor for cardiovascular disease. However, the age-specific association of diabetes with cardiovascular risk, especially in the elderly, remains unclear in non-Western populations.

Methods

A pooled analysis was conducted using 8 cohort studies (mean follow-up period, 10.3 years) in Japan, combining the data from 38,854 individual participants without history of cardiovascular disease. In all, 1867 of the participants had diabetes, defined based on the 1998 World Health Organization criteria. The association between diabetes and the risk of death from cardiovascular disease, coronary heart disease (CHD), and stroke was estimated using a stratified Cox model, accounting for variability of baseline hazard functions among cohorts.

Results

During the follow-up, 1376 subjects died of cardiovascular disease (including 268 of coronary heart disease and 621 of stroke). Diabetes was associated with an increased risk of cardiovascular death after multivariable adjustment (hazard ratio [HR] 1.62; 95% confidence interval [CI], 1.35–1.94). Similarly, diabetes was a risk factor for CHD (HR 2.13; 95% CI, 1.47–3.09) and stroke (HR 1.40; 95% CI, 1.05–1.85). In the age-stratified analysis of the risk of cardiovascular death, the relative effects of diabetes were consistent across age groups (p for heterogeneity = 0.18), whereas the excess absolute risks of diabetes were greater in participants in their 70s and 80s than in younger subjects.

Conclusions

The management of diabetes is important to reduce the risk of death from cardiovascular disease, not only in midlife but also in late life, in the Japanese population.

•

We conducted meta-analysis of individual data from 8 Japanese cohorts (n = 38,854).

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Diabetes raised cardiovascular mortality in Japan.

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Impact of diabetes on cardiovascular death was similar across 10-year age groups.

Impact of drinking and smoking habits on cerebrovascular disease risk among male employees

OBJECTIVE

We aimed to analyze the impact of drinking and smoking behavior on the risk of developing cerebrovascular diseases among male employees aged 20-46 years. Twenty years of follow-up data of male employees enrolled in the DENSO Health Insurance Program were used for analyses.

SUBJECTS AND METHODS

Of 29,048 male employees aged 20-46 years who were enrolled in the insurance program in 1994, 25,084 (86.4%) employees underwent annual health check-ups until 2003 without missing an appointment. Of these 25,084 employees, the data of 11,784 (40.6%) employees who self-reported drinking and smoking habits were used for analyses. The hazard ratio and 95% confidence intervals (CIs) for developing cerebrovascular disease in 2004-2013 were calculated in four risk groups categorized as per drinking and smoking behavior in the young group who were in their 20s and the middle-aged group who were in their 30s-40s in 1994. Based on their drinking behavior, participants were categorized into two groups: "not drinking or drinking sometimes" and "drinking every day." Based on their smoking behavior, participants were also categorized into two groups: "not smoking for 10 years" and "smoking for 10 years."

RESULTS

A Cox's proportional hazard model revealed that after controlling for body mass index, systolic blood pressure, triglycerides, total cholesterol, fasting plasma glucose, and age, the hazard ratios for "smoking and drinking every day" were 3.82 (95% CI: 1.40-10.41) in the young group and 2.31 (95% CI: 1.27-4.17) in the middle-aged group.

DISCUSSION

Male employees who had been drinking and smoking for 10 years had a higher risk of developing cerebrovascular diseases. To prevent cerebrovascular diseases among male employees, it may be effective to offer behavior change interventions for both drinking and smoking habits, regardless of the age group.

TLR7 rs2897827 Polymorphism Affects TLR7 Gene mRNA Expression and Serum Apolipoprotein A1 Level of Ischemic Stroke Patients in a Chinese Han Population

Stroke is a multi-factorial disorder that has become the leading cause of death and disability worldwide. Previous studies reported that TLR7 mRNA expression is associated with poor outcome of ischemic stroke (IS). This study aimed to assess whether TLR7 mRNA expression affects IS occurrence, as well as the association of TLR7 rs2897827 with susceptibility to IS and TLR7 mRNA expression and serum apolipoprotein and lipid levels in a Chinese Han population. A total of 816 stroke patients and 816 healthy controls were included in this study. mRNA expression was determined by quantitative real-time PCR. The Sequenom MassARRAY iPLEX platform was used to genotype the TLR7 rs2897827 polymorphism. TLR7 mRNA expression of the IS cases was statistically significantly higher than that of the controls in the male or female group (male, P = 0.014; female, P = 0.025). In the male IS cases, TLR7 mRNA expression of the T allele carriers was statistically significantly higher than that of the C allele carriers (P = 0.018). However, a significant difference was not observed in the female cases (P = 0.545). In either the male or female group, the distribution of genotype or allele had no statistical significance (P > 0.050). The ApoA1 level of the T carriers was statistically significantly higher than the C carriers in males (t = -2.383, P = 0.020); however, the ApoB and lipid levels were not associated with rs2897827 (P > 0.050). In female patients, no significant difference was observed between different genotypic/allelic carriers in serum apolipoprotein and lipid levels (all P > 0.050). The expression of the TLR7 gene may affect IS occurrence. TLR7 gene rs2897827 may influence TLR7 mRNA expression and the plasma ApoA1 level in male IS patients.

Serum Uric Acid and Mortality Form Cardiovascular Disease: EPOCH-JAPAN Study

AIM

To investigate the relationship between serum uric acid levels and cardiovascular disease in Asians.

METHODS

We examined the above relationship using the data of Evidence for Cardiovascular Prevention from Observational Cohorts in Japan (EPOCH-JAPAN Study). The data of 36,313 subjects (15,628 men and 20,685 women aged 35-89 years without histories of stroke, coronary heart disease, or cancer at baseline) were used for the analyses. Sex-specific hazard ratios (HRs) of mortality from cardiovascular disease were estimated according to the quintiles of serum uric acid using Cox hazard models stratified by cohorts.

RESULTS

During 441,771 person-years of follow-up, we documented 1,288 cardiovascular deaths. A J- or U-shaped relationship between serum uric acid level and cardiovascular disease mortality was observed. Compared with the lowest quintile of serum uric acid levels, the highest quintile was associated with an increased cardiovascular disease mortality in men [HR: 1.28; 95% confidence interval (CI): 1.01-1.63] and women (HR: 1.51; 95% CI: 1.14-1.99). However, there was no significant association with mortality from stroke, coronary heart disease or heart failure in both men and women.

CONCLUSION

This large pooled analysis in Japan suggested a J- or U-shaped relationship between serum uric acid levels and cardiovascular mortality. The highest quintile of serum uric acid levels was associated with increased cardiovascular disease mortality in both Japanese men and women.

Serum γ-glutamyltransferase and Mortality due to Cardiovascular Disease in Japanese Men and Women

AIM

Whether the association between serum γ-glutamyltransferase (γ-GTP) levels and total cardiovascular disease (CVD) mortality is independent of alcohol drinking in East Asian populations is not well known. We conducted a pooled analysis of Japanese men and women that enabled an analysis restricted to never-drinkers.

METHODS

A total of 15,987 men and 25,053 women aged 40-79 years, pooled from seven cohort studies throughout Japan, were followed-up to examine sex-specific relationship between serum γ-GTP levels and total CVD mortality. Cox regression model was used that was adjusted for age, smoking status, body mass index, and systolic blood pressure and serum triglyceride, total cholesterol, aspartate aminotransferase, and alanine aminotransferase levels.

RESULTS

During an average follow-up of 8.7 years, we documented 361 and 340 deaths from total CVD, 146 and 168 from stroke, and 101 and 53 from coronary heart disease (CHD) for men and women, respectively. Among the never-drinkers, hazard ratios (HRs) for mortality for one standard deviation of log-γ-GTP for men were 1.89 (1.00-3.58) for stroke, 1.04 (0.57-1.90) for CHD, and 1.43 (1.04-1.96) for total CVD. For women, HRs were 1.28 (1.06-1.54), 1.81 (1.34-2.44), and 1.30 (1.14-1.49), respectively.

CONCLUSION

γ-GTP may be a risk factor for total CVD mortality independent of alcohol drinking status in Japanese men and women.

Calibration between the Estimated Probability of the Risk Assessment Chart of Japan Atherosclerosis Society and Actual Mortality Using External Population: Evidence for Cardiovascular Prevention from Observational Cohorts in Japan (EPOCH-JAPAN)

AIM

In Japan Atherosclerosis Society guidelines for the prevention of atherosclerotic cardiovascular diseases 2012 (JAS2012), NIPPON DATA80 risk assessment chart (ND80RAC) was adopted to estimate the 10-year probability of coronary artery disease (CAD) mortality. However, there was no comparison between the estimated mortality calculated by ND80RAC and actual mortality in external populations. Accordingly, we used the large pooled database of cohorts in Japan, EPOCH-JAPAN, as an external population.

METHODS

The participants of EPOCH-JAPAN without a history of cardiovascular disease (15,091 men and 18,589 women aged 40-74 years) were analyzed based on sex. The probability of a 10-year risk of CAD/stroke mortality was estimated by ND80RAC. The participants were divided into both decile of their estimated mortality and three categories according to JAS2012. The calibration between the mean estimated mortality and the actual mortality was performed by the Hosmer and Lemeshow (H-L) test.

RESULTS

In both sexes, the estimated CAD mortality was higher than the actual mortality, particularly in higher deciles of estimated mortality, and the estimated stroke mortality was almost concordant with the actual mortality in low/moderate deciles of estimated mortality. As for the categories according to JAS2012, the estimated CAD mortality was higher than the actual mortality in both sexes; actual mortality in Category III was lower than that in Category II in women. However, it increased in the ascending order of category when we excluded the presence of diabetes from Category III.

CONCLUSIONS

The estimated CAD mortality by ND80RAC tended to be higher than the actual mortality in the population in which the baseline survey was more recently performed.

Rapid emergence of atherosclerosis in Asia: a systematic review of coronary atherosclerotic heart disease epidemiology and implications for prevention and control strategies

PURPOSE OF REVIEW

There is a global epidemic of coronary heart disease (CHD) caused by atherosclerosis. We discussed its emergence, underlying reasons, and implications for prevention and control strategies in Asia.

RECENT FINDINGS

Most countries in Asia are experiencing the challenges from CHD, with the mortality rate varying from 103 to 366 per 100 000 adult populations, reported by recently published studies. Raised population cholesterol levels played a pivotal role. Men, older adults, and those with dyslipidemia, hypertension, and diabetes were high-risk individuals. During the past decade, there was a marked rising trend of atherosclerosis-related burden particularly in Eastern Asia where an alarming increase of 117.2 and 115.3% of total deaths and disability adjusted life-years, respectively, were observed. The rise of CHD could be attributed to unhealthy lifestyles, clinical-risk factors, psychosocial factors, and public health transitions. Ageing, urbanization, and increase in prosperity may serve as underlying key drivers.

SUMMARY

The burden of CHD is substantial, whereas contributors are multifactorial. This grand challenge should be a top priority for injecting healthcare resources. The formulation of public health measures will need to adopt an integrated and life-course approach, based on the need and risks of different population subgroups in Asia.

Relationships between the smoking status and plasma fibrinogen, white blood cell count and serum C-reactive protein in Japanese workers

OBJECTIVE

Confirmation of the association between smoking status and biological inflammatory or anticoagulant markers is required in the field of occupational therapy to promote anti-smoking education. The associations between the smoking status and biological markers were clarified.

METHODS

The study was performed in 5102 working men aged 30-60 years old. The author measured the plasma fibrinogen, white blood cell count (WBC) and serum high-sensitivity C-reactive protein (CRP) as biomarkers of the smoking status.

RESULTS

After adjustment for age, the mean plasma fibrinogen level in never-smokers was significantly lower than that in current smokers. The mean WBC count was also significantly lower in the never-smokers than that in current smokers and ex-smokers who had quit within the previous 1 year. Furthermore, the mean log-transformed serum CRP value in never-smokers was significantly lower than that in current smokers smoking ≥20 cigarettes daily. Spearman's rank correlation coefficients between the plasma fibrinogen and the serum CRP and WBC were 0.561 and 0.243, respectively. The mean plasma fibrinogen, serum CRP and WBC count in the ex-smokers showed a trend toward decreasing as the duration of abstinence became longer.

CONCLUSION

Among the three biomarkers, the plasma fibrinogen was the most strongly associated with the smoking status, its value being to be the highest in current smokers smoking ≥20 cigarettes daily. The same trend was also observed for the WBC count.

[Risk factors for ischemic heart disease in males in the prime of life: An eight-year follow-up study]

OBJECTIVE

In order to prevent ischemic heart disease in working adult males, we analyzed risk factors by age groups based on data from an eight-year follow-up study of male employees enrolled in the Denso Health Insurance Program.

SUBJECTS AND METHODS

Of the 27,945 male employees aged 30 to 55 enrolled in the program in 2003, the data of 19,742 (70.6%) who underwent regular health checkups were analyzed. Information obtained from health insurance claims for hospitalization and cause of death from discontinuation data were used to analyze risk factors for ischemic heart disease by age group. Hazard ratios and 95% confidence intervals were estimated from Cox proportional-hazards models.

RESULTS

In males aged 30-39 years, a BMI of 25.0-27.5 was associated with a 2.21 higher risk of ischemic heart disease (95%CI: 1.01-4.84) than those not overweight (BMI of <25.0); LDL of 160 mg/dl or more was associated with a 3.85 higher risk (95%CI:1.62-9.14) than LDL of less than 120 mg/dl; and FPG of 160 mg/dl or more was associated with a 6.43 higher risk (95%CI: 1.02-40.63) than a FPG of less than 110 mg/dl. For males aged 40-55 years, higher LDL was a risk factor of ischemic heart disease (1.95 (95%CI: 1.28-2.98) and 1.97 (95%CI: 1.34-2.90) for LDL of more than 160 mg/dl and 140-159 mg/dl, respectively), compared to those with LDL of less than 120 mg/dl. In the same age group, compared to those unaffected, the risk of ischemic heart disease was 1.94 times higher (95%CI: 1.27-2.97) and 1.61 times higher (95%CI: 1.08-2.40) for those treated for hypertension and hyperlipidemia, respectively. Furthermore, compared to non-smokers, those smoking more than 20 cigarettes a day had 3.12 higher risk (95%CI: 1.21-8.06) and 1.81 higher risk (95%CI: 1.25-2.62) of ischemic heart disease in the 30-39 and 40-55 years age groups, respectively. Interaction effects with age group were not significant.

DISCUSSION

In males aged 30-39 years having a high BMI, LDL, FPG, and smoking more than 20 cigarettes increased the risk of ischemic heart disease. For males aged 40-55 years taking medication for hypertension and hyperlipidemia increased the risk. To prevent ischemic heart disease during the prime of life, offering support for weight control and stopping smoking is necessary in younger age groups. Moreover, implementing a long-term risk management plan to prevent the onset of hypertension, diabetes, or hyperlipidemia is also important.

Neurologic Complications of Psychomotor Stimulant Abuse

Psychomotor stimulants are drugs that act on the central nervous system (CNS) to increase alertness, elevate mood, and produce a sense of well-being. These drugs also decrease appetite and the need for sleep. Stimulants can enhance stamina and improve performance in tasks that have been impaired by fatigue or boredom. Approved therapeutic applications of stimulants include attention deficit hyperactivity disorder (ADHD), narcolepsy, and obesity. These agents also possess potent reinforcing properties that can result in excessive self-administration and abuse. Chronic use is associated with adverse effects including psychosis, seizures, and cerebrovascular accidents, though these complications usually occur in individuals with preexisting risk factors. This chapter reviews the adverse neurologic consequences of chronic psychomotor stimulant use and abuse, with a focus on two prototypical stimulants methamphetamine and cocaine.

Risk of hypercholesterolemia for cardiovascular disease and the population attributable fraction in a 24-year Japanese cohort study

AIMS

The population-attributable fraction (PAF) is an indicator of the disease burden. In Western countries, the PAF of hypercholesterolemia in cardiovascular disease (CVD) is the highest among that for traditional risk factors; however, data for Asian populations are limited.

METHODS

A 24-year cohort study was conducted among 9,209 randomly selected participants who were not taking statins. We estimated the hazard ratio (HR) after adjusting for covariates and PAF associated with the serum total cholesterol (TC) levels in relation to CVD mortality.

RESULTS

The TC level was found to be positively associated with an increased risk of CVD, coronary heart disease (CHD) and cardiac death (CHD plus heart failure), with an HR of 1.08 (95% confidence interval [CI]: 1.00-1.16), 1.33 (95% CI: 1.14-1.55) and 1.21 (95% CI: 1.08-1.35) for a 1-SD increment in the serum TC level, respectively. Similar positive associations between the TC level and both CHD and cardiac death were observed after classifying the patients by age and sex. Furthermore, the highest serum TC level (≥ 6.72 mmol/L) was positively associated with CVD death, with an HR of 1.76 (95% CI: 1.25-2.47), as well as both CHD death and cardiac death. In contrast, no significant relationships were observed between the serum TC level and stroke. Meanwhile, the PAF for CVD, CHD, and cardiac deaths due to hypercholesterolemia (serum TC level ≥ 5.69 mmol/L, defined by the Japan Atherosclerosis Society) was 1.7%, 10.6% and 5.6%, respectively.

CONCLUSIONS

The estimated PAF of CVD death due to hypercholesterolemia is moderately high, but lower than that for other risk factors, such as hypertension.

Cocaine use and risk of stroke: a systematic review

BACKGROUND

Both cocaine use and strokes impact public health. Cocaine is a putative cause of strokes, but no systematic review of the scientific evidence has been published.

METHODS

All relevant bibliographic-databases were searched until January 2014 for articles on the epidemiological association between cocaine use and strokes. Search strings were supervised by expert librarians. Three researchers independently reviewed studies for inclusion and data extraction following STROBE recommendations. Quality appraisal included study validity and bias. Both ischemic and hemorrhagic strokes were considered.

RESULTS

Of 996 articles, 9 were selected: 7 case-control studies (CCS) and 2 cross-sectional (CSS) studies. One CCS (aOR=6.1; 95% CI: 3.3-11.8) and one CSS (aOR=2.33; 95% CI: 1.74-3.11) showed an association between cocaine and hemorrhagic strokes. The latter study also found a positive relationship with ischemic stroke (aOR=2.03; 95% CI: 1.48-2.79). Another CCS found the exposure to be associated with stroke without distinguishing between types (aOR=13.9; 95% CI: 2.8-69.4). One forensic CCS found that deaths with cocaine-positive toxicology presented a 14.3-fold (95% CI: 5.6-37) and 4.6-fold (95% CI: 2.5-8.5) increased risk of atherosclerosis compared to opioid-related deaths and hanging-deaths respectively. One CCS did not provide an aOR but found a statistically significant association between cocaine and hemorrhagic stroke. Three CCS and one CSS did not find any relationship between cocaine and strokes. Inadequate control for confounding was not uncommon.

CONCLUSIONS

Epidemiological evidence suggests that cocaine use increases the risk of stroke. Larger, more rigorous observational studies, including cohort approaches, are needed to better quantify this risk, and should consider stroke type, hypertension variation, frequency/length of cocaine use, amphetamines co-use, and other factors.

Hypertension and medical expenditure in the Japanese population: Review of prospective studies

Hypertension is a major determinant of health and is likely to have an effect on medical economics. The economic burden due to hypertension may be attributable not only to antihypertensive medication but also to the very expensive procedures required for cases of cardiovascular disease that occur more frequently in hypertensive compared with normotensive individuals. The objective of this article was to review articles published on prospective cohort studies that measured medical expenditure attributable to hypertension in community-dwelling populations in Japan. Many medical services in these populations are provided under the medical insurance system that requires the enrolment of all Japanese residents. Personal medical expenditure attributable to hypertension increases with worsening severity of the condition. Medical expenditure was increased further in cases of hypertensive patients who have another concomitant cardiovascular risk factor. In particular, hypertension, especially moderate-to-severe untreated hypertension, increases the risk of long-term hospitalization resulting in considerably higher medical expenditure, compared with non-hospitalized cases. Therefore, assuming that the use of antihypertensive medication is essential for hypertensive patients to prevent serious vascular diseases, a cost-effective high-risk strategy needs to be considered to reduce both ill-health and the economic burden due to hypertension. However, from a population perspective, medical expenditure attributable to hypertension comes mainly from pre-to-mild hypertension. Therefore, there is also a need to consider a population strategy that aims to shift the entire population to lower levels of blood pressure.

Trends in prevalence of dyslipidaemias and the risk of mortality in Lithuanian urban population aged 45-64 in relation to the presence of the dyslipidaemias and the other cardiovascular risk factors

The aim of this study was to provide reliable information on dyslipidaemias, to estimate the trend of the prevalence of dyslipidaemias and other selected cardiovascular disease (CVD) risk factors at population level, and to evaluate the risk of all-cause and CVD mortality in relation to presence of mixed dyslipidaemias and other CVD risk factors.

Methods

Data from the five surveys (1983–2008) are presented. A random sample of 9,209 subjects aged 45–64 was selected for statistical analysis. During follow-up there were 1653 death cases from any cause, 864 deaths from CVD. Estimates of hazard ratios (HR) and 95% confidence intervals (CI) were based on the multivariate Cox proportional hazards regression for all-cause mortality and CVD mortality.

Results

During 25 year period the prevalence of normal total cholesterol level (<5.2 mmol/L) significantly increased only in women; triglycerides and high density lipoprotein (HDL) cholesterol did not change in men and women. Findings in our longitudinal study showed that in men and women mixed dyslipidaemias (HDL cholesterol <1.03 mmol/L plus triglycerides ≥1.70 mmol/L) significantly increased the risk for all-cause and CVD mortality (respectively in men HR = 1.30; HR = 1.15, in women HR = 1.83; HR = 2.13). These mixed dyslipidaemia combinations combination with the other risk factors such as arterial hypertension, high fasting glucose level increased all-cause and CVD mortality risk in men and women; while, these mixed dyslipidaemias plus smoking increased all-cause and CVD mortality risk only in men compared to never smokers without these dyslipidaemias (respectively HR = 1.89; HR = 1.92); and these dyslipidaemias plus obesity increased all-cause and CVD mortality risk in women (respectively HR = 2.25; HR = 2.39) and CVD mortality risk in men (HR = 1.72), as compared to responders without obesity and these dyslipidaemias.

Conclusion

Mixed dyslipidaemias (reduced HDL cholesterol plus elevated triglycerides) significantly increased the risk for all-cause and CVD mortality in this Lithuanian population aged 45–64 years.

Meta-analyses using individual participant data from cardiovascular cohort studies in Japan: current status and future directions

Meta-analysis of individual participant data (IPD meta-analysis) has several advantages over meta-analysis using aggregated published data, including the possibility of using statistical methods such as a fine stratification analysis, interaction analysis between 2 risk factors, and absolute risk estimation. The Evidence for Cardiovascular Prevention from Observational Cohorts in Japan Study (EPOCH-JAPAN), which was initiated in 2005, is a collaborative research project for IPD meta-analysis and includes 13 participating cohort studies in Japan. We generated 2 pooled databases with data on all-cause mortality (n = 199 047) and cardiovascular outcomes (n = 90 528) and applied a stratified Cox model to account for the different baseline hazards between cohorts. The results of our analyses show the age- and sex-specific associations between all-cause and cardiovascular disease mortality and established cardiovascular risk factors (blood pressure, smoking, total cholesterol, proteinuria, and kidney function). During the 9 years of its existence, the results generated by EPOCH-JAPAN have had important implications for clinical medicine and public health policy in Japan. The project is expected to draw upon new analytical methods such as interaction analysis and absolute risk evaluation in the near future. We believe that, over the next decade, this project will continue to provide new insights that can be applied to research on other Asian populations.

Synergistic effect of ALOX5AP polymorphisms and cigarette smoking on the risk of atherosclerotic cerebral infarction in a Northern Han Chinese population

The effect of activating 5-lipoxygenase (ALOX5AP) gene polymorphisms on stroke risk may be influenced by the coexistence of modifiable predisposing conditions. We explored the interactions of ALOX5AP polymorphisms and cigarette smoking in a case-control study of patients with atherosclerotic cerebral infarction (ACI). Three polymorphisms of the ALOX5AP gene (rs10507391, rs4769874, and rs9551963) were analyzed in 420 ACI patients and 488 unrelated healthy controls matched for age and sex from a Northern Han Chinese population. Among the three single nucleotide polymorphisms, only rs10507391 genotype TT/TA was observed to be associated with an increased risk of ACI on multivariate analysis (odds ratio [OR]=1.82, 95% confidence interval [CI]=1.14-2.92, p=0.012) compared with the AA genotype. However, after stratifying by smoking status, multivariate logistic regression analysis revealed that rs10507391 genotype TT/TA and rs9551963 genotype CC/CA had a 5.63-fold (OR=5.63, 95%CI=2.00-15.84, p=0.001) and a 2.71-fold (OR=2.71, 95%CI=1.28-5.73, p=0.009) increased risk for ACI patients who smoked compared with the AA genotype, respectively. Additionally, according to the haplotype analysis, the risk of haplotype TGC (OR=3.12, 95%CI=2.00-4.88, p<0.001, corrected p [pc]<0.001) increased for ACI patients who smoked compared to the data (OR=1.60, 95%CI=1.28-1.98, p<0.001, pc<0.001) in total samples. These results suggest that ALOX5AP polymorphisms are associated with ACI, and cigarette smoking along with ALOX5AP could increase the risk of ACI.

Smoking status and severity of ischemic stroke. A population-based study

We aimed to investigate the impact of smoking status on clinical severity in patients with ischemic stroke event (IS). Patients were prospectively identified among residents of the city of Dijon, France (ca. 151,000 inhabitants), using a population-based registry, between 2006 and 2011. Demographic and clinical data were recorded. The initial clinical severity was quantified by the means of the National Institutes of Health Stroke Scale (NIHSS). Multivariable ordinal logistic regression was used to assess the effect of smoking status on severity. Among the 1,056 recorded patients with IS, data about smoking status were available for 973 (92.1%), of whom 658 (67.3%) were non-smokers, 187 (19.2%) were current smokers, and 128 (13.2%) were former smokers. Compared with non-smoking, former smoking was associated with less severe IS (OR 0.55; 95% CI 0.38-0.82, p = 0.003), whereas this association was not found for current smokers (OR 0.97; 95% CI 0.69-1.36, p = 0.856). Further work is needed to understand the underlying mechanisms of this finding.

Effects of smoking on outcomes after acute atherothrombotic stroke in Japanese men

BACKGROUND

The effects of smoking on clinical outcomes following acute stroke remain controversial.

METHODS

We evaluated the influence of smoking on 90-day outcomes after acute atherothrombotic stroke in 292 Japanese men extracted from the database of the Edaravone and Argatroban Stroke Therapy for Acute Ischemic Stroke randomized parallel-group trial that tested the safety and efficacy of edaravone and argatroban therapy in 814 patients in 2004-2008. Smokers were matched with non-smokers of the same age for identical age distribution in the smoker and non-smoker groups. Poor 90-day outcomes (defined as death, Barthel index<60, or modified Rankin score>3) were evaluated using a logistic regression model. Significant variables (P<0.05) in univariate analysis were further evaluated by multivariate logistic regression analysis using a forward-selection method.

RESULTS

Body temperature, age, National Institute of Health Stroke Scale score at admission, systolic blood pressure, and smoking status were selected in the final model. Smokers had significantly increased odds of poor 90-day functional outcomes independent of other statistically significant predictor variables (adjusted odds ratio, 2.28; 95% confidence interval, 1.15-4.55; P=0.019).

CONCLUSIONS

In Japanese men, smoking leads to poor functional outcomes at 3 months after acute atherothrombotic stroke.

Smoking as a risk factor for stroke in women compared with men: a systematic review and meta-analysis of 81 cohorts, including 3,980,359 individuals and 42,401 strokes

BACKGROUND AND PURPOSE

It is currently unknown whether the excess risk of stroke by smoking is the same for women and men. We performed a systematic review and meta-analysis to estimate the effect of smoking on stroke in women compared with men.

METHODS

PubMed MEDLINE was systematically searched for prospective population-based cohort studies published between January 1, 1966, and January 26, 2013. Studies that presented sex-specific estimates of the relative risk of stroke comparing current smoking with nonsmoking and its associated variability were selected. The sex-specific relative risks and their ratio (RRR), comparing women with men, were pooled using random-effects meta-analysis with inverse variance weighting. Similarly, the RRR for former versus never smoking was pooled.

RESULTS

Data from 81 prospective cohort studies that included 3,980,359 individuals and 42,401 strokes were available. Smoking was an independent risk factor for stroke in both sexes. Overall, the pooled multiple-adjusted RRR indicated a similar risk of stroke associated with smoking in women compared with men (RRR, 1.06 [95% confidence interval, 0.99-1.13]). In a regional analysis, there was evidence of a more harmful effect of smoking in women than in men in Western (RRR, 1.10 [1.02-1.18)] but not in Asian (RRR, 0.97 [0.87-1.09]) populations. Compared with never-smokers, the beneficial effects of quitting smoking among former smokers on stroke risk were similar between the sexes (RRR, 1.10 [0.99-1.22]).

CONCLUSIONS

Compared with nonsmokers, the excess risk of stroke is at least as great among women who smoke compared with men who smoke.

Studies of a microchip flow-chamber system to characterize whole blood thrombogenicity in healthy individuals

INTRODUCTION

A whole blood flow-chamber system, the Total Thrombus-formation Analysis System (T-TAS), was developed for quantitative analysis of platelet thrombus formation (PTF) using microchips with thrombogenic surfaces (collagen, PL chip; collagen plus tissue thromboplastin, AR chip) under shear stress conditions. We evaluated the usefulness of the T-TAS for assessing individual thrombogenicity compared with other platelet function tests.

MATERIALS AND METHODS

Blood samples from 31 healthy volunteers were applied to the T-TAS to measure PTF starting time (T10: time to reach 10 kPa), occlusion time (T60 for PL chip; T80 for AR chip), and area under the curve (AUC10, area under curve until 10 min for PL chip; AUC30, 30 min for AR chip) under various shear rates (1000, 1500, 2000s(-1) for PL chip; 300 s(-1) for AR chip). Platelet functions were also tested using platelet aggregometry, the PFA-100 (collagen and epinephrine [C/EPI], collagen and adenosine diphosphate [C/ADP]), and the VerifyNow P2Y12 assay.

RESULTS

Individual pressure waveforms, including PTF starting and ending points, varied among healthy subjects. In the PL chip, T10 and AUC10 showed a shear-dependent correlation with C/EPI or C/ADP. VerifyNow P2Y12 values were not significantly associated with the parameters of the T-TAS. Platelet counts were correlated with all AR measurements, and mostly with PL measurements.

CONCLUSION

The results of the T-TAS were associated with those of the PFA-100 in many respects, indicating that its characteristics are related to shear-induced PTF. The T-TAS showed few correlations with platelet aggregometry and the VerifyNow P2Y12 assay. The T-TAS may allow for the measurement of comprehensive parameters of individual thrombogenicity under whole blood flow conditions.

Fatal stroke after the death of a sibling: a nationwide follow-up study from Sweden

BACKGROUND

Although less studied than other types of familial losses, the loss of a sibling could be a potential trigger of stroke as it represents a stressful life event. We studied the association between loss of a sibling and fatal stroke up to 18 years since bereavement.

METHODOLOGY/PRINCIPAL FINDINGS

We conducted a follow-up study between 1981 and 2002, based on register data covering the total population of Swedes aged 40-69 years (n = 1,617,010). An increased risk of fatal stroke (1.31 CI: 1.05, 1.62) was found among women who had experienced the loss of a sibling. No increase in the overall mortality risk was found in men (1.11 CI: 0.92, 1.33). An elevated risk in the short term (during the second and third half-year after the death) was found among both men and women, whereas longer-term elevation in risk was found primarily for women. Both external (1.47 CI: 1.00, 2.17) and not external (1.26 CI: 1.00, 1.60) causes of sibling death showed associations among women. In men, an association was found only if the sibling also died from stroke (1.78 CI: 1.00, 3.17). However, among women, we found an increased risk of stroke mortality if the sibling died from causes other than stroke (1.30 CI: 1.04, 1.62).

CONCLUSIONS/SIGNIFICANCE

The findings suggest an increased risk of dying from stroke mortality after the death of a sibling, and that bereavement affects particularly women. It is important for health care workers to follow bereaved siblings and recognize potential changes of stress-levels and health related behaviours that could lead to risk of stroke.